What Is a Sibling Anyway? Full, Half, Three-Quarters, Step, Adopted, Donor-Conceived & Twins

I’ve seen the term sibling used many different ways, sometimes incorrectly.

When referring to their own siblings, people usually use the term brother or sister, regardless of whether they are talking about a full, half or step-sibling. It’s a term of heart or description. It’s often genealogists who are focused on which type of sibling. As far as I’m concerned, my brother is my brother, regardless of which type of brother. But in terms of genetics, and genealogy, there’s a huge difference. How we feel about our sibling(s) and how we are biologically related are two different things.

Let’s cover the various types of siblingship and how to determine which type is which.

  • Full Siblings – Share both parents
  • Half-Siblings – Share only one parent
  • Three-Quarter Siblings – It’s complicated
  • Adopted Siblings
  • Donor-Conceived
  • Step-Siblings – Share no biological parent
  • Twins – Fraternal and Identical

Full Siblings

Full siblings share both parents and share approximately 50% of their DNA with each other.

You can tell if you are full siblings with a match in various ways.

  1. You share the same fairly close matches on both parents’ sides. For example, aunts or uncles or their descendants.

Why do I say close matches? You could share one parent and another more distant relative on the other parent’s side. Matching with close relatives like aunts, uncles or first cousins at the appropriate level is an excellent indicator unless your parents or grandparents are available for testing. If you are comparing to grandparents, be sure to confirm matches to BOTH grandparents on each side.

  1. Full siblings will share in the ballpark of 2600 cM, according to DNAPainter’s Shared cM Tool.

Keep in mind that you can share more or less DNA, hence the range. It’s also worth noting that some people who reported themselves as full siblings in the Shared cM project were probably half siblings and didn’t realize it.

  1. Full siblings will share a significant amount of fully identical regions (FIR) of DNA with each other, meaning they share DNA at the same DNA address from both parents, as illustrated above. Shared DNA with each other inherited from Mom and Dad are blocked in green. The fully identical regions, shared with both parents, are bracketed in purple. You can’t make this determination at FamilyTreeDNA, MyHeritage or Ancestry, but you can at both 23andMe and GEDmatch.

At GEDmatch, the large fully green areas in the chromosome browser “graphics and positions” display indicates full siblings, where DNA is shared from both parents at that location.

I wrote about the details of how to view fully identical regions (FIR) versus half identical regions (HIR) in the article, DNA: In Search of…Full and Half-Siblings.

  1. If your parents/grandparents have tested, you and your full sibling will both match both parents/grandparents. Yes, I know this sounds intuitive, but sometimes it’s easy to miss the obvious.

At FamilyTreeDNA, you can use the matrix tool to see who matches each other in a group of people that you can select. In this case, both siblings are compared to the father, but if the father isn’t available, a close paternal relative could substitute. Remember that all people who are 2nd cousins or closer will match.

  1. At Ancestry, full siblings will be identified as either “brother” or “sister,” while half-siblings do not indicate siblingship. Half-siblings are called “close family” and a range of possible relationships is given. Yes, Ancestry, is looking under the hood at FIR/HIR regions. I have never seen a full sibling misidentified as anything else at Ancestry. Unfortunately, Ancestry does not give customers access to their matching chromosome segment location data.
  2. Y-DNA of males who are full siblings will match but may have some slight differences. Y-DNA alone cannot prove a specific relationship, with very rare exceptions, but can easily disprove a relationship if two males do not match. Y-DNA should be used in conjunction with autosomal DNA for specific relationship prediction when Y-DNA matches.
  3. Y-DNA testing is available only through FamilyTreeDNA, but high-level haplogroup-only estimates are available through 23andMe. Widely divergent haplogroups, such as E versus R, can be considered a confirmed non-match. Different haplogroups within the same base haplogroup, such as R, but obtained from different vendors or different testing levels may still be a match if they test at the Big Y-700 level at FamilyTreeDNA.
  4. Mitochondrial DNA, inherited matrilineally from the mother, will match for full siblings (barring unusual mutations such as heteroplasmies) but cannot be used in relationship verification other than to confirm nonmatches. For both Y-DNA and mitochondrial DNA, it’s possible to have a lineage match that is not the result of a direct parental relationship.
  5. Mitochondrial DNA testing is available only through FamilyTreeDNA, but haplogroup-only estimates are included at 23andMe. Different base haplogroups such as H and J can be considered a non-match.
  6. A difference in ethnicity is NOT a reliable indicator of half versus full siblings.

Half-Siblings

Half-siblings share only one parent, but not both, and usually share about 25% of their DNA with each other.

You will share as much DNA with a half-sibling as you do some other close matches, so it’s not always possible for DNA testing companies to determine the exact relationship.

Referencing the MyHeritage cM Explainer tool, you can see that people who share 1700 cM of DNA could be related in several ways. I wrote about using the cM Explainer tool here.

Hints that you are only half-siblings include:

  1. At testing vendors, including Ancestry, a half-sibling will not be identified as a sibling but as another type of close match.
  2. If your parents or grandparents have tested, you will only match one parent or one set of grandparents or their descendants.
  3. You will not have shared matches on one parent’s side. If you know that specific, close relatives have tested on one parent’s side, and you don’t match them, but your other family members do, that’s a very big hint. Please note that you need more than one reference point, because it’s always possible that the other person has an unknown parentage situation.
  4. At 23andMe, you will not show fully identical regions (FIR).
  5. At GEDmatch, you will show only very minimal FIR.

Scattered, very small green FIR locations are normal based on random recombination. Long runs of green indicate that significant amounts of DNA was inherited from both parents. The example above is from half-siblings.

  1. At FamilyTreeDNA and 23andMe, most men who share a mother will also share an X chromosome match since men only inherit their X chromosome from their mother. However, it is possible for the mother to give one son her entire X chromosome from her father, and give the other son her entire X chromosome from her mother. Therefore, two men who do share a mother but don’t have an X chromosome match could still be siblings. The X is not an entirely reliable relationship predictor. However, if two men share an entire X chromosome match, it’s very likely that they are siblings on their mother’s side, or that their mothers are very close relatives.

Three-Quarter Siblings

This gets a little more complicated.

Three-quarter siblings occur when one parent is the same, and the other parents are siblings to each other.

Let’s use a real-life example.

A couple marries and has children. The mother dies, and the father marries the mother’s sister and has additional children. Those children are actually less than full siblings, but more than half-siblings.

Conversely, a woman has children by two brothers and those children are three-quarter siblings.

These were common situations in earlier times when a man needed a female companion to raise children and women needed a male companion to work on the farm. Neither one could perform both childcare and the chores necessary to earn a living in an agricultural society, and your deceased spouse’s family members were already people you knew. They already loved your children too.

Neither of these situations is historically unusual, but both are very difficult to determine using genetics alone, even in the current generation.

Neither X-DNA nor mitochondrial DNA will be helpful, and Y-DNA will generally not be either.

Unfortunately, three-quarter siblings’ autosomal DNA will fall in the range of both half and full siblings, although not at the bottom of the half-sibling range, nor at the top of the full sibling range – but that leaves a lot of middle ground.

I’ve found it almost impossible to prove this scenario without prior knowledge, and equally as impossible to determine which of multiple brothers is the father unless there is a very strong half-sibling match in addition.

The DNA-Sci blog discusses this phenomenon, but I can’t utilize comparison screenshots according to their terms of service.

Clearly, what we need are more known three-quarter siblings to submit data to be studied in order to (possibly) facilitate easier determination, probably based on the percentage frequency distribution of FIR/HIR segments. Regardless, it’s never going to be 100% without secondary genealogical information.

Three-quarter siblings aren’t very common today, but they do exist. If you suspect something of this nature, really need the answer, and have exhausted all other possibilities, I recommend engaging a very experienced genetic genealogist with experience in this type of situation. However, given the random nature of recombination in humans, we may never be able to confirm using any methodology, with one possible exception.

There’s one possibility using Y-DNA if the parents in question are two brothers. If one brother has a Y-DNA SNP mutation that the other does not have, and this can be verified by testing either the brothers who are father candidates or their other known sons via the Big Y-700 test – the father of the siblings could then be identified by this SNP mutation as well. Yes, it’s a long shot.

Three-quarter sibling situations are very challenging.

Step-siblings, on the other hand, are easy.

Step-Siblings

Step-siblings don’t share either parent, so their DNA will not match to each other unless their parents are somehow related to each other. Please note that this means either of their parents, not just the parents who marry each other.

One child’s parent marries the other child’s parent, resulting in a blended family. The children then become step-siblings to each other.

The terms step-sibling and half-sibling are often used interchangeably, and they are definitely NOT the same.

Adopted Siblings

Adopted siblings may not know they are adopted and believe, until DNA testing, that they are biological siblings.

Sometimes adopted siblings are either half-siblings or are otherwise related to each other but may not be related to either of their adoptive parents. Conversely, adopted siblings, one or both, may be related to one of their adoptive parents.

The same full and half-sibling relationship genetic clues apply to adopted siblings, as well as the tools and techniques in the In Search of Unknown Family series of articles.

Donor-Conceived Siblings

Donor-conceived siblings could be:

  • Half-siblings if the donor is the same father but a different mother.
  • Half-siblings if they share an egg donor but not a father.
  • Full siblings if they are full biological siblings to each other, meaning both donors are the same but not related to the woman into whom the fertilized egg was implanted, nor to her partner, their legal parents.
  • Not biologically related to each other or either legal parent.
  • Biologically related to one or both legal parents when a family member is either an egg or sperm donor.

Did I cover all of the possible scenarios? The essence is that we literally know nothing and should assume nothing.

I have known of situations where the brother (or brothers) of the father was the sperm donor, so the resulting child or children appear to be full or three-quarters siblings to each other. They are related to their legal father who is the mother’s partner. In other words, in this situation, the mother’s husband was infertile, and his brother(s) donated sperm resulting in multiple births. The children from this family who were conceived through different brothers and had very close (half-sibling) matches to their “uncles'” children were very confused until they spoke with their parents about their DNA results.

The same techniques to ascertain relationships would be used with donor-conceived situations. Additionally, if it appears that a biological relationship exists, but it’s not a full or half-sibling relationship, I recommend utilizing other techniques described in the In Search of Unknown Family series.

Twins or Multiple Birth Siblings

Two types of twin or multiple birth scenarios exist outside of assisted fertilization.

Fraternal twins – With fraternal or dizygotic twins, two eggs are fertilized independently by separate sperm. Just view this as one pregnancy with two siblings occupying the same space for the same 9 months of gestation. Fraternal twins can be male, female or one of each sex.

Fraternal twins are simply siblings that happen to gestate together and will match in the same way that full siblings match.

Please note that it’s possible for two of a woman’s eggs to be fertilized at different times during the same ovulation cycle, potentially by different men, resulting in twins who are actually half-siblings.

A difference in ethnicity is NOT a reliable indicator of fraternal or identical twins. Submitting your own DNA twice often results in slightly different ethnicity results.

Identical twins – Identical or monozygotic twins occur when one egg is fertilized by one sperm and then divides into multiple embryos that develop into different children. Those children are genetically identical since they were both developed from the same egg and sperm.

Two of the most famous identical twins are astronauts Mark and Scott Kelly.

Identical twins are the same sex and will look the same because they have the same DNA, except for epigenetic changes, but of course external factors such as haircuts, clothes and weight can make identical twins physically distinguishable from each other.

DNA testing companies will either identify identical twins as “self,” “identical twin” or “parent/child” due to the highest possible shared cM count plus fully matching FIR regions.

For identical twins, checking the FIR versus HIR is a positive identification as indicated above at GEDmatch with completely solid green FIR regions. Do not assume twins that look alike are identical twins.

Siblings

Whoever thought there would be so many kinds of siblings!

If you observe the need to educate about either sibling terminology or DNA identification methodologies, feel free to share this article. When identifying relationships, never assume anything, and verify everything through multiple avenues.

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So, You Want to Become a Professional Genetic Genealogist

I get asked quite often about what is required to become a professional genetic genealogist.

That’s actually two separate questions.

  • What is required to become a professional genealogist?
  • Then, what is required to specialize as a genetic genealogist?

What It’s Not

Before we have this discussion, I need to make sure that you understand that I’m NOT talking about forensics, meaning IGG, or investigative genetic genealogy in this article.

  • This is NOT forensics (IGG)
  • This is also not a specialty in finding missing parents for adoptees and others searching for unknown parents.

Both IGG and adoption searches utilize the same methodology, a subset of genetic genealogy. I wrote about that in Identifying Unknown Parents and Individuals Using DNA Matching.

The difference between genetic genealogy more broadly and IGG is:

  • What you’re searching for
  • The perspective
  • The methods utilized.

Essentially, the functional difference is that genealogists know who they are and have some information about their ancestors. For example, they know who their parents are and probably at least their grandparents. Genealogists are using both DNA testing and traditional genealogical paper trail research methods to focus and make discoveries going backwards in time.

Both IGG and unknown parent research uses DNA and (sometimes some) paper trail genealogy to find ways to connect the closest matches to the DNA tester (or DNA sample) together to each other to identify either living or recently living people. For example, two people who are are first cousins to the tester should both have the same grandparents if they are related to the tester through the same parent.

If two people who are related to the tester as first cousins do not share the same grandparent(s), then they are related to the tester through different parents of the tester.

The commonality is that DNA testing and some types of records are used for:

  • IGG where you’re searching for the identity of the tester or DNA sample
  • Unknown parent(s) searches where you are searching for the identity of the parent(s)
  • Genetic genealogy

However, the search methodology is different for IGG and unknown parents than for genealogy.

With IGG and unknown parent searches, you’re looking for your closest matches, then attempting to connect them together to identify either currently living or recently living people.

This article focuses specifically on genealogy and genetic genealogy, meaning looking backwards in time to identify ancestors.

I wrote about the techniques used for both IGG and parental searching in the article, Identifying Unknown Parents and Individuals Using DNA Matching.

What Do Genealogists Do?

Genealogy is the study of family history and the descent of a person or a family. Genealogists use a variety of sources and methods to discover and show the ancestry of their subjects and in doing so, create the family trees that are familiar to all of us.

Genealogists use different sources and methods to find and show the descent and kinship of their subjects.

Traditional sources include but are not limited to the following record types:

  • Vital records (birth, marriage, and death certificates)
  • Census
  • Military
  • Immigration
  • Land and tax records
  • Wills and probate
  • Church records
  • Newspapers
  • Obituaries
  • Published and online books
  • Oral histories
  • Genealogy databases
  • And more

Of course, today the four types of DNA can be added to that list.

A professional genealogist needs to know how and where to find these types of records in the target area, any unique cultural or regional factors affecting those records, and how to interpret them both individually and together.

For example, in a deed record in colonial Virginia, why would, or wouldn’t a female release her dower right? What is dower right, and why is it important? How might that record, or lack thereof, affect future probate for that woman/couple? In what type of historical or court record book might one look for these types of records?

Genealogists also need to know how to weigh different types of information in terms of potential accuracy and how to interpret primary and secondary sources.

Primary sources are those that were created at or near the time of an event by someone who was present at the event or who had first-hand knowledge of it. Examples of primary sources include birth certificates, marriage licenses, and census records, although census records are far more likely to be inaccurate or incomplete than a birth certificate or marriage record. Genealogists need to understand why, and where to look for corroboration. Primary sources are considered to be most accurate.

Secondary sources are those that were created later by someone who did not have first-hand knowledge of the event. Examples of secondary sources include family histories and genealogies, published biographies, and sometimes, newspaper articles.

The genealogists “go to” source for understanding and interpreting evidence is Evidence Explained by Elizabeth Shown Mills, available here.

Of course, DNA understanding and analysis needs to be added to this list and has become an important resource in genealogy. Additionally, genetic genealogy has become a specialty within the broader field of genealogy, as has IGG.

Put another way, a genealogist should have expertise and a specialty in some area. Maybe Italian records, or Native American genealogy, or New England records, in addition to the basic skills. At one time, a genealogist didn’t necessarily HAVE TO have expertise in genetic genealogy as well, but that has changed in the past few years. A professional genealogist should MINIMALLY understand the basics of genetic genealogy and when/how it can be useful. They may or may not have ready access to a genetic genealogist within the company where they work.

Being an independent genealogist, unless you specialize only in a specific area, like Dutch genealogy, is much more challenging because you’ll need to be proficient in BOTH Dutch genealogy AND genetic genealogy. It’s tough keeping up with one specialty, let alone two, although in this case, Yvette does an amazing job. However, her primary specialty is Dutch genealogy, and genetic genealogy is the booster rocket when appropriate. Genetic genealogy is not always needed for traditional genealogy, which is why genetic genealogy is a specialty skill.

In addition to all that, you also need to be proficient and comfortable with technology and a good communicator. Walking on water is also helpful:)

Job Description

So, what does the job description for a genealogist look like?

I reached out to Legacy Tree Genealogists because they are one of the largest, if not the largest genealogy research company, and they partner with 23andMe, FamilyTreeDNA, and MyHeritage. Legacy Tree has specialists in many regions and languages, in addition to six genetic genealogists on staff.

Fortunately, they have a job listing posted right now, here, with an excellent description of what is expected.

If you’re interested or wish to sign up for notifications, click here.

Understanding that this job description won’t be posted forever, I reached out to the owner, Jessica Dalley Taylor, and asked if she would send me a sample description to include in this article.

Here you go, courtesy of Jessica:

About You

It’s not easy to make each client’s experience the very best it can possibly be, and it means we can only hire an exceptional genealogist for this position. You will be a great fit if:

    • You are fluent in English and can explain your genealogy discoveries in a way that clients connect with and understand
    • You have taken at least one genetic genealogy test or administered the test of a relative
    • You have introductory genetic genealogy abilities
    • You have at least intermediate traditional genealogical research experience in any geographic locality
    • You are familiar with the repositories of the areas for which you claim expertise and have worked with them to obtain documents
    • You are passionate about genealogy and are a creative problem solver
    • You are great at working independently and hitting deadlines (please don’t overlook this line about deadlines)
    • You are comfortable with Microsoft Office suite
    • You’re familiar with genealogical technology such as pedigree software
    • You have a quiet place to work without distractions, a computer, and great internet
    • You have a strong desire to work as a professional genetic genealogist

Even better if:

    • You have a basic understanding of genetic inheritance and its application to genealogy
    • You have beginning experience with interpretation and use of genetic genealogy test results
    • You have intermediate-level genetic genealogy abilities

What you’ll be doing at Legacy Tree:

    • You’ll be learning how to use genetic testing in identifying family
    • You’ll be learning how to create high-quality research reports
    • You’ll be reading and formatting reports by professional researchers
    • You’ll be assisting with researching and writing genealogy reports
    • You’ll be performing genetic genealogy analysis under the direction of professional mentors
    • You’ll be developing advanced-level genetic genealogy skills and abilities
    • With your input, you’ll do other things as opportunities and needs arise

Please note that Legacy Tree offers both traditional genealogy services, combined with genetic genealogy, along with adoption and unknown parent searches.

As a measure of fundamental basic genetic genealogy skills, you should be able to create and teach a class like First Steps When Your DNA Results Are Ready – Sticking Your Toe in the Genealogy Water.

You should also be able to read and fully comprehend the articles on this blog, as well as explain the content to others. A very wise person once told me that if you can’t explain or teach a topic, you don’t understand it.

As luck would have it, Ancestry also posted a job opening for a genealogist as I was finishing this article. Here’s part of the job requirements.

Contractor or Employee

Please note that many companies have shifted their primary hiring strategy to utilizing contractors for not more than half time, especially now that working remotely has become the norm.

This may or may not be good news for you.

It allows the company to avoid paying benefits like insurance, vacation, leave, and retirement programs which reduces their costs. You may not need these benefits, and it may represent an opportunity for you. For others who need those benefits, it’s a deal-breaker.

Contracting may provide the ability to work part-time, but contracting probably means you need to have business management skills not required when you work for someone else. Let’s just say that I make quarterly estimated tax payments and my annual CPA bill is in the $2,000 range.

Compensation

Pay, either as an employee or contractor for a company, is a sticky wicket in this field.

First, there’s a consumer mindset, although not universal, that genealogy “should be” free. In part, this is due to search angels and a history of well-intentioned people making things free. I’m one of them – guilty as charged – this blog is free. My hourly work, however, when I accepted clients (which I DO NOT now,) was not free.

However, that “should be free” mindset makes it difficult to shift to a “pay to play” mentality when people can go on social media and get what they want for free.

Professional services are not and should not be free.

Professionals should be able to earn a respectable living. The full-time Ancestry job, posted above, with those credentials, nets out to $21.63 per hour for a 40-hour week, with a graduate degree preferred. For comparison, google other jobs and professions.

If you doubt for one second whether professional services should or should not be free, especially ones that require a bachelor’s degree or master’s, just think about what your CPA would do if you asked them to do your taxes because they have the ability, for free. Same for a doctor, lawyer, or any other professional.

People are often shocked at the rates paid to employees versus the rates charged to prospective customers. This discussion has recently gotten spicy on social media, so I’m not going to comment other than to say that when I did take private clients, which I DO NOT ANYMORE, I found it much more beneficial to operate independently than to work for a company.

However, I also had a readily recognizable specialty and an avenue to reach potential clients.

I also already had a business structure set up, and a CPA, and perhaps more important than either of those – I had medical insurance already in place.

The need for benefits is what drives many people to work for companies, which I fully understand. It’s also a big factor in why there are more female genealogists than male genealogists. Married women in the US are eligible to be covered by their spouse’s insurance, assuming the spouse has insurance through their employer.

My very strong recommendation to you is to weigh all of the factors and NEVER to find yourself without medical insurance or coverage.

If you’re going to be “self-employed,” set up a company. If you’re going to set up a company, do it properly, understand the tax ramifications of the various types of corporations and engage a competent CPA to shepherd you through the process from day 1 through taxes. They are worth every penny.

Look at various jobs in the market, review at the associated pay, get a quote for genealogy services of the type you would be providing from the various companies – and decide if this profession is really for you.

I don’t mean to be a wet blanket, just a realist.

Training and Certification

Now for the good news and the bad news.

  • There is professional training for genealogy
  • There are certifications for genealogy
  • There is no “one place” for either
  • There is no certification for genetic genealogy
  • There’s a LOT of misunderstanding and misinformation about genetic genealogy
  • Genetic genealogy changes often

You need to view your education for genealogy/genetic genealogy in the same way you’d view obtaining a college degree – plus continuing education to maintain your education and skills at a current and functional level.

And yes, all of that costs money. If you decide to work for a company, be sure to ask if continuing ed is on their dime and time, or yours.

Genealogy Training

The Board for Certification of Genealogists, BCG, allows graduates to append CG, for Certified Genealogist after their name. BCG is focused on certification of skills and is not a training platform, although they do provide some webinars, etc. It’s not a college curriculum though. Certification is the “end game” for many. Candidates must submit a portfolio for evaluation, complete in a specific timeframe, and must reapply every five years to maintain their certification.

Not all genealogists are certified by BCG, and BCG only lists references of BCG members.

In the field of Genetic Genealogy, that can be problematic because many competent and well-known people are not BCG certified. BCG does not have a genetic genealogy certification.

Lack of BCG certification does not mean that someone is not qualified, and BCG certification certainly does NOT mean or imply that the individual is competent in genetic genealogy, which has more and more become a part of almost every genealogical puzzle. If not for initial discovery, for confirmation.

There are many avenues for genealogical training, including, but not limited to:

  • Brigham Young University Family History Degree
  • NGS Home Study Course
  • Salt Lake Institute of Genealogy (SLIG)
  • Genealogical Research Institute of Pittsburgh (GRIP)
  • Boston University Certificate program
  • Genealogical Institute on Federal Records (Gen-Fed)
  • Institute of Genealogy and Historical Research (IGHR)
  • University of Strathclyde
  • University of Dundee
  • Major Conferences, including RootsTech and NGS, among others
  • Specialty conferences such as the International Conference on Jewish Genealogy (IAJGS)
  • Online conferences and conference proceedings such as Rootstech who maintains a free library of their virtual and recorded conference sessions.
  • Legacy Family Tree Webinars
  • Videos produced by major genealogy companies such as MyHeritage, FamilyTreeDNA and Ancestry, often available through their website, Youtube or both
  • Blogs and learning/help centers of the major genealogy companies

Genetic Genealogy Training

Genetic genealogy training is more challenging because there is no specific program, curriculum, or certification.

Many genetic genealogists obtained their experience as a part of genealogy over 15 or 20 years and have focused on the genetic aspect of genealogy. Several of us had a scientific background that meshed well with this field and is part of why we discovered that our passion is here.

Before I provide this resource list, I need to emphatically state that probably 95% of answers that I see provided on social media platforms in response to questions asked by people are either entirely incorrect, partially incorrect in a way that makes me want to say, “well, not exactly,” or are incomplete in a way that makes a significant difference.

I chose and choose to focus on creating educational tools and making explanations available for everyone, in one place, not one question at a time.

I began publishing my blog in 2012 as an educational tool and I’m dumbstruck by how many people just want a yes or no answer instead of learning. If one doesn’t take the time to learn, they have no idea if the answers they receive are valid, or if there’s more to the story that they are missing.

Social media can mislead you badly if you don’t have the ability to discern between accurate answers, partially accurate answers, and incorrect answers. Furthermore, opinions differ widely on some topics.

Unfortunately, because there is no genetic genealogy credentialling, there is also no “post-nominal letters,” such as CG for certified genealogist. Therefore, a novice has absolutely no idea how to discern between an expert and another overly helpful novice who is unintentionally providing incorrect or partial information.

Many of us who at one time reliably answered questions have simply gotten burned out at the same question being asked over and over, and no longer regularly engage. Burnout is real. Another issue is that askers often don’t provide enough, or accurate, information, so a significant amount of time is spent in clarifying the information around a question. Furthermore, your CPA, lawyer, and physician don’t answer questions online for free, and neither do most people who are busy earning a living in this field.

DNA educational opportunities, some of which are contained within larger conference agendas, include:

There are other blogs, of course, some of which were launched by well-known genetic genealogists but are no longer maintained. Blogging is quite time-consuming.

I’ve covered all kinds of genetic genealogy topics in my blog articles. They are a good source of information, education and hands-on training. I attempt to publish two articles weekly, and there are over 1600 available for your enjoyment.

In addition to the initial learning period, you’ll need to make time to stay engaged and maintain your genealogy and genetic genealogy skills.

Apprenticeship

In addition to training, I think you’d need at least a year interning or working at a junior learning level, minimum. Think of it as your genealogy residency.

  • You could choose to work for a vendor in their help center.
  • You could choose to work for a genealogy company. I’ve mentioned the largest ones, but there are others as well.
  • You could choose to work on your own case studies and those of your friends and family, but if you do, be aware that you won’t have anyone reviewing your work. If you make a mistake or should have approached something differently, and you’re working alone, there’s no one to tell you.
  • You could work as a search angel for others. I have mixed emotions about this, in part due to the lack of review and oversight. But also, in part because “free search angels” perpetuate the idea that genealogy “should be” free.

If you want to work in IGG, after training, an internship under an established mentor is ABSOLUTELY ESSENTIAL for a minimum of 100 or so successful closures.

Genealogists and genetic genealogists have the ethical responsibility to NOT MAKE MISTAKES when working on other people’s family. You need to know what you know, what you don’t know, when to get help, from where and with whom.

Networking Opportunity

A Facebook group named “Genealogy Jobs” has been established to discuss opportunities and all of the topics surrounding this subject.

There’s a Genealogy Career Day event on April 22nd where you can interact with professionals including authors, freelance genealogists, certified genealogists, business owners, and an investigative genetic genealogist. Take a look at the topics. If you’re considering whether or not you want to go pro, you’ll be interested. You can sign up here.

The sessions will be uploaded to their YouTube channel, here, after the event.

I hope you’ve found this article useful and helps you decide if this profession is for you. If so, create a plan and execute.

If you decide you do want to go pro, I wish you the best and welcome you to the fast-paced world of professional genealogy or its specialty, genetic genealogy.

____________________________________________________________

Follow DNAexplain on Facebook, here or follow me on Twitter, here.

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X Chromosome Master Class

The X chromosome can be especially useful to genetic genealogists because it has a unique inheritance path. Thanks to that characteristic, some of the work of identifying your common ancestor is done just by simply HAVING an X match.

Unfortunately, X-DNA and X matching is both underutilized and somewhat misunderstood – in part because not all vendors utilize the X chromosome for matching.

The X chromosome has the capability of reaching further back in time and breaking down brick walls that might fall no other way.

Hopefully, you will read this article, follow along with your own DNA results and make important discoveries.

Let’s get started!

Who Uses the X Chromosome?

The X chromosome is autosomal in nature, meaning it recombines under some circumstances, but you only inherit your X chromosome from certain ancestors.

It’s important to understand why, and how to utilize the X chromosome for matching. In this article, I’ve presented this information in a variety of ways, including case studies, because people learn differently.

Of the four major testing vendors, only two provide X-DNA match results.

  • FamilyTreeDNA – provides X chromosome results and advanced matching capabilities including filtered X matching
  • 23andMe – provides X chromosome results, but not filtered X matching without downloading your results in spreadsheet format
  • Ancestry and MyHeritage do not provide X-DNA results but do include the X in your raw DNA file so you can upload to vendors who do provide X matching
  • GEDmatch – not a DNA testing vendor but a third-party matching database that provides X matching in addition to other tools

It’s worth noting at this point that X-DNA and mitochondrial DNA is not the same thing. I wrote about that, here. The source of this confusion is that the X chromosome and mitochondrial DNA are both associated in some way with descent from females – but they are very different and so is their inheritance path.

So, what is X-DNA and how does it work?

What is X-DNA?

Everyone inherits two copies of each of chromosomes 1-22, one copy of each chromosome from each of your parents.

That’s why DNA matching works and each match can be identified as “maternal” or “paternal,” depending on how your match is related to you. Each valid match (excluding identical by chance matches) will be related either maternally, or paternally, or sometimes, both.

Your 23rd chromosome is your sex determination chromosome and is inherited differently. Chromosome 23 is comprised of X and Y DNA.

Everyone inherits one copy of chromosome 23 from each parent.

  • Males inherit a Y chromosome from their father, which is what makes males male. They do not inherit an X chromosome from their father.
  • Males always inherit an X chromosome from their mother.
  • Females inherit an X chromosome from both parents, which is what makes them female. Females have two X chromosomes, and no Y chromosome.
Chromosome 23 Father Contributes Mother Contributes
Male Child Y chromosome X chromosome
Female Child X chromosome X chromosome

X-DNA and mitochondrial DNA are often confused, but they are not the same thing. In fact, they are completely different.

Mitochondrial DNA, in BOTH males and females is always inherited from only the mother and only descends from the direct matrilineal line, so only the mother’s mother’s mother’s direct line. X DNA can be inherited from a number of ancestors based on a specific inheritance path.

Everyone has both X-DNA AND mitochondrial DNA.

Because males don’t inherit an X chromosome from their father, X chromosome matching has a unique and specific pattern of descent which allows testers who match to immediately eliminate some potential common ancestors.

  • Males only inherit an X chromosome from their mother, which means they can only have legitimate X matches on their mother’s side of their tree.
  • Females, on the other hand, inherit an X chromosome from both their mother and father. Their father only has one X chromosome to contribute, so his daughter receives her paternal grandmother’s X chromosome intact.
  • Both males and females inherit their mother’s X chromosome just like any of the other 22 autosomes. I wrote about chromosomes, here.

However, the unique X chromosome inheritance path provides us with a fourth very useful type of DNA for genealogy, in addition to Y-DNA, mitochondrial and autosomal DNA.

For the vendors who provide X-matching, it’s included with your autosomal test and does not need to be purchased separately.

The Unique X Chromosome

The X chromosome, even though it is autosomal in nature, meaning it does recombine and divide in certain circumstances, is really its own distinct tool that is not equivalent to autosomal matching in the way we’re accustomed. We just need to learn about the message it’s delivering and how to interpret X matches.

FamilyTreeDNA is one of two vendors who utilizes X chromosome matching, along with 23andMe, which is another good reason to encourage your matches at other vendors to upload their DNA file to FamilyTreeDNA for free matching.

The four major vendors do include X-DNA results in their raw DNA download file, even if they don’t provide X-matching themselves. This means you can upload the results to either FamilyTreeDNA or GEDmatch where you can obtain X matches. I provided step-by-step download/upload instructions for each vendor here.

Let’s look how X matching is both different, and beneficial.

My X Chromosome Family Tree

We are going to build a simple case study. A case study truly is worth 1000 descriptions.

This fan chart of my family tree colorizes the X chromosome inheritance path. In this chart, males are colored blue and females pink, but the salient point is that I can inherit some portion of (or all of) a copy of my X chromosome from the colorized ancestors, and only those ancestors.

Because males don’t inherit an X chromosome from their father, they CANNOT inherit any portion of an X chromosome from their father’s ancestors.

Looking at my father’s half of the chart, at left, you see that I inherited an X chromosome from both of my parents, but my father only inherited an X chromosome from his mother, Ollie Bolton. His father’s portion of the tree is uncolored, so no X chromosome could have descended from his paternal ancestors to him. Therefore he could not pass any X chromosome segments to me from his paternal side – because he doesn’t have X DNA from his father.

Hence, I didn’t inherit an X chromosome from any of the people whose positions in the chart are uncolored, meaning I can only inherit an X chromosome from the pink or blue people.

Essentially any generational male to male, meaning father/son relationship is an X-DNA blocker.

I know positively that I inherited my paternal grandmother, Ollie Bolton’s entire X chromosome, because hers is the only X chromosome my father, in the fan chart above, had to give me. His entire paternal side of the fan chart is uncolored.

Men only ever inherit their X chromosome from their mother. The only exception to this is if a male has the rare genetic condition of Klinefelter Syndrome, also known as XXY. If you are an adult male, it’s likely that you’ll already know if you have Klinefelters, so that’s probably the last possibility you should consider if you appear to have paternal X matches, not the first.

Sometimes, men appear to have X matches on their father’s side, but (barring Klinefelter’s) this is impossible. Those matches must either be identical by chance, or somehow related in an unknown way on their mother’s side.

Everyone inherits an X chromosome from their mother that is some combination of the X from her father and mother. It’s possible to inherit all of your maternal grandmother or maternal grandfather’s X chromosome, meaning they did not recombine during meiosis.

Using DNA Painter as an X Tool

I use DNAPainter to track my matches and correlate segments with ancestors.

I paint my DNA segments for all my chromosomes at DNAPainter which provides me with a central tracking mechanism that is visual in nature and allows me to combine matches from multiple vendors who provide segment information. I provide step-by-step instructions for using DNAPainter, here.

This is my maternal X chromosome with my matches painted. I’ve omitted my matches’ names for privacy.

On the left side of the shaded grey column, those matches are from my maternal grandmother’s ancestors. On the right side, those matches are from my maternal grandfather’s ancestors.

The person in the grey column descends from unknown ancestors. In other words, I can tell that they descend from my maternal line, but I can’t (yet) determine through which of my two maternal grandparents.

There’s also an area to the right of the grey column where there are no matches painted, so I don’t know yet whether I inherited this portion of my X chromosome from my maternal grandmother or maternal grandfather.

The small darker pink columnar band is simply marking the centromere of the chromosome and does not concern us for this discussion.

Click on any image to enlarge

In this summary view of my paternal X chromosome, above, it appears that I may well have inherited my entire X chromosome from my paternal great-grandmother. We know, based on our inheritance rules that I clearly received my paternal grandmother’s X chromosome, because that’s all my father had to give me.

However, by painting my matches based on their ancestors, and selecting the summary view, you can see that most of my paternal X chromosome can be accounted for, with the exception of rather small regions with the red arrows.

It’s not terribly unusual for either a male or female to inherit their entire maternal X chromosome from one grandparent, or in this case, great-grandparent.

Of course, a male doesn’t inherit an X chromosome from their father, but a female can inherit her paternal X chromosome from either or both paternal grandparents.

Does Size Matter?

Generally speaking, an X match needs to be larger than a match on the other chromosomes to be considered genealogically equivalent in the same timeframe as other autosomal matches. This is due to:

  • The unique inheritance pattern, meaning fewer recombination events occurred.
  • The fact that X-DNA is NOT inherited from several lines.
  • The X chromosome has lower SNP density, meaning it contains fewer SNPs, so there are fewer possible locations to match when compared to the other chromosomes.

I know this equivalency requirement sounds negative, but it’s actually not. It means 7 cM (centimorgans) of DNA on the X chromosome will reach back further in time, so you may carry the DNA of an ancestor on the X chromosome that you no longer carry on other chromosomes. It may also mean that older segments remain larger. It’s actually a golden opportunity.

It sounds much more positive to say that a 16 cM X match for a female, or a 13 cM X match for a male is about the same as a 7 cM match for any other autosomal match in the same generation.

Of course, if the 7 cM match gets divided in the following generation, it has slipped below the matching threshold. If a 16 or 13 cM X match gets divided, it’s still a match. Plus, in some generations, if passed from father to daughter, it’s not divided or recombined. So a 7 cM X match may well be descended from ancestors further back in time.

X Chromosome Differences are Important!

Working with our great-great grandparent’s generation, we have 16 direct ancestors as illustrated in the earlier fan chart.

Given that females inherit from 8 X-chromosome ancestors in total, they are going to inherit an average of 45.25 cM of X-DNA from each of those ancestors. Females have two X chromosomes for a total length of 362 cM of X-DNA from both parents.

A male only has one X chromosome, 181 cM in length, so he will receive an average of 36.2 cM from each of 5 ancestors, and it’s all from his mother’s side.

In this chart, I’ve shown the total number of cMs for all of the autosomes, meaning chromosomes 1-22 and, separately, the X for males and females.

  • The average total cM for chromosomes 1-22 individually is 304 cM. (Yes, each chromosome is a different length, but that doesn’t matter for averages.)
  • That 304 cM can be inherited from any of 16 ancestors (in your great-grandparent’s generation)
  • The total number of cM on the X chromosomes for both parents for females totals 362
  • The total cM of X-DNA for males is 181 cM
  • The calculated average cM inherited for the X chromosome in the same generation is significantly different, shown in the bottom row.

The actual average for males and females for any ancestor on any random non-X chromosome (in the gg-grandparent generation) is still 19 cM. Due to the inheritance pattern of the X chromosome, the female X-chromosome average inheritance is 45.25 cM and the male average is 36.2 cM, significantly higher than the average of 19 cM that genetic genealogists have come to expect at this relationship distance on the other chromosomes, combined.

How Do I Interpret an X Match?

It’s important to remember when looking at X matching that you’re only looking at the amount of DNA from one chromosome. When you’re looking at any other matching amount, you’re looking at a total match across all chromosomes, as reported by that vendor. Vendors report total matching DNA differently.

  • The total amount of matching autosomal DNA does not include the X chromosome cMs at FamilyTreeDNA. X-DNA matching cMs are reported separately.
  • The total amount of matching autosomal DNA does include the X chromosome cMs in the total cM match at 23andMe
  • X-DNA is not used for matching or included in the match amount at either MyHeritage or Ancestry, but is included in the raw DNA data download files for all four vendors.
  • The total match amount shows the total for 22 (or 23) chromosomes, NOT just the X chromosome(s). That’s not apples to apples.

Therefore, an X match of 45 cM for a female or 36 for a male is NOT (necessarily) equivalent to a 19 cM non-X match. That 19 cM is the total for 22 chromosomes, while the X match amount is just for one chromosome.

You might consider a 20 cM match on the regular autosomes significant, but a 20 cM X-only match *could* be only roughly equivalent to a 10ish cM match on chromosomes 1-22 in the same generation. That’s the dog-leg inheritance pattern at work.

This is why FamilyTreeDNA does not report an X-only match if there is no other autosomal match. A 19 cM X match is not equivalent to a 19cM match on chromosomes 1-22. Not to mention, calculating relationships based on cM ranges becomes more difficult when the X is included.

However, the flip side is that because of the inheritance pattern of the X chromosome, that 19 cM match, if valid and not IBC, may well reach significantly further back in time than a regular autosomal matches. This can be particularly important for people seeking either Native or enslaved African ancestors for whom traditional records are elusive if they exist at all.

Critical Take-Away Messages

Here are the critical take-away messages:

  1. Because there are fewer ancestral lineages contributing to the tester’s X chromosome, the amount of X chromosomal DNA that a tester inherits from the ancestors who contribute to their X chromosome is increased substantially.
  2. The DNA of the contributing ancestors is more likely to be inherited, because there are fewer other possible contributing ancestors, meaning fewer recombination events or DNA divisions/recombinations.
  3. X-DNA is also more likely to be inherited because when passed from mother to son, it’s passed intact and not admixed with the DNA of the father.
  4. X matches cannot be compared equally to either percentages or cM amounts on any of the other chromosomes, or autosomal DNA in total, because X matching only reports the amount on one single chromosome, while your total cM match amount reports the amount of DNA that matches from all chromosomes (which includes the X at 23andMe).
  5. If you have X matches at 23andMe and/or FamilyTreeDNA, you can expect your total matching to be higher at 23andMe because they include the X matching cM in the total amount of shared DNA. FamilyTreeDNA provides the amount of X matching DNA separately, but not included in the total. MyHeritage and Ancestry do not include X matching DNA.

For clarity, at FamilyTreeDNA, you can see my shared DNA match with my mother. Of course, I match her on the total length of all my chromosomes, which is 3563 cM, the total Shared DNA for chromosomes 1-22. This includes all chromosomes except for the X chromosome which is reported separately at 181 cM. The longest contiguous block of shared DNA is 284 cM, the entire length of chromosome 1, the longest chromosome.

Because I’m a female, I match both parents on the full length of all 23 chromosomes, including 181 cM on both X chromosomes, respectively. Males will only match their mother on their X chromosome, meaning their total autosomal DNA match to their father, because the X is excluded, is 181 cM less than to their mother.

This difference in the amount of shared DNA with each parent, plus the differences in how DNA totals are reported by various vendors is also challenging for tools like DNAPainter’s Shared cM Tool which is based on the crowd sourced Shared cM Project that averages shared DNA numbers for known relationships at various vendors and translates those numbers into possible relationships for unknown matches.

Not all vendors report their total amount of shared DNA the same way. This is true for both X-DNA and half identical (HIR) versus fully identical (FIR) segments at 23andMe. This isn’t to say either approach is right or wrong, just to alert you to the differences.

Said Another Way

Let’s look at this another way.

If the average on any individual chromosome is 19 cMs for a relationship that’s 5 generations back in time. The average X-DNA for the same distance relationship is substantially more, which means that:

  • The X-DNA probably reaches further back in time than an equivalent relationship on any other autosome.
  • The X-DNA will have (probably) divided fewer times, and more DNA will descend from individual ancestors.
  • The inheritance path, meaning potential ancestors who contributed the X chromosomal DNA, is reduced significantly.

It’s challenging to draw equivalences when comparing X-DNA matching to the other chromosomes due to several variables that make interpretation difficult.

Based on the X-match size in comparison to the expected 19 cM single chromosome match at this genealogical distance, what is the comparable X-DNA segment size to the minimum 7 cM size generally accepted as valid on other chromosomes? What would be equal to a 7 cM segment on any other single random autosomal match, even though we know the inheritance probabilities are different and this isn’t apples to apples? Let’s pretend that it is.

This calculation presumes at the great-great-grandparent level that the 19 cM is in one single segment on a single chromosome. Now let’s divide 19 cM by 7 cM, which is 2.7, then divide the X amounts by the same number for the 7 cM equivalent of 16.75 cM for a female and 13.4 cM for a male.

When people say that you need a “larger X match to be equivalent to a regular autosomal match,” this is the phenomenon being referenced. Clearly a 7 cM X match is less relevant, meaning not equivalent, in the same generation as a 7 cM regular autosomal match.

Still, X matching compared to match amounts shown on the other chromosomes is never exact;u apples to apples because:

  • You’re comparing one X chromosome to the combined DNA amounts of many chromosomes.
  • The limited recombination path.
  • DNA from the other autosomes is less likely to be inherited from a specific ancestor.
  • The X chromosome has a lower SNP density than the other chromosomes, meaning fewer SNPs per cM.
  • The X-DNA may well reach further back in time because it has been divided less frequently.

Bottom Line

The X chromosome is different and holds clues that the other autosomes can’t provide.

Don’t dismiss X matches even if you can’t identify a common ancestor. Given the inheritance path, and the reduced number of divisions, your X-DNA may descend from an ancestor further back in time. I certainly would NOT dismiss X matches with smaller cMs than the 13 and 16 shown above, even though they are considered “equivalent” in the same generation.

X chromosome matching can’t really be equated to matching on the other chromosomes. They are two distinct tools, so they can’t be interpreted identically.

Different vendors treat the X chromosome differently, making comparison challenging.

  • 23andMe includes not only the X chromosome in their cM total, but doubles the Fully Identical Regions (FIR) when people, such as full siblings, share the same DNA from both parents. I wrote about that here.
  • Ancestry does not include the X in their cM match calculations.
  • Neither does MyHeritage.
  • FamilyTreeDNA shows an X match only when it’s accompanied by a match on another chromosome.

The Shared cM Project provides an average of all of the data input by crowdsourcing from all vendors, by relationship, which means that the cM values for some relationships are elevated when compared to the same relationship or even same match were it to be reported from a different vendor.

The Best Part!

The X chromosome inheritance pattern means that you’re much more likely to carry some amount of a contributing ancestor’s X-DNA than on any other chromosome.

  • X-DNA may well be “older” because it’s not nearly as likely to be divided, given that there are fewer opportunities for recombination.
  • When you’re tracking your X-DNA back in your tree, whenever you hit a male, you get an automatic “bump” back a generation to his mother. It’s like the free bingo X-DNA square!
  • You can immediately eliminate many ancestors as your most recent common ancestor (MRCA) with an X-DNA match.
  • Because X-DNA reaches further back in time, sometimes you match people who descend from common ancestors further back in time as well.

If you match someone on multiple segments, if one of those matching segments is X-DNA, that segment is more likely to descend from a different ancestor than the segments on chromosomes 1-22. I’ve found many instances where an X match descends from a different ancestor than matching DNA segments on the autosomes. Always evaluate X matches carefully.

Sometimes X-DNA is exactly what you need to solve a mystery.

Ok, now let’s step through how to use X-DNA in a real-life example.

Using X DNA to Solve a Mystery

Let’s say that I have a 30 cM X match with a male.

  • I know immediately that our most recent common ancestor (MRCA) is on HIS mother’s side.
  • I know, based on my fan chart, which ancestral lines are eliminated in my tree. I’ve immediately narrowed the ancestors from 16 to 5 on his side and 16 to 8 on my side.
  • Two matching males is even easier, because you know immediately that the common ancestor must be on both of their mother’s sides, with only 5 candidate lines each at the great-great-grandparent generation.

Female to female matches are slightly more complex, but there are still several immediately eliminated lines each. That means you’ve already eliminated roughly half of the possible relationships by matching another female on their X chromosome.

In this match with a female second cousin, I was able to identify who she was via our common ancestor based on the X chromosome path. In this chart, I’m showing the relevant halves of her chart at left (paternal), and mine (maternal), side by side.

I added blockers on her chart and mine too.

As it turns out, we both inherited most of our X chromosome from our great-grandparents, marked above with the black stars.

Several lines are blocked, and my grandfather’s X chromosome is not a possibility because the common ancestor is my maternal grandmother’s parents. My grandfather is not one of her ancestors.

Having identified this match as my closest relative (other than my mother) to descend on my mother’s maternal side, I was able to map that portion of my X chromosome to my great-grandparents Nora Kirsch and Curtis Benjamin Lore.

My X Chromosome at DNA Painter

Here’s my maternal X chromosome at DNAPainter and how I utilized chromosome painting to push the identification of the ancestors whose X chromosome I inherited back an additional two generations.

Using that initial X chromosome match with my second cousin, shown by the arrow at bottom of the graphic, I mapped a large segment of my maternal X chromosome to my maternal great-grandparents.

By viewing the trees of subsequent X maternal matches, I was then able to push those common segments, shown painted directly above that match with the same color, back another two generations, to Joseph Hill, born in 1790, and Nabby Hall. I was able to do that based on the fact that other matches descend from Joseph and Nabby through different children, meaning we all triangulate on that common segment. I wrote about triangulation at DNAPainter, here.

I received no known X-DNA from my great-grandmother, Nora Kirsch, although a small portion of my X chromosome is still unassigned in yellow as “Uncertain.”

I received a small portion of my maternal X chromosome, in magenta, at left, from my maternal great-great-grandparents, John David Miller and Margaret Lentz.

The X chromosome is a powerful tool and can reach far back in time.

In some cases, the X, and other chromosomes can be inherited intact from one grandparent. I could have inherited my mother’s entire copy of her mother’s, or her father’s X chromosome based on random recombination, or not. As it turns out, I didn’t, and I know that because I’ve mapped my chromosomes to identify my ancestors based on common ancestors with my matches.

X-DNA Advanced Matches at FamilyTreeDNA

At FamilyTreeDNA, the Advanced Matches tab includes the ability to search for X matches, either within the entire database, or within specific projects. I find the project selection to be particularly useful.

For example, within the Claxton project, my father’s maternal grandmother’s line, I recognize my match, Joy, which provides me an important clue as to the possible common ancestor(s) of our shared segments.

Joy’s tree shows that her 4-times great-grandparents are my 3-times great-grandparents, meaning we are 4th cousins once removed and share 17 cM of DNA on our X chromosome across two segments.

Don’t be deceived by the physical appearance of “size” on your chromosomes. The first segment that spans the centromere, or “waist” of the chromosome, above, is 10.29 cM, and the smaller segment at right is 7.02 cM. SNPs are not necessarily evenly distributed along chromosomes.

Remember, an X or other autosomal match doesn’t necessarily mean the entire match is contained in one segment so long as it’s large enough to be divided in two parts and survive the match threshold.

It’s worth noting that Joy and I actually share at least two different, unrelated ancestral lines, so I need to look at Joy’s blocked lines to see if one of those common ancestral lines is not a possibility for our X match. It’s important to evaluate all possible ancestors, plus the inheritance path to eliminate any lineage that involves a father to son inheritance on the X chromosome.

Last but not least, you may match on your X chromosome through a different ancestor than on other chromosomes. Every matching segment has its own individual history. It’s not safe to assume.

Now, take a look at your X chromosome matches at FamilyTreeDNA, 23andMe, and GedMatch. What will you discover?

_____________________________________________________________

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Thank you so much.

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The Best of 2022

It’s that time of year where we look both backward and forward.

Thank you for your continued readership! Another year under our belts!

I always find it interesting to review the articles you found most interesting this past year.

In total, I published 97 articles in 2022, of which 56 were directly instructional about genetic genealogy. I say “directly instructional,” because, as you know, the 52 Ancestors series of articles are instructional too, but told through the lives of my ancestors. That leaves 41 articles that were either 52 Ancestors articles, or general in nature.

It has been quite a year.

2022 Highlights

In a way, writing these articles serves as a journal for the genetic genealogy community. I never realized that until I began scanning titles a year at a time.

Highlights of 2022 include:

Which articles were your favorites that were published in 2022, and why?

Your Favorites

Often, the topics I select for articles are directly related to your comments, questions and suggestions, especially if I haven’t covered the topic previously, or it needs to be featured again. Things change in this industry, often. That’s a good thing!

However, some articles become forever favorites. Current articles don’t have enough time to amass the number of views accumulated over years for articles published earlier, so recently published articles are often NOT found in the all-time favorites list.

Based on views, what are my readers’ favorites and what do they find most useful?

In the chart below, the 2022 ranking is not just the ranking of articles published in 2022, but the ranking of all articles based on 2022 views alone. Not surprisingly, six of the 15 favorite 2022 articles were published in 2022.

The All-Time Ranking is the ranking for those 2022 favorites IF they fell within the top 15 in the forever ranking, over the entire decade+ that this blog has existed.

Drum roll please!!!

Article Title Publication Date 2022 Ranking All-Time Ranking
Concepts – Calculating Ethnicity Percentages January 2017 1 2
Proving Native American Ancestry Using DNA December 2012 2 1
Ancestral DNA Percentages – How Much of Them in in You? June 2017 3 5
AutoKinship at GEDmatch by Genetic Affairs February 2022 4
442 Ancient Viking Skeletons Hold DNA Surprises – Does Your Y or Mitochondrial DNA Match? Daily Updates Here September 2020 5
The Origins of Zana of Abkhazia July 2021 6
Full or Half Siblings April 2019 7 15
Ancestry Rearranged the Furniture January 2022 8
DNA from 459 Ancient British Isles Burials Reveals Relationships – Does Yours Match? February 2022 9
DNA Inherited from Grandparents and Great-Grandparents January 2020 10
Ancestry Only Shows Shared Matches of 20 cM and Greater – What That Means & Why It Matters May 2022 11
How Much Indian Do I Have in Me??? June 2015 12 8
Top Ten RootsTech 2022 DNA Sessions + All DNA Session Links March 2022 13
FamilyTreeDNA DISCOVER Launches – Including Y DNA Haplogroup Ages June 2022 14
Ancient Ireland’s Y and Mitochondrial DNA – Do You Match??? November 2020 15

2023 Suggestions

I have a few articles already in the works for 2023, including some surprises. I’ll unveil one very soon.

We will be starting out with:

  • Information about RootsTech where I’ll be giving at least 7 presentations, in person, and probably doing a book signing too. Yes, I know, 7 sessions – what was I thinking? I’ve just missed everyone so very much.
  • An article about how accurately Ancestry’s ThruLines predicts Potential Ancestors and a few ways to prove, or disprove, accuracy.
  • The continuation of the “In Search Of” series.

As always, I’m open for 2023 suggestions.

In the comments, let me know what topics you’d like to see.

_____________________________________________________________

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Concepts: Your Matches on the Same Segment are NOT Necessarily Related to Each Other

Just because two (or more) people match you on the same segment does NOT mean they are related to each other.

This is a fundamental concept of DNA matching and of using a chromosome browser.

I want to make this concept crystal clear.

This past week, I’ve had two people contact me with the same question that’s based up on a critical misunderstanding, or maybe just lack of understanding.

It’s not intuitive – in fact, it’s counter-intuitive. I understand why they don’t understand.

It seems logical that if two or more people show up as a match to you on the chromosome browser, on the same segment, you’ve hit a home run and all you need to do is to identify their common ancestor who will also be your common ancestor, or at least related. Right?

NOT SO FAST!

Let’s walk through this, step-by-step. Once you “get it,” you’ll never forget it, and you can use this to help other people understand too. Please notice there are lots of links here to other articles I’ve written if you need refreshers or help with terms.

Yay! – I’ve Got Matches

OK, so you’ve just discovered that you have a close match with three people, on the same segment. You’re thrilled! Maybe you’re trying to identify your grandparent, so first or second cousin matches are VERY exciting for you.

They are also close enough matches with large enough segments that you don’t need to worry about false positive matches, meaning identical by chance.

Let’s take a look. I’m using FamilyTreeDNA because that’s where the majority of my family has tested, plus they have a nice chromosome browser and their unique matrix tool.

We have three nice-sized matches to people estimated to be my first or second cousins. I’ve selected all three and compared them in the chromosome browser. The large red match is 87 cM and the blue and teal matches are 39 cM each, and completely within the 87 cM segment, so completely overlapping.

I’ve hit the mother-lode, right?

All I need to do is identify THEIR common ancestor and I’ll surely find mine.

Right???

Nope

Just because they all three match ME on this same segment does NOT mean they all match each other and are from the same side of my family. All three people DO NOT NECESSARILY have the same ancestor. From this information alone, we cannot tell.

I know this seems counterintuitive, especially since you’re seeing them all on MY chromosomes – which are the background pallet.

However, remember that I have two chromosomes. One from my father and one from my mother.

These matches are ALWAYS FROM THE PERSPECTIVE OF THE TESTER.

So, I’m going to see matches in exactly the same location – matches on my mother’s chromosome and matches on my father’s chromosomes – painted on the same segment locations of my chromosome.

Let’s prove that in the simplest of ways.

Mom and Dad

This is my kit, compared with my Dad and Mom.

I only took a screen shot of my first several chromosomes, but you can see that I match both of my parents on the full length of each chromosome – on the same exact segments.

I am the background – the pallet upon which my matches are painted.

First, my father is painted, then my mother – their match to me displayed on my chromosomes.

I assure you, my father and mother are NOT related to each other. I’ll prove it.

I could simply select one parent, then look for the other parent on the shared matches list.

Or, I could use the Matrix tool, especially if I wanted to see if a group of people are related to me and also to each other.

The Matrix

The Matrix tool is available under “See More,” in the Autosomal DNA Results & Tools section.

The Matrix allows you to select 10 or fewer matches to see if they are matches to each other. We already know they are matches to you.

I added my parents into the matrix.

My parents do not match each other, meaning they are not genetically related, because their intersecting cell is not blue.

Next, let’s select those three other people I match and see if they match each other.

Yes indeed, we can see that Cheryl and Donald match each other, but Amos matches NEITHER Cheryl nor Don. Yet, the segments of Cheryl and Donald, who had the 39 cM blue and teal segments on the chromosome browser fall entirely within Amos’s 87 cM segment.

Therefore, if Cheryl and Donald do not match Amos, that means that Cheryl and Donald are from one side of my family, and Amos is from the other. This is absolutely true in this instance because we are comparing the exact same segment on my DNA, so everyone has to match me maternally or paternally, or by chance (IBC.) The segment size alone removes the possibility of IBC.

Each parent gave me one copy of chromosome 4, so everyone who matches me on chromosome 4 must match one or the other parent on that chromosome segment.

I’ve added my parents back into the comparison, at the bottom, with the three matches on chromosome 4. Now you can see that same segment again, and everyone matches me, parents included, of course.

There’s no way to tell the difference whether the blue, red and teal match is on my mother’s or father’s side without additional information.

Again, let’s prove it.

Everybody, Let’s Dance

I added my Mom and Dad back into the matrix.

You can see that Mom and Cheryl and Donald all match each other, plus me of course, by inference because these are my matches.

You can see that Amos and my Dad match each other, and me of course, but not the other people.

Settled

So, we’ve settled that, right.

In my case, I could provide this great example, because I do in fact have parental tests to use for comparison.

You can see when I remove my Dad and Amos that Cheryl and Donald and my Mom all match each other. If I were to remove my Mom, Cheryl and Donald would match each other.

If I remove Mom, Donald and Cheryl, Dad and Amos match each other.

Of course, you may not have either of your parents’ DNA to use as an anchor for matching. You may, in fact, be searching for a parent or close relative.

If you do have “anchor people,” by all means, use them. In fact, upload or create a tree, link your anchor people and as many others as possible to their profiles in your tree at FamilyTreeDNA so your matches will be automatically bucketed, meaning assigned maternally or paternally. FamilyTreeDNA is the only company that offers linking and triangulated bucketing.

But, if you’re searching for your parents or know nothing about your family, you won’t have an anchor point, so what’s next?

What’s Next?

Using a combination of matching, shared matches and the matrix, you can create your own grouping of matches.

My suggestion is to start with your 10 closest matches.

Pull all 10 into the matrix.

Remember, you will match these people across your chromosomes. The only question the matrix answers is “do my matches match each other,” and a “yes” doesn’t’ necessarily mean they match each other on the same line you match either or both of them on.

I’ve noted how each person is related to me.

You can see that there’s a large block of matches on my paternal side. Some are labeled “Father- both.” These people are related both maternally and paternally to my father, because either the families intermarried, or they are descendants of my paternal grandparents.

Three, Donald, Dennis and Cheryl are related on my mother’s side, but it’s worth noting that Dennis doesn’t match Cheryl or Donald. That doesn’t mean he’s not on my mother’s side, it simply means he descends through her maternal line, not the paternal line like Donald and Cheryl. Remember, we’re not comparing people who match on the same chromosome this time – we’re comparing my closest matches across all chromosomes, so it makes sense that my mother’s maternal matches won’t match her paternal matches, but they would both match Mom if she were in the matrix. Clearly they all match me or they would not be in my match list in the first place.

You could also run a Genetic Affairs AutoCluster or AutoTree to cluster your matches for you into groups, although you can’t select specifically which individuals to include, except by upper and lower thresholds.

Regardless of the method you select, you still need to do the homework to figure out the common ancestors, but it’s a lot easier knowing who also match each other.

Circling Back to the Beginning

Now, when you see those two or three or more people all matching you on the same segment on the chromosome browser, you KNOW that you can’t immediately assume they match you and therefore are all related to each other. It’s possible, and even probable that some of them will match you because they match your mother’s chromosome and some will match your father’s chromosome – so they are from different sides of your family.

The Matrix tool shows you, for groups of 10 or less, who also matches each other.

What you are doing by determining if multiple people share common segments and match each other is triangulation. I wrote about triangulation at each company in the articles below:

Unfortunately, Ancestry does not provide a chromosome browser, so triangulation is not possible, but Ancestry does provide shared matching with some caveats. However, some Ancestry customers do upload their DNA file to FamilyTreeDNA, MyHeritage or GEDmatch. You can find step-by-step download/upload instructions for all vendors, here.

Additional Resources

You’ve probably noticed there are lots of links in this article to other articles that I’ve written. You might want to go back and take a look at those if you’re in the process of educating yourself or need help wrapping your head around the “same segment address – two parents – your matches are not created equal” phenomenon.

Here are a couple of additional articles that will help you understand matching on both parents’ sides, and how to get the most out of matching, segments, triangulation and chromosome browsers.

I prepared a triangulation resource summary article, here:

Enjoy!!
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Y DNA Genealogy Case Study: SNPs, STRs & Autosomal – Why the Big Y-700 Rocks!

An expanded version of this article, including the genealogical aspects written for the Speak family, is available here. There is significantly more DNA information and analysis in this article, including STR values and autosomal analysis which can sometimes augment Y DNA results.

In 2004, 18 years ago, I founded the Speak(e)(s) Family DNA Project at FamilyTreeDNA in collaboration with the Speaks Family Association (SFA).

The goal of the Association broadly was to share research and to determine if, and how, the various Speak lines in America were related. The “rumor” was that the family was from England, but no one knew for sure. We didn’t even know who was actually “in” the family, or how many different families there might be.

The good news is that to answer these types of questions, you don’t need a huge study, and with today’s tools, you certainly don’t need 18 years. Don’t let that part scare you. In fact, any Speak(e)(s) man who takes a Y-DNA test today will have the answer plopped into his lap thanks to earlier testers.

When I established the Speaks DNA Project, our goal was stated, in part, as follows:

This project was begun to determine the various Speak(e)(s) lines around the world. According to family legend, the original ancestor came to England with William the Conqueror and his last name then was L’Espec. It was later spelled Speke and then the derivatives of Speake, Speak, Speakes, and Speaks carried by descendants today.

We knew there was a Thomas Speak (c1634-1681) who settled in St. Mary’s County, MD by 1661 and had two sons, John the InnKeeper or InnHolder (1665-1731) and Bowling (c1674-1755), named after his mother’s birth surname.

Fast forwarding two or three generations, my ancestor, Nicholas Speak or Speaks was born about 1782 and was first found in Washington County, Virginia in 1804 when he married Sarah Faires. That’s a long way from Maryland. Who was Nicholas? Who were his parents? How did Nicholas get to Washington County, Virginia? There aren’t any other Speaks men, or women, in Washington County. Was he dropped fully grown by the stork?

In 2005, I attended my first Speaks Family Association Convention and gave an introductory talk about Y-DNA. Speaks males volunteered to test.

By the 2006 Convention, we had 8 Y-DNA testers.

At first, everything was fine. Two testers each from Thomas the Immigrant through sons John and Bowling.

  • Thomas, Bowling and then two different sons. They matched.
  • Thomas, John, and his son Richard. They matched too.
  • All four men above match each other.

Everything’s good, right?

Not so fast…

Then, a father/son pair tested who were also supposed to descend from the Thomas, Bowling, and Thomas line. Thankfully, they matched each other, but they did NOT match the other descendants of Thomas the Immigrant.

Because we had multiple men through both of Thomas the Immigrant’s sons, we had confirmed the Y-DNA STR marker signature of Thomas – which means that the father/son pair had experienced a genetic disconnect, or, they were actually descended from a different Speak line.

That wasn’t all though. Two more men tested who believed they descended from Thomas the Immigrant through John and then Richard. They didn’t match each other, nor any of the other men either.

This was a difficult, painful situation, and not what was anticipated. Of course, I reviewed the results privately with the men involved before presenting them at the convention, and only did so with their permission.

In an effort to identify their genealogical lines, we discovered seven other mentions of early colonial Speak immigrants, including one named Thomas.

Over time, we would discover additional Y-DNA genetic Speak lines.

Bonus Cousin

Y-DNA also revealed an amazing new cousin, Henry, who didn’t know who his father was, but thanks to DNA, discovered he is a genetic Speaks AND identified his father.

In 2006, our Y-DNA haplogroup was known only as I1b1. We knew it was fairly rare and found in the rough Dinaric Alps border region between Bosnia and Croatia.

We weren’t wrong. We were just early. Our ancestors didn’t stop in the Alps.

Haplogroups have come a long way since that time.

Today, using the new maps in the Discover tool, the migration path into Europe-proper looks like this.

By the 2009 Convention, more Speaks men were taking Y-DNA tests, but we still had no idea where the Speaks line originated overseas.

The Holy Grail

The Holy Grail of Y-DNA testing is often a match with a man either from the “old country,” wherever that is, or someone who unquestionably knows where their ancestor is from. Through a match with them, other testers get to jump the pond too.

In early 2010, a man in New Zealand was interested in taking a Y-DNA test and knew where, in England, his ancestors originated.

A few weeks later, the New Zealand tester matched our Thomas Speaks, the Immigrant, line, which meant our ancestors might be from where his ancestors were from. Where was that?

Gisburn.

Gisburn? Where the heck was Gisburn?

Gisburn

Gisburn is a tiny, ancient village in Lancashire, England located in the Ribble Valley on the old Roman road. It appears in the Domesday Book of 1086 as Ghiseburne and is believed to have been established in the 9th century.

This was no longer speculation or unsourced oral history, but actual genetic evidence.

We knew that Thomas Speake, the Immigrant, was Catholic. Maryland was a safe haven for Catholics hoping to escape persecution in England.

Thomas was rumored to have been born to a John, but we had no idea where that rumor arose.

Was our Thomas born in Gisburn too?

Shortly, we discovered that St. Mary’s Church in Gisburn held 50 marked Speaks burials in addition to many unmarked graves.

Next, we discovered that the records of St. Mary’s and All Saints Church in Whalley, eleven miles from Gisburn, held pages and pages of Speak family records. The earliest Speak burial there was in 1540.

In 2011, the SFA Convention was held near Thomas and Bowlng Speak’s land in Charles County, Maryland. My Convention presentation contained a surprise – the information about our Gisburn match, and what we had found. A Y-DNA match, plus church records, and graves. How could that get better?

I showed this cemetery map from St. Mary’s Church in Gisburn, where our New Zealand cousin’s family was buried.

It felt like we were so excruciatingly close, but still so far away.

We knew unquestionably that we were in the neighborhood, but where was our Thomas born?

Who was his family?

I closed with this photo of St. Mary’s in Gisburn and famously said, “I don’t know about you, but I want to stand there.”

It was a throw-away comment, or so I thought, but as it turned out, it wasn’t.

2013 – The Trip Home

Gisburn

Two years later, our Convention was held in Lancashire, and indeed, I got to stand there.

So did our Speak cousin from New Zealand whose Y-DNA test bulldozed this brick wall for us. To be clear, had this ONE PERSON not tested, we would NOT have known where to dig for records, or where to visit.

St. Mary’s Church was surrounded by the cemetery, with many Speak stones. The church itself was built as a defensive structure sometime before 1135 with built-in arrowslits for archers in many locations, including the tower. Our family history was thick and rich here.

St. Mary’s Church in Whalley

Our next stop was St. Mary’s Church in Whalley, where Henry Speke was granted a lease in 1540.

This church is ancient, built in the 1200s, replacing an earlier church in the same location, and stunningly beautiful.

The little green men carved into the wooden choir seats are a wink and a nod to an earlier pagan era. Our ancestors would have known that era too.

In addition to the churches in Gisburn and Whalley, we visited St. Leonard’s Church in Downham which is a chapelry of the church in Whalley.

Downham

This church, in the shadow of Pendle Hill, proved to be quite important to our hunt for family.

Downham, on the north side of Pendle Hill was small then, and remains a crossroad village today with a population of about 150 people, including Twiston.

Twiston is located less than 3 miles away, yet it’s extremely remote, at the foot or perhaps on the side of Pendle Hill.

During our visit, Lord Clitheroe provided us with a transcription of the Downham church records wherein one Thomas Speak was baptized on January 1, 1633/34, born to Joannis, the Latin form of John, in nearby Twiston.

Is this Thomas our Thomas the Immigrant who was born about that same time? We still don’t know. There are clues but they are inconclusive and some conflict with each other.

Records in this area are incomplete. A substantial battle was fought in Whalley in 1643. Churches were often used for quartering soldiers and horses. Minister’s notes could well have been displaced, or books destroyed entirely. There could easily have been more than one Thomas born about this time.

Probate files show that in 1615, “John Speake of Twiston, husbandman” mentions his son William and William’s children, including John who was the administrator of his will. For John to be an administrator, he had to be age 21 or over, so born in 1594 or earlier. Some John Speak married Elizabeth Biesley at Whalley in 1622 and is believed to be the John Speak Sr. recorded in Downham Parish Registers.

The Whalley, Gisburn, and Twiston Speake families are closely connected. The difference may well be that our Thomas’s line remained secretly Catholic, so preferred the “uninhabited” areas of the remote Twiston countryside. Even today, Gisburn is described as being “rural, surrounded by hilly and relatively unpopulated areas.” And that’s Gisburn, with more than 500 residents. Downham is much smaller, about 20% of the size of Gisburn.

What do we know about Twiston?

Twiston

Twiston is too small to even be called a hamlet. The original farm and corn mill was owned originally by Whalley Abbey at least since the 1300s and stands near an old lime kiln, probably in use since Roman times.

This is where you know the earth holds the DNA of your ancestors, and their blood watered the landscape.

When the Speak family lived here, it was considered a “wild and lawless region” by local authorities, probably due in part to its remoteness – not to mention the (ahem) rebellious nature of the inhabitants.

If you were a Catholic, living in a hotbed of “recussants,” and trying to be invisible, Twiston, nestled at the base of Pendle Hill would be a location where you might be able to successfully disappear among those of like mind.

Yes, of course, you’d show up, hold your nose, and baptize your baby in the Anglican church because you needed to, but then you would retreat into the deep hillside woodlands until another mandatory church appearance was required.

The road to Twiston was twisty, rock-lined, and extremely narrow, with rock walls on both sides. If only these ancient buildings and stone walls could speak, share their stories, and reveal their secrets.

Old documents, however, do provide some insight.

This document, originally penned in Latin, was provided by the Lancashire archives.

John Speak, in 1609, was a farmer, with a house (messauge), garden, orchard, 10 acres of farmland, 5 of meadow, and 10 acres of pasture.

Indeed, Twiston is where John Speak lived. If the Thomas born in Twiston to Joannis, Latin for John, in 1633 and baptized on January 1, 1633/34 in old St. Leonard’s Church in Downham is our Thomas, this is his birth location.

For our family, this is, indeed, hallowed ground.

Local Testers

Prior to our visit, we published small ads in local newspapers and contacted historical societies. We found several Speak(e)(s) families and invited them to dinner where the after-dinner speaker explained all about DNA testing. You probably can’t see them clearly, but there are numerous DNA kits lying on the table, just waiting for people to have a swab party.

Our guests brought their family histories, and one of those families traced their line to…you guessed it…Twiston.

Five men from separate Speak families tested. None of them knew of any connection between their families, and all presumed they were not related.

I carried those men’s DNA tests back in my hand luggage like the gold that they were.

They were wrong. All five men matched each other’s Y-DNA and our Thomas Speake line. We got busy connecting the dots genealogically, as best we could given the paucity of extant records.

  • Two of our men descended from Henry Speak born in 1650 who married Alice Hill and lived in Downham/Twiston.
  • Two of our men descended from John Speak born about 1540 who married Elina Singleton and lived in Whalley.
  • Two of our men, including our New Zealand tester, descend from John born sometime around 1700, probably in Gisburn where his son, James, was born about 1745.

We indeed confirmed that we had found our way “home” and that our Speake family has lived there a long time. But how long?

2022 DNA Analysis

Today, the Speaks family DNA Project has 146 members comprised of:

  • 105 autosomal testers
  • 32 Speak Y-DNA testers
  • 24 of whom are Thomas the Immigrant descendants
  • 8 Big Y testers

Over the years, we’ve added another goal. We need to determine HOW a man named Aaron Lucky Speaks is related to the rest of us.

Autosomal DNA confirms that Aaron Luckey is related, but we need more information.

Aaron Lucky is first found in 1787 purchasing land and on the 1790 Iredell County, NC census. We finally located a Y-DNA tester and confirmed that his paternal line is indeed the Lancashire Speaks line, but how?

After discovering that all 5 Lancashire Speaks men descend from the same family as Thomas the Immigrant, we spent a great deal of time trying to both sort them out, and tie the family lines together using STR 25-111 markers, with very limited success.

Can Y-DNA make that connection for us, even though the records can’t?

Yes, but we needed to upgrade several testers, preferably multiple people from each line to the Big Y-700 test.

The Y-DNA Block Tree

When men take or upgrade to a Big Y-700 DNA test, they receive the most detailed information possible, including all available (700+) STR markers plus the most refined haplogroup, including newly discovered mutations in their own test, placing them as a leaf on the very tip of their branch of the tree of mankind.

The only other men “in that branch neighborhood” are their closest relatives. Sometimes they match exactly and are sometimes separated by a single or few mutations. Testers with 30 or fewer mutations difference are shown on the Block Tree by name. Eight Speaks men have taken or upgraded to the Big Y test, providing information via matching that we desperately needed.

This Big Y block tree view shown below is from the perspective of a descendant of Nicholas Speaks (b1782) and includes the various mutations that define branches, shown as building blocks. Each person shown on the Block Tree is a match to the tester with 30 or fewer mutations difference.

Think of haplogroups as umbrellas. Each umbrella shelters and includes everything beneath it.

At the top of this block tree, we have one solid blue block that forms an umbrella over all three branches beneath it. The top mutation name is I-BY14004, which is the haplogroup name associated with that block.

We have determined that all of the Speak men descended from the Lancashire line are members of haplogroup I-BY14004 and therefore, fall under that umbrella. The other haplogroup names in the same block mean that as other men test, a new branch may split off beneath the I-BY14004 branch.

Next, let’s look at the blue block at far left.

The Lancashire men, meaning those who live there, plus our New Zealand tester, also carry additional mutations that define haplogroup I-BY14009, which means that our Thomas the Immigrant line split off from theirs before that mutation was formed.

They all have that mutation, and Thomas didn’t, but he has a mutation that they don’t. This is how the tree forms branches.

Thomas the Immigrant’s line has the mutation defining haplogroup I-FTA21638, forming an umbrella over both of Thomas the Immigrant’s sons – meaning descendants of both sons carry this mutation.

Bowling’s line is defined by haplogroup I-BY215064, but John’s line does not carry this mutation, so John’s descendants are NOT members of this haplogroup, which turns out to be quite important.

We are very fortunate that one of Thomas’s sons, Bowling, developed a mutation, because it allows us to differentiate between Bowling and his brother, John’s, descendants easily if testers take the Big Y test.

Those teal Private Variants are haplogroups-in-waiting, meaning that when someone else tests, and matches that variant, it will be named and become a haplogroup, splitting the tree in that location by forming a new branch.

Aaron Luckey Speak

As you can see, the descendants of Aaron Lucky Speak, bracketed in blue above, carry the Bowling line mutation, so Aaron Luckey descends from one of Bowling’s sons. That makes sense, especially since two of Bowling’s grandsons are also found in Iredell County during the same timeframe and are candidates to be Aaron Luckey’s father.

Here’s a different view of the Big Y testers along with STR Y-DNA testers in a spreadsheet that I maintain.

Thomas the Immigrant (tan band top row) is shown with son, Bowling, who carries haplogroup BY215064. Bowling’s descendants are tan too, near the bottom.

Thomas’s son, John the InnKeeper, shown in the blue bar does NOT have the BY215064 mutation that defines Bowling’s group.

However, the bright green Aaron Lucky line, disconnected at far right, does have the Bowling mutation, BY215064, so this places Aaron Luckey someplace beneath Bowling, meaning his descendant. We just don’t know where he fits yet. The key word is yet.

Can STR Markers Be Utilized for Lineage Grouping?

Sometimes we can utilize STR marker mutations for subgrouping within haplogroups, but in this case, we cannot because STR mutations in this family have:

  • Occurred independently in different lines
  • Potentially back mutated

Between both of these issues, STR mutations are inconsistent and, therefore, in this case, entirely unreliable. I have found this phenomenon repeatedly in DNA projects that I manage where the genealogy line of descent is known and documented.

Let’s analyze the STR mutations.

I’ve created a table based on our 26 Y-DNA testers. However, not everyone tested at 111 markers, so there is a mix.

You can view the Speak DNA Project results, here.

I’ve divided the testers into the same groupings indicated by genealogy combined with the Big Y SNP mutations, which do agree with each other. Those groups are:

  • The Lancaster men that never left, except for the New Zealand tester whose ancestor left just two generations ago. They all share a defining SNP which provides them with an identifying haplogroup that the American line does not have.
  • The Thomas the Immigrant line through son Bowling.
    • The Aaron Luckey line who descends, somehow, from Bowling.
  • The Thomas the Immigrant line through son John the InnKeeper.
  • Two men who have provided no genealogy

We already know that Aaron Luckey descends from Bowling, somehow, but I’m keeping them separate just in case STR values can be helpful.

Let’s look at a total of five STR markers where multiple descendants have experienced mutations and see if we can discern any message. The mutations in the bright yellow Lancashire groups on the project page are summarized and analyzed in the chart, below.

You read the chart below, as follows:

  • For marker DYS-19, the testers who have a value of 16 – then the numbers indicated the number of testers in that group with that value. The Lancaster group has 5, the Bowling group has 7, the Aaron Luckey group has 4, and so forth.
  • The next row, colored the same, shows the value of 17 for marker DYS19.
  • Rows for values of the same marker are colored the same.

This chart does not include several markers where there are one-offs, meaning one mutation in the entire group, or one in each of two different groups that are different from each other. This chart includes markers with mutations that occur in multiple descendants only.

If these mutations were predictive and could be used for lineage assignment, we would expect to see the same mutation only within one of the lines, descended from a common ancestor, consistently, and not scattered across multiple lines.

Let’s start our analysis with the only marker that may be consistently predictive in this group. Marker DYS389ii has an ancestral value of 28, We know this because that value is consistently found in all of the Speaks descendants. A value of 29 is ONLY found in the 4 descendants of Aaron Luckey, and the value of 29 is consistently found in all of his known descendants who have tested. Therefore, it could be predictive.

However, given the nature of STR mutations, it’s difficult to place a lot of confidence in STR-based lineage predictions. Let’s look at the other four markers.

  • Marker DYS19 has a value of 16 in every line, which would be the ancestral value. However, we also find a mutation of 17 in 1 of Bowling’s children, and in 2 of John the InnKeeper’s descendants. That can’t be lineage-defining.
  • Looking at the CDY a/b marker, we find one instance of 35/36, which is a one-off. I wouldn’t have included it if I wasn’t using the other two combinations as examples. The values of 36/36 are found in every line except for the one with no genealogy and only one person has tested at 111 markers. A value of 36/37 is found in only the Bowling line, but not the Aaron Luckey line. The MRCA, or most recent common ancestor between the Bowling descendants is his son, Thomas of Zachia. The best candidates for Aaron Luckey’s father are two of Thomas of Zachia’s sons, but his descendants have a hodgepodge mixture of the two values, so this, again, cannot be a lineage-defining marker.
  • Looking at DYS534, we see a 15 in one of Bowling’s descendants and in 4 of John the InnKeeper’s descendants. Obviously not lineage-specific. There’s a value of 16 in every line which would be ancestral.
  • A value of 33 at DYS710 is found in every lineage, so would be the ancestral value. The value of 34 is found once in each line except for Bowling, which precludes it from being lineage-defining.

Inconsistent lineage results is one of the best reasons to purchase or upgrade to the Big Y-700 test.

Unfortunately, STR placement and lineage determination can be very deceptive and lead genealogists astray. At one time, we didn’t have advanced tools like the Big Y, but today we do.

STR Tests Are Useful When…

To be clear, STR marker tests, meaning the 37 and 111 marker tests available for purchase today, ARE very useful for:

  • Matching other testers
  • Identifying surnames of interest
  • Ruling out a connection, meaning determining that you don’t match a particular line
  • Introductory testing with limited funds that provides matching, a high-level haplogroup, and additional tools. You can always upgrade to the Big Y-700 test.

However, the Big Y-700 is necessary to place groups of people reliably into lineages and determine relationships accurately.

In some cases, autosomal DNA is useful, but in this case, autosomal doesn’t augment Y-DNA due, in part, to record loss and incomplete genealogy in the generations following Thomas of Zachia.

Family Finder Autosomal Analysis

In total, we have the following total Family Finder testers whose genealogy is confirmed:

  • 8 Aaron Luckey
  • 6 Lancashire testers
  • 15 John the InnKeeper testers
  • 33 Bowling testers

An autosomal analysis shows that Aaron Luckey Speak’s descendants match each other (green to green) most closely than they match either of Thomas the Immigrant’s sons, Bowling (tan) or John’s (blue) descendants. We would expect Aaron Luckey’s descendants to match each other the most closely, of course.

The numbers in the cells are total matching centiMorgans/longest segment cM match.

Click on any image to enlarge

Aaron Luckey’s descendants don’t collectively match John or Bowling’s descendants more closely than the other group using centiMorgans as the comparison. Although they match more of Bowling’s descendants (21%) than John’s (13%). This too would be expected since we know Aaron Luckey descends from Bowling’s line, not John’s.

At best, Aaron Luckey’s descendants are 8 or 9 generations removed from a common ancestor with other descendants of Thomas of Zachia, making them 6th or 7th cousins, plus another couple of generations back to Thomas the Immigrant. We can’t differentiate genetically between sibling ancestors or cousin lines at this distance.

Furthermore, we have a large gap in known descendants beneath Thomas of Zachia, other than Charles Beckworth Speak’s son Nicholas’s line. We have at least that many other testers in the project who don’t can’t confirm their Speaks ancestral lineage.

Combining genetic and genealogy information, we know that both Charles Beckworth Speak and Thomas Bowling Speak, in yellow, are found in Iredell County, NC. The children of Thomas of Zachia, shown in purple, are born in the 1730s and any one of them could potentially be the father of Aaron Luckey.

The men in green, including William, Bowling’s other son, are also candidates to be Aaron Luckey’s ancestor, although the two yellow men are more likely due to geographic proximity. They are both found in Iredell County.

We don’t know anything about William’s children, if any, nor much about Edward. John settled in Kentucky. Nicholas (green) stayed in Maryland.

There may be an additional generation between Charles Beckworth Speak (yellow) and Nicholas (born 1782), also named Charles. There’s a lot of uncertainty in this part of the tree.

It seems that Aaron’s middle name of Lucky is likely to be very significant. Aaron Luckey’s descendants may be able to search their autosomal matches for a Luckey family, found in both Iredell County AND Maryland, which may assist with further identification and may help identify Aaron’s father.

If all of the Speak men who took STR tests would upgrade to the Big Y, it’s probable that more branches would be discovered through those Private Variants, and it’s very likely that Aaron Luckey could be much more accurately placed on the tree. Another Aaron Luckey Speak Big Y-700 DNA tester would be useful too.

Connecting the Genetic Dots in England

What can we discern about the Speak family in the US and in Lancashire?

Reaching back in time, before Thomas the Immigrant was born about 1633, what can we tell about the Speak family, how they are connected, and when?

The recently introduced Discover tool allows us to view Y-DNA haplogroups and when they were born, meaning when the haplogroup-defining mutation occurred.

The Time Tree shows the haplogroups, in black above the profile dots. The scientifically calculated approximate dates of when those haplogroups were “born,” meaning when those mutations occurred, are found across the top.

I’ve added genealogical information, in red, at right.

  • Reading from the bottom red dot, Bowling’s haplogroup was born about the year 1660. Bowling was indeed born in 1674, so that’s VERY close
  • Moving back in time, Thomas’s haplogroup was born about 1617, and Thomas himself was born about 1633, but his birth certainly could have been a few years earlier.
  • The Lancashire testers’ common haplogroup was born about 1636, and the earliest known ancestor of those men is Henry, born in Twiston in 1650.
  • The common Speak ancestor of BOTH the Lancashire line and the Thomas the Immigrant line was born about 1334. The earliest record of any Speak was Henry Speke, of Whalley, born before 1520.

The lines of Thomas the Immigrant and the Lancashire men diverged sometime between about 1334, when the umbrella mutation for all Speaks lines was born, and about 1617 when we know the mutation defining the Thomas the Immigrant line formed and split off from the Lancashire line.

But that’s not all.

Surprise!

As I panned out and viewed the block tree more broadly, I noticed something.

This is quite small and difficult to read, so let me explain. At far left is the branch for our Speaks men. The common ancestor of that group was born about 1334 CE, meaning “current era,” as we’ve discussed.

Continuing up the tree, we see that the next haplogroup umbrella occurs about 1009 CE, then the year 850 at the top is the next umbrella, encompassing everything beneath.

Looking to the right, the farthest right blocks date to 1109 CE, then 1318 CE, then progressing on down the tree branch to the bottom, I see one surname in three separate blocks.

What is that name?

Here, let me enlarge the chart for you!

Standish.

The name is Standish, as in Myles Standish, the Pilgrim.

Miles is our relative, and even though he has a different surname, we share a common ancestor, probably before surnames were adopted. Our genetic branches divided about the year 1000.

The Discover tool also provides Notable Connections for each haplogroup, so I entered one of the Speaks haplogroups, and sure enough, the closest Speak Notable Connection is Myles Standish 1584-1656.

And look, there’s the Standish Pew in Chorley, another church that we visited during our Lancashire trip because family members of Thomas Speake’s Catholic wife, Elizabeth Bowling, are found in the Chorley church records.

Our common ancestor with the Standish line was born in about the year 850. Our line split off, as did the Standish line about the year 1000. That’s about 1000 years ago, or 30-40 generations.

Our family names are still found in the Chorley church records

Ancient Connections

The Discover tool also provides Ancient Connections from archaeological digs, by haplogroup.

Sure enough, there’s an ancient sample on the Time Tree named Heslerton 20641.

Checking the Discover Ancient Connections, the man named Heslerton 20641 is found in West Heslerton, Yorkshire, and lived about the year 450-650, based on carbon dating.

The mutation identifying the common ancestor between the Speak/Standish men and Heslerton occurred about 2450 BCE, or 4500 years ago. Twiston and West Heslerton are only 83 miles apart.

Where Are We?

What have we learned from the information discovered through genealogy combined with Big Y testing?

  • We found a Speek family in Whalley in 1385.
  • One of our Lancashire testers descends from a John born about 1540 in Whalley.
  • One of our Lancashire testers descends from Henry born about 1650 in Downham/Twiston
  • Thomas Speake was baptized in Downham and born in Twiston in 1733.
  • Our New Zealand tester’s ancestor was found in Gisburn, born about 1745.

All of these locations are within 15 miles of each other.

  • Chorley, where the Standish family is found in the 1500s is located 17 miles South of Whalley. Thomas Speake’s wife, Elizabeth Bowlings’ family is found in the Chorley church records.

What about the L’Espec origin myth?

  • The Speak family clearly did not arrive in 1066 with the Normans.
  • We have no Scandinavian DNA matches.
  • No place is the surname spelled L’Espec in any Lancashire regional records.
  • The Speak family is in the Whalley/Chorley area by 1000 when the Speak/Standish lines diverged
  • The common ancestor with the Standish family lived about the year 850, although that could have occurred elsewhere. Clearly, their common ancestor was in the Chorley/Whalley area by 1000 when their lines diverged.

The cemetery at Whalley includes Anglo-Saxon burials, circa 800-900. The Speak men, with no surname back then, greeted William the Conqueror and lived to tell the tale, along with their Standish cousins, of course. This, in essence, tells us that they were useful peasants, working the land and performing other labor tasks, and not landed gentry.

Little is known of Lancashire during this time, but we do know more generally that the Anglo-Saxons, a Germanic people, arrived in the 5th century when there was little else in this region.

Are our ancestors buried in these and other early Anglo-Saxon graves? I’d wager that the answer is yes. We are likely related one way or another to every family who lived in this region over many centuries.

Y-DNA connected the dots between recent cousins, connected them to their primary line in America, provided a lifeline back to Twiston, Whalley, and Gisburn, and then to the Anglo-Saxons – long before surnames.

Aaron Luckey Speak’s descendants now know that he descends, somehow, from Bowling, likely through one of two sons of Thomas of Zachia. They don’t have the entire answer yet, but they are within two generations, a lot closer than they were before.

And this, all of this, was a result of Big-Y DNA tests. We could not have accomplished any of this without Y-DNA testing.

Our ancestors are indeed speaking across the ages.

We found the road home, that path revealed by the DNA of our ancestors. You can find your road home too.

_____________________________________________________________

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In Search of…How Am I Related to That Close Match?

My friend recently reached out to me for some help with a close match at Ancestry. Which vendor doesn’t matter – the process for figuring out who my friend is related to her match would be essentially the same at any vendor.

My friend has no idea who the match is, nor how they are related. That match has not replied, nor is any of her information recognizable, such as an account name or photo. She has no tree, so there are literally no clues provided by the match.

We need to turn to science and old-fashioned sleuthing.

This eighth article in the “In Search of…” series steps you through the process I’m stepping my friend through.

This process isn’t difficult, per se, but there are several logical, sequential steps. I strongly recommend you read through this (at least) once, then come back and work through the process if you’re trying to solve a similar mystery.

The “In Search of…” Series

Please note that I’ve written an entire series of “In Search of…” articles that will step you through the search process and help you understand how to unravel your results. If you’re new, reading these, in order, before proceeding, would be a good idea.

  • I introduced the “In Search of” series in the article, DNA: In Search of…New Series Launches.
  • In the second article, DNA: In Search of…What Do You Mean I’m Not Related to My Family? – and What Comes Next? we discussed the discovery that something was amiss when you don’t match a family member that you expect to match, then how to make sure a vial or upload mix-up didn’t happen. Next, I covered the basics of the four kinds of DNA tests you’ll be able to use to solve your mystery.
  • In the third article, In Search of…Vendor Features, Strengths, and Testing Strategies, we discussed testing goals and strategies, including testing with and uploading to multiple autosomal DNA vendors, Y DNA, and mitochondrial DNA testing. We reviewed the vendor’s strengths and the benefits of combining vendor information and resources.
  • In the fourth article, DNA: In Search of…Signs of Endogamy, we discussed the signs of endogamy and various ways to determine if you or your recent ancestors descend from an endogamous population.
  • In the fifth article, DNA: In Search of…Full and Half-Siblings we discussed how to determine if you have a sibling match, if they are a half or full sibling, and how to discern the difference.
  • In the sixth article, Connect Your DNA test, and Others, to Your Tree, I explained how to optimize your DNA tests in order to take advantage of the features offered by each our primary DNA testing vendors.
  • In the seventh article, How to Share DNA Results and Tree Access at Ancestry, I wrote step-by-step instructions for providing access to another person to allow them to view your DNA results, AND to share your tree – which are two different things. If you have a mystery match, and they are willing to allow you access, in essence “to drive,” you can just send them the link to this article that provides detailed instructions. Note that Ancestry has changed the user interface slightly with the rollout of their new “sides” matches, but I can’t provide the new interface screenshots yet because my account has not been upgraded.

Sarah – The Mystery Match

My friend, who I’ll be calling the Tester, matches Sarah (not her name) at 554 cM. At that close level, you don’t have to worry about segments being removed by Timber at Ancestry, so that is an actual cM match level. Timber only removes segments when the match is under 90 cM. Other vendors don’t remove cMs at all.

Ancestry shows the possible relationships at that level as follows:

Some of these relationships can be immediately dismissed in this situation. For example, the Tester knows that Sarah is not her grandchild or great-grandchild.

Our tester does not have any full siblings, or any known half-siblings, but like many genealogists, she is always open-minded. Both of her parents are living, and her father has already tested. Sarah does not match her father. So, this match is on her mother’s side.

It’s obvious that Sarah is not a full sibling, nor is she a half-sibling, based on the cM values, but she might be a child, or grandchild of a maternal half-sibling.

Let’s begin with observations and questions that will help our Tester determine how she and Sarah are related.

  1. It’s clear that IF this is a half-sibling descendant match, it’s on her mother’s side, because Sarah does not match our Tester’s father.
  2. The tester’s mother has six siblings, none of whom have tested directly, but three of whom have children or grandchildren who have tested.
  3. By viewing shared matches, Sarah matches known relatives of BOTH the maternal grandmother AND maternal grandfather of our tester, which means Sarah is NOT the product of an unknown half-sibling of her mother. Remember, Ancestry does not display shared matches of less than 20 cM. Other vendors do not restrict your shared matches.
  4. Ancestry does not provide mitochondrial DNA information, so that cannot be utilized, but could be utilized if this match was at FamilyTreeDNA, and partially utilized in an exclusionary manner if the match was at 23andMe.

DNAPainter

DNAPainter’s Shared cM Tool provides a nice visual display of possible relationships, so I entered the matching cM amount

The returned relationships are similar to Ancestry’s possible relationships.

The grid display shows the possible relationships. Relationships that fall outside of this probability range are muted.

The color shading is by generation, meaning dark grey is through great-great-grandparents, apricot is through great-grandparents, green is through grandparents, grey is through one or both parents, and blue are your own descendants.

Based on known factors, I put a red X in the boxes that can’t apply to Sarah and our Tester after evaluating each relationship. I bracketed the statistically most likely relationships in red, although I must loudly say, “do not ignore those other possibilities.”

Let’s step through the logic which will be different for everyone’s own situation, of course.

  • Age alone eliminates the great and half-great grandparents, aunts, and uncles. They are all deceased and would be well over 100 years old if they were living.
  • The green half relationships are eliminated because we know via shared matches that Sarah matches BOTH of the Tester’s maternal grandparent’s sides.
  • We know that Sarah is not a second cousin because second cousins match only ONE maternal grandparent’s ancestor’s descendants, and Sarah matches both of the tester’s maternal grandparents through their descendants. In other words, Sarah and our Tester both match people who descend from both of the Tester’s maternal grandmother AND grandfather’s lines, which, unless they are related, means Sarah’s closest common ancestor (MCRA – most recent common ancestor) with our Tester are either her maternal grandparents, or her mother.
  • Therefore, we know that Sarah cannot be any of the apricot-colored relationships because she matches BOTH of our Tester’s maternal grandparents. She would only be related through one of the Tester’s maternal grandparents to be related on the apricot level.
  • Sarah cannot be a full great-niece or nephew, or great or great-great niece or nephew because the Tester has no full siblings, confirmed by the fact that Sarah does not match the Tester’s father.
  • We know that Sarah is not the great-grandchild of the Tester, in part due to age, but the definitive scientific ax to that possibility is that Sarah does not match our Tester’s father. (Yes, our Tester does match her father at the appropriate level.)

We know that Sarah is somehow a descendant of BOTH of Tester’s maternal grandparents, so must be in either the green band of relationships, the grey half-relationships, or the blue direct relationships. All of these relationships would be descended from the Tester’s maternal grandparents (plural.)

We’ve eliminated the blue direct relationship because Sarah does not match the Tester’s father. This removes the possibility that the Tester’s children have an unknown great-grandchild, although in this case, age removes that possibility anyway.

This process-of-elimination leaves as possible relationships:

  • Grey band half niece/nephew and half great-niece/nephew, meaning that the Tester has an unknown half-sibling on their mother’s side whose child or grandchild has tested.
  • Green band first cousin which means that the tester descends from one of the Tester’s maternal aunts or uncles. Given that Sarah is not a known child of any of the Tester’s six aunts and uncles, that opens the possibility that her mother’s sibling has a previously unknown child. Three of the Tester’s mother’s siblings are females, and three are males.
  • Green band first cousin once removed is one generation further down the tree, meaning a child of a first cousin.

Using facts we know, we’ve already restricted the possible relationships to four.

Hypothesis and Shared Matches

In situations like this, I use a spreadsheet, create hypothesis scenarios and look for eliminators.

I worked with the Tester to assemble an easy spreadsheet with each of her mother’s siblings in a column, along with their year of birth. All names have been changed.

The hypothesis we are working with is that the Tester’s mother has a previously unknown child and that Sarah is that person’s child or grandchild.

Across the top of our spreadsheet, which you could also simply create as a chart, I’ve written the names of the maternal grandparents.

The Tester’s mother, Susie, is shown in the boxes that are colored red, and her siblings are listed in their birth order. Siblings who have anyone in their line who has tested are shown by colored boxes.

The Tester is shown in red beneath her mother, Susie, and a potential mystery half-sibling is shown beneath Susie.

This is importantthe relationships shown are FROM THE PERSPECTIVE OF THE TESTER.

This means, at far left, with the red arrow, these people at the top, meaning the mother’s siblings are the Tester’s aunts and uncles.

The next generation down are the Tester’s first cousins, followed by the next row, with 1C1R. The cell colors in that column correspond to the DNAPainter generation columns.

In the red “Mother” group, you’ll see that I’ve included that mystery half-sibling and beneath, the relationships that could exist at that same generation level. So, if the mystery half-sibling had a child, that person would be the half-niece/nephew of the Tester.

The cM value pointed to by the arrows, is the cM value at which the TESTER matches that person.

In this case, Ginger’s son, Jacob matches our Tester at 946 cM, which is exactly normal for a first cousin. Ginger’s son, Aaron, has not tested, but his daughter, Crystal, has and matches our Tester at 445 cM.

Three of the Tester’s aunts/uncles, John, Jim, and Elsie are not represented in this matrix, because no one from their line has yet tested. The Tester has contacted members of those families asking if they will accept a testing scholarship.

Analysis Grids

Some of the children of our Tester’s aunts/uncles have tested, and their matches to Sarah are shown in the bottom row in yellow, on the chart below.

Of course, obtaining Sarah’s matching cM information required the Tester to contact her aunts/uncles and cousins to ask them to look at their match to Sarah at Ancestry.

For each set of relationships with Sarah, I’ve prepared a mini-relationship grid below Sarah’s matches with one of the Tester’s aunts/uncles’ descendants.

  • If Sarah is related to the Tester through an unknown half-sibling, Sarah will match the tester more closely than she will match any of the children of the Tester’s aunts and uncles.
  • If Sarah descends through one of the Tester’s aunts’ or uncles’ lines, Sarah will match someone in those lines more closely than our Tester, but we may need to compensate for generations in our analysis.

I pasted the DNAPainter image in the spreadsheet in a convenient place to remind myself of which relationships are possible between our Tester and Sarah, then I created a small grid beneath the Tester’s match to Sarah, who is the yellow row.

Let me explain, beginning with our Tester’s match to Sarah.

Tester’s Match to Sarah

The Tester matches Sarah at 554 cM, which can potentially be a number of different relationships. I’ve listed the possible relationships with the most likely, at 87%, at the top. I have not listed any relationships we’ve positively eliminated, even though they would be scientifically possible.

I can’t do this for our Tester’s Uncle David, because the Tester has not yet heard back from David’s son, Gary, as to how many cMs he shares with Sarah.

Our tester’s aunts, Ginger and Barbara do have descendants who have tested, so let’s evaluate those relationships.

Ginger and Sarah

We know less about Ginger and Sarah than we do about our Tester and Sarah. However, many of the same relationship constraints remain constant.

  • For example, we know that Sarah matches both of Ginger’s grandparents, because Ginger is our tester’s aunt, Susie’s full sibling.
  • Our tester and all of the other family members who have tested match on both maternal grandparents’ sides.
  • Therefore, we also know that the 2C relationships won’t work either because Sarah matches both maternal grandparents.
  • Based on ages, it’s very unlikely that Sarah is a great-grandchild of Ginger’s children, in part, because I’m operating under the assumption that Sarah is old enough to purchase her own test, so not a child. Ancestry’s terms of service require testers to be 18 years of age to purchase or activate a DNA test. Also, Sarah’s test is not managed by someone else.
  • We don’t know about great-nieces and nephews though, because if one of Ginger’s sibling’s children had an unknown child, that person could be Sarah or Sarah’s parent.

Ginger’s son Jacob

Using the closest match in Ginger’s line, her son Jacob, we find the following possibilities using Jacob’s match to Sarah of 284cM.

The DNAPainter grid shows the more distant relationship clearly.

You can quickly determine that Sarah probably does not descend from Ginger’s line, but let’s add this to our spreadsheet for completeness.

You can see that the MOST likely relationship, of the possible relationships based on our known factors, is 1C2R, which is the least likely relationship between our Tester and Sarah. It’s important to note that our Tester and Jacob are in the same generation, so we don’t need to do any compensating for a generational difference.

Comparing those relationships, you can see that the least likely relationship between Sarah and Jacob is much more likely between Sarah and our Tester.

Therefore, we can rule out Ginger’s line as a candidate. Sarah is not a descendant of Ginger.

Let’s move on to Barbara’s line.

Barbara’s Daughter Cindy

This time, we’re going to do a bit of inferring because we do have a generational difference.

Barbara’s granddaughter, Mary, has tested and matches Sarah at 230 cM. While we know that Sarah probably wouldn’t match Mary’s mother, Cindy, at exactly double that, 460 cM, it would certainly be close.

So, for purposes of this comparison, I’m using 460 cM for Sarah to match Cindy.

That makes this comparison in the same generation as Ginger and our Tester to Sarah. We are comparing apples to apples and not apples to half an apple (an apple once removed, technically, but I digress.) 😊

You can see that this analysis is MUCH closer to the cM amounts and relationship possibilities of Sarah and our Tester.

Here are the possible relationships of Sarah and Cindy, with the most likely being boxed in red.

Where Are We?

Here is my completed spreadsheet, so far, less the two DNAPainter graphs for Ginger and Barbara’s lines.

To date, we’ve eliminated Ginger as Sarah’s ancestor.

Both Susie, the mother of our Tester, and Susie’s sister Barbara are still candidates to have an unknown child based on DNA, or one of their children possibly having an unknown child.

Of course, we still have one more sister, Elsie, and those three silent brothers sitting over there. It’s much easier for a male to have an unknown child than a female. By unknown, in this situation, I mean truly unknown, not hidden.

What’s Needed?

Of course, what we really need is tests from each of Susie’s siblings, but that’s not going to happen. What can we potentially do with what we have, how, and why?

Our Tester can refine these results in a number of ways.

  • Talk to living siblings or other family members and tactfully ask what they know about the four women during their reproductive years. Were they missing, off at school, visiting “aunts” in another location, separated from a spouse, etc.?
  • Check to see if Sarah shared her ethnicity results (View match, then click on “Ethnicity.”) If Sarah has a significant ethnicity that is impossible to confuse, this might be significant. For example, if Sarah is 50% Korean, and one of Susie’s brothers served in Korea, that makes him a prime candidate.
  • If possible, ask John, David, Jim, Ginger, Barbara, and Elsie to take DNA tests themselves. The best test is ALWAYS the oldest generation because their DNA is not yet divided in subsequent generations.
  • If that’s not possible, find a child or grandchild of Elsie, Jim, and John to test.
  • The Tester needs to find out how closely David’s son, Gary matches Sarah, then perform the same analysis that we stepped through above.
  • Ask Ginger’s son, Jacob to see if Sarah also shares matches with the closest family members of the known father of Ginger’s children. One of Ginger’s children could have had an unknown child. This is unlikely, based on what we’ve already determined about Sarah’s match level to Jacob, but it’s worth asking.
  • Ask Barbara’s granddaughter, Mary, to see if she and Sarah share matches with the closest family members of the known father of Barbara’s children. This scenario is much more likely.
  • If the answer is yes to either of the last two questions, we have identified which line Sarah descends from, because she can only descend from both Barbara AND the father of her children if Sarah descends from that couple.
  • If the answer is no, we’ve only eliminated full siblings to Ginger and Barbara’s children, not half-siblings.
  • If our Tester can make contact with Gary, ask him if he and Sarah share matches with David’s wife’s line. One of David’s children could have an unknown child.
  • If our Tester can actually make contact with Sarah, and if Sarah is willing and interested, our Tester can create a list of people to look for in her matches – for example, the spouses’ lines of all of Susie’s siblings. If Sarah matches NONE of the spouses’ lines, then one of Susie’s siblings (our Tester’s aunts/uncles,) or Susie’s mother, has an unknown child. However, if Sarah is a novice tester or genealogist, she might well be quite overwhelmed with understanding how to perform these searches. She may already be overwhelmed by discovering that she doesn’t match who she expected to match. Or, she may already know the answer to this question.
  • It would be easier if Sarah granted our Tester access to her DNA results to sort through all of these possibilities, but that’s not something I would expect a stranger to do, especially if this result is something Sarah wasn’t expecting.

I wrote instructions for providing access to DNA results in the article, How to Share DNA Results and Tree Access at Ancestry.

_____________________________________________________________

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Share the Love!

You’re always welcome to forward articles or links to friends and share on social media.

If you haven’t already subscribed (it’s free,) you can receive an email whenever I publish by clicking the “follow” button on the main blog page, here.

You Can Help Keep This Blog Free

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Uploads

Genealogy Products and Services

My Book

Genealogy Books

Genealogy Research

DNA: In Search of…Full and Half-Siblings

This is the fifth article in our series of articles about searching for unknown close family members, specifically; parents, grandparents, or siblings. However, these same techniques can be applied by genealogists to identify ancestors further back in time as well.

Please note that if a family member has tested and you do NOT see their results, ask them to verify that they have chosen to allow matching and for other people to view them in their match list. That process varies at different vendors.

You can also ask if they can see you in their results.

All Parties Need to Test

Searching for unknown siblings isn’t exactly searching, because to find them, they, themselves, or their descendant(s) must have taken a DNA test at the same vendor where you tested or uploaded a DNA file.

You may know through any variety of methods that they exist, or might exist, but if they don’t take a DNA test, you can’t find them using DNA. This might sound obvious, but I see people commenting and not realizing that the other sibling(s) must test too – and they may not have.

My first questions when someone comments in this vein are:

  1. Whether or not they are positive their sibling actually tested, meaning actually sent the test in to the vendor, and it was received by the testing company. You’d be surprised how many tests are living in permanent residence on someone’s countertop until it gets pushed into the drawer and forgotten about.
  2. If the person has confirmed that their sibling has results posted. They may have returned their test, but the results aren’t ready yet or there was a problem.
  3. AND that both people have authorized matching and sharing of results. Don’t hesitate to reach out to your vendor’s customer care if you need help with this.

Sibling Scenarios

The most common sibling scenarios are when one of two things happens:

  • A known sibling tests, only to discover that they don’t match you in the full sibling range, or not at all, when you expected they would
  • You discover a surprise match in the full or half-sibling range

Let’s talk about these scenarios and how to determine:

  • If someone is a sibling
  • If they are a full or half-sibling
  • If a half-sibling, if they descend from your mother or father

As with everything else genetic, we’ll be gathering and analyzing different pieces of evidence along the way.

Full and Half-Siblings

Just to make sure we are all on the same page:

  • A full sibling is someone who shares both parents with you.
  • A half-sibling is someone who shares one parent with you, but not the other parent.
  • A step-sibling is someone who shares no biological parents with you. This situation occurs when your parent marries their parent, after you are both born, and their parent becomes your step-parent. You share neither of your biological parents with a step-sibling, so you share no DNA and will not show up on each other’s match lists.
  • A three-quarters sibling is someone with whom you share one parent, but two siblings are the other parent. For example, you share the same mother, but one brother fathered you, and your father’s brother fathered your sibling. Yes, this can get very messy and is almost impossible for a non-professional to sort through, if even then. (This is not a solicitation. I do not take private clients.) We will not be addressing this situation specifically.

Caution

With any search for unknown relatives, you have no way of knowing what you will find.

In one’s mind, there are happy reunions, but you may experience something entirely different. Humans are human. Their stories are not always happy or rosy. They may have made mistakes they regret. Or they may have no regrets about anything.

Your sibling may not know about you or the situation under which you, or they, were born. Some women were victims of assault and violence, which is both humiliating and embarrassing. I wrote about difficult situations, here.

Your sibling or close family member may not be receptive to either you, your message, or even your existence. Just be prepared, because the seeking journey may not be pain-free for you or others, and may not culminate with or include happy reunions.

On the other hand, it may.

Please step back and ponder a bit about the journey you are about to undertake and the possible people that may be affected, and how. This box, once opened, cannot be closed again. Be sure you are prepared.

On the other hand, sometimes that box lid pops off, and the information simply falls in your lap one day when you open your match list, and you find yourself sitting there, in shock, staring at a match, trying to figure out what it all means.

Congratulations, You Have a Sibling!

This might not be exactly what runs through your mind when you see that you have a very close match that you weren’t expecting.

The first two things I recommend when making this sort of discovery, after a few deep breaths, a walk, and a cup of tea, are:

  • Viewing what the vendor says
  • Using the DNAPainter Shared cM Relationship Chart

Let’s start with DNAPainter.

DNAPainter

DNAPainter provides a relationship chart, here, based on the values from the Shared cM Project.

You can either enter a cM amount or a percentage of shared DNA. I prefer the cM amount, but it doesn’t really matter.

I’ll enter 2241 cM from a known half-sibling match. To enter a percent, click on the green “enter %.”

As you can see, statistically speaking, this person is slightly more likely to be a half-sibling than they are to be a full sibling. In reality, they could be either.

Looking at the chart below, DNAPainter highlights the possible relationships from the perspective of “Self.”

The average of all the self-reported relationships is shown, on top, so 2613 for a full sibling. The range is shown below, so 1613-3488 for a full sibling.

In this case, there are several possibilities for two people who share 2241 cM of DNA.

I happen to know that these two people are half-siblings, but if I didn’t, it would be impossible to tell from this information alone.

The cM range for full siblings is 1613-3488, and the cM range for half-siblings is 1160-2436.

  • The lower part of the matching range, from 1160-1613 cM is only found in half-siblings.
  • The portion of the range from 1613-2436 cM can be either half or full siblings.
  • The upper part of the range, from 2436-3488 cM is only found in full siblings.

If your results fall into the center portion of the range, you’re going to need to utilize other tools. Fortunately, we have several.

If you’ve discovered something unexpected, you’ll want to verify using these tools, regardless. Use every tool available. Ranges are not foolproof, and the upper and lower 10% of the responses were removed as outliers. You can read more about the shared cM Project, here and here.

Furthermore, people may be reporting some half-sibling relationships as full sibling relationships, because they don’t expect to be half-siblings, so the ranges may be somewhat “off.”

Relationship Probability Calculator

Third-party matching database, GEDmatch, provides a Relationship Probability Calculator tool that is based on statistical probability methods without compiled user input. Both tools are free, and while I haven’t compared every value, both seem to be reasonably accurate, although they do vary somewhat, especially at the outer ends of the ranges.

When dealing with sibling matches, if you are in all four databases, GEDmatch is a secondary resource, but I will include GEDmatch when they have a unique tool as well as in the summary table. Some of your matches may be willing to upload to GEDmatch if the vendor where you match doesn’t provide everything you need and GEDmatch has a supplemental offering.

Next, let’s look at what the vendors say about sibling matches.

Vendors

Each of the major vendors reports sibling relationships in a slightly different way.

Sibling Matches at Ancestry

Ancestry reports sibling relationships as Sister or Brother, but they don’t say half or full.

If you click on the cM portion of the link, you’ll see additional detail, below

Ancestry tells you that the possible relationships are 100% “Sibling.” The only way to discern the difference between full and half is by what’s next.

If the ONLY relationship shown is Sibling at 100%, that can be interpreted to mean this person is a full sibling, and that a half-sibling or other relationship is NOT a possibility.

Ancestry never stipulates full or half.

The following relationship is a half-sibling at Ancestry.

Ancestry identifies that possible range of relationships as “Close Family to First Cousin” because of the overlaps we saw in the DNAPainter chart.

Clicking through shows that there is a range of possible relationships, and Ancestry is 100% sure the relationship is one of those.

DNAPainter agrees with Ancestry except includes the full-sibling relationship as a possibility for 1826 cM.

Sibling Matches at 23andMe

23andMe does identify full versus half-siblings.

DNAPainter disagrees with 23andMe and claims that anyone who shares 46.2% of their DNA is a parent/child.

However, look at the fine print. 23andMe counts differently than any of the other vendors, and DNAPainter relies on the Shared cM Project, which relies on testers entering known relationship matching information. Therefore, at any other vendor, DNAPainter is probably exactly right.

Before we understand how 23andMe counts, we need to understand about half versus fully identical segments.

To determine half or full siblings, 23andMe compares two things:

  1. The amount of shared matching DNA between two people
  2. Fully Identical Regions (FIR) of DNA compared to Half Identical Regions (HIR) of DNA to determine if any of your DNA is fully identical, meaning some pieces of you and your sibling’s DNA is exactly the same on both your maternal and paternal chromosomes.

Here’s an example on any chromosome – I’ve randomly selected chromosome 12. Which chromosome doesn’t matter, except for the X, which is different.

Your match isn’t broken out by maternal and paternal sides. You would simply see, on the chromosome browser, that you and your sibling match at these locations, above.

In reality, though, you have two copies of each chromosome, one from Mom and one from Dad, and so does your sibling.

In this example, Mom’s chromosome is visualized on top, and Dad’s is on the bottom, below, but as a tester, you don’t know that. All you know is that you match your sibling on all of those blue areas, above.

However, what’s actually happening in this example is that you are matching your sibling on parts of your mother’s chromosome and parts of your father’s chromosome, shown above as green areas

23andMe looks at both copies of your chromosome, the one you inherited from Mom, on top, and Dad, on the bottom, to see if you match your sibling on BOTH your mother’s and your father’s chromosomes in that location.

I’ve boxed the green matching areas in purple where you match your sibling fully, on both parents’ chromosomes.

If you and your sibling share both parents, you will share significant amounts of the same DNA on both copies of the same chromosomes, meaning maternal and paternal. In other words, full siblings share some purple fully identical regions (FIR) of DNA with each other, while half-siblings do not (unless they are also otherwise related) because half-siblings only share one parent with each other. Their DNA can’t be fully identical because they have a different parent that contributed the other copy of their chromosome.

Total Shared DNA Fully Identical DNA from Both Parents
Full Siblings ~50% ~25%
Half Siblings ~25% 0
  • Full siblings are expected to share about 50% of the same DNA. In other words, their DNA will match at that location. That’s all the green boxed locations, above.
  • Full siblings are expected to share about 25% of the same DNA from BOTH parents at the same location on BOTH copies of their chromosomes. These are fully identical regions and are boxed in purple, above.

You’ll find fully identical segments about 25% of the time in full siblings, but you won’t find fully identical segments in half-siblings. Please note that there are exceptions for ¾ siblings and endogamous populations.

You can view each match at 23andMe to see if you have any completely identical regions, shown in dark purple in the top comparison of full siblings. Half siblings are shown in the second example, with less total matching DNA and no FIR or completely identical regions.

Please note that your matching amount of DNA will probably be higher at 23andMe than at other companies because:

  • 23andMe includes the X chromosome in the match totals
  • 23andMe counts fully identical matching regions twice. For full siblings, that’s an additional 25%

Therefore, a full sibling with an X match will have a higher total cM at 23andMe than the same siblings elsewhere because not only is the X added into the total, the FIR match region is added a second time too.

Fully Identical Regions (FIR) and Half Identical Regions (HIR) at GEDmatch

At GEDMatch, you can compare two people to each other, with an option to display the matching information and a painted graphic for each chromosome that includes FIR and HIR.

If you need to know if you and a match share fully identical regions and you haven’t tested at 23andMe, you can both upload your DNA data file to GEDmatch and use their One to One Autosomal DNA Comparison.

On the following page, simply enter both kit numbers and accept the defaults, making sure you have selected one of the graphics options.

While GEDmatch doesn’t specifically tell you whether someone is a full or half sibling, you can garner additional information about the relationship based on the graphic at GEDmatch.

GEDMatch shows both half and fully identical regions.

The above match is between two full siblings using a 7 cM threshold. The blue on the bottom bar indicates a match of 7 cM or larger. Black means no match.

The green regions in the top bar indicate places where these two people carry the same DNA on both copies of their chromosome 1. This means that both people inherited the same DNA from BOTH parents on the green segments.

In the yellow regions, the siblings inherited the same DNA from ONE parent, but different DNA in that region from the other parent. They do match each other, just on one of their chromosomes, not both.

Without a tool like this to differentiate between HIR and FIR, you can’t tell if you’re matching someone on one copy of your chromosome, or on both copies.

In the areas marked with red on top, which corresponds to the black on the bottom band, these two siblings don’t match each other because they inherited different DNA from both parents in that region. The yellow in that region is too scattered to be significant.

Full siblings generally share a significant amount of FIR, or fully identical regions of DNA – about 25%.

Half siblings will share NO significant amount of FIR, although some will be FIR on very small, scattered green segments simply by chance, as you can see in the example, below.

This half-sibling match shares no segments large enough to be a match (7 cM) in the black section. In the blue matching section, only a few small green fragments of DNA match fully, which, based on the rest of that matching segment, must be identical by chance or misreads. There are no significant contiguous segments of fully identical DNA.

When dealing with full or half-siblings, you’re not interested in small, scattered segments of fully identical regions, like those green snippets on chromosome 6, but in large contiguous sections of matching DNA like the chromosome 1 example.

GEDmatch can help when you match when a vendor does not provide FIR/HIR information, and you need additional assistance.

Next, let’s look at full and half-siblings at FamilyTreeDNA

Sibling Matches at FamilyTreeDNA

FamilyTreeDNA does identify full siblings.

Relationships other than full siblings are indicated by a range. The two individuals below are both half-sibling matches to the tester.

The full range when mousing over the relationship ranges is shown below.

DNAPainter agrees except also gives full siblings as an option for the two half-siblings.

FamilyTreeDNA also tells you if you have an X match and the size of your X match.

We will talk about X matching in a minute, which, when dealing with sibling identification, can turn out to be very important.

Sibling Matches at MyHeritage

MyHeritage indicates brother or sister for full siblings

MyHeritage provides other “Estimated relationships” for matches too small to be full siblings.

DNAPainter’s chart agrees with this classification, except adds additional relationship possibilities.

Be sure to review all of the information provided by each vendor for close relationships.

View Close Known Relationships

The next easiest step to take is to compare your full or half-sibling match to known close family members from your maternal and paternal sides, respectively. The closer the family members, the better.

It’s often not possible to determine if someone is a half sibling or a full sibling by centiMorgans (cMs) alone, especially if you’re searching for unknown family members.

Let’s start with the simplest situation first.

Let’s say both of your parents have tested, and of course, you match both of them as parents.

Your new “very close match” is in the sibling range.

The first thing to do at each vendor is to utilize that vendor’s shared matches tool and see whether your new match matches one parent, or both.

Here’s an example.

Close Relationships at FamilyTreeDNA

This person has a full sibling match, but let’s say they don’t know who this is and wants to see if their new sibling matches one or both of their parents.

Select the match by checking the box to the left of the match name, then click on the little two-person icon at far right, which shows “In Common” matches

You can see on the resulting shared match list that both of the tester’s parents are shown on the shared match list.

Now let’s make this a little more difficult.

No Parents, No Problem

Let’s say neither of your parents has tested.

If you know who your family is and can identify your matches, you can see if the sibling you match matches other close relatives on both or either side of your family.

You’ll want to view shared matches with your closest known match on both sides of your tree, beginning with the closest first. Aunts, uncles, first cousins, etc.

You will match all of your family members through second cousins, and 90% of your third cousins. You can view additional relationship percentages in the article, How Much of Them is in You?.

I recommend, for this matching purpose, to utilize 2nd cousins and closer. That way you know for sure if you don’t share them as a match with your sibling, it’s because the sibling is not related on that side of the family, not because they simply don’t share any DNA due to their distance.

In this example, you have three sibling matches. Based on your and their matches to the same known first and second cousins, you can see that:

  • Sibling 1 is your full sibling, because you both match the same maternal and paternal first and second cousins
  • Sibling 2 is your paternal half-sibling because you both match paternal second cousins and closer, but not maternal cousins.
  • Sibling 3 is your maternal half-sibling because you both match maternal second cousins and closer, but not paternal cousins.

Close Relationships at Ancestry

Neither of my parents have tested, but my first cousin on my mother’s side has. Let’s say I have a suspected sibling or half-sibling match, so I click on the match’s name, then on Shared Matches.

Sure enough, my new match also matches my first cousin that I’ve labeled as “on my mother’s side.”

If my new match in the sibling range also matches my second cousins or closer on my father’s side, the new match is a full sibling, not a half-sibling.

Close Relationships at MyHeritage

Comparing my closest match provided a real surprise. I wonder if I’ve found a half-sibling to my mother.

Now, THIS is interesting.

Hmmm. More research is needed, beginning with the age of my match. MyHeritage provides ages if the MyHeritage member authorizes that information to be shared.

Close Relationships at 23andMe

Under DNA Relatives, click on your suspected sibling match, then scroll down and select “Find Relatives in Common.”

The Relatives in Common list shows people that match both of you.

The first common match is very close and a similar relationship to my closest match on my father’s side. This would be expected of a sibling. I have no common matches with this match to anyone on my mother’s side, so they are only related on my father’s side. Therefore they are a paternal half-sibling, not a full sibling.

More Tools Are Available

Hopefully, by now, you’ve been able to determine if your mystery match is a sibling, and if so, if they are a half or full sibling, and through which parent.

We have some additional tools that are relevant and can be very informative in some circumstances. I suggest utilizing these tools, even if you think you know the answer.

In this type of situation, there’s no such thing as too much information.

X Matching

X matching, or lack thereof, may help you determine how you are related to someone.

There are two types of autosomal DNA. The X chromosome versus chromosomes 1-22. The X chromosome (number 23) has a unique inheritance path that distinguishes it from your other chromosomes.

The X chromosome inheritance path also differs between men and women.

Here’s my pedigree chart in fan form, highlighting the ancestors who may have contributed a portion of their X chromosome to me. In the closest generation, this shows that I inherited an X chromosome from both of my parents, and who in each of their lines could have contributed an X to them.

The white or uncolored positions, meaning ancestors, cannot contribute any portion of an X chromosome to me based on how the X chromosome is inherited.

You’ll notice that my father inherited none of his X chromosome from any of his paternal ancestors, so of course, I can’t inherit what he didn’t inherit. There are a very limited number of ancestors on my father’s side whom I can inherit any portion of an X chromosome from.

Men receive their Y chromosome from their fathers, so men ONLY receive an X chromosome from their mother.

Therefore, men MUST pass their mother’s X chromosome on to their female offspring because they don’t have any other copy of the X chromosome to pass on.

Men pass no X chromosome to sons.

We don’t need to worry about a full fan chart when dealing with siblings and half-siblings.

We only need to be concerned with the testers plus one generation (parents) when utilizing the X chromosome in sibling situations.

These two female Disney Princesses, above, are full siblings, and both inherited an X chromosome from BOTH their mother and father. However, their father only has one X (red) chromosome to give them, so the two females MUST match on the entire red X chromosome from their father.

Their mother has two X chromosomes, green and black, to contribute – one from each of her parents.

The full siblings, Melody, and Cinderella:

  • May have inherited some portion of the same green and black X chromosomes from their mother, so they are partial matches on their mother’s X chromosome.
  • May have inherited the exact same full X chromosome from their mother (both inherited the entire green or both inherited the entire black), so they match fully on their mother’s X chromosome.
  • May have inherited the opposite X from different maternal grandparents. One inherited the entire green X and one inherited the entire black X, so they don’t match on their mother’s X chromosome.

Now, let’s look at Cinderella, who matches Henry.

This female and male full sibling match can’t share an X chromosome on the father’s side, because the male’s father doesn’t contribute an X chromosome to him. The son, Henry, inherited a Y chromosome instead from his father, which is what made them males.

Therefore, if a male and female match on the X chromosome, it MUST be through HIS mother, but could be through either of her parents. In a sibling situation, an X match between a male and female always indicates the mother.

In the example above, the two people share both of their mother’s X chromosomes, so are definitely (at least) maternally related. They could be full siblings, but we can’t determine that by the X chromosome in this situation, with males.

However, if the male matches the female on HER father’s X chromosome, there a different message, example below.

You can see that the male is related to the female on her father’s side, where she inherited the entire magenta X chromosome. The male inherited a portion of the magenta X chromosome from his mother, so these two people do have an X match. However, he matches on his mother’s side, and she matches on her father’s side, so that’s clearly not the same parent.

  • These people CAN NOT be full siblings because they don’t match on HER mother’s side too, which would also be his mother’s side if they were full siblings.
  • They cannot be maternal half-siblings because their X DNA only matches on her father’s side, but they wouldn’t know that unless she knew which side was which based on share matches.
  • They cannot be paternal half-siblings because he does not have an X chromosome from his father.

They could, however, be uncle/aunt-niece/nephew or first cousins on his mother’s side and her father’s side. (Yes, you’re definitely going to have to read this again if you ever need male-female X matching.)

Now, let’s look at X chromosome matching between two males. It’s a lot less complicated and much more succinct.

Neither male has inherited an X chromosome from their father, so if two males DO match on the X, it MUST be through their mother. In terms of siblings, this would mean they share the same mother.

However, there is one slight twist. In the above example, you can see that the men inherited a different proportion of the green and black X chromosomes from their common mother. However, it is possible that the mother could contribute her entire green X chromosome to one son, Justin in this example, and her entire black X chromosome to Henry.

Therefore, even though Henry and Justin DO share a mother, their X chromosome would NOT match in this scenario. This is rare but does occasionally happen.

Based on the above examples, the X chromosome may be relevant in the identification of full or half siblings based on the sexes of the two people who otherwise match at a level indicating a full or half-sibling relationship.

Here’s a summary chart for sibling X matching.

X Match Female Male
Female Will match on shared father’s full X chromosome, mother’s X is the same rules as chromosomes 1-22 Match through male’s mother, but either of female’s parents. If the X match is not through the female’s mother, they are not full siblings nor maternal half-siblings. They cannot have an X match through the male’s father. They are either full or half-siblings through their mother if they match on both of their mother’s side. If they match on his mother’s side, and her father’s side, they are not siblings but could be otherwise closely related.
Male Match through male’s mother, but either of female’s parents. If the X match is not through the female’s mother, they are not full siblings nor maternal half-siblings. They cannot have an X match through the male’s father. They are either full or half-siblings through their mother if they match on both or their mother’s side. If they match on his mother’s side, and her father’s side, they are not siblings but could be otherwise closely related. Both males are related on their mother’s side – either full or half-siblings.

Here’s the information presented in a different way.

DOES match X summary:

  • If a male DOES match a female on the X, he IS related to her through HIS mother’s side, but could match her on her mother or father’s side. If their match is not through her mother, then they are not full siblings nor maternal half-siblings. They cannot match through his father, so they cannot be paternal half-siblings.
  • If a female DOES match a female on the X, they could be related on either side and could be full or half-siblings.
  • If a male DOES match a male on the X, they ARE both related through their mother. They may also be related on their father’s side, but the X does not inform us of that.

Does NOT match X summary:

  • If a male does NOT match a female on the X, they are NOT related through HIS mother and are neither full siblings nor maternal half-siblings. Since a male does not have an X chromosome from his father, they cannot be paternal half-siblings based on an X match.
  • If a male does NOT match a male, they do NOT share a mother.
  • If a female does NOT match another female on the X, they are NOT full siblings and are NOT half-siblings on their paternal side. Their father only has one X chromosome, and he would have given the same X to both daughters.

Of the four autosomal vendors, only 23andMe and FamilyTreeDNA report X chromosome results and matching, although the other two vendors, MyHeritage and Ancestry, include the X in their DNA download file so you can find X matches with those files at either FamilyTreeDNA or GEDMatch if your match has or will upload their file to either of those vendors. I wrote step-by-step detailed download/upload instructions, here.

X Matching at FamilyTreeDNA

In this example from FamilyTreeDNA, the female tester has discovered two half-sibling matches, both through her father. In the first scenario, she matches a female on the full X chromosome (181 cM). She and her half-sibling MUST share their father’s entire X chromosome because he only had one X, from his mother, to contribute to both of his daughters.

In the second match to a male half-sibling, our female tester shares NO X match because her father did not contribute an X chromosome to his son.

If we didn’t know which parents these half-sibling matches were through, we can infer from the X matching alone that the male is probably NOT through the mother.

Then by comparing shared matches with each sibling, Advanced Matches, or viewing the match Matrix, we can determine if the siblings match each other and are from the same or different sides of the family.

Under Additional Tests and Tools, Advanced Matching, FamilyTreeDNA provides an additional tool that can show only X matches combined with relationships.

Of course, you’ll need to view shared matches to see which people match the mother and/or match the father.

To see who matches each other, you’ll need to use the Matrix tool.

At FamilyTreeDNA, the Matrix, located under Autosomal DNA Results and Tools, allows you to select your matches to see if they also match each other. If you have known half-siblings, or close relatives, this is another way to view relationships.

Here’s an example using my father and two paternal half-siblings. We can see that the half-siblings also match each other, so they are (at least) half-siblings on the paternal side too.

If they also matched my mother, we would be full siblings, of course.

Next, let’s use Y DNA and mitochondrial DNA.

Y DNA and Mitochondrial DNA

In addition to autosomal DNA, we can utilize Y DNA and mitochondrial DNA (mtDNA) in some cases to identify siblings or to narrow or eliminate relationship possibilities.

Given that Y DNA and mitochondrial DNA both have distinctive inheritance paths, full and half-siblings will, or will not, match under various circumstances.

Y DNA

Y DNA is passed intact from father to son, meaning it’s not admixed with any of the mother’s DNA. Daughters do not inherit Y DNA from their father, so Y DNA is only useful for male-to-male comparisons.

Two types of Y DNA are used for genealogy, STR markers for matching, and haplogroups, and both are equally powerful in slightly different ways.

Y DNA at FamilyTreeDNA

Men can order either 37 or 111 STR marker tests, or the BIg Y which provides more than 700 markers and more. FamilyTreeDNA is the only one of the vendors to offer Y DNA testing that includes STR markers and matching between men.

Men who order these tests will be compared for matching on either 37, 111 or 700 STR markers in addition to SNP markers used for haplogroup identification and assignment.

Fathers will certainly match their sons, and paternal line brothers will match each other, but they will also match people more distantly related.

However, if two men are NOT either full or half siblings on the paternal side, they won’t match at 111 markers.

If two men DON’T match, especially at high marker levels, they likely aren’t siblings. The word “likely” is in there because, very occasionally, a large deletion occurs that prevents STR matching, especially at lower levels.

Additionally, men who take the 37 or 111 marker test also receive an estimated haplogroup at a high level for free, without any additional testing.

However, if men take the Big Y-700 test, they not only will (or won’t) match on up to 700 STR markers, they will also receive a VERY refined haplogroup via SNP marker testing that is often even more sensitive in terms of matching than STR markers. Between these two types of markers, Y DNA testing can place men very granularly in relation to other men.

Men can match in two ways on Y DNA, and the results are very enlightening.

If two men match on BOTH their most refined haplogroup (Big Y test) AND STR markers, they could certainly be siblings or father/son. They could also be related on the same line for another reason, such as known or unknown cousins or closer relationships like uncle/nephew. Of course, Y DNA, in addition to autosomal matching, is a powerful combination.

Conversely, if two men don’t have a similar or close haplogroup, they are not a father and son or paternal line siblings.

FamilyTreeDNA offers both inexpensive entry-level testing (37 and 111 markers) and highly refined advanced testing of most of the Y chromosome (Big Y-700), so haplogroup assignments can vary widely based on the test you take. This makes haplogroup matching and interpretation a bit more complex.

For example, haplogroups R-M269 and I-BY14000 are not related in thousands of years. One is haplogroup R, and one is haplogroup I – completely different branches of the Y DNA tree. These two men won’t match on STR markers or their haplogroup.

However, because FamilyTreeDNA provides over 50,000 different haplogroups, or tree branches, for Big Y testers, and they provide VERY granular matching, two father/son or sibling males who have BOTH tested at the Big Y-700 level will have either the exact same haplogroup, or at most, one branch difference on the tree if a mutation occurred between father and son.

If both men have NOT tested at the Big Y-700 level, their haplogroups will be on the same branch. For example, a man who has only taken a 37/111 marker STR test may be estimated at R-M269, which is certainly accurate as far as it goes.

His sibling who has taken a Big Y test will be many branches further downstream on the tree – but on the same large haplogroup R-M269 branch. It’s essential to pay attention to which tests a Y DNA match has taken when analyzing the match.

The beauty of the two kinds of tests is that even if one haplogroup is very general due to no Big Y test, their STR markers should still match. It’s just that sometimes this means that one hand is tied behind your back.

Y DNA matching alone can eliminate the possibility of a direct paternal line connection, but it cannot prove siblingship or paternity alone – not without additional information.

The Advanced Matching tool will provide a list of matches in all categories selected – in this case, both the 111 markers and the Family Finder test. You can see that one of these men is the father of the tester, and one is the full sibling.

You can view haplogroup assignments on the public Y DNA tree, here. I wrote about using the public tree, here.

In addition, recently, FamilyTreeDNA launched the new Y DNA Discover tool, which explains more about haplogroups, including their ages and other fun facts like migration paths along with notable and ancient connections. I wrote about using the Discover tool, here.

Y DNA at 23andMe

Testers receive a base haplogroup with their autosomal test. 23andMe tests a limited number of Y DNA SNP locations, but they don’t test many, and they don’t test STR markers, so there is no Y DNA matching and no refined haplogroups.

You can view the haplogroups of your matches. If your male sibling match does NOT share the same haplogroup, the two men are not paternal line siblings. If two men DO share the same haplogroup, they MIGHT be paternal siblings. They also might not.

Again, autosomal close matching plus haplogroup comparisons include or exclude paternal side siblings for males.

Paternal side siblings at 23andMe share the same haplogroup, but so do many other people. These two men could be siblings. The haplogroups don’t exclude that possibility. If the haplogroups were different, that would exclude being either full or paternal half-siblings.

Men can also compare their mitochondrial DNA to eliminate a maternal relationship.

These men are not full siblings or maternal half-siblings. We know, unquestionably, because their mitochondrial haplogroups don’t match.

23andMe also constructs a genetic tree, but often struggles with close relative placement, especially when half-relationships are involved. I do not recommend relying on the genetic tree in this circumstance.

Mitochondrial DNA

Mitochondrial DNA is passed from mothers to all of their children, but only females pass it on. If two people, males or females, don’t match on their mitochondrial DNA test, with a couple of possible exceptions, they are NOT full siblings, and they are NOT maternal half-siblings.

Mitochondrial DNA at 23andMe

23andMe provides limited, base mitochondrial haplogroups, but no matching. If two people don’t have the same haplogroup at 23andMe, they aren’t full or maternal siblings, as illustrated above.

Mitochondrial DNA at FamilyTreeDNA

FamilyTreeDNA provides both mitochondrial matching AND a much more refined haplogroup. The full sequence test (mtFull), the only version sold today, is essential for reliable comparisons.

Full siblings or maternal half-siblings will always share the same haplogroup, regardless of their sex.

Generally, a full sibling or maternal half-sibling match will match exactly at the full mitochondrial sequence (FMS) level with a genetic distance of zero, meaning fully matching and no mismatching mutations.

There are rare instances where maternal siblings or even mothers and children do not match exactly, meaning they have a genetic distance of greater than 0, because of a mutation called a heteroplasmy.

I wrote about heteroplasmies, here.

Like Y DNA, mitochondrial DNA cannot identify a sibling or parental relationship without additional evidence, but it can exclude one, and it can also provide much-needed evidence in conjunction with autosomal matching. The great news is that unlike Y DNA, everyone has mitochondrial DNA and it comes directly from their mother.

Once again, FamilyTreeDNA’s Advanced Matching tool provides a list of people who match you on both your mitochondrial DNA test and the Family Finder autosomal test, including transfers/uploads, and provides a relationship.

You can see that our tester matches both a full sibling and their mother. Of course, a parent/child match could mean that our tester is a female and one of her children, of either sex, has tested.

Below is an example of a parent-child match that has experienced a heteroplasmy.

Based on the comparison of both the mitochondrial DNA test, plus the autosomal Family Finder test, you can verify that this is a close family relationship.

You can also eliminate potential relationships based on the mitochondrial DNA inheritance path. The mitochondrial DNA of full siblings and maternal half-siblings will always match at the full sequence and haplogroup level, and paternal half-siblings will never match. If paternal half-siblings do match, it’s happenstance or because of a different reason.

Sibling Summary and Checklist

I’ve created a quick reference checklist for you to use when attempting to determine whether or not a match is a sibling, and, if so, whether they are half or full siblings. Of course, these tools are in addition to the DNAPainter Shared cM Tool and GEDmatch’s Relationship Predictor Calculator.

FamilyTreeDNA Ancestry 23andMe MyHeritage GEDmatch
Matching Yes Yes Yes Yes Yes
Shared Matches Yes – In Common With Yes – Shared Matches Yes – Relatives in Common Yes – Review DNA Match Yes – People who match both or 1 of 2 kits
Relationship Between Shared Matches No No No Yes, under shared match No
Matches Match Each Other* Yes, Matrix No Yes, under “View DNA details,” then, “compare with more relatives” Partly, through triangulation Yes, can match any kits
Full Siblings Yes Sibling, implies full Yes Brother, Sister, means full No
Half Siblings Sibling, Uncle/Aunt-Niece/Nephew, Grandparent-Grandchild Close Family – 1C Yes Half sibling, aunt/uncle-niece-nephew No
Fully Identical Regions (FIR) No No Yes No Yes
Half Identical Regions (HIR) No No Yes No Yes
X matching Yes No Yes No Yes
Unusual Reporting or Anomalies No No, Timber is not used on close relationships X match added into total, FIR added twice No Matching amount can vary from vendors
Y DNA Yes, STRs, refined haplogroups, matching No High-level haplogroup only, no matching No No, only if tester enters haplogroup manually
Mitochondrial DNA Yes, full sequence, matching, refined haplogroup No High-level haplogroup only, no matching No No, only if tester enters haplogroup manually
Combined Tools (Autosomal, X, Y, mtDNA) Yes No No No No

*Autoclusters through Genetic Affairs show cluster relationships of matches to the tester and to each other, but not all matches are included, including close matches. While this is a great tool, it’s not relevant for determining close and sibling relationships. See the article, AutoClustering by Genetic Affairs, here.

Additional Resources

Some of you may be wondering how endogamy affects sibling numbers.

Endogamy makes almost everything a little more complex. I wrote about endogamy and various ways to determine if you have an endogamous heritage, here.

Please note that half-siblings with high cM matches also fall into the range of full siblings (1613-3488), with or without endogamy. This may be, but is not always, especially pronounced in endogamous groups.

As another resource, I wrote an earlier article, Full or Half Siblings, here, that includes some different examples.

Strategy

You have a lot of quills in your quiver now, and I wish you the best if you’re trying to unravel a siblingship mystery.

You may not know who your biological family is, or maybe your sibling doesn’t know who their family is, but perhaps your close relatives know who their family is and can help. Remember, the situation that has revealed itself may be a shock to everyone involved.

Above all, be kind and take things slow. If your unexpected sibling match becomes frightened or overwhelmed, they may simply check out and either delete their DNA results altogether or block you. They may have that reaction before you have a chance to do anything.

Because of that possibility, I recommend performing your analysis quickly, along with taking relevant screenshots before reaching out so you will at least have that much information to work with, just in case things go belly up.

When you’re ready to make contact, I suggest beginning by sending a friendly, short, message saying that you’ve noticed that you have a close match (don’t say sibling) and asking what they know about their family genealogy – maybe ask who their grandparents are or if they have family living in the area where you live. I recommend including a little bit of information about yourself, such as where you were born and are from.

I also refrain from using the word adoption (or similar) in the beginning or giving too much detailed information, because it sometimes frightens people, especially if they know or discover that there’s a painful or embarrassing family situation.

And, please, never, ever assume the worst of anyone or their motives. They may be sitting at their keyboard with the same shocked look on their face as you – especially if they have, or had, no idea. They may need space and time to reach a place of acceptance. There’s just nothing more emotionally boat-capsizing in your life than discovering intimate and personal details about your parents, one or both, especially if that discovery is disappointing and image-altering.

Or, conversely, your sibling may have been hoping and waiting just for you!

Take a deep breath and let me know how it goes!

Please feel free to share this article with anyone who could benefit.

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DNA: In Search of…Signs of Endogamy

This is the fourth in our series of articles about searching for unknown close family members, specifically; parents, grandparents, or siblings. However, these same techniques can be applied by genealogists to ancestors further back in time as well.

In this article, we discuss endogamy – how to determine if you have it, from what population, and how to follow the road signs.

After introductions, we will be covering the following topics:

  • Pedigree collapse and endogamy
  • Endogamous groups
  • The challenge(s) of endogamy
  • Endogamy and unknown close relatives (parents, grandparents)
  • Ethnicity and Populations
  • Matches
  • AutoClusters
  • Endogamous Relationships
  • Endogamous DNA Segments
  • “Are Your Parents Related?” Tool
  • Surnames
  • Projects
  • Locations
  • Y DNA, Mitochondrial DNA, and Endogamy
  • Endogamy Tools Summary Tables
    • Summary of Endogamy Tools by Vendor
    • Summary of Endogamous Populations Identified by Each Tool
    • Summary of Tools to Assist People Seeking Unknown Parents and Grandparents

What Is Endogamy and Why Does It Matter?

Endogamy occurs when a group or population of people intermarry among themselves for an extended period of time, without the introduction of many or any people from outside of that population.

The effect of this continual intermarriage is that the founders’ DNA simply gets passed around and around, eventually in small segments.

That happens because there is no “other” DNA to draw from within the population. Knowing or determining that you have endogamy helps make sense of DNA matching patterns, and those patterns can lead you to unknown relatives, both close and distant.

This Article

This article serves two purposes.

  • This article is educational and relevant for all researchers. We discuss endogamy using multiple tools and examples from known endogamous people and populations.
  • In order to be able to discern endogamy when we don’t know who our parents or grandparents are, we need to know what signs and signals to look for, and why, which is based on what endogamy looks like in people who know their heritage.

There’s no crystal ball – no definitive “one-way” arrow, but there are a series of indications that suggest endogamy.

Depending on the endogamous population you’re dealing with, those signs aren’t always the same.

If you’re sighing now, I understand – but that’s exactly WHY I wrote this article.

We’re covering a lot of ground, but these road markers are invaluable diagnostic tools.

I’ve previously written about endogamy in the articles:

Let’s start with definitions.

Pedigree Collapse and Endogamy

Pedigree collapse isn’t the same as endogamy. Pedigree collapse is when you have ancestors that repeat in your tree.

In this example, the parents of our DNA tester are first cousins, which means the tester shares great-grandparents on both sides and, of course, the same ancestors from there on back in their tree.

This also means they share more of those ancestors’ DNA than they would normally share.

John Smith and Mary Johnson are both in the tree twice, in the same position as great-grandparents. Normally, Tester Smith would carry approximately 12.5% of each of his great-grandparents’ DNA, assuming for illustration purposes that exactly 50% of each ancestor’s DNA is passed in each generation. In this case, due to pedigree collapse, 25% of Tester Smith’s DNA descends from John Smith, and another 25% descends from Mary Johnson, double what it would normally be. 25% is the amount of DNA contribution normally inherited from grandparents, not great-grandparents.

While we may find first cousin marriages a bit eyebrow-raising today, they were quite common in the past. Both laws and customs varied with the country, time, social norms, and religion.

Pedigree Collapse and Endogamy is NOT the Same

You might think that pedigree collapse and endogamy is one and the same, but there’s a difference. Pedigree collapse can lead to endogamy, but it takes more than one instance of pedigree collapse to morph into endogamy within a population. Population is the key word for endogamy.

The main difference is that pedigree collapse occurs with known ancestors in more recent generations for one person, while endogamy is longer-term and systemic in a group of people.

Picture a group of people, all descended from Tester Smith’s great-grandparents intermarrying. Now you have the beginnings of endogamy. A couple hundred or a few hundred years later, you have true endogamy.

In other words, endogamy is pedigree collapse on a larger scale – think of a village or a church.

My ancestors’ village of Schnait, in Germany, is shown above in 1685. One church and maybe 30 or 40 homes. According to church and other records, the same families had inhabited this village, and region, for generations. It’s a sure bet that both pedigree collapse and endogamy existed in this small community.

If pedigree collapse happens over and over again because there are no other people within the community to marry, then you have endogamy. In other words, with endogamy, you assuredly DO have historical pedigree collapse, generally back in time, often before you can identify those specific ancestors – because everyone descends from the same set of founders.

Endogamy Doesn’t Necessarily Indicate Recent Pedigree Collapse

With deep, historic endogamy, you don’t necessarily have recent pedigree collapse, and in fact, many people do not. Jewish people are a good example of this phenomenon. They shared ancestors for hundreds or thousands of years, depending on which group we are referring to, but in recent, known, generations, many Jewish people aren’t related. Still, their DNA often matches each other.

The good news is that there are telltale signs and signals of endogamy.

The bad news is that not all of these are obvious, meaning as an aid to people seeking clues about unknown close relatives, and other “signs” aren’t what they are believed to be.

Let’s step through each endogamy identifier, or “hint,” and then we will review how we can best utilize this information.

First, let’s take a look at groups that are considered to be endogamous.

Endogamous Groups

Jewish PeopleSpecifically groups that were isolated from other groups of Jewish (and other) people; Ashkenazi (Germany, Northern France, and diaspora), Sephardic (Spanish, Iberia, and diaspora), Mizrahi (Israel, Middle Eastern, and diaspora,) Ethiopian Jews, and possibly Jews from other locations such as Mountain Jews from Kazakhstan and the Caucasus.

AcadiansDescendants of about 60 French families who settled in “Acadia” beginning about 1604, primarily on the island of Nova Scotia, and intermarried among themselves and with the Mi’kmaq people. Expelled by the English in 1755, they were scattered in groups to various diasporic regions where they continued to intermarry and where their descendants are found today. Some Acadians became the Cajuns of Louisiana.

Anabaptist Protestant FaithsAmish, Mennonite, and Brethren (Dunkards) and their offshoots are Protestant religious sects founded in Europe in the 14th, 15th, and 16th centuries on the principle of baptizing only adults or people who are old enough to choose to follow the faith, or rebaptizing people who had been previously baptized as children. These Anabaptist faiths tend to marry within their own group or church and often expel those who marry outside of the faith. Many emigrated to the American colonies and elsewhere, seeking religious freedom. Occasionally those groups would locate in close proximity and intermarry, but not marry outside of other Anabaptist denominations.

Native American (Indigenous) People – all indigenous peoples found in North and South America before European colonization descended from a small number of original founders who probably arrived at multiple times.

Indigenous Pacific Islanders – Including indigenous peoples of Australia, New Zealand, and Hawaii prior to colonization. They are probably equally as endogamous as Native American people, but I don’t have specific examples to share.

Villages – European or other villages with little inflow or whose residents were restricted from leaving over hundreds of years.

Other groups may have significant multiple lines of pedigree collapse and therefore become endogamous over time. Some people from Newfoundland, French Canadians, and Mormons (Church of Jesus Christ of Latter-Day Saints) come to mind.

Endogamy is a process that occurs over time.

Endogamy and Unknown Relatives

If you know who your relatives are, you may already know you’re from an endogamous population, but if you’re searching for close relatives, it’s helpful to be able to determine if you have endogamous heritage, at least in recent generations.

If you know nothing about either parent, some of these tools won’t help you, at least not initially, but others will. However, as you add to your knowledge base, the other tools will become more useful.

If you know the identity of one parent, this process becomes at least somewhat easier.

In future articles, we will search specifically for parents and each of your four grandparents. In this article, I’ll review each of the diagnostic tools and techniques you can use to determine if you have endogamy, and perhaps pinpoint the source.

The Challenge

People with endogamous heritage are related in multiple, unknown ways, over many generations. They may also be related in known ways in recent generations.

If both of your parents share the SAME endogamous culture or group of relatives:

  • You may have significantly more autosomal DNA matches than people without endogamy, unless that group of people is under-sampled. Jewish people have significantly more matches, but Native people have fewer due to under-sampling.
  • You may experience a higher-than-normal cM (centiMorgan) total for estimated relationships, especially more distant relationships, 3C and beyond.
  • You will have many matches related to you on both your maternal and paternal sides.
  • Parts of your autosomal DNA will be the same on both your mother’s and father’s sides, meaning your DNA will be fully identical in some locations. (I’ll explain more in a minute.)

If either (or both) of your parents are from an endogamous population, you:

  • Will, in some cases, carry identifying Y and mitochondrial DNA that points to a specific endogamous group. This is true for Native people, can be true for Jewish people and Pacific Islanders, but is not true for Anabaptist people.

One Size Does NOT Fit All

Please note that there is no “one size fits all.”

Each or any of these tools may provide relevant hints, depending on:

  • Your heritage
  • How many other people have tested from the relevant population group
  • How many close or distant relatives have tested
  • If your parents share the same heritage
  • Your unique DNA inheritance pattern
  • If your parents, individually, were fully endogamous or only partly endogamous, and how far back generationally that endogamy occurred

For example, in my own genealogy, my maternal grandmother’s father was Acadian on his father’s side. While I’m not fully endogamous, I have significantly more matches through that line proportionally than on my other lines.

I have Brethren endogamy on my mother’s side via her paternal grandmother.

Endogamous ancestors are shown with red stars on my mother’s pedigree chart, above. However, please note that her maternal and paternal endogamous ancestors are not from the same endogamous population.

However, I STILL have fewer matches on my mother’s side in total than on my father’s side because my mother has recent Dutch and recent German immigrants which reduces her total number of matches. Neither of those lines have had as much time to produce descendants in the US, and Europe is under-sampled when compared with the US where more people tend to take DNA tests because they are searching for where they came from.

My father’s ancestors have been in the US since it was a British Colony, and I have many more cousins who have tested on his side than mother’s.

If you looked at my pedigree chart and thought to yourself, “that’s messy,” you’d be right.

The “endogamy means more matches” axiom does not hold true for me, comparatively, between my parents – in part because my mother’s German and Dutch lines are such recent immigrants.

The number of matches alone isn’t going to tell this story.

We are going to need to look at several pieces and parts for more information. Let’s start with ethnicity.

Ethnicity and Populations

Ethnicity can be a double-edged sword. It can tell you exactly nothing you couldn’t discern by looking in the mirror, or, conversely, it can be a wealth of information.

Ethnicity reveals the parts of the world where your ancestors originated. When searching for recent ancestors, you’re most interested in majority ethnicity, meaning the 50% of your DNA that you received from each of your parents.

Ethnicity results at each vendor are easy to find and relatively easy to understand.

This individual at FamilyTreeDNA is 100% Ashkenazi Jewish.

If they were 50% Jewish, we could then estimate, and that’s an important word, that either one of their parents was fully Jewish, and not the other, or that two of their grandparents were Jewish, although not necessarily on the same side.

On the other hand, my mother’s ethnicity, shown below, has nothing remarkable that would point to any majority endogamous population, yet she has two.

The only hint of endogamy from ethnicity would be her ~1% Americas, and that isn’t relevant for finding close relatives. However, minority ancestry is very relevant for identifying Native ancestors, which I wrote about, here.

You can correlate or track your ethnicity segments to specific ancestors, which I discussed in the article, Native American & Minority Ancestors Identified Using DNAPainter Plus Ethnicity Segments, here.

Since I wrote that article, FamilyTreeDNA has added the feature of ethnicity or population Chromosome Painting, based on where each of your populations fall on your chromosomes.

In this example on chromosome 1, I have European ancestry (blue,) except for the pink Native segment, which occurs on the following segment in the same location on my mother’s chromosome 1 as well.

Both 23andMe, and FamilyTreeDNA provide chromosome painting AND the associated segment information so you can identify the relevant ancestors.

Ancestry is in the process of rolling out an ethnicity painting feature, BUT, it has no segment or associated matching information. While it’s interesting eye candy, it’s not terribly useful beyond the ethnicity information that Ancestry already provides. However, Jonny Perl at DNAPainter has devised a way to estimate Ancestry’s start and stop locations, here. Way to go Jonny!

Now all you need to do is convince your Ancestry matches to upload their DNA file to one of the three databases, FamilyTreeDNA, MyHeritage, and GEDMatch, that accept transfers, aka uploads. This allows matching with segment data so that you can identify who matches you on that segment, track your ancestors, and paint your ancestral segments at DNAPainter.

I provided step-by-step instructions, here, for downloading your raw DNA file from each vendor in order to upload the file to another vendor.

Ethnicity Sides

Three of the four DNA testing vendors, 23andMe, FamilyTreeDNA, and recently, Ancestry, attempt to phase your ethnicity DNA, meaning to assign it to one parental “side” or the other – both in total and on each chromosome.

Here’s Ancestry’s SideView, where your DNA is estimated to belong to parent 1 and parent 2. I detailed how to determine which side is which, here, and while that article was written specifically pertaining to Ancestry’s SideView, the technique is relevant for all the vendors who attempt to divide your DNA into parents, a technique known as phasing.

I say “attempt” because phasing may or may not be accurate, meaning the top chromosome may not always be parent 1, and the bottom chromosome may not always be chromosome 2.

Here’s an example at 23andMe.

See the two yellow segments. They are both assigned as Native. I happen to know one is from the mother and one is from the father, yet they are both displayed on the “top” chromosome, which one would interpret to be the same parent.

I am absolutely positive this is not the case because this is a close family member, and I have the DNA of the parent who contributed the Native segment on chromosome 1, on the top chromosome. That parent does not have a Native segment on chromosome 2 to contribute. So that Native segment had to be contributed by the other parent, but it’s also shown on the top chromosome.

The DNA segments circled in purple belong together on the same “side” and were contributed to the tester by the same parent. The Native segment on chromosome 2 abuts a purple African segment, suggesting perhaps that the ancestor who contributed that segment was mixed between those ethnicities. In the US, that suggests enslavement.

The other African segments, circled, are shown on the second chromosome in each pair.

To be clear, parent 1 is not assigned by the vendors to either mother or father and will differ by person. Your parent 1, or the parent on the top chromosome may be your mother and another person’s parent 1 may be their father.

As shown in this example, parents can vary by chromosome, a phenomenon known as “strand swap.” Occasionally, the DNA can even be swapped within a chromosome assignment.

You can, however, get an idea of the division of your DNA at any specific location. As shown above, you can only have a maximum of two populations of DNA on any one chromosome location.

In our example above, this person’s majority ancestry is European (blue.) On each chromosome where we find a minority segment, the opposite chromosome in the same location is European, meaning blue.

Let’s look at another example.

At FamilyTreeDNA, the person whose ethnicity painting is shown below has a Native American (pink) ancestor on their father’s side. FamilyTreeDNA has correctly phased or identified their Native segments as all belonging to the second chromosome in each pair.

Looking at chromosome 18, for example, most of their father’s chromosome is Native American (pink). The other parent’s chromosome is European (dark blue) at those same locations.

If one of the parents was of one ethnicity, and the other parent is a completely different ethnicity, then one bar of each chromosome would be all pink, for example, and one would be entirely blue, representing the other ethnicity.

Phasing ethnicity or populations to maternal and paternal sides is not foolproof, and each chromosome is phased individually.

Ethnicity can, in some cases, give you a really good idea of what you’re dealing with in terms of heritage and endogamy.

If someone had an Ashkenazi Jewish father and European mother, for example, one copy of each chromosome would be yellow (Ashkenazi Jewish), and one would be blue (European.)

However, if each of their parents were half European Jewish and half European (not Jewish), then their different colored segments would be scattered across their entire set of chromosomes.

In this case, both of the tester’s parents are mixed – European Jewish (green) and Western Europe (blue.) We know both parents are admixed from the same two populations because in some locations, both parents contributed blue (Western Europe), and in other locations, both contributed Jewish (green) segments.

Both MyHeritage and Ancestry provide a secondary tool that’s connected to ethnicity, but different and generally in more recent times.

Ancestry’s DNA Communities

While your ethnicity may not point to anything terribly exciting in terms of endogamy, Genetic Communities might. Ancestry says that a DNA Community is a group of people who share DNA because their relatives recently lived in the same place at the same time, and that communities are much smaller than ethnicity regions and reach back only about 50-300 years.

Based on the ancestors’ locations in the trees of me and my matches, Ancestry has determined that I’m connected to two communities. In my case, the blue group is clearly my father’s line. The orange group could be either parent, or even a combination of both.

My endogamous Brethren could be showing up in Maryland, Pennsylvania, and Ohio, but it’s uncertain, in part, because my father’s ancestral lines are found in Virginia, West Virginia, and Maryland too.

These aren’t useful for me, but they may be more useful for fully endogamous people, especially in conjunction with ethnicity.

My Acadian cousin’s European ethnicity isn’t informative.

However, viewing his DNA Communities puts his French heritage into perspective, especially combined with his match surnames.

I wrote about DNA Communities when it was introduced with the name Genetic Communities, here.

MyHeritage’s Genetic Groups

MyHeritage also provides a similar feature that shows where my matches’ ancestors lived in the same locations as mine.

One difference, though, is that testers can adjust their ethnicity results confidence level from high, above, to low, below where one of my Genetic Groups overlaps my ethnicity in the Netherlands.

You can also sort your matches by Genetic Groups.

The results show you not only who is in the group, but how many of your matches are in that group too, which provides perspective.

I wrote about Genetic Groups, here.

Next, let’s look at how endogamy affects your matches.

Matches

The number of matches that a person has who is from an entirely endogamous community and a person with no endogamy may be quite different.

FamilyTreeDNA provides a Family Matching feature that triangulates your matches and assigns them to your paternal or maternal side by using known matches that you have linked to their profile cards in your tree. You must link people for the Family Matching feature known as “bucketing” to be enabled.

The people you link are then processed for shared matches on the same chromosome segment(s). Triangulated individuals are then deposited in your maternal, paternal, and both buckets.

Obviously, your two parents are the best people to link, but if they haven’t tested (or uploaded their DNA file from another vendor) and you have other known relatives, link them using the Family Tree tab at the top of your personal page.

I uploaded my Ancestry V4 kit to use as an example for linking. Let’s pretend that’s my sister. If I had not already linked my Ancestry V4 kit to “my sister’s” profile card, I’d want to do that and link other known individuals the same way. Just drag and drop the match to the correct profile card.

Note that a full or half sibling will be listed as such at FamilyTreeDNA, but an identical twin will show as a potential parent/child match to you. You’re much more likely to find a parent than an identical twin, but just be aware.

I’ve created a table of FamilyTreeDNA bucketed match results, by category, comparing the number of matches in endogamous categories with non-endogamous.

Total Matches Maternal Matches Paternal Matches Both % Both % DNA Unassigned
100% Jewish 34,637 11,329 10,416 4,806 13.9 23.3
100% Jewish 32,973 10,700 9,858 4,606 14 23.7
100% Jewish 32,255 9,060 10,970 3,892 12 25.8
75% Jewish 24,232 11,846 Only mother linked Only mother linked Only mother linked
100% Acadian 8093 3826 2299 1062 13 11
100% Acadian 7828 3763 1825 923 11.8 17
Not Endogamous 6760 3845 1909 13 0.19 14.5
Not Endogamous 7723 1470 3317 6 0.08 38
100% Native American 1,115 Unlinked Unlinked Unlinked
100% Native American 885 290 Unknown Can’t calculate without at least one link on both sides

The 100% Jewish, Acadian, and Not Endogamous testers both have linked their parents, so their matches, if valid (meaning not identical by chance, which I discussed here,) will match them plus one or the other parent.

One person is 75% Jewish and has only linked their Jewish mother.

The Native people have not tested their parents, and the first Native person has not linked anyone in their tree. The second Native person has only linked a few maternal matches, but their mother has not tested. They are seeking their father.

It’s very difficult to find people who are fully Native as testers. Furthermore, Native people are under-sampled. If anyone knows of fully Native (or other endogamous) people who have tested and linked their parents or known relatives in their trees, and will allow me to use their total match numbers anonymously, please let me know.

As you can see, Jewish, Acadian, and Native people are 100% endogamous, but many more Jewish people than Native people have tested, so you CAN’T judge endogamy by the total number of matches alone.

In fact, in order:

  • Fully Jewish testers have about 4-5 times as many matches as the Acadian and Non-endogamous testers
  • Acadian and Non-endogamous testers have about 5-6 times as many matches as the Native American testers
  • Fully Jewish people have about 30 times more matches than the Native American testers

If a person’s endogamy with a particular population is only on their maternal or paternal side, they won’t have a significant number of people related to both sides, meaning few people will fall into the “Both” bucket. People that will always be found in the ”Both” bucket are full siblings and their descendants, along with descendants of the tester, assuming their match is linked to their profiles in the tester’s tree.

In the case of our Jewish testers, you can easily see that the “Both” bucket is very high. The Acadians are also higher than one would reasonably expect without endogamy. A non-endogamous person might have a few matches on both sides, assuming the parents are not related to each other.

A high number of “Both” matches is a very good indicator of endogamy within the same population on both parents’ sides.

The percentage of people who are assigned to the “Both” bucket is between 11% and 14% in the endogamous groups, and less than 1% in the non-endogamous group, so statistically not relevant.

As demonstrated by the Native people compared to the Jewish testers, the total number of matches can be deceiving.

However, being related to both parents, as indicated by the “Both” bucket, unless you have pedigree collapse, is a good indicator of endogamy.

Of course, if you don’t know who your relatives are, you can’t link them in your tree, so this type of “hunt” won’t generally help people seeking their close family members.

However, you may notice that you’re matching people PLUS both of their parents. If that’s the case, start asking questions of those matches about their heritage.

A very high number of total matches, as compared to non-endogamous people, combined with some other hints might well point to Jewish heritage.

I included the % DNA Unassigned category because this category, when both parents are linked, is the percentage of matches by chance, meaning the match doesn’t match either of the tester’s parents. All of the people with people listed in “Both” categories have linked both of their parents, not just maternal and paternal relatives.

Matching Location at MyHeritage

MyHeritage provides a matching function by location. Please note that it’s the location of the tester, but that may still be quite useful.

The locations are shown in the most-matches to least-matches order. Clicking on the location shows the people who match you who are from that location. This would be the most useful in situations where recent immigration has occurred. In my case, my great-grandfather from the Netherlands arrived in the 1860s, and my German ancestors arrived in the 1850s. Neither of those groups are endogamous, though, unless it would be on a village level.

AutoClusters

Let’s shift to Genetic Affairs, a third-party tool available to everyone.

Using their AutoCluster function, Genetic Affairs clusters your matches together who match both each other and you.

This is an example of the first few clusters in my AutoCluster. You can see that I have several colored clusters of various sizes, but none are huge.

Compare that to the following endogamous cluster, sample courtesy of EJ Blom at Genetic Affairs.

If your AutoCluster at Genetic Affairs looks something like this, a huge orange blob in the upper left hand corner, you’re dealing with endogamy.

Please also note that the size of your cluster is also a function of both the number of testers and the match threshold you select. I always begin by using the defaults. I wrote about using Genetic Affairs, here.

If you tested at or transferred to MyHeritage, they too license AutoClusters, but have optimized the algorithm to tease out endogamous matches so that their Jewish customers, in particular, don’t wind up with a huge orange block of interrelated people.

You won’t see the “endogamy signature” huge cluster in the corner, so you’re less likely to be able to discern endogamy from a MyHeritage cluster alone.

The commonality between these Jewish clusters at MyHeritage is that they all tend to be rather uniform in size and small, with lots of grey connecting almost all the blocks.

Grey cells indicate people who match people in two colored groups. In other words, there is often no clear division in clusters between the mother’s side and the father’s side in Jewish clusters.

In non-endogamous situations, even if you can’t identify the parents, the clusters should still fall into two sides, meaning a group of clusters for each parent’s side that are not related to each other.

You can read more about Genetic Affairs clusters and their tools, here. DNAGedcom.com also provides a clustering tool.

Endogamous Relationships

Endogamous estimated relationships are sometimes high. Please note the word, “sometimes.”

Using the Shared cM Project tool relationship chart, here, at DNAPainter, people with heavy endogamy will discover that estimated relationships MAY be on the high side, or the relationships may, perhaps, be estimated too “close” in time. That’s especially true for more distant relationships, but surprisingly, it’s not always true. The randomness of inheritance still comes into play, and so do potential unknown relatives. Hence, the words “may” are bolded and underscored.

Unfortunately, it’s often stated as “conventional wisdom” that Jewish matches are “always” high, and first cousins appear as siblings. Let’s see what the actual data says.

At DNAPainter, you can either enter the amount of shared DNA (cM), or the percent of shared DNA, or just use the chart provided.

I’ve assembled a compilation of close relationships in kits that I have access to or from people who were generous enough to share their results for this article.

I’ve used Jewish results, which is a highly endogamous population, compared with non-endogamous testers.

The “Jewish Actual” column reports the total amount of shared DNA with that person. In other words, someone to their grandparent. The Average Range is the average plus the range from DNAPainter. The Percent Difference is the % difference between the actual number and the DNAPainter average.

You’ll see fully Jewish testers, at left, matching with their family members, and a Non-endogamous person, at right, matching with their same relative.

Relationship Jewish Actual Percent Difference than Average Average -Range Non-endogamous Actual Percent Difference than Average
Grandparent 2141 22 1754 (984-2482) 1742 <1 lower
Grandparent 1902 8.5 1754 (984-2482) 1973 12
Sibling 3039 16 2613 (1613-3488) 2515 3.5 lower
Sibling 2724 4 2613 (1613-3488) 2761 5.5
Half-Sibling 2184 24 1759 (1160-2436) 2127 21
Half-Sibling 2128 21 1759 (1160-2436) 2352 34
Aunt/Uncle 2066 18.5 1741 (1201-2282) 1849 6
Aunt/Uncle 2031 16.5 1741 (1201-2282) 2097 20
1C 1119 29 866 (396-1397) 959 11
1C 909 5 866 (396-1397) 789 9 lower
1C1R 514 19 433 (102-980) 467 8
1C1R 459 6 433 (102-980) 395 9 lower

These totals are from FamilyTreeDNA except one from GEDMatch (one Jewish Half-sibling).

Totals may vary by vendor, even when matching with the same person. 23andMe includes the X segments in the total cMs and also counts fully identical segments twice. MyHeritage imputation seems to err on the generous side.

However, in these dozen examples:

  • You can see that the Jewish actual amount of DNA shared is always more than the average in the estimate.
  • The red means the overage is more than 100 cM larger.
  • The percentage difference is probably more meaningful because 100 cM is a smaller percentage of a 1754 grandparent connection than compared to a 433 cM 1C1R.

However, you can’t tell anything about endogamy by just looking at any one sample, because:

  • Some of the Non-Endogamous matches are high too. That’s just the way of random inheritance.
  • All of the actual Jewish match numbers are within the published ranges, but on the high side.

Furthermore, it can get more complex.

Half Endogamous

I requested assistance from Jewish genealogy researchers, and a lovely lady, Sharon, reached out, compiled her segment information, and shared it with me, granting permission to share with you. A HUGE thank you to Sharon!

Sharon is half-Jewish via one parent, and her half-sibling is fully Jewish. Their half-sibling match to each other at Ancestry is 1756 cM with a longest segment of 164 cM.

How does Jewish matching vary if you’re half-Jewish versus fully Jewish? Let’s look at 21 people who match both Sharon and her fully Jewish half-sibling.

Sharon shared the differences in 21 known Jewish matches with her and her half-sibling. I’ve added the Relationship Estimate Range from DNAPainter and colorized the highest of the two matches in yellow. Bolding in the total cM column shows a value above the average range for that relationship.

Total Matching cMs is on the left, with Longest Segment on the right.

While this is clearly not a scientific study, it is a representative sample.

The fully Jewish sibling carries more Jewish DNA, which is available for other Jewish matches to match as a function of endogamy (identical by chance/population), so I would have expected the fully Jewish sibling to match most if not all Jewish testers at a higher level than the half-Jewish sibling.

However, that’s not universally what we see.

The fully Jewish sibling is not always the sibling with the highest number of matches to the other Jewish testers, although the half-Jewish tester has the larger “Longest Segment” more often than not.

Approximately two-thirds of the time (13/21), the fully Jewish person does have a higher total matching cM, but about one-third of the time (8/21), the half-Jewish sibling has a higher matching cM.

About one-fourth of the time (5/21), the fully Jewish sibling has the longest matching segment, and about two-thirds of the time (13/21), the half-Jewish sibling does. In three cases, or about 14% of the time, the longest segment is equal which may indicate that it’s the same segment.

Because of endogamy, Jewish matches are more likely to have:

  • Larger than average total cM for the specific relationship
  • More and smaller matching segments

However, as we have seen, neither of those are definitive, nor always true. Jewish matches and relationships are not always overestimated.

Ancestry and Timber

Please note that Ancestry downweights some matches by removing some segments using their Timber algorithm. Based on my matches and other accounts that I manage, Ancestry does not downweight in the 2-3rd cousin category, which is 90 cM and above, but they do begin downweighting in the 3-4th cousin category, below 90 cM, where my “Extended Family” category begins.

If you’ve tested at Ancestry, you can check for yourself.

By clicking on the amount of DNA you share with your match on your match list at Ancestry, shown above, you will be taken to another page where you will be able to view the unweighted shared DNA with that match, meaning the amount of DNA shared before the downweighting and removal of some segments, shown below.

Given the downweighting, and the information in the spreadsheet provided by Sharon, it doesn’t appear that any of those matches would have been in a category to be downweighted.

Therefore, for these and other close matches, Timber wouldn’t be a factor, but would potentially be in more distant matches.

Endogamous Segments

Endogamous matches tend to have smaller and more segments. Small amounts of matching DNA tend to skew the total DNA cM upwards.

How and why does this happen?

Ancestral DNA from further back in time tends to be broken into smaller segments.

Sometimes, especially in endogamous situations, two smaller segments, at one time separated from each other, manage to join back together again and form a match, but the match is only due to ancestral segments – not because of a recent ancestor.

Please note that different vendors have different minimum matching cM thresholds, so smaller matches may not be available at all vendors. Remember that factors like Timber and imputation can affect matching as well.

Let’s take a look at an example. I’ve created a chart where two ancestors have their blue and pink DNA broken into 4 cM segments.

They have children, a blue child and a pink child, and the two children, shown above, each inherited the same blue 4 cM segment and the same pink 4 cM segment from their respective parents. The other unlabeled pink and blue segments are not inherited by these two children, so those unlabeled segments are irrelevant in this example.

The parents may have had other children who inherited those same 4 cM labeled pink and blue segments as well, and if not, the parents’ siblings were probably passing at least some of the same DNA down to their descendants too.

The blue and pink children had children, and their children had children – for several generations.

Time passed, and their descendants became an endogamous community. Those pink and blue 4 cM segments may at some time be lost during recombination in the descendants of each of their children, shown by “Lost pink” and “Lost blue.”

However, because there is only a very limited amount of DNA within the endogamous community, their descendants may regain those same segments again from their “other parent” during recombination, downstream.

In each generation, the DNA of the descendant carrying the original blue or pink DNA segment is recombined with their partner. Given that the partners are both members of the same endogamous community, the two people may have the same pink and/or blue DNA segments. If one parent doesn’t carry the pink 4 cM segment, for example, their offspring may receive that ancestral pink segment from the other parent.

They could potentially, and sometimes do, receive that ancestral segment from both parents.

In our example, the descendants of the blue child, at left, lost the pink 4 cM segment in generation 3, but a few generations later, in generation 11, that descendant child inherited that same pink 4 cM segment from their other parent. Therefore, both the 4 cM blue and 4 cM pink segments are now available to be inherited by the descendants in that line. I’ve shown the opposite scenario in the generational inheritance at right where the blue segment is lost and regained.

Once rejoined, that pink and blue segment can be passed along together for generations.

The important part, though, is that once those two segments butt up against each other again during recombination, they aren’t just two separate 4 cM segments, but one segment that is 8 cM long – that is now equal to or above the vendors’ matching threshold.

This is why people descended from endogamous populations often have the following matching characteristics:

  • More matches
  • Many smaller segment matches
  • Their total cM is often broken into more, smaller segments

What does more, smaller segments, look like, exactly?

More, Smaller Segments

All of our vendors except Ancestry have a chromosome browser for their customers to compare their DNA to that of their matches visually.

Let’s take a look at some examples of what endogamous and non-endogamous matches look like.

For example, here’s a screen shot of a random Jewish second cousin match – 298 cM total, divided into 12 segments, with a longest segment of 58 cM,

A second Jewish 2C with 323 cM total, across 19 segments, with a 69 cM longest block.

A fully Acadian 2C match with 600 cM total, across 27 segments, with a longest segment of 69 cM.

A second Acadian 2C with 332 cM total, across 20 segments, with a longest segment of 42 cM.

Next, a non-endogamous 2C match with 217 cM, across 7 segments, with a longest segment of 72 cM.

Here’s another non-endogamous 2C example, with 169 shared cM, across 6 segments, with a longest segment of 70 cM.

Here’s the second cousin data in a summary table. The take-away from this is the proportion of total segments

Tester Population Total cM Longest Block Total Segments
Jewish 2C 298 58 12
Jewish 2C 323 69 19
Acadian 2C 600 69 27
Acadian 2C 332 42 20
Non-endogamous 2C 217 72 7
Non-endogamous 2C 169 70 6

You can see more examples and comparisons between Native American, Jewish and non-endogamous DNA individuals in the article, Concepts – Endogamy and DNA Segments.

I suspect that a savvy mathematician could predict endogamy based on longest block and total segment information.

Lara Diamond, a mathematician, who writes at Lara’s Jewnealogy might be up for this challenge. She just published compiled matching and segment information in her Ashkenazic Shared DNA Survey Results for those who are interested. You can also contribute to Laura’s data, here.

Endogamy, Segments, and Distant Relationships

While not relevant to searching for close relatives, heavily endogamous matches 3C and more distant, to quote one of my Jewish friends, “dissolve into a quagmire of endogamy and are exceedingly difficult to unravel.”

In my own Acadian endogamous line, I often simply have to label them “Acadian” because the DNA tracks back to so many ancestors in different lines. In other words, I can’t tell which ancestor the match is actually pointing to because the same DNA segments or segments is/are carried by several ancestors and their descendants due to founder effect.

The difference with the Acadians is that we can actually identify many or most of them, at least at some point in time. As my cousin, Paul LeBlanc, once said, if you’re related to one Acadian, you’re related to all Acadians. Then he proceeded to tell me that he and I are related 137 different ways. My head hurts!

It’s no wonder that endogamy is incredibly difficult beyond the first few generations when it turns into something like multi-colored jello soup.

“Are Your Parents Related?” Tool

There’s another tool that you can utilize to determine if your parents are related to each other.

To determine if your parents are related to each other, you need to know about ROH, or Runs of Homozygosity (ROH).

ROH means that the DNA on both strands or copies of the same chromosome is identical.

For a few locations in a row, ROH can easily happen just by chance, but the longer the segment, the less likely that commonality occurs simply by chance.

The good news is that you don’t need to know the identity of either of your parents. You don’t need either of your parent’s DNA tests – just your own. You’ll need to upload your DNA file to GEDmatch, which is free.

Click on “Are your parents related?”

GEDMatch analyzes your DNA to see if any of your DNA, above a reasonable matching threshold, is identical on both strands, indicating that you inherited the exact same DNA from both of your parents.

A legitimate match, meaning one that’s not by chance, will include many contiguous matching locations, generally a minimum of 500 SNPs or locations in a row. GEDmatch’s minimum threshold for identifying identical ancestral DNA (ROH) is 200 cM.

Here’s my result, including the graphic for the first two chromosomes. Notice the tiny green bars that show identical by chance tiny sliver segments.

I have no significant identical DNA, meaning my parents are not related to each other.

Next, let’s look at an endogamous example where there are small, completely identical segments across a person’s chromosome

This person’s Acadian parents are related to each other, but distantly.

Next, let’s look at a Jewish person’s results.

You’ll notice larger green matching ROH, but not over 200 contiguous SNPs and 7 cM.

GEDMatch reports that this Jewish person’s parents are probably not related within recent generations, but it’s clear that they do share DNA in common.

People whose parents are distantly related have relatively small, scattered matching segments. However, if you’re seeing larger ROH segments that would be large enough to match in a genealogical setting, meaning multiple greater than 7 cM and 500 SNPs,, you may be dealing with a different type of situation where cousins have married in recent generations. The larger the matching segments, generally, the closer in time.

Blogger Kitty Cooper wrote an article, here, about discovering that your parents are related at the first cousin level, and what their GEDMatch “Are Your Parents Related” results look like.

Let’s look for more clues.

Surnames

There MAY be an endogamy clue in the surnames of the people you match.

Viewing surnames is easier if you download your match list, which you can do at every vendor except Ancestry. I’m not referring to the segment data, but the information about your matches themselves.

I provided instructions in the recent article, How to Download Your DNA Match Lists and Segment Files, here.

If you suspect endogamy for any reason, look at your closest matches and see if there is a discernable trend in the surnames, or locations, or any commonality between your matches to each other.

For example, Jewish, Acadian, and Native surnames may be recognizable, as may locations.

You can evaluate in either or both of two ways:

  • The surnames of your closest matches. Closest matches listed first will be your default match order.
  • Your most frequently occurring surnames, minus extremely common names like Smith, Jones, etc., unless they are also in your closest matches. To utilize this type of matching, sort the spreadsheet in surname order and then scan or count the number of people with each surname.

Here are some examples from our testers.

Jewish – Closest surname matches.

  • Roth
  • Weiss
  • Goldman
  • Schonwald
  • Levi
  • Cohen
  • Slavin
  • Goodman
  • Sender
  • Trebatch

Acadian – Closest surname matches.

  • Bergeron
  • Hebert
  • Bergeron
  • Marcum
  • Muise
  • Legere
  • Gaudet
  • Perry
  • Verlander
  • Trombley

Native American – Closest surname matches.

  • Ortega
  • Begay
  • Valentine
  • Hayes
  • Montoya
  • Sun Bear
  • Martin
  • Tsosie
  • Chiquito
  • Yazzie

You may recognize these categories of surnames immediately.

If not, Google is your friend. Eliminate common surnames, then Google for a few together at a time and see what emerges.

The most unusual surnames are likely your best bets.

Projects

Another way to get some idea of what groups people with these surnames might belong to is to enter the surname in the FamilyTreeDNA surname search.

Go to the main FamilyTreeDNA page, but DO NOT sign on.

Scroll down until you see this image.

Type the surname into the search box. You’ll see how many people have tested with that surname, along with projects where project administrators have included that surname indicating that the project may be of interest to at least some people with that surname.

Here’s a portion of the project list for Cohen, a traditional Jewish surname.

These results are for Muise, an Acadian surname.

Clicking through to relevant surname projects, and potentially contacting the volunteer project administrator can go a very long way in helping you gather and sift information. Clearly, they have an interest in this topic.

For example, here’s the Muise surname in the Acadian AmerIndian project. Two great hints here – Acadian heritage and Halifax, Nova Scotia.

Repeat for the balance of surnames on your list to look for commonalities, including locations on the public project pages.

Locations

Some of the vendor match files include location information. Each person on your match list will have the opportunity at the vendor where they tested to include location information in a variety of ways, either for their ancestors or themselves.

Where possible, it’s easiest to sort or scan the download file for this type of information.

Ancestry does not provide or facilitate a match list, but you can still create your own for your closest 20 or 30 matches in a spreadsheet.

MyHeritage provides common surname and ancestral location information for every match. How cool is that!

Y DNA, Mitochondrial DNA, and Endogamy

Haplogroups for both Y and mitochondrial DNA can indicate and sometimes confirm endogamy. In other cases, the haplogroup won’t help, but the matches and their location information just might.

FamilyTreeDNA is the only vendor that provides Y DNA and mitochondrial DNA tests that include highly granular haplogroups along with matches and additional tools.

23andMe provides high-level haplogroups which may or may not be adequate to pinpoint a haplogroup that indicates endogamy.

Of course, only males carry Y DNA that tracks to the direct paternal (surname) line, but everyone carries their mother’s mitochondrial DNA that represents their mother’s mother’s mother’s, or direct matrilineal line.

Some haplogroups are known to be closely associated with particular ethnicities or populations, like Native Americans, Pacific Islanders, and some Jewish people.

Haplogroups reach back in time before genealogy and can give us a sense of community that’s not available by either looking in the mirror or through traditional records.

This Native American man is a member of high-level haplogroup Q-M242. However, some men who carry this haplogroup are not Native, but are of European or Middle Eastern origin.

I entered the haplogroup in the FamilyTreeDNA Discover tool, which I wrote about, here.

Checking the information about this haplogroup reveals that their common ancestor descended from an Asian man about 30,000 years ago.

The migration path in the Americans explains why this person would have an endogamous heritage.

Our tester would receive a much more refined haplogroup if he upgraded to the Big Y test at FamilyTreeDNA, which would remove all doubt.

However, even without additional testing, information about his matches at FamilyTreeDNA may be very illuminating.

The Q-M242 Native man’s Y DNA matches men with more granular haplogroups, shown above, at left. On the Haplogroup Origins report, you can see that these people have all selected the “US (Native American)” country option.

Another useful tool would be to check the public Y haplotree, here, and the public mitochondrial tree here, for self-reported ancestor location information for a specific haplogroup.

Here’s an example of mitochondrial haplogroup A2 and a few subclades on the public mitochondrial tree. You can see that the haplogroup is found in Mexico, the US (Native,) Canada, and many additional Caribbean, South, and Central American countries.

Of course, Y DNA and mitochondrial DNA (mtDNA) tell a laser-focused story of one specific line, each. The great news, if you’re seeking information about your mother or father, the Y is your father’s direct paternal (surname) line, and mitochondrial is your mother’s direct matrilineal line.

Y and mitochondrial DNA results combined with ethnicity, autosomal matching, and the wide range of other tools that open doors, you will be able to reveal a great deal of information about whether you have endogamous heritage or not – and if so, from where.

I’ve provided a resource for stepping through and interpreting your Y DNA results, here, and mitochondrial DNA, here.

Discover for Y DNA Only

If you’re a female, you may feel left out of Y DNA testing and what it can tell you about your heritage. However, there’s a back door.

You can utilize the Y DNA haplogroups of your closest autosomal matches at both FamilyTreeDNA and 23andMe to reveal information

Haplogroup information is available in the download files for both vendors, in addition to the Family Finder table view, below, at FamilyTreeDNA, or on your individual matches profile cards at both 23andMe and FamilyTreeDNA.

You can enter any Y DNA haplogroup in the FamilyTreeDNA Discover tool, here.

You’ll be treated to:

  • Your Haplogroup Story – how many testers have this haplogroup (so far), where the haplogroup is from, and the haplogroup’s age. In this case, the haplogroup was born in the Netherlands about 250 years ago, give or take 200 years. I know that it was 1806 or earlier based on the common ancestor of the men who tested.
  • Country Frequency – heat map of where the haplogroup is found in the world.
  • Notable Connections – famous and infamous (this haplogroup’s closest notable person is Leo Tolstoy).
  • Migration Map – migration path out of Africa and through the rest of the world.
  • Ancient Connections – ancient burials. His closest ancient match is from about 1000 years ago in Ukraine. Their shared ancestor lived about 2000 years ago.
  • Suggested Projects – based on the surname, projects that other matches have joined, and haplogroups.
  • Scientific Details – age estimates, confidence intervals, graphs, and the mutations that define this haplogroup.

I wrote about the Discover tool in the article, FamilyTreeDNA DISCOVER Launches – Including Y DNA Haplogroup Ages.

Endogamy Tools Summary Tables

Endogamy is a tough nut sometimes, especially if you’re starting from scratch. In order to make this topic a bit easier and to create a reference tool for you, I’ve created three summary tables.

  • Various endogamy-related tools available at each vendor which will or may assist with evaluating endogamy
  • Tools and their ability to detect endogamy in different groups
  • Tools best suited to assist people seeking information about unknown parents or grandparents

Summary of Endogamy Tools by Vendor

Please note that GEDMatch is not a DNA testing vendor, but they accept uploads and do have some tools that the testing vendors do not.

 Tool 23andMe Ancestry FamilyTreeDNA MyHeritage GEDMatch
Ethnicity Yes Yes Yes Yes Use the vendors
Ethnicity Painting Yes + segments Yes, limited Yes + segments Yes
Ethnicity Phasing Yes Partial Yes No
DNA Communities No Yes No No
Genetic Groups No No No Yes
Family Matching aka Bucketing No No Yes No
Chromosome Browser Yes No Yes Yes Yes
AutoClusters Through Genetic Affairs No Through Genetic Affairs Yes, included Yes, with subscription
Match List Download Yes, restricted # of matches No Yes Yes Yes
Projects No No Yes No
Y DNA High-level haplogroup only No Yes, full haplogroup with Big Y, matching, tools, Discover No
Mitochondrial DNA High-level haplogroup only No Yes, full haplogroup with mtFull, matching, tools No
Public Y Tree No No Yes No
Public Mito Tree No No Yes No
Discover Y DNA – public No No Yes No
ROH No No No No Yes

Summary of Endogamous Populations Identified by Each Tool

The following chart provides a guideline for which tools are useful for the following types of endogamous groups. Bolded tools require that both parents be descended from the same endogamous group, but several other tools give more definitive results with higher amounts of endogamy.

Y and mitochondrial DNA testing are not affected by admixture, autosomal DNA or anything from the “other” parent.

Tool Jewish Acadian Anabaptist Native Other/General
Ethnicity Yes No No Yes Pacific Islander
Ethnicity Painting Yes No No Yes Pacific Islander
Ethnicity Phasing Yes, if different No No Yes, if different Pacific Islander, if different
DNA Communities Yes Possibly Possibly Yes Pacific Islander
Genetic Groups Yes Possibly Possibly Yes Pacific Islander
Family Matching aka Bucketing Yes Yes Possibly Yes Pacific Islander
Chromosome Browser Possibly Possibly Yes, once segments or ancestors identified Possibly Pacific Islander, possibly
Total Matches Yes, compared to non-endogamous No No No No, unknown
AutoClusters Yes Yes Uncertain, probably Yes Pacific Islander
Estimated Relationships High Not always Sometimes No Sometimes Uncertain, probably
Relationship Range High Possibly, sometimes Possibly Possibly Possibly Pacific Islander, possibly
More, Smaller Segments Yes Yes Probably Yes Pacific Islander, probably
Parents Related Some but minimal Possibly Uncertain Probably similar to Jewish Uncertain, Possibly
Surnames Probably Probably Probably Not Possibly Possibly
Locations Possibly Probably Probably Not Probably Probably Pacific Islander
Projects Probably Probably Possibly Possibly Probably Pacific Islander
Y DNA Yes, often Yes, often No Yes Pacific Islander
Mitochondrial DNA Yes, often Sometimes No Yes Pacific Islander
Y public tree Probably not alone No No Yes Pacific Islander
MtDNA public tree Probably not No No Yes Pacific Islander
Y DNA Discover Yes Possibly Probably not, maybe projects Yes Pacific Islander

Summary of Endogamy Tools to Assist People Seeking Unknown Parents and Grandparents

This table provides a summary of when each of the various tools can be useful to:

  • People seeking unknown close relatives
  • People who already know who their close relatives are, but are seeking additional information or clues about their genealogy

I considered rating these on a 1 to 10 scale, but the relative usefulness of these tools is dependent on many factors, so different tools will be more or less useful to different people.

For example, ethnicity is very useful if someone is admixed from different populations, or even 100% of a specific endogamous population. It’s less useful if the tester is 100% European, regardless of whether they are seeking close relatives or not. Conversely, even “vanilla” ethnicity can be used to rule out majority or recent admixture with many populations.

Tools Unknown Close Relative Seekers Known Close Relatives – Enhance Genealogy
Ethnicity Yes, to identify or rule out populations Yes
Ethnicity Painting Yes, possibly, depending on population Yes, possibly, depending on population
Ethnicity Phasing Yes, possibly, depending on population Yes, possibly, depending on population
DNA Communities Yes, possibly, depending on population Yes, possibly, depending on population
Genetic Groups Possibly, depending on population Possibly, depending on population
Family Matching aka Bucketing Not if parents are entirely unknown, but yes if one parent is known Yes
Chromosome Browser Unlikely Yes
AutoClusters Yes Yes, especially at MyHeritage if Jewish
Estimated Relationships High Not No
Relationship Range High Not reliably No
More, Smaller Segments Unlikely Unlikely other than confirmation
Match List Download Yes Yes
Surnames Yes Yes
Locations Yes Yes
Projects Yes Yes
Y DNA Yes, males only, direct paternal line, identifies surname lineage Yes, males only, direct paternal line, identifies and correctly places surname lineage
Mitochondrial DNA Yes, both sexes, direct matrilineal line only Yes, both sexes, direct matrilineal line only
Public Y Tree Yes for locations Yes for locations
Public Mito Tree Yes for locations Yes for locations
Discover Y DNA Yes, for heritage information Yes, for heritage information
Parents Related – ROH Possibly Less useful

Acknowledgments

A HUGE thank you to several people who contributed images and information in order to provide accurate and expanded information on the topic of endogamy. Many did not want to be mentioned by name, but you know who you are!!!

If you have information to add, please post in the comments.

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Ancestry Only Shows Shared Matches of 20 cM and Greater – What That Means & Why It Matters

Recently, I’ve noticed an uptick in confused people who’ve taken Ancestry’s DNA test.

They are using shared matches, which is a great tool and exactly what they should be doing, but they become confused when no shared matches appear with some specific people.

This is especially perplexing when they know through information sharing or because they manage multiple DNA kits that those two people who both match them actually do share DNA and match each other, meaning they “should” appear on a shared match list. Or worse, yet, conflicting match information is displayed, with one person showing the shared match, but the other person reciprocally does not.

What gives?

That’s exactly what this article addresses. It’s not quite as simple as it sounds, but it’s certainly easier once you understand.

What Are Matches and Shared Matches?

Matches occur when two people match each other. From your perspective as a DNA tester, matches are people who have taken DNA tests and appear on your match list because you share some level of DNA equal to or greater than the match threshold of the vendor in question.

At Ancestry, that minimum matching threshold is 8 cM (centimorgans) of matching DNA.

Individual matches are always one-to-one. Your match list is a list of people who all match you.

So, you match person 1, and you match person 2, individually.

Your matches may or may not also match each other. If they do match each other in addition to matching you, that’s a shared match which is a hint as to a potential common ancestor between all three people.

Shared matches are a list of people who match you PLUS any one other match on your list. In other words, shared matches are three-way matches.

In the diagram above, you can see that you match Match 1 and you also match Match 2. In this case, Match 1 and Match 2 also match each other, so all three of you match each other, but not necessarily on the same segment. Therefore, you’re all three shared matches, as shown in the center of the three circles.

Viewing Shared Matches

To view a list of people who match you and Match 1, you would request shared matches with Match 1 by clicking on “View Match” or “Learn More” on your match list, then on “Shared Matches” on the next screen.

The resulting shared match list consist of people who match you AND Match 1, both. It’s easy to make assumptions about why you have shared matches, but don’t.

Shared Matches are Hints

A shared match CAN mean:

  • That all three people share a common ancestral line.
  • You share a common ancestor with Match 1 and Match 2, but Match 1 and 2 match each other because they share an entirely different ancestor.
  • You match Match 1 because you share DNA from Ancestor A and you match Match 2 because you share DNA from Ancestor B. Match 1 and 2 match each other either because they share one or both of those common ancestors.
  • Match 1 and Match 2 might match because Match 1 and Match 2 share an ancestor that isn’t related to you.
  • That one (or more) of the matches is identical by chance, meaning the DNA combined from two parents in a random way that just happens to match with someone else.

Shared matches are great hints to be sifted for relevance. The operative word here is hint.

What If We Don’t Have Shared Matches?

Conversely, NOT having a shared match doesn’t mean you don’t share a common ancestor.

Sorry about the triple negative. Let me say that another way, because this is important.

Even though you and someone else aren’t on a shared match list, you might still share DNA and you may share a common ancestor, whether you share their DNA or not.

Ancestry’s shared matches work differently than shared matches at other vendors. Before we discuss that, let’s talk about why shared matches are important.

Why Do Shared Matches Matter Anyway?

Matches and shared matches are how genealogists perform two critically important functions:

  • Verifying “known” ancestors. Sometimes paper trails aren’t accurate and certainly, neither are trees.
  • Identifying unknown ancestors. Looking for common families among shared DNA matches is a HUGE hint when tracking down those pesky unknown ancestors.

I wrote about shared matches, here, when Ancestry purged segments under 8 cM, but I think the message about the limitations of shared matches and how the process actually works deserves its own article, especially for new users. Shared matches and segment cM numbers can be quite confusing, but they don’t need to be.

I wrote an article titled DNA Beginnings: Matching at Ancestry and What It Means that includes lots of useful information.

Ok, now let’s look specifically at using shared matches and why sometimes shared matches just don’t seem to make sense.

Matches

By far, the majority of your matches at any vendor will be more distant matches. That’s because you have thousands of distant relatives, most of whom you don’t know (yet).

You’ll only have a few closer relatives.

At Ancestry, I have 102,000+ total matches, of which more than 97,000 are distant matches. Based on these numbers, keep in mind that about 95.74% of my matches are distant, meaning 20 cM or below, and yours probably are too. You’ll need that number later.

Note that 20 cM is Ancestry’s threshold between close matches and distant matches.

That’s about exactly where you’d expect, on average, to see a 20 cM match – generally at or further back than 4th cousins. 20 cM is roughly the 4th to 6th cousin level.

Of course, you won’t match most of your 5th cousins at all, yet you’ll match some with more than 20 cM. That’s just the roll of the genetic dice.

Closer ancestors (meaning closer matches) is also the area of genealogy where much of the lower-hanging fruit has been plucked.

In my case, the closest unknown ancestor in my tree occurs at the 6th generation level and I have 5 or 6 missing sixth-generation ancestors – all females with no surnames. Two have no names at all.

Click to enlarge any image

How Much DNA Do Cousins Share?

One of my priorities as a genealogist is to identify those unknown people, which is why matches, and shared matching at that level are critical for me.

Ancestry tells me that this 20 cM match is likely my 4th-6th cousin.

At DNAPainter, in the Shared cM Tool, you can enter the total cM number of a match, which is the total amount of DNA that you share after Ancestry’s Timber algorithm has been applied. The range of relationship probabilities for 20 cM is shown below.

For a total match of 20 cM with another individual, several relationships ranging between half 3C2R/3C3R and 8th cousins are the most probable relationships at 58%.

For the record, this is total cM, which does not necessarily mean one segment. Ancestry reports the number of segments, but Ancestry does not show you the segment locations, nor do they have a chromosome browser. Without a chromosome browser, you have no way of determining whether or not you match with shared matches on the same segment(s). In other words, there is no triangulation at Ancestry, meaning confirmation of a specific shared DNA segment descended from a common ancestor. You can find triangulation resources, here.

Close Matches

The best way to figure out how you are related to closer matches (assuming you don’t already know them and Ancestry has not found a common ancestor) is using shared matches. Hopefully, you will share matches with people you do know or with whom you’ve already identified your common ancestor.

One of my relatively close DNA matches at Ancestry is Lonnie. I don’t know Lonnie, but it looks like I should because he’s probably a 1st or 2nd cousin. We share 357 cM of DNA over 20 segments.

I thought I knew all of my 1st and 2nd cousins. Let’s see if I can figure out how I’m related to Lonnie.

By clicking on Lonnie’s name on my match list, then on Shared Matches, I can determine that Lonnie and I connect through my Estes and Vannoy lines based on who we both match, which means that our common ancestor is either my paternal grandfather or my great-grandparents, Lazarus Estes and Elizabeth Vannoy.

You can see the notes I’ve made about these matches I share with Lonnie.

Viewing Lonnie’s unlinked tree verifies the ancestral line that shared matches suggest. An unlinked tree means that Lonnie has not linked his DNA test to himself in his tree. Since Ancestry doesn’t know who he is in the tree, they can’t find a common ancestor for me and Lonnie. However, I can by viewing his tree.

Our common ancestor is Lazarus Estes and his wife, Elizabeth Vannoy. Therefore, Lonnie is my 2nd cousin.

That wasn’t difficult, in part because I had already worked on the genealogy of our common matches and Lonnie had a small unlinked tree where I could confirm our common ancestor.

Now let’s move to more distant, not-so-easy matches.

Distant Matches

I’ve spent a lot of time over the years identifying common ancestors with my matches.

When I make that connection, whether or not Ancestry has been able to identify our common ancestor, I make notes about common ancestors and anything else that seems relevant. Notes very conveniently show on my match list so I don’t need to open each match to see how we are related.

Ancestry does identify potential common ancestors using ThruLines. Note the word potential. Ancestry compares the trees of you and your matches searching for common ancestors and suggests connections. It’s up to you to verify. ThruLines are hints, not gospel. Additionally, you may have multiple ancestral links to your matches. Ancestry can only work with the fact that you have a DNA match with someone AND the user-provided trees of your matches.

Ancestry’s ThruLines only reach back a maximum of 7 generations to suggest common ancestors. At 7 generations distance, you’d be a 5th cousin to a descendant who is also 7 generations downstream from that ancestor.

The information from DNAPainter, who utilizes the Shared CM Project compiled data shows that the most likely amount of shared DNA for 5th cousins, is, you’ve guessed it – 20 cM.

Jacob Dobkins is my 7th generation ancestor. I have ThruLines for him and his wife, but not for their parents who are one generation too distant for ThruLines. I’d LOVE to see Ancestry extend ThruLines another 2 or 3 generations.

ThruLines matches me with people who descend from Jacob through his other children. Other children are important because the only ancestors you share with those people are (presumably) that ancestral couple.

Matches with Jacob’s descendants range from 8 cM (the smallest amount Ancestry reports) to 32 cM.

Here’s an example.

Ancestry displays some shared matches with all of your matches, regardless of the size of your match to that person. However, Ancestry ONLY shows shared matches to a third person if you share more than 20 cM of DNA with that third person.

For example, I match KO with 8 cM of DNA. Ancestry shows my shared matches with KO, below.

I only have 3 shared matches with KO. I only match KO at 8 cM, but I match our shared matches at 39, 31 and 21 cM, respectively.

Ancestry does NOT show shared matches below 20 cM, so it’s unknown how many additional shared matches KO and I actually have if shared matches less than 20 cM were displayed.

Perspective is Critical

Whether you see a shared match or not is sometimes a matter of perspective, meaning which of two people you request shared matches with.

In this case, I requested shared matches with KO. I only share 8 cM of DNA with KO, but that doesn’t matter. The amount of DNA you share with the person you’re requesting shared matches with is irrelevant.

Ancestry’s Shared Matches with KO include Ker

I will see shared matches with KO to anyone we mutually share as matches above 20 cM, including Ker.

If I request shared matches with Ker, with whom I share 39 cM of DNA, I will see all of our mutual matches at 20 cM (or greater) of DNA. However, that does NOT include KO because I only share 8 cM of DNA with KO.

This restriction applies regardless of how much DNA KO and Ker share, which is an unknown to me of course.

Ancestry’s Shared Matches with Ker does NOT include KO

Nothing has changed between these matches, yet KO does not appear on my shared matches list with Ker when I request shared matches with Ker.

I still share 8 cM with KO and 39 cM with Ker. KO and Ker still both match each other. The only difference is that Ker shows up on my shared match list with KO because I share more than 20 cM with Ker. However, when I request a match list with Ker, KO does NOT appear because I only share 8 cM with KO.

This is the source of the confusion and often, why people disagree about shared matches. It’s kind of a “now you see it, now you don’t” situation.

If a person shows as a shared match depends on:

  1. Whether the third person actually does share DNA with the tester and the person they’ve asked for shared matches with
  2. Whether the third person shares 20 cM DNA or more with the tester, the person requesting the shared match list with one of their matches

Whether someone appears on a shared match list can literally be a matter of perspective unless the match and the shared matches all match the tester at 20 cM or larger.

Another Example

Let’s look at a larger match to a descendant of the same ancestor.

I share exactly 20 cM with Joyce, my 5C1R.

Viewing my shared matches with Joyce, I match 50 other people that she matches as well.

I only share 25 cM of DNA with the smallest match with Joyce. Apparently, there are no matches with Joyce with whom I share between 20 and 25 cM of DNA.

Bottom Line

Here’s the bottom line.

Ancestry NEVER shows any shared matches below 20 cM from the perspective of the tester, meaning people who match you and someone else, both.

If you recall our earlier math, that means that approximately 95.74% of my shared matches aren’t shown.

This puts shared matches in a different perspective because now I realize just how many matches I’m not seeing.

Why is This Confusing?

If you aren’t aware of this shared match limitation, and that a majority of your shared matches are actually below 20 cM, you may interpret shared match results to mean you actually DON’T share specific matches with that other person. That isn’t necessarily true, as we saw above with KO and Ker.

Furthermore, let’s say you manage your DNA kit plus 3 more, A, B and C. Because you manage all 4 kits, that means you can see the results for all 4 people.

  • A – 10 cM
  • B – 20 cM
  • C – 40 cM

From the perspective of YOUR kit, you will see some shared matches FOR all of those matches.

What you won’t see is shared matches if you don’t match the shared match (third person) at 20 cM or greater.

Always remember, shared match information at Ancestry is ALWAYS from the perspective of your DNA kit combined with the person with whom you request the match.

I’ve put this information in a grid because that’s how I make sense of things like this.

Here are your matches. When you click on shared matches with person A who you match at 10 cM, you’ll see both person B and person C as shared matches since you match both of those people at 20 cM or larger. You WILL see 20 cM shared matches, but you will not see 19 cM shared matches.

When you request shared matches for A, you will see both B and C.

When you request shared matches with kits B and C, you will not see A because you only match them at 10 cM.

However, from the perspective of DNA kits A, B and C, shared matches look different.

Let’s look at shared matches from the perspective of Kits A, B and C.

Kit A matches you, Kit B and C, but can only see Kit B as a shared match because matches with you and Kit C are under 20 cM.

Kit B doesn’t match C at all, so they clearly won’t have shared matches. However, they do match you and Kit A, both at 20 cM and over, so Kit B will see you as a shared match with Kit A, and Kit A as a shared match with you.

Kit C doesn’t match Kit B, so no shared matches with that person at all. Kit C does match you and Kit A. However, when Kit C clicks on shared matches for you, Kit A doesn’t show up because they only match Kit A on 9 cM. When Kit C clicks on Kit A for shared matches, you ARE listed as a shared match because you share 40 cM of DNA with Kit C.

There’s no way to discern whether two of your matches match each other unless they show as a match in the shared match tool. You can’t tell if their absence on the shared match list means they actually don’t match, or their shared match absence is because they match you at less than 20 cM.

Whew, that was a mouthful.

You may need to refer back to this from time to time if you’re confused by your shared matches at Ancestry.

If you need to remember rules, remember this.

  1. You can obtain shared matches with yourself plus any match, regardless of how much or how little DNA you share with that one match. Prove this to yourself by finding a match under 20 cM, like my 8 cM match, and viewing your shared matches.
  2. No one will show on a shared match list with another person unless they match you at 20 cM or greater. Prove this to yourself by viewing the smallest shared match with anyone.

Strategy

The takeaway of this is if you have a larger (20 cM or over) and smaller match (under 20 cM), always request shared matches from the perspective of the smaller match because the smaller match won’t show up as a shared match on any shared match list.

The only way you can see shared matches that includes people under 20 cM is to request to view shared matches with individual people who match you below 20 cM. 

In my case, I will never see KO on any shared match list because I only match KO at 8 cM. However, I can request my shared matches with KO in which case I’ll see all 20 cM or greater shared matches with KO.

Alternatives

Every vendor provides a shared match feature, and each functions differently.

In the chart below, I’ve provided basic shared match information for each vendor.

If you’re interested in uploading your DNA file from Ancestry or another vendor, I’ve provided upload/download step-by-step instructions for each vendor, here.

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You’re always welcome to forward articles or links to friends and share on social media.

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You Can Help Keep This Blog Free

I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase the price you pay but helps me to keep the lights on and this informational blog free for everyone. Please click on the links in the articles or to the vendors below if you are purchasing products or DNA testing.

Thank you so much.

DNA Purchases and Free Uploads

Genealogy Products and Services

My Book

Genealogy Books

Genealogy Research