Concepts – Why Genetic Genealogy and Triangulation?

One of the questions often asked is why triangulation in genetic genealogy is so important.

Before I answer that, let’s take a look at why genealogists use autosomal DNA for genetic genealogy in the first place.

Why Genetic Genealogy?

Aside from ethnicity testing, genetic genealogists utilize autosomal DNA testing to further their genealogical research or confirm the research they have already performed. Genetic genealogy cannot stand alone on DNA evidence, but must include traditional genealogical research. DNA is simply another tool in the genealogist’s tool box – albeit a critical one.

There are three established primary vendors in this field, Family Tree DNA, Ancestry and 23andMe, plus a few newcomers. All three vendors offer autosomal DNA tests utilized by genetic genealogists in various ways. If you want to learn more about the differences between these vendors’ offerings, please read the article, “Which DNA Test is Best?”

In order to achieve genealogical goals, there are four criteria that need to be met. All are required to achieve triangulation which is the only way to confirm a genealogical ancestral match to a specific ancestor.

  • DNA Matching – The tester’s DNA matches that of other testers at the company where they tested, or at GedMatch. All three vendors provide matching information, along with GedMatch, a third-party tool utilized by genetic genealogists.

Family Tree DNA assigns matches to either maternal, paternal or both sides of the tester’s tree based on connecting the DNA of relatives, up through third cousins, who have tested to their appropriate location in the tester’s tree.

In the example above, you can see the individuals linked to my tree include my mother with her Family Finder test, plus her two first cousins, Donald and Cheryl Ferverda who have also tested.

  • Ancestor Matching – The testers identify a common ancestor or ancestral line based on their previous work, aka, genealogy and family trees.  In the example above, the common ancestors are the parents of the brothers, John and Roscoe Ferverda.  Identifying a common ancestor is an easy task with known close relatives, but becomes more challenging the more distant the common ancestor.

Of the vendors, 23andMe does not have a Gedcom upload or ability for testers to display trees and for the vendor to utilize to match surnames, although they can link to external trees. Ancestry provides “tree matching,” shown above, and Ancestry and Family Tree DNA, shown below, both provide surname matching.

  • Segment Matching – Utilizing chromosome browsers or downloaded match lists including segment information to identify actual DNA segments that match other testers.

Family Tree DNA’s chromosome browser is shown above.

Each individual tester will have two groups of matches on the same segment, one group from their mother’s side of the tree and one from their father’s side of the tree. Each tester carries DNA inherited from both parents on two different “sides” of each chromosome. You can read more about that in the article, One Chromosome, Two Sides, No Zipper – ICW and the Matrix.

Of the three vendors, Ancestry does not provide segment matching, a chromosome browser, nor any segment information, so testers cannot perform this step at Ancestry.

23andMe does provide this information, but each tester must individually “opt in” to data sharing, and many do not. If testers do not globally “opt in” they must authorize sharing individually for every match, so testers will not be able to see the chromosome segment information for many 23andMe matches. In my case, only about 60% are sharing.

Family Tree DNA provides a chromosome browser, the file download capability with segment information, and everyone authorizes sharing of information when they initially test – so there is no opt-in confusion.

Ancestry and 23andMe raw DNA data files can be transferred to both Family Tree DNA and GedMatch where chromosome browsers and other tools are available. For more information about transferring files, please read Autosomal DNA Transfers – Which Companies Accept Which Tests?

Triangulation – The process used to combine all three of the above steps in order to assign specific segments of the tester’s DNA to specific ancestors, by virtue of:

  • The tester’s DNA matching the DNA of other testers on a specific segment.
  • Identifying that the individuals who match the tester on that segment also match each other. This is part of the methodology employed to group the testers matches into two groups, the maternal and paternal groupings.
  • Identifying which ancestor contributed that segment to all of the people who match the tester and each other on that same segment.

In order for a group of matches to triangulate, they must match each other on the same segment of DNA and they must all share a common ancestor.

Triangulation is part DNA, meaning the inheritance, part technology, meaning the ability to show that all testers in a match group all match each other and on the same segment, and part genealogy, meaning the ability to identify the common ancestor of the group of individuals.

The following chart shows a portion of my match download file on chromosome 5 from Family Tree DNA.

As you can see, these matches all cover significant portions of the same segment on chromosome 5.

Without further investigation, we know that I match all of these people, but we don’t know what that information is telling us about my genealogy. We don’t know who matches each other, and we can’t tell which people are from my mother’s and father’s sides. We also don’t know who the common ancestor is or common ancestors are.

However, looking at the trees of the individuals involved, or contacting them for further information, and/or recognizing known cousins from a specific line all combine to contribute to the identification of our common ancestors.

Below is the same spreadsheet, now greatly enriched after my genealogy work is applied to the DNA matches in two additional columns.

I’ve colored my triangulated groups pink for my mother’s side and blue for my father’s side.

In this case, I also have access to my cousins’ DNA match results, so I can view their matches as well, looking for common matches on my match list.

One of the reasons genealogists always suggest testing older family members and as many cousins as possible is because triangulation becomes much easier with known cousins from particular lines to point the way to the common ancestor. In this case, one cousin, Joe, is from my mother’s side and one, Lou, is from my father’s side.

By looking at my matches’ genealogy, I’ve now been able to assign this particular segment on chromosome 5, on my mother’s side to ancestors Johann Michael Miller and his wife Susanna Berchtol. The same segment, on my father’s side is inherited from Charles Dodson and his wife, Ann, last name unknown.

In order to achieve triangulation, the common ancestor must be determined for the match group. Once triangulation is achieved, descent from the common ancestor is confirmed.

Unless you are dealing with very close known relatives, like the Ferverda first cousins, there is no other way to prove a genetic connection to a specific ancestor.

At Family Tree DNA, I can utilize the chromosome browser and the ICW and matrix tools to determine which of this group matches each other. At 23andMe, I can utilize their shared DNA matching tool. This information can then be recorded in my DNA spreadsheet, as illustrated above.

Triangulation cannot be achieved at Ancestry or utilizing their tools. Ancestry’s DNA Circles provide extended match groups, indicating who matches whom for a particular ancestor shown in a tester’s tree, but do not indicate that the matches are on the same segment. Circles do not guarantee that Circle members are matching on DNA from that ancestor, only that they do match and show a common ancestor in their tree.  The third triangulation step of segment matching is missing.  Ancestry does not provide segment information in any format, so Ancestry customers who want to triangulate can either retest elsewhere or download their data files to either Family Tree DNA or GedMatch for free.

Summary

Before the advent of genetic genealogy, genealogists had to take it on faith that the paper trail was accurate, and that there was no misattributed parentage – either through formal or informal adoption or hanky-panky.  That’s not the case anymore.

Today, DNA through triangulation can prove ancestry for groups of people to a common ancestor by identifying segments that have descended from that ancestor and are found in multiple descendants today.

Of course, the next step is to break down those remaining brick walls. For example, what is the birth name of Ann, wife of Charles Dodson, whose surname is unknown? Logically, the DNA descended from a couple, meaning Charles and Ann, contains DNA from both individuals. We don’t know if that segment on chromosome 5 is from Ann, Charles, or parts from both, BUT, if we begin to see a further breakdown to another, unknown family line among the Charles and Ann segments, that might be a clue.

One day, in the future, we’ll be able to identify our unknown family lines through DNA matches and other people’s triangulation. That indeed, is the Holy Grail.

Additional Resources

If you’d like to read more specific information about autosomal DNA matching and triangulation, be sure to read the links in the article, above. The following articles may be of interest as well:

DeMystifying Autosomal DNA Matching

Autosomal DNA Testing 101 – What Now?

Autosomal DNA Matching Confidence Spectrum

Concepts – Segment Size, Legitimate and False Matches

How Your Autosomal DNA Identifies Your Ancestors

Concepts – Identical by Descent, State, Population and Chance

Nine Autosomal Tools at Family Tree DNA

If you think you might come up short, because you have only one known cousin who has tested, well, think again.

Just One Cousin

Here’s wishing you lots of triangulated matches!!!

Concepts – The Faces of Endogamy

Recently, while checking Facebook, I saw this posting from my friend who researches in the same Native admixed group of families in North Carolina and Virginia that I do. Researchers have been trying for years to sort through these interrelated families. As I read Justin’s post, I realized, this is a great example of endogamy and often how it presents itself to genealogists.

I match a lot of people from the Indian Woods [Bertie County, NC] area via DNA, with names like Bunch, Butler, Mitchell, Bazemore, Castellow, and, of course, Collins. While it’s hard to narrow in on which family these matching segments come from, I can find ‘neighborhoods’ that fit the bill genetically. This [census entry] is from near Quitsna in 1860. You see Bunch, Collins, Castellow, Carter, and Mitchell in neighboring households.

Which begs the question, what is endogamy, do you have it and how can you tell?

Definition

Endogamy is the practice or custom or marrying within a specific group, population, geography or tribe.

Examples that come to mind are Ashkenazi Jews, Native Americans (before European and African admixture), Amish, Acadians and Mennonite communities.

Some groups marry within their own ranks due to religious practices. Jewish, Amish and Mennonite would fall under this umbrella. Some intermarry due to cultural practices, such as Acadians, although their endogamy could also partly be attributed to their staunch Catholic beliefs in a primarily non-Catholic region. Some people practice endogamy due to lack of other eligible partners such as Native Americans before contact with Europeans and Africans.  People who live on  islands or in villages whose populations were restricted geographically are prime candidates for endogamy.

In the case of Justin’s group of families who were probably admixed with Native, European and African ancestors, they intermarried because there were socially no other reasonable local options. In Virginia during that timeframe, mixed race marriages were illegal. Not only that, but you married who lived close by and who you knew – in essence the neighbors who were also your relatives.

Endogamy and Genetic Genealogy

In some cases, endogamy is good news for the genealogist. For example, if you’re working with Acadian records and know which Catholic church your ancestors attended. Assuming those church records still exist, you’re practically guaranteed that you’ll find the entire family because Acadians nearly always married within the Acadian community, and the entire Acadian community was Catholic. Catholics kept wonderful records. Even when the Acadians married a Native person, the Native spouse is almost always baptized and recorded with a non-Native name in the Catholic church records, which paved the way for a Catholic marriage.

In other cases, such as Justin’s admixed group, the Brethren who notoriously kept no church records or the Jewish people whose records were largely destroyed during the Holocaust, endogamy has the opposite effect – meaning that actual records are often beyond the reach of genealogists – but the DNA is not.

It’s in cases like this that people reach for DNA to help them find their families and connections.

What Does Endogamy Look Like?

If you know nothing about your heritage, how would you know whether you are endogamous or not? What does it look like? How do you recognize it?

The answer is…it depends. Unfortunately, there’s no endogamy button that lights up on your DNA results, but there are a range of substantial clues.  Let’s divide up the question into pieces that make sense and look at a variety of useful tools.

Full or Part?

First of all, fully and partly endogamous ancestry, and endogamy from different sources, has different signs and symptoms, so to speak.

A fully endogamous person, depending on their endogamy group, may have either strikingly more than average autosomal DNA matches, or very few.

Another factor will be geography, where you live, which serves to rule out some groups entirely. If you live in Australia, your ancestors may be European but they aren’t going to be Native American.

How many people in your endogamous group that have DNA tested is another factor that weighs very heavily in terms of what endogamy looks like, as is the age of the group. The older the group, generally the more descendants available to test although that’s not always the case. For example warfare, cultural genocide and disease wiped out many or most of the Native population in the United States, especially east of the Mississippi and particularly in the easternmost seaboard regions.

Because of the genocide perpetrated upon the Jewish people, followed by the scattering of survivors, Jewish descendants are inclined to test to find family connections. Jewish surnames may have been changed or not adopted in some cases until late, in the 1800s, and finding family after displacement was impossible in the 1940s for those who survived.

Let’s look at autosomal DNA matches for fully and partly endogamous individuals.

Jewish people, in particular Ashkenazi, generally have roughly three times as many matches as non-endogamous individuals.

Conversely, because very few Native people have tested, Native testers, especially non-admixed Native individuals, may have very few matches.

It’s ironic that my mother, the last person listed, with two endogamous lines, still has fewer matches than I do, the first person listed.  This is because my father has deep colonial roots with lots of descendants to test, and my mother has recent immigration in her family line – even though a quarter of her ancestry is endogamous.

To determine whether we are looking at endogamy, sometimes we need to look for other clues.

There are lots of ways to discover additional clues.

Surnames

Is there a trend among the surnames of your matches?

At the top of your Family Finder match page your three most common surnames are displayed.

A fully endogamous Jewish individual’s most common surnames are shown above. If you see Cohen among your most common surnames, you are probably Jewish, given that the Kohanim have special religious responsibilities within the Jewish faith.

Of course, especially with autosomal DNA, the person’s current surname may not be indicative, but there tends to be a discernable pattern with someone who is highly endogamous. When someone who is fully endogamous, such as the Jewish population, intermarries with other Jewish people, the surnames will likely still be recognizably Jewish.

Our Jewish individual’s first matching page, meaning his closest matches, includes the following surnames:

  • Cohen
  • Levi
  • Bernstein
  • Kohn
  • Goldstein

The Sioux individual only has 137 matches, but his first page of matches includes the following surnames:

  • Sunbear
  • Deer With Horns
  • Eagleman
  • Yelloweyes
  • Long Turkey
  • Fire
  • Bad Wound
  • Growing Thunder

These surnames are very suggestive of Native American ancestry in a tribe that did not adopt European surnames early in their history. In other words, not east of the Mississippi.

At Family Tree DNA, every person has the opportunity to list their family surnames and locations, so don’t just look at the tester’s surname, but at their family surnames and locations too. The Ancestral Surname column is located to the far right on the Family Finder matches page. If you can’t see all of the surnames, click on the person’s profile picture to see their entire profile and all of the surnames they have listed.

Please note that you can click to enlarge all graphics.

If you haven’t listed your family surnames, now would be a good time. You can do this by clicking on the orange “Manage Personal Information” link near your profile picture on the left of your personal page.

The orange link takes you to the account settings page. Click on the Genealogy tab, then on surnames. Be sure to click the orange “save” when you are finished.

Partial Endogamy

Let’s take a look at a case study of someone who is partially endogamous, meaning that they have endogamous lines, but aren’t fully endogamous. My mother, who is the partially endogamous individual with 1231 matches is a good example.

Mother is a conglomeration of immigrants. Her 8 great-grandparents break down as follows:

In mother’s case, a few different forces are working against each other. Let’s take a look.

The case of recent immigration from the Netherlands, in the 1850s, would serve to reduce mother’s matches because there has been little time in the US for descendants to accrue and test. Because people in the Netherlands tend to be very reluctant about DNA testing, very few have tested, also having the effect of reducing her number of matches.

Mother’s Dutch ancestors were Mennonites, an endogamous group within the Netherlands, which would further reduce her possibilities of having matches on these lines since she would be less likely to match the general population and more likely to match individuals within the endogamous group. If people from the Mennonite group tested, she would likely match many within that group. In other words, for her to find Dutch matches, people descended from the endogamous Dutch Mennonite population would need to test. At Family Tree DNA, there is a Low Mennonite Y DNA and Anabaptist autosomal DNA project both, but these groups tend to attract the Mennonites that migrated to Russia and Poland, not the group that stayed in the Netherlands. Another issue, at least in mother’s case, is that her Mennonite relatives “seem” to have been later converts, not part of the original Mennonite group – although it’s difficult to tell for sure in the records that exist.

Mother’s Kirsch and Drechsel ancestors were also recent immigrants in the 1850s, from Germany, with very few descendants in the US today. The villages from where her Kirsch ancestors immigrated, based on the church records, did tend to be rather endogamous.  However, that endogamy would only have reached back about 200 years, as far as the 30 Years’ War when that region was almost entirely, if not entirely, depopulated. So while there was recent endogamy, there (probably) wasn’t deep endogamy. Of course, it would require someone from those villages to test so mother could have matches before endogamy can relevant. DNA testing is not popular in Germany either.

Because of recent immigration, altogether one half of mother’s heritage would reduce her number of matches significantly. Recent immigrants simply have fewer descendants to test.

On the other hand, mother’s English line has been in the US for a long time, some since the Mayflower, so she could expect many matches from that line, although they are not endogamous. If you’re thinking to yourself that deep colonial ancestry can sometime mimic endogamy in terms of lots of matches, you’re right – but still not nearly to the level of a fully endogamous Jewish person.

Mother’s Acadian line has been settled in North America in Nova Scotia since the early 1600s, marrying within their own community, mixing with the Native people and then scattering in different directions after 1755 when they were forcibly removed. Acadians, however, tended to remain in their cultural groups, even after relocation. Many Acadian descendants DNA test and all Acadians descend from a limited and relatively well documented original population. That level of documentation is very unusual for endogamous groups. Acadian surnames are well known and are French. The best Acadian genealogical resource in is Karen Theriot’s comprehensive tree on Rootsweb in combination with the Mothers of Acadia DNA project at Family Tree DNA. I wish there was a similar Fathers of Acadia project.

Mother’s Brethren line is much less well documented due to a lack of church records. The Brethren community immigrated in the early 1700s from primarily Switzerland and Germany, was initially relatively small, lived in clusters in specific areas, traveled together and did not marry outside the Brethren faith. Therefore, Brethren heritage and names also tend to be rather specific, but not as recognizable as Acadian names. After all, the Brethren were German/Swiss and in mother’s case, she also has another 1/4th of her heritage that are recently immigrated Germans – so differentiating one German group from the other can be tricky. The only way to tell Brethren matches from other German matches is that the Brethren also tend to match each other.

In Common With

If you notice a group of similar appearing surnames, use the ICW (in common with) tool at Family Tree DNA to see who you match in common with those individuals. If you find that you match a whole group of people with similar surnames or geography, contact your matches and ask if they know any of the other matches and how they might be related. I always recommend beginning with your closest matches because your common ancestor is likely to be closer in time than people who match you more distantly.

In the ICW match example below, all of the matches who do show ancestral surnames include Acadian surnames and/or locations.

Acadians, of course, became Cajuns in Louisiana where one group settled after their displacement in Nova Scotia. The bolded surnames match surnames on the tester’s surname list.

The ICW tools work particular well if you know of or can identify one person who matches you within a group, or simply on one side of your family.

Don Worth’s Autosomal DNA Segment Analyzer is an excellent tool to genetically group your matches by chromosome. It’s then easy to use the chromosome browser at Family Tree DNA to see which of these people match you on the same segments. These tools work wonderfully together.

The group above is an Acadian match group. By hovering over the match names, you can see their ancestral surnames which make the Acadian connection immediately evident.

The Matrix

In addition to seeing the people you match in common with your matches by utilizing the ICW tool at Family Tree DNA, you can also utilize the Matrix tool to see if your matches also match each other. While this isn’t the same as triangulation, because it doesn’t tell you if they match each other on the same exact segment, it’s a wonderful tool, because in the absence of cooperation or communication from your matches to determine triangulation between multiple people, the Matrix is a very good secondary approach and often predicts triangulation accurately.

In the Matrix, above, the blue boxes indicates that these individuals (from your match list) also match each other.

For additional information on various autosomal tools available for your use, click here to read the article, Nine Autosomal Tools at Family Tree DNA.

MyOrigins

Everyone who takes the Family Finder test also receives their ethnicity estimates on the MyOrigins tab.

In the case of our Jewish friend, above, his MyOrigins map clearly shows his endogamous heritage. He does have some Middle Eastern region admixture, but I’ve seen Ashkenazi Jewish results that are 100% Ashkenazi Jewish.

The same situation exists with our Sioux individual, above. Heavily Native, removing any doubt about his ancestry.

However, mother’s European admixture blends her MyOrigins results into a colorful but unhelpful European map, at least in terms of determining whether she is endogamous or has endogamous lines.

European endogamous admixture, except for Jewish heritage, tends to not be remarkable enough to stand out as anything except European heritage utilizing ethnicity tools. In addition, keep in mind that DNA testing in France for genealogy is illegal, so often there is a distinct absence in that region that is a function of the lack of testing candidates. Acadians may not show up as French.

Ethnicity testing tends to be excellent at determining majority ethnicity, and determining differences between continental level ethnicity, but less helpful otherwise. In terms of endogamy, Jewish and Native American tend to be the two largest endogamous groups that are revealed by ethnicity testing – and for that purpose, ethnicity testing is wonderful.

Y and Mitochondrial DNA and Endogamy

Autosomal tools aren’t the only tools available to the genetic genealogist. In fact, if someone is 100% endogamous, or even half endogamous, chances are very good that either the Y DNA for males on the direct paternal line, or the mitochondrial DNA for males and females on the direct matrilineal line will be very informative.

On the pedigree chart above, the blue squares represent the Y DNA that the father contributes to only his sons and the red circles represent the mitochondrial DNA (mtDNA) that mothers contribute to both genders of their children, but is only passed on by the females.

By utilizing Y and mtDNA testing, you can obtain a direct periscope view back in time many generations, because the Y and mitochondrial DNA is preserved intact, except for an occasional mutation. Unlike autosomal DNA, the DNA of the other parent is not admixed with the Y or mitochondrial DNA. Therefore, the DNA that you’re looking at is the DNA of your ancestors, generations back in time, as opposed to autosomal DNA which can only reliably reach back 5 or 6 generations in terms of ethnicity because it gets halved in every generation and mixed with the DNA of the other parent.

With autosomal DNA, we can see THAT it exists, but not who it came from.  With Y and mtDNA DNA, we know exactly who in your tree that specific DNA came from

We do depend on occasional Y and mtDNA mutations to allow our lines to accrue enough mutations to differentiate us from others who aren’t related, but those mutations accrue very slowly over hundreds to thousands of years.

Our “clans,” over time, are defined by haplogroups and both our individual matches and our haplogroup or clan designation can be very useful. Your haplogroup will indicate whether you are European, Jewish, Asian, Native American or African on the Y and/or mtDNA line.

In cases of endogamous groups where the members are known to marry only within the group, Y and mtDNA can be especially helpful in identifying potential families of origin.  This is evident in the Mothers of Acadia DNA project as well a particular brick wall I’m working on in mother’s Brethren line. Success, of course, hinges on members of that population testing their Y or mtDNA and being available for comparison.

Always test your Y (males only) and mitochondrial DNA (males and females.) You don’t know what you don’t know, and sometimes those lines may just hold the key you’re looking for. It would be a shame to neglect the test with the answer, or at least a reasonably good hint! Stories of people discovering their ethnic heritage, at least for that line, by taking a Y or mtDNA test are legendary.

Jewish Y and Mitochondrial DNA

Fortunately, for genetic genealogists, Jewish people carry specific sub-haplogroups that are readily identified as Jewish, although carrying these subgroups don’t always mean you’re Jewish. “Jewish” is a religion as well as a culture that has been in existence as an endogamous group long enough in isolation in the diaspora areas to develop specific mutations that identify group members. Furthermore, the Jewish people originated in the Near East and are therefore relatively easy, relative to Y and mtDNA, to differentiate from the people native to the regions outside of the Near East where groups of Jewish people settled.

The first place to look for hints of your heritage is your main page at Family Tree DNA. First, note your haplogroups and any badges you may have in the upper right hand corner of your results page.

In this man’s case, the Cohen badge is this man’s first clue that he matches or closely matches the known DNA signature for Jewish Cohen men.

Both Y DNA and mitochondrial DNA results have multiple tabs that hold important information.

Two tabs, Haplogroup Origins and Ancestral Origins are especially important for participants to review.

The Haplogroup Origins tab shows a combination of academic research results identifying your haplogroup with locations, as well as some Ancestral Origins mixed in.

A Jewish Y DNA Haplogroup Origins page is shown above.

The Ancestral Origins page, below, reflects the location where your matches SAY their most distant direct matrilineal (for mtDNA) or patrilineal (for Y DNA) ancestors were found. Clearly, this information can be open to incorrect interpretation, and sometimes is. For example, people often don’t understand that “most distant maternal ancestor” means the direct line female on your mother’s mother’s mother’s side.  However, you’re not looking at any one entry. You are looking instead for trends.

The Ancestral Origins page for a Jewish man’s Y DNA is shown above.

The Haplogroup Origins page for Jewish mitochondrial DNA, below, looks much the same, with lots of Ashkenazi entries.

The mitochindrial Ancestral Origins results, below, generally become more granular and specific with the higher test levels. That’s because the more general results get weeded out a higher levels. Your closest matches at the highest level of testing are the most relevant to you, although sometimes people who tested at lower levels would be relevant, if they upgraded their tests.

Native American Y and Mitochondrial DNA

Native Americans, like Jewish people, are very fortunate in that they carry very specific sub-haplogroups for Y and mitochondrial DNA. The Native people had a very limited number of founders in the Americas when they originally arrived, between roughly 10,000 and 25,000 years ago, depending on which model you prefer to use. Descendants had no choice but to intermarry with each other for thousands of years before European and African contact brought new genes to the Native people.

Fortunately, because Y and mtDNA don’t mix with the other parents’ DNA, no matter how admixed the individual today, testers’ Y and mtDNA still shows exactly the origins of that lineage.

Native American Y DNA shows up as such on the Haplogroup Origins and Ancestral Origins tabs, as illustrated below.

The haplogroup assigned is shown along with a designation as Native on the Haplogroup Origins and Ancestral Origins pages. The haplogroup is assigned through DNA testing, but the Native designation and location is entered by the tester. Do be aware that some people record the fact that their “mother’s side” or “father’s side” is reported to have a Native ancestor, which is not (necessarily) the same as the matrilineal or patrilineal line. Their “mother’s side” and “father’s side” can have any number of both male and female ancestors.

If the tester’s haplogroup comes back as non-Native, the erroneous Native designation shows up in their matches Ancestral Origins page as “Native,” because that is what the tester initially entered.  I wrote about this situation here, but there isn’t much that can be done about this unless the tester either realizes their error or thinks to go back and change their designation from Native American when they realize the DNA does not support the family story, at least not on this particular line line. Erroneous labeling applies to both Y and mtDNA.

Native Y DNA falls within a subset of haplogroups C and Q. However, most subgroups of C and Q are NOT Native, but are European or Asian or in one case, a subgroup of haplogroup Q is Jewish. This does NOT means that the Jewish people and the Native people are related within many thousands of years. It means they had a common ancestor in Asia thousands of years ago that gave birth to both groups. In essence, one group of the original Q moved east and eventually into the Americas, and one moved west, winding up in Europe. Today, mutations (SNPs) have accrued to each group that very successfully differentiate them from one another. In order to determine whether your branch of C or Q is Native, you must take additional SNP tests which further identify your haplogroup – meaning which branch of haplogroup C or Q that you belong to.

Native Americans Y-DNA, to date, must fall into a subset of haplogroup C-P39, a subgroup of C-M217 or Q-M3, Q-M971/Z780 or possibly Q-B143 (ancient Saqquq in Greenland), according to The study of human Y chromosome variation through ancient DNA. Each of these branches also has sub-branches except for Q-B143 which may be extinct. This isn’t to say additional haplogroups or sub-haplogroups won’t be discovered in the future. In fact, haplogroup O is a very good candidate, but enough evidence doesn’t yet exist today to definitively state that haplogroup O is also Native.

STR marker testing, meaning panels of markers from 12-111, provides all participants with a major haplogroup estimate, such as C or Q. However, to confirm the Y DNA haplogroup subgroup further down the tree, one must take additional SNP testing. I wrote an article about the differences between STR markers and SNPs, if you’d like to read it, here and why you might want to SNP test, here.

Testers can purchase individual SNPs, such as the proven Native SNPs, which will prove or disprove Native ancestry, a panel of SNPs which have been combined to be cost efficient (for most haplogroups), or the Big Y test which scans the entire Y chromosome and provides additional matching.

When financially possible, the Big Y is always recommended. The Big Y results for the Sioux man showed 61 previously unknown SNPs. The Big Y test is a test of discovery, and is how we learn about new branches of the Y haplotree. You can see the most current version of the haplogroup C and Q trees on your Family Tree DNA results page or on the ISOGG tree.

Native mitochondrial DNA can be determined by full sequence testing the mitochondrial DNA. The mtPlus test only tests a smaller subset of the mtDNA and assigns a base haplogroup such as A. To confirm Native ancestry, one needs to take the full sequence mitochondrial test to obtain their full haplogroup designation which can only be determined by testing the full mitochondrial sequence.

Native mitochondrial haplogroups fall into base haplogroups A, B, C, D, X and M, with F as a possibility. The most recent paper on Native Mitochondrial DNA Discoveries can be found here and a site containing all known Native American mitochondrial DNA haplogroups is here.

Not Native or Jewish

Unfortunately, other endogamous groups aren’t as fortunate as Jewish and Native people, because they don’t have haplogroups or subgroups associated with their endogamy group. However, that doesn’t mean there aren’t a few other tools that can be useful.

Don’t forget about your Matches Maps. While your haplogroup may not be specific enough to identify your heritage, your matches may hold clues. Each individual tester is encouraged to enter the identity of their most distant ancestor in both their Y (if male) and mtDNA lines. Additionally, on the bottom of the Matches Map, testers can enter the location where that most distant ancestor is found. If you haven’t done that yet, this is a good time to do that too!

When looking at your Matches Map, clusters and distribution of your matches most distant ancestor locations are important.

This person’s matches, above, suggest that they might look at the history of Nova Scotia and French immigrants – and the history of Nova Scotia is synonymous with the Acadians but the waterway distribution can also signal French, but not Acadian. Native people are also associated with Nova Scotia and river travel. The person’s haplogroup would add to this story and focus on or eliminate some options.

This second example above, suggests the person look to the history of Norway and Sweden, although their ancestor, indicated by the white balloon, is from Germany. If the tester’s genealogy is stuck in the US, this grouping could be a significant clue relative to either recent or deeper history. Do they live in a region where Scandinavian people settled? What history connects the region where the ancestor is found with Scandinavia?

This third example, above, strongly suggests Acadian, given the matches restricted to Nova Scotia, and, as it turns out, this individual does have strong Acadian heritage. Again, their haplogroup is additionally informative and points directly to the European or Native side of the Acadian heritage for this particular line.

In Summary

Sometimes endogamy is up front and in your face, evident from the minute your DNA results are returned. Other times, endogamous lines in ethnically mixed individuals reveal themselves more subtly, like with my friend Justin. Fortunately, the different types of DNA tests and the different tools at our disposal each contain the potential for a different puzzle piece to be revealed. Many times, our DNA results need to be interpreted with some amount of historical context to reveal the story of our ancestors.

When I first discovered that my mother’s line was Acadian, my newly found cousin said to me, “If you’re related to one Acadian, you’re related to all Acadians.” He wasn’t kidding. For that very reason, endogamous genetic genealogy is tricky at best and frustrating at worst.

When possible, Y and mtDNA is the most definitive answer, because the centuries or millennia or intermarriage don’t affect Y and mtDNA. If you are Jewish or Native on the appropriate lines for testing, Y and mtDNA is very definitive. If you’re not Jewish or Native on your Y or mtDNA lines, check your matches for clues, including surnames, Haplogroup and Ancestral Origins, and your Matches Map.

Consider building a DNA pedigree chart that documents each of your ancestors’ Y and mtDNA for lines that aren’t revealed in your own test. The story of Y and mtDNA is not confused or watered down by admixture and is one of the most powerful, and overlooked, tools in the genealogist’s toolbox.

Autosomal DNA when dealing with endogamy can be quite challenging, even when working with well-documented Acadian genealogy – because you truly are related to everyone.  Trying to figure out which DNA segments go with, or descend from, which ancestors reaching back several generations is the ultimate jigsaw puzzle. Often, I work with a specific segment and see how far back I can track that segment in the ancestral line of me and my matches. On good days, we arrive at one common ancestor. On other days, we arrive at dead ends that are not a common ancestor – which means of course that we keep searching genealogically – or pick a different segment to work with.

When working with autosomal DNA of endogamous individuals (or endogamous lines of partially endogamous individuals,) I generally use a larger matching threshold than with non-endogamous, because we already know that these people will have segments that match because they descend from the same populations. In general, I ignore anything below 10cM and often below 15cM if I’m looking for a genealogical connection in the past few generations. If I’m simply mapping DNA to ancestors, then I use the smaller segments, down to either 7 or 5cM. If you want to read more about segments that are identical by chance (also known as false matches,) identical by population and identical by descent (genealogically relevant matches,) click here.

The good news about endogamy is that its evidence persists in the DNA of the population, literally almost forever, as long as that “population” exists in descendants – meaning you can find it!  In my case, my Acadian brick wall would have fallen much sooner had I know what endogamy looked like and what I was seeing actually meant.

A perfect example of persistent endogamy is that our Sioux male today, along with other nearly fully Native people, including people from South America, matches the ancient DNA of the Anzick child who died and was buried in Montana 12,500 years ago.

These people don’t just match on small segments, but at contemporary matching levels at Family Tree DNA and GedMatch, both.  One individual shows a match of 109 total cM and a single largest segment of DNA at 20.7 cM, a match that would indicate a contemporary relationship of between 3.5 and 4 generations distant – meaning 2nd to 3rd cousins. Clearly, that isn’t possible, but the DNA shared by Anzick Child and that individual today has been intact in the Native population for more than 12,500 years.

The DNA that Anzick Child carried is the same DNA that the Sioux people carry today – because there was no DNA from outside the founder population, no DNA to wash out the DNA carried by Anzick Child’s ancestors – the same exact ancestors of the Sioux and other Native or Native admixed people today.

While endogamy can sometimes be frustrating, the great news is that you will have found an entire population of relatives, a new “clan,” so to speak.  You’ll understand a lot more about your family history and you’ll have lots of new cousins!

Endogamy is both the blessing and the curse of genetic genealogy!

Increasing “In Common With” (ICW) Functionality at Family Tree DNA

You know how Murphy’s Law works, right?

Right after I wrote the article Nine Autosomal Tools at Family Tree DNA, as in minutes later (Ok, that’s probably an exaggeration), Family Tree DNA made a change and the ICW (in common with) tool functioned differently.  Murphy lives at my house, I swear!

I initially thought perhaps this was unintended, but it may well be a design change since additional functionality was provided and three months have elapsed.

So regardless of whether or not this change is permanent or will change minutes after I publish this article, I’m providing instructions on how this feature works NOW. If it changes or works differently in the future, I’ll let you know!

In all fairness, it’s the addition of the combination searches, I think, that has caused the confusion. Combo searches are great features and powerful, if you know how to use the functionality correctly for what you want to accomplish.

Let’s take a look at how to utilize the various kinds of searches, individually and in combination, step-by-step.

Example One – Regular “In Common With” Matches

The ICW feature shows you who your matches match in common with you. I’ve signed on as my mother for these examples to illustrate this feature since she is a generation more closely related to these folks than I am.

First, let’s do a normal “in common with” search between my mother and her cousin, Donald.  The results of this search will show us everyone that matches mother and Donald, both.

icw-donald-arrow

In this example, I’ve done the following:

  1. Selected Donald (who appears on mother’s match list, above) by clicking on the box to the left of his name, which you can see in the “Selected Matches” box at the bottom left indicating he has been selected.
  2. Click on the “in common with” function button above the list of names.

icw-donald-results-arrow

After clicking on the “in common with” button, what I see (above) are all 91 people that match mother in common with Donald, meaning that mother and Donald both match all 91 of these people. This does NOT mean mother and Donald both match them on the same segment(s), only that they do match on at least one segment over the matching threshold.

As you can see, Donald’s name appears now in the “In Common With” box at the top left, along with a total of 91 people who match Donald and my mother both.

To clear any search, meaning all options, at any time, just click on the “reset filter” blue button, located to the right of the “not in common with” function button.

There are multiple features that work together for “in common with” matching and surname searching. Let’s take a look.

Example Two – Surname Searches Plus ICW, Combined

Now, I’ll enter the name Miller in the search box at the upper right. This shows me everyone who has name of Miller, or Miller appearing in their ancestral surnames, who match my mother.

Next, I want to select someone from that Miller match list to see which other people on the Miller match list they match in common with mother. Hey, let’s pick Donald!!!

To utilize a surname search (Miller) and ICW (Donald) together, do the following:

  1. Enter the surname Miller in the search box on the upper right and click enter or the search (blue magnifying glass) icon. Donald appears on the Miller match list, as well as 90 other people.  This means that Donald has Miller appearing in his list of ancestral surnames, since his surname is not Miller.
  2. When the match results are returned, select Donald by clicking on the box to the left of his name.
  3. Then click on the “in common with” function box above the list of matches.

icw-work-arrows

I selected Donald, as you can see, by clicking the box beside his name, and his name now appears in the “Selected Matches” box in the lower left hand corner of the page, indicating that he has been selected. However, note that the name Miller still appears in the search box in the upper right hand corner.

Next, I click on the ICW function button, above the list of matches, and I see the following 22 matches that all share the Miller surname or Miller on their list of ancestral names AND match Donald and mother, both. I’m NOT seeing all of mother’s 91 Miller matches, but ONLY her Miller matches that are ALSO “in common with” Donald.  This immediately gives me a list of people that are very likely descended from this same ancestral Miller line, and some of them will likely triangulate by utilizing the chromosome browser and other tools described in the Nine Autosomal Tools article.

icw-combo-results-arrow

This combination search is a wonderful feature, but this isn’t always what people want to do. Sometimes you want to first see the Miller matches, then select someone from that match list to run the full ICW tool and see ALL of their matches, not just the ICW Miller matches. This is the functionality that works differently than previously, but it’s actually very easy to accomplish.

Surname Search, Then ICW to Person on Match List, but not Combined

Often, you’ll find someone in the ICW Miller match list, for example, and you then want to see ALL of the ICW matches to that person, NOT just the ICW matches with Miller. Said another way, you want to utilize the name of someone found in the Miller search, but not limit the ICW results to just the Miller surname.

In this case, simply follow these steps:

  1. Run the Miller search as in Example One.
  2. Select Donald from the results by clicking on the box beside his name – step #2 in Example Two.  Do NOT click on the ICW button, yet.
  3. REMOVE Miller from the search box at upper right. After removing Miller, you will see the full match list load again (replacing the Miller match list), but Donald remains selected in the “Selected Matches” box in the lower left corner.
  4. Click on the “in common with” function button to see the full ICW match list for the person selected.

Once again, you will see the full match list of 91 people between mother and Donald, as if Miller was never selected.

What Doesn’t Work

One function doesn’t work that worked previously, and that’s the ability to search for a location, meaning those locations in parenthesis in the ancestral surnames.  This type of search is particularly important to people with Scandinavian ancestors whose surnames are patronymic, meaning they derive from a father’s first name, such as Johnsson for John’s son.  These surnames changed generationally and locations are often more reliable in terms of genealogy searches.

This is probably a function of a feature that was being utilized by users in a way never imagined by the designers.  Regardless, a bug report or enhancement request, depending in your perspective, has been submitted, but there is no known work-around today.

Nine Autosomal Tools at Family Tree DNA

The introduction of the Phased Family Finder Matches has added a new way to view autosomal DNA results at Family Tree DNA and a powerful new tool to the genealogists toolbox.

The Phased Family Finder Matches are the 9th tool provided for autosomal test results by Family Tree DNA. Did you know where were 9?

Each of the different methodologies provides us with information in a unique way to assist in our relentless search for cousins, ancestors and our quests to break down brick walls.

That’s the good news.

The not-so-good news is that sometimes options are confusing, so I’d like to review each tool for viewing autosomal match information, including:

  • When to use each tool
  • How to use each tool
  • What the results mean to you
  • The unique benefits of each tool
  • The cautions and things you need to know about each tool including what they are not

The tools are:

  1. Regular Matching
  2. ICW (In Common With)
  3. Not ICW (Not In Common With)
  4. The Matrix
  5. Chromosome Browser
  6. Phased Family Matching
  7. Combined Advanced Matching
  8. MyOrigins Matching
  9. Spreadsheet Matching

You Have Options

Family Tree DNA provides their clients with options, for which I am eternally grateful. I don’t want any company deciding for me which matches are and are not important based on population phasing (as opposed to parental phasing), and then removing matches they feel are unimportant. For people who are not fully endogamous, but have endogamous lines, matches to those lines, which are valid matches, tend to get stripped away when a company employs population based phasing – and once those matches are gone, there is no recovery unless your match happens to transfer their results to either Family Tree DNA or GedMatch.

The great news is that the latest new option, Phased Family Matching, is focused on making easy visual comparisons of high quality parental matches which is especially useful for those who don’t want to dig deeply.

There are good options for everyone at all ranges of expertise, from beginners to those who like to work with spreadsheets and extract every teensy bit of information.

So let’s take a look at all of your matching options at Family Tree DNA. If you’re not taking advantage of all of them, you’re missing out. Each option is unique and offers something the other options don’t offer.

In case you’re curious, I’ll be bouncing back and forth between my kit, my mother’s kit and another family member’s kit because, based on their matches utilizing the various tools, different kits illustrate different points better.

Also, please note that you can click on any image to see a larger version.

Selecting Options

FF9 options

Your selection options for Family Finder are available on both your Dashboard page under the Family Finder heading, right in the middle of the page, and the dropdown myFTDNA menu, on the upper left, also under Family Finder.

Ok, let’s get started. 

#1 – Regular Matching

By regular matching, I’m referring to the matches you see when you click on the “Matches” tab on your main screen under Family Finder or in the dropdown box.

FF9 regular matching

Everyone uses this tool, but not everyone knows about the finer points of various options provided.

There’s a lot of information here folks. Are you systematically using this information to its full advantage?

Your matches are displayed in the highest match first order. All of the information we utilize regularly (or should) is present, including:

  • Relationship Range
  • Match Date
  • Shared CentiMorgans
  • Longest (shared) Block
  • X-Match
  • Known Relationship
  • Ancestral Surnames (double click to see entire list)
  • Notes
  • E-mail envelope icon
  • Family Tree
  • Parental “side” icon

The Expansion “+” at the right side of each match, shown below, shows us:

  • Tests Taken
  • mtDNA haplogroup
  • Y haplogroup

Clicking on your match’s profile (their picture) provides additional information, if they have provided that information:

  • Most distant maternal ancestor
  • Most distant paternal ancestor
  • Additional information in the “about me” field, sometimes including a website link

On the match page, you can search for matches either by their full name, first name, last name or click on the “Advanced Search” to search for ancestral surname. These search boxes can be found at the top right.

FF9 advanced search

The Advanced Search feature, underneath the search boxes at right, also provides you with the option of combining search criteria, by opening two drop down boxes at the top left of the screen.

FF9 search combo

Let’s say I want to see all of my matches on the X chromosome. I make that selection and the only people displayed as matches are those whom I match on the X chromosome.

You can see that in this case, there are 280 matches. If I have any Phased Family Matches, then you will see how many X matches I have on those tabs too.

The first selection box works in combination with the second selection box.

FF9 search combo 2

Now, let’s say I want to sort in Longest Block Order. That section sorts and displays the people who match me on the X chromosome in Longest Block Order.

FF9 longest block

Prerequisites

  • Take the Family Finder test or transfer your results from either 23andMe (V3 only) or Ancestry (V1 only, currently.)
  • Match must be over the matching threshold of 9cM if shared cM are less than 20, or, the longest block must be at least 7.69 cM if the total shared cM is 20 or greater.

Power Features

  • The ability to customize your view by combining search, match and sort criteria.

Cautions

  • It’s easy to forget that you’re ONLY working with X matches, for example, once you sort, and not all of your matches. Note the Reset Filter button above your matches which clears all of the sort and search criteria. Always reset, just to be on the safe side, before you initiate another sort.

FF9 reset filter

  • Please note that the search boxes and logic are in the process of being redesigned, per a conversation Michael Davila, Director of Product Development, on 7-20-2016. Currently, if you search for the name “Donald,” for example, and then do an “in common with” match to someone on the Donald match list, you’ll only see those individuals who are in common with “Donald,” meaning anyone without “Donald” as one of their names won’t show as a match. The logic will be revised shortly so that you will see everyone “in common with,” not just “Donald.” Just be aware of this today and don’t do an ICW with someone you’ve searched for in the search box until this is revised.

#2 – In Common With (ICW)

You can select anyone from your match list to see who you match in common with them.

This is an important feature because it gives me a very good clue as to who else may match me on that same genealogical line.

For example, cousin Donald is related on the paternal line. I can select Donald by clicking the box to the left of his profile which highlights his row in yellow. I can then select what I want to do with Don’s match.

FF9 ICW

You will see that Don is selected in the match selection box on the lower left, and the options for what I can do with Don are above the matches. Those options are:

  • Chromosome Browser
  • In Common With
  • Not in Common With

Let’s select “In Common With.”

Now, the matches displayed will ONLY be those that I match in common with Don, meaning that Donald and I both match these people.

FF9 ICW matches

As you can see, I’m displaying my matches in common with Don in longest block order. You can click on any of the header columns to display in reverse order.

There are a total of 82 matches in common with Don and of those, 50 are paternally assigned. We’ll talk about how parental “side” assignments happen in a minute.

Prerequisites

  • None

Power Features

  • Can see at a glance which matches warrant further inspection and may (or may not) be from a common genealogical line.

Cautions

  • An ICW match does NOT mean that the matching individual IS from the same common line – only genealogical research can provide that information.
  • An ICW matches does NOT mean that these three people, you, your match and someone who matches both of you is triangulated – meaning matching on the same segment. Only individual matching with each other provides that information.
  • It’s easy to forget that you’re not working with your entire match list, but a subset. You can see that Donald’s name appears in the box at the upper left, along with the function you performed (ICW) and the display order if you’ve selected any options from the second box.

# 3 – Not In Common With

Now, let’s say I want to see all of my X matches that are not in common with my mother, who is in the data base, which of course suggests that they are either on my father’s side or identical by chance. My father is not in the data base, and given that he died in 1963, there is no chance of testing him.

Keep in mind though that because X matches aren’t displayed unless you have another qualifying autosomal segment, that they are more likely to be valid matches than if they were displayed without another matching segment that qualifies as a match.

For those who don’t know, X matches have a unique inheritance pattern which can yield great clues as to which side of your tree (if you’re a male), and which ancestors on various sides of your tree X matches MUST come from (males and females both.) I wrote about this here, along with some tools to help you work with X matches.

To utilize the “Not In Common With” feature, I would select my mother and then select the “Not In Common With” option, above the matches.

FF9 NICW

I would then sort the results to see the X matches by clicking on the top of the column for X-Match – or by any other column that I wanted to see.

FF9 NICW X

I have one very interesting not in common with match – and that’s with a Miller male that I would have assumed, based on the surname, was a match from my mother’s side. He’s obviously not, at least based on that X match. No assuming allowed!

Prerequisites

  • None

Power Features

  • Can see at a glance which matches warrant further inspection and may be from a common genealogical line – or are NOT in common with a particular person.

Cautions

  • Be sure to understand that “not in common with” means that you, the person you match and the list of people shown as a result of the “Not ICW” do not all match each other.  You DO match the person on your match list, but the list of “not in common with” matches are the people who DON’T match both of you.  Not in common with is the opposite of “in common with” where your match list does match you and the person you’re matching in common with.
  • The X and other chromosome matches may be inherited from different ancestors. Every matching segment needs to be analyzed separately.

#4 – The Matrix

Let’s say that I have a list of matches, perhaps a list of individuals that I found doing an ICW with my cousin, and I wonder if these people match each other. I can utilize the Matrix grid to see.

Going back to the ICW list with cousin Donald, let’s see if some of those people match each other on the Matrix.

Let’s pick 5 people.

I’m selecting Cheryl, Rex, Charles, Doug and Harold.

Margaret Lentz chart

I’m making these particular selections because I know that all of these people, except Harold, are related to my mother, Barbara, shown on the bottom row of the chart above.  This chart, borrowed from another article (William is not in this comparison), shows how Cheryl, Rex, Charles and Barbara who have all DNA tested are related to each other.  Some are related through the Miller line, some through the dual Lentz/Miller line, and some just from the Lentz line.  Doug is related through the Miller line only, and at least 4 generations upstream. Doug may also be related through multiple lines, but is not descended from the Lentz line.

The people I’ve selected for the matrix are not all related to each other, and they don’t all share one common ancestral line.

Harold is a wild card – I have no idea how he is related or who he is related to, so let’s see what we can determine.

FF9 Matrix choices

As you make selections on the Matrix page, up to 10 selections are added to the grid.

FF9 Matrix grid

You can see that Charles matches Cheryl and Harold.

You can see that Rex matches Charles and Cheryl and Harold.

You can see that Doug matches only Cheryl, but this isn’t surprising as the common line between Doug and the known cousins is at least 4 generations further back in time on the Miller line.

The known relationship are:

  • Don and Cheryl are siblings, descended from the Lentz/Miller.
  • Rex is a known cousin on the Miller/Lentz line
  • Charles is a known cousin on the Lentz line only
  • Doug is a known cousin on the Miller line only

Let me tell you what these matches indicate to me.

Given that Harold matches Rex and Charles and Cheryl, IF and that’s a very big IF, he descends from the same lines, then he would be related to both sides of this family, meaning both the Miller and Lentz lines.

  • He could be a downstream cousin after the Lentz and Miller lines married, meaning a descendant of Margaret Lentz and John David Miller, or other Miller/Lentz couples
  • He could be independently related to both lines upstream. They did intermarry.
  • He could be related to Charles or Rex through an entirely separate line that has nothing to do with Lentz or Miller.

So I have no exact answer, but this does tell me where to look. Maybe I could find additional known Lentz or Miller line descendants to add to the Matrix which would provide additional information.

Prerequisites

  • None

Power Features

  • Can see at a glance which matches match each other as well.

Cautions

  • Matrix matches do NOT mean that these individuals match on the same segments, it just means they do match on some segment. A matrix match is not triangulation.
  • Matrix matches can easily be from different lines to different ancestors. For example, Harold could match each one of three individuals that he matches on different ancestral lines that have nothing to do with their common Lentz or Miller line.

#5 – Chromosome Browser

I want to know if the 5 individuals that I selected to compare in the Matrix match me on any of the same segments.

I’m going back to my ICW list with cousin Donald.

I’ve selected my 5 individuals by clicking the box to the left of their profiles, and I’m going to select the chromosome browser.

FF9 chromosome browser choices

The chromosome browser shows you where these individuals match you.

Overlapping segments mean the people who overlap all match you on that segment, but overlapping segments do NOT mean they also match each other on these same segments.

Translated, this means they could be matching you on different sides of your family or are identical by chance. Remember, you have two sides to your chromosome, a Mom’s side and a Dad’s side, which are intermingled, and some people will match you by chance. You can read more about this here.

The chromosome browser shows you THAT they match you – it doesn’t tell you HOW they match you or if they match each other.

FF9 chromosome browser view2

The default view shows matches of 5cM or greater. You can select different thresholds at the top of the comparison list.

You’ll notice that all 5 of these people match me, but that only two of them match me on overlapping segments, on chromosome 3. Among those 5 people, only those who match me on the same segments have the opportunity to triangulate.

This gives you the opportunity to ask those two individuals if they also match each other on this same chromosome. In this case, I have access to both of those kits, and I can tell you that they do match each other on those segments, so they do triangulate mathematically. Since I know the common ancestor between myself, Cheryl and Rex, I can assign this segment to John David Miller and Margaret Lentz. That, of course, is the goal of autosomal matching – to identify the common ancestor of the individuals who match.

You also have the option to download the results of this chromosome browser match into a spreadsheet. That’s the left-most download option at the top of the chromosomes. We’ll talk about how to utilize spreadsheets last.

The middle option, “view in a table” shows you these results, one pair of individuals at a time, in a table.

This is me compared to Rex. You will have a separate table for each one of the individuals as compared to you. You switch between them at the bottom right.

FF9 chromosome browser table2

The last download option at the furthest right is for your entire list of matches and where they match you on your chromosomes.

Prerequisites

  • None

Power Features

  • Can visually see where individuals and multiple people match you on your chromosomes, and where they overlap which suggests they may triangulate.

Cautions

  • When two people match you on the same chromosome segment, this does not mean that they also match each other on that segment. Matching on overlapping segments is not triangulation, although it’s the first step to triangulation.
  • For triangulation, you will need to contact your matches to determine if they also match each other on the same segment where they both match you. You may also be able to deduce some family matching based on other known individuals from the same line that you also match on that same segment, if your match matches them on that segment too.
  • The chromosome browser is limited to 5 people at a time, compared to you. By utilizing spreadsheet matching, you can see all of your matches on a particular segment, together.

#6 – Phased Family Matching

Phased Family Matching is the newest tool introduced by Family Tree DNA. I wrote about it here. The icons assigned to matches make it easy to see at a glance which side of your family, maternal or paternal, or both, a match derives from.

ff9 parental iconPhased Family Matching allows you to link the DNA results of qualified relatives to your tree and by doing so, Family Tree DNA assigns matches to maternal or paternal buckets, or sometimes, both, as shown in the icon above.

This phased matching utilizes both parental phasing in addition to a slightly higher threshold to assure that the matches they assign to parental sides can be done so with confidence. In order to be assigned a maternal or paternal icon, your match must match you and your qualifying relative at 9cM or greater on at least one of the same segments over the matching threshold. This is different than an ICW match, which only tells you that you do match, not how you match or that it’s on the same segment.

Qualifying relatives, at this time, are parents, grandparents, uncles, aunts and first cousins. Additional relatives are planned in the near future.

Icons are ONLY placed based on phased match results that meet the criteria.

These icons are important because they indicate which side of your family a match is from with a great deal of precision and confidence – beyond that of regular matching.

This is best illustrated by an example.

Phased FF2

In this example, this individual has their father and mother both in the system. You can see that their father’s side is assigned a blue icon and their mother’s side is assigned a pink (red) icon. This means they match this person on only one side of their family.  A purple icon with both a male and female image means that this person is related to you on both sides of your family.  Full siblings, when both parents are in the system to phase against, would receive both icons.

This sibling is showing as matching them on both sides of their family, because both parents are available for phasing.

If only one parent was available, the father, for example, then the sibling would only shows the paternal icon. The maternal icon is NOT added by inference. In Phased Family Matching, nothing is added by inference – only by exact allele by allele matching on the same segment – which is the definition of parentally phased matching.

These icons are ONLY added as a result of a high quality phased matches at or above the phased match threshold of 9cM.

You can read more about the Family Matching System in the Family Tree DNA Learning Center, here.

Prerequisites

  • You must have tested (or transferred a kit) for a qualifying relative. At this time qualifying relatives parents, grandparents, aunts, uncles and first cousins.
  • You must have uploaded a GEDCOM file or created a tree.
  • You must link the DNA of qualifying kits to that person your tree. I provided instructions for how to do this in this article.
  • You must match at the normal matching threshold to be on the match list, AND then match at or above the Phased Family Match threshold in the way described to be assigned an icon.
  • You must match on at least one full segment at or above 9cM.

Power Features

  • Can visually see which side of your family an individual is related to. You can be confident this match is by descent because they are phased to your parent or qualifying family member.

Cautions

  • If someone does not have an icon assigned, it does NOT mean they are not related on that particular side of the family. It only means that the match is not strong enough to generate an icon.
  • If someone DOES match on a particular side of the family, you will still need to do additional matching and genealogy work to determine which ancestor they descend from.
  • If someone is assigned to one side of your family, it does NOT preclude the possibility that they have a smaller or weaker match to your other side of the family.
  • If you upload a new Gedcom file after linking DNA to people in your tree, you will overwrite your DNA links and will have to relink individuals.
  • Having an icon assigned indicates mathematical triangulation for the person who tested, their parents or close relative against whom they were phased and their match with the icon.  However, technically, it’s not triangulation in cases where very close relatives are involved.  For example, parents, aunts, uncles and siblings are too closely related to be considered the third leg of the triangulation stool.  First cousins, however, in my opinion, could be considered the third leg of the three needed for triangulation.  Of course when triangulation is involved, more than three is always better – the more the merrier and the more certain you can be that you have identified the correct ancestor, ancestral couple, or ancestral line to assign that particular triangulated segment to.

# 7 – Combined Advanced Matching

One of the comparison tools often missed by people is Combined Advanced Matching.

Combined matching is available through the “Tools and Apps” button, then select “Advanced Matching.”

Advanced Matching allows you to select various options in combination with each other.

For example, one of my favorites is to compare people within a project.

You can do this a number of ways.

In the case of my mother, I’ll select everyone she matches on the Family Finder test in the Miller-Brethren project. This is a very focused project with the goal of sorting the Miller families who were of the Brethren faith.

FF9 combined matching

You can see that she has several matches in that project.

You can select a variety of combinations, including any level of Y or mtDNA testing, Family Finder, X matching, projects and “last name begins with.”

One of the ways I utilize this feature often is within a surname project, for males in particular, I select one Y level of matching at a time, combined with Family Finder, “show only people I match on all tests” and then the project name. This is a quick way to determine whether someone matches someone on Family Finder that is also in a particular surname project. And when your surname is Smith, this tool is extremely valuable. This provides a least a hint as to the possible distance to a common ancestor between individuals.

Another favorite way to utilize this feature is for non-surname projects like the American Indian project. This is perfect for people who are hunting for others with Native roots that they match – and you can see their Y and mtDNA haplogroups as a bonus!

Prerequisites

  • Must have joined the particular project if you want to use the project match feature within that project.

Power Features

  • The ability to combine matching criteria across products.
  • The ability to match within projects.
  • The ability to specify partial surnames.

Cautions

  • If you match someone on both Family Finder and either Y or mtDNA haplogroups, this does NOT mean that your common Family Finder ancestor is on that haplogroup line. It might be a good place to begin looking. Check to see if you match on the Y or mtDNA products as well.
  • All matches have their haplogroup displayed, not just IF you also match that haplogroup, unless you’ve specified the Y or mtDNA options and then you would only see the people you match which would be in the same major haplogroup, although not always the same subgroup because not everyone tests at the same level.
  • Not all surname project administrators allow people who do not carry that surname in the present generation to join their projects.

# 8 – MyOrigins Matching

One tool missed by many is the MyOrigins matching by ethnicity. For many, especially if you have all European, for example, this tool isn’t terribly useful, but if you are of mixed heritage, this tool can be a wonderful source of information.

Your matches (who have authorized this type of matching) will be displayed, showing only if they match you on your major world categories.  Only your matching categories will show.  For example, if my match, Frances, also has African heritage and I do not, I won’t see Frances’s African percentage and vice versa.

FF9 myOrigins

In this example, the person who tested falls into the major categories of European and Middle Eastern. Their matches who fall into either of these same categories will be displayed in the Shared Origins box. You may not be terribly excited about this – unless you are mixed African, Asian, European and Native American – and you have “lost ancestors” you can’t find. In that case, you may be very excited to contact other matches with the same ethnic heritage.

When you first open your myOrigins page, you will be greeted with a choice to opt in (by clicking) or to opt out (by doing nothing) of allowing your ethnic matches to view the same ethnic groups you carry. Your matches will not be able to see your ethnic groups that they don’t have in common with you.

FF9 myorigins opt in

You can also access those options to view or change by clicking on Account Settings, Privacy and Sharing, and then you can view or change your selection under “My DNA Results.”

FF9 myorigins security

Prerequisites

  • Must authorize Shared Origins matching.

Power Features

  • The ability to discern who among your matches shares a particular ethnicity, and to what degree.

Cautions

  • Just because you share a particular ethnicity does NOT mean you match on the shared ethnic line. Your common ancestor with that person may be on an entirely unrelated line.

# 9 – Spreadsheet Matching

Family Tree DNA offers you the ability to download your entire list of matches, including the specific segments where your matches match you, to a spreadsheet.

This is the granddaddy of the tools and it’s a tool used by all serious genetic genealogists. It’s requires the most investment from you both in terms of understanding and work, but it also yields the most information.

The power of spreadsheet comparisons isn’t in the 5 people I pushed through to the chromosome browser, in and of themselves, but in the power of looking at the locations where all of your matches match you and known relatives on particular segments.

Utilizing the chromosome browser, we saw that chromosome 3 had an overlap match between Rex (green) and Cheryl (blue) as compared to my mother (background chromosome.)

FF9 chr 3

We see that same overlap between Cheryl and Rex when we download the match spreadsheet for those 5 people.

However, when we download all of my mother’s matches, we have a much more powerful view of that segment, below. The 2 segments we saw overlapping on the chromosome browser are shown in green. All of these people colored pink match my mother on some part of the 37cM segment she shares with Rex.

FF9 spreadsheet match

This small part of my master spreadsheet combines my own results, rows in white, with those of my mother, rows in pink.

In this case, I only match one of these individuals that mother also matches on the same segment – Rex. That’s fine. It just means that I didn’t receive the rest of that DNA from mother – meaning the portions of the segments that match Sam, Cheryl, Don, Christina and Sharon.

On the first two rows, I did receive part of that DNA from mother, 7.64 of the 37cMs that Rex matches to Mom at a threshold of 5cM.

We know that Cheryl, Don and Rex all share a common ancestor on mother’s father’s side three generations removed – meaning John David Miller and Margaret Lentz. By looking at Cheryl, Don and Rex’s matches as well, I know that several of her matches do triangulate with Cheryl, Don and/or Rex.

What I didn’t know was how Christina fit into the picture. She is a new match. Before the new Phased Family Matching, I would have had to go into each account, those of Rex, Cheryl and Don, all of which I manage, to be sure that Christina matched all of them individually in addition to Mom’s kit.

I don’t have to do that now, because I can utilize the phased Family Matching instead. The addition of the Family Matching tool has taken this from three additional steps, assuming I have access to all kits, which most people don’t, to one quick definitive step.

Cheryl and Don are both mother’s first cousins, so matches can be phased against them. I have linked both of them to mother’s kit so she how has several individuals who are phased to Don and Cheryl which generate paternal icons since Don and Cheryl are related to mother on her father’s side.

Now, instead of looking at all of the accounts individually, my first step is to see if Christina has a paternal icon, which, in this case, means she phased against either Don and/or Cheryl since those are the only two people linked to mother who qualify for phasing, today.

FF9 parental phased match

Look, Christina does have a paternal icon, so I can add “Dad” into the side column for Christine in the spreadsheet for mother’s matches AND I know Christina triangulates to Mom and either Cheryl or Don, which ever cousin she phased against.

FF9 Christina chr 3

I can see which cousin she phased against by looking at the chromosome browser and comparing mother against Cheryl, Don and Christina.  As it turns out, Christina, in green, above, phased against both Cheryl and Don whose results are in orange and blue.

It’s a great day in the neighborhood to be able to use these tools together.

Prerequisites

  • Must download matches spreadsheet through the chromosome browser, adding new matches to your spreadsheet as they occur.
  • Must have a familiarity with Excel or another spreadsheet.
  • Must learn about matching, match groups and triangulation.

Power Features

  • The ability to control the threshold you wish to work with. For matches over the match threshold, Family Tree DNA provides all segment matches to 1cM with a total of 500 SNPs.
  • The ability to see trends and groups together.
  • The ability to view kits from all of your matches for more powerful matching.
  • The ability to combine your results with those of a parent (or sibling if parents not available) to see joint matching where it occurs.

Cautions

  • There is a comparatively steep learning curve if you’re not familiar with using spreadsheets, but it’s well worth the effort if you are serious about proving ancestors through triangulation.

Summary

I’m extremely grateful for the full complement of tools available at Family Tree DNA.

They provide a range of solutions for users at all levels – people who just want to view their ethnicity or to utilize matches at the vendor site as well as those who want tools like a chromosome browser, projects, ICW, not ICW, the Matrix, ethnicity matching, combined advanced matching and chromosome browser downloads for those of us who want actual irrefutable proof.  No one has to use the more advanced tools, but they are there for those of us who want to utilize them.

I’m sorry, I’m not from Missouri, but I still want to see it for myself. I don’t want any vendor taking the “trust me” approach or doing me any favors by stripping out my data. I’m glad that Family Tree DNA gives us multiple options and doesn’t make one size fit all by using a large hammer and chisel.

The easier, more flexible and informative Family Tree DNA makes the tools, the easier it will be to convince people to test or download their data from other vendors. The more testers, the better our opportunity to find those elusive matches and through them, ancestors.

The Concepts Series

I’ve been writing a “Concepts” series of articles. Recent articles have been about how to utilize and work with autosomal matches on a spreadsheet.

You might want to read these Concepts articles if you’re serious about working with autosomal DNA.

Concepts – How Your Autosomal DNA Identifies Your Ancestors

Concepts – Identical by…Descent, State, Population and Chance

Concepts – CentiMorgans, SNPs and Pickin’ Crab

Concepts – Parental Phasing

Concepts – Downloading Autosomal Data from Family Tree DNA

Concepts – Managing Autosomal DNA Matches – Step 1 – Assigning Parental Sides

Please join me shortly for the next Concepts article – Step 2 – Who’s Related to Whom?

In the meantime:

  • Make full use of the autosomal tools available at Family Tree DNA.
  • Test additional relatives meaning parents, grandparents, aunts, uncles, half-siblings, siblings, any cousin you can identify and talk into testing.
  • Take test kits to family reunions and holiday gatherings. No, I’m not kidding.
  • Don’t forget Y or mtDNA which can provide valuable tools to identify which line you might have in common, or to quickly eliminate some lines that you don’t have in common. Some cousins will carry valuable Y or mtDNA of your direct ancestral lines – and that DNA is full of valuable and unique information as well.
  • Link the DNA kits of those individuals you know to their place in your tree.
  • Transfer family kits from other vendors.

The more relatives you can identify and link in the system, the better your chances for meaningful matches, confirming ancestral relations, and solving puzzles.

Have fun!!!

Concepts – Parental Phasing

I recently used a technique called parental phasing as part of the proof that one Curtis Lore found in Pennsylvania was the same person as Curtis Benjamin Lore, found later in Indiana.  Given that I’ve already used parental phasing as part of a proof argument, I’d like to break it down further and explain the concepts behind parental phasing, what it is, why it is so important, and why it works so well.

For those of you who don’t have at least one parent available to test, I’m truly sorry, and not just because of the lost DNA opportunity. But please do read this article, because you may be able to substitute other family members and derive at least some of the benefits, although clearly not all.

What is Parental Phasing?

The fundamental concept of parental phasing is that the only way you can obtain your DNA is through one or the other of your parents, so every one of your matches should match you plus one of your parents. Right?

Should, yes, but that’s not exactly how autosomal matching works in real life.

You can match someone in one of two ways:

  1. Because you received the matching segment from one of your two parents, and they received that same segment from one of their two parents, a circumstance that is called identical by descent or IBD.
  2. Because your match’s DNA is zigzagging back and forth between the DNA you inherited from both of your parents, or your DNA is zigzagging back and forth between their parents, either of which is called identical by chance or IBC.

I wrote about his in the article titled, Concepts – Identical by…Descent, State, Population and Chance.

Here’s the matching “Identical By” cheat sheet since you may find it helpful in this article as well.

Identical by Chart

How Does Parental Phasing Work?

Parental phasing works by comparing your DNA against your matches DNA, then comparing your matches DNA against your parents DNA, and telling you which, if either, or both, parents they match in addition to you. Oh yes, and there’s one more tiny tidbit – they must match you and your parent(s) on the same segment(s).

As bizarre as it sounds, sometimes your match will match you on one segment, and match your parents on an entirely different segment.  While this was not an expected finding, it does happen, and frequently enough that it was found in every parental phasing test run – so it’s not an anomaly or something so rare you won’t see it.

Therefore, parental phasing may be a two part process, where:

  • Step 1 is determining whether or not your match matches either or both of your parents.
  • Step 2 is determining if your match matches you and your parent on the same segment(s), or at least part of the same segment? If not, then it’s not a phased IBD match – even though they do match you and your parent.

Conceptually, each of your matches will fall nice and cleanly into one, or both, of your parent’s buckets. Let’s look at a couple of examples.  For each of the people who match you, they will also match your parents on the same segment as follows:

Match Matches Your Mother Matches Your Father Matches Neither Parent Comment
Susie Yes No From Mom’s side, IBD
John No Yes From Dad’s side, IBD
Bob Yes Yes Matches both parents lines, IBD and may be IBP
Roxanne No No Yes Identical by Chance, IBC

Please Note: Your match list will change if you change your matching threshold, and so will your phased matches to your parents.  In other words, while someone might not match you and a parent both on the same segment at 15cM, you might well match on a common segment at a 10, 7 or 5cM threshold.

So in essence, parental phasing puts your matches into very useful buckets for you and helps eliminate false positives – or matches that appear real but aren’t.

How Can Someone Match Me But Not My Parents?

That’s a really good question. Sometimes you match someone because you received common DNA from an ancestor, through your parents, which means you’re identical by descent (IBD), a legitimate genealogical match.  But other times, you match someone just by chance because their DNA is matching pieces of both of your parents’ DNA, and not because you actually share a common ancestor.

Let’s take a look.

This first graphic shows you with an identical by descent match to your match’s father’s DNA. Your match’s father shares a common relative with (at least) one of your mother’s lines.

Phase IBD

In the most basic terms, an identical by descend (IBD) match looks like this, where your match is matching you on one of your parent’s strands of DNA. Both matching strands are colored green in this example.

Of course, your DNA does not come labeled as to which side is mother’s and which side is father’s. You can read more about that here. If it did, we wouldn’t even need to be having this discussion at all – because that’s what parental phasing does.  It tells you which side of your family your DNA match came from.

You can see in the above example that you and your match both share an actual strand of DNA. You inherited yours from your Mom and your match inherited theirs from their Dad, which means your Mom and their Dad share a common ancestor.  However, to be able to discern that fact, that your Mom and your match’s Dad share a common ancestor, you need to be able to phase the DNA of both you and your match to know which parent that strand came from.

In reality, your DNA and their DNA is entirely mixed in each of you, shown in the chart below, and without additional information, neither of you will know which strand of DNA you match on, or who you inherited it from.  Initially, you will only know THAT you match.

Phase IBD2

So here’s what your DNA really looks like. It’s up to the DNA matching software to look at the two strands of your DNA that’s mixed together, and the two strands of your match’s DNA that’s mixed together and see if there is a common grouping of DNA at each location that extends for at least 10 locations in length, which is the “threshold” for our example that signifies a match that is likely to be “real” versus IBC, or identical by chance.  In my example, that common grouping is the green “Matching Portions” column, above.

An identical by chance match looks like the chart below. You can see that the green matching DNA is zigzagging back and forth between your parents’ DNA.

Phase IBC

It can even be worse where your match’s Mom’s and Dad’s DNA is also zigzagging back and forth, but you can certainly get the idea that there are all kinds of ways to NOT match but only three ways to legitimately match – Mom’s side, Dad’s side, or both.

So you can see that indeed, you do technically match, but not because you share a DNA segment of any size with one parent, but because your match’s DNA matches part of your Mom’s DNA and part of your Dad’s, which means that DNA segment does NOT come from one common ancestor, meaning not IBD. However, the matching software can’t tell the difference, because your strands aren’t coded to Mom and Dad.

What parental phasing does is to assign your matches to “sides” or buckets based on whether they match your Mom or Dad in addition to you.

One Parent Matches

In my case, I only have one parent whose DNA is available. Therefore, all of my matches will either match both my mother and me, or not.  The balance that do not match me and my mother, both, will either match to my father or will be IBC, identical by chance matches.  Unfortunately, just by utilizing one-parent phasing, I can’t tell if the “non-Mom” matches are really to my father or are IBC.

Let’s look at an example.

Match Mom’s Side Dad or IBC Comment
Denny Yes Probably not Mom’s side, could also match on Dad’s side but we have no way to tell. My parents lines come from different parts of the world except that they both married into Native American lines.
Sally No Yes Can’t tell whether Dad’s side or IBC
Derrell No Yes Also matches cousin on Dad’s side on same segments, so Derrell is assigned to Dad’s side pending triangulation.

By using the ICW tool at Family Tree DNA, shown below, I can see who matches me and my matches, both – in this case, me and my mother.

No Parent Matches

If I have no parents in the system, but several other close family members, like uncles or cousins, I can easily see who else I match in common with my match.

In other words, without my mother to match, Denny will either match my Mom’s side family members, and I can tentatively group him there, my Dad’s side family members, and I can tentatively group him there, or neither, in which case I can’t do anything with him except note that fact.

An Example

I’m going to use my proven cousin Denny for my examples, because that’s who I used in my Curtis Lore case study and our connection is proven both genetically and genealogically.

Here’s Denny’s match list. My mother is Denny’s closest match and I’m his second closest.

Phase match list

Therefore, I can use the ICW technique to effectively put my matches into buckets that divide my DNA in half, if I have both parents.

If I have one parent, I can fill one bucket for sure by putting everyone who matches both my mother and me into the “mother” bucket. The balance will be in the “Father +IBC” bucket.

This is easy to do at Family Tree DNA by using the crossed arrow ICW tool to find everyone who matches me in common with my mother.

Phase iCW

If I don’t have either parent, but I have an uncle or a cousin, I can still assign some matches to buckets by utilizing this same ICW tool. What I can’t do without both parents is to eliminate IBC or identical by chance matches from my match list.  I need both parents or at least well fleshed out match groups to do that.  There are examples of using match groups to identify IBC matches in the article, Identical By…Descent, Chance, Population and State.

Furthermore, I will need to download my match lists for both my mother and myself to verify that each person matches both my mother and myself on a common segment.

Testing the Theory

Let’s use my real life example and see how this works. I’m going to utilize three generations, because this gives us the ability to see the parental phasing work twice.  In this illustration, below, four people have tested, Denny, Mother, Me and My Child.

Phase pedigree

Denny and my child, who are 3rd cousins once removed, match on the following DNA segments, utilizing the Family Tree DNA chromosome browser.  We are comparing against Denny, meaning he is the “background” black chromosome.  The orange illustrates where my child matches Denny.

Phase browser denny child

There are no matching segments on chromosomes 18-22.  I have not included X chromosome matching.

Here’s the same information in chart format.

Phase chart denny child

You can see that Denny and my child have several fairly significant segment matches, along with some smaller ones too. The question is, which of those segments are legitimate, meaning IBD and which are not, meaning IBC?

Let’s phase my child against my DNA and see which of these segment matches hold up.

My child is orange, and I am blue and we are both matching against cousin Denny.

phase browser denny child me

As you can see, many of those segments are legitimate because Denny matches both me and my child on the same segments. So they are not IBC, or identical by chance, but IBD, identical, literally, by descent – because my child received them from me.

In some cases, Denny matches only me, blue, which is fine because all that means is that either our matches are IBC or I didn’t pass that DNA to my child. Both matches on chromosome 3 are to me (blue) and not to my child (orange).

However, in the cases where Denny matches my child (orange,) and not me (blue,) on the same segments, that means that either Denny and my child share an ancestor that is through my child’s father or the matches are IBC.  Those matches are not through me.  In other words, those segments did not pass phasing.  You can see examples of that on chromosomes 1, 4 and 14, and partial matches on 11 and 12.

Chromosome 16 shows a really good example of a crossover event where my child, orange, received part of my DNA, blue, but about half way through my segment, it was divided and my child inherited part of mine and the other half from their father.  So, visually, you can see that my child only matches Denny on about half of the segment where I match Denny.

Matches Spreadsheet

I downloaded the results of both Denny’s matches to me and Denny’s matches to my child into one Matches Spreadsheet and have color coded them so that you can see the relationships.  If Denny matches both me and my child, you will see a common segment on that chromosome for both me and my child in the spreadsheet.  Rows where Denny matches my child are light orange and rows where Denny matches me are light blue, similar to the chromosome browser colors.

Denny Me Child

There are only three possible conditions and I have colored the chromosome column accordingly:

  • Denny matches me only – dark teal – may be a legitimate match but we don’t have enough information to tell at this point
  • Denny matches my child only, but not me – red – NOT a legitimate match – identical by chance (IBC)
  • Denny matches me and my child both – boxed green – a legitimate identical by descent (IBD) match

You’ll note that some of these matches are exact. For example on the first matching segment of chromosome 2, below, my child received this entire segment of my DNA.  It was not divided at all.

Denny Me Child 2

However, in the next two matching groups on chromosome 2, my child received most of the DNA I share with Denny, but some was shaved off, but not half.

Denny Me Child 2 shaved

On chromosome 16, my child received almost exactly half of the DNA segment that I share with Denny.

Denny Me Child 16

On chromosomes 11 and 17, my child shares more DNA with Denny than I do, which means that all of that DNA isn’t ancestral though me. In this case, either there are some fuzzy boundaries, a read error, part of the DNA is IBD and part is IBC or part of the DNA is matching through both parents.

Denny Me Child 17 c

On chromosome 14, I match Denny, but my child received none of that DNA, which is why I’ve added the color teal.

Denny Me Child 14 c

Now, let’s phase me against my mother and see how the DNA matches hold up in a third generation.

Adding the Next Generation

The view of the chromosome browser below shows Denny matching my child, in orange, me in blue and my mother in green.

Amazingly, many of these segments follow through all three generations.

phase browser denny child me mother

Let’s see how the various matches stacked up, pardon the pun.

I’ve added Denny’s matches to mother to the Matches Spreadsheet and her rows are colored green.

On the Matches Spreadsheet from the first example, there were several segments where Denny matched only me and not my child. They were colored teal.  In the chart below, so we can track those segments, I have colored them teal in the matchname column, and you can see the resolution of how they did or didn’t survive phasing against my mother in the chromosome column.

Of those 11 segments, 2 phased with my mother, the rest did not. That makes sense, since none of those are segments I passed on to my child, so they would be more likely to be IBC.

Denny me Child Mom SS

The legend for the spreadsheet above is as follows:

  • Dark teal in chromosome column – Denny matches Mom only – may be a legitimate match but we don’t have enough information to know (chromosomes 1, 2, 4, 5, 6, 7, 9, 12 and 15)
  • Dark teal in matchname column, plus red in chromosome column – previously Denny matched only me, now I do not phase against my mother, so this is an IBC match (chromosomes 1, 3, 4, 5, 6, 7, 10, 12 and 17)
  • Dark teal in matchname column, plus green box in chromosome column – previously Denny only matched me, but now this segment is parentally phased and considered legitimate (chromosomes 2 and 10)
  • Red in chromosome column – does not phase against parent, so not a legitimate match – IBC (chromosomes 1, 3, 4, 5, 6, 7, 10, 11, 12, 14 and 17)
  • Green box indicates a phased match – considered IBD and legitimate (chromosomes 1, 2, 10, 14, 15, 16 and 17)

Anomalies

*So what the heck happened with chromosome 11?

In the first example, this segment received a green box because Denny matched both me and my child on a partial segment, which means that partial segment is phased and considered legitimate.

denny me child mom ss 11 grn

When we moved to the next generation, phasing against my mother, Denny does not match my mother on this segment, so it could NOT have arrived in me and my child via my mother, so it is not IBD, even though it appeared that way initially. Because of this, I’ve changed the box color to red for a non-IBD match.

Denny me Child Mom SS 11

How could this happen?

First, it’s a very small segment overlap match, and second, Denny matched more to my child than to me, which is a neon warning sign that this segment match is suspect, especially those two conditions in combination with each other.

Here’s an example of how, genetically, a match could phase with a parent in one generation, but not hold into the next generation.

phase n o phase

This match matches both me and my child (gold), but not my mother, who has no gold. As you can see, the match does accrue 10 gold location matches in a row, but not 10 green ones, so doesn’t match my mother.  The larger the number of locations in a row required to be considered a match, the less likely this type of random matching will be to occur.

This is both the purpose and the quandry of thresholds.  Finding that sweet spot that doesn’t eliminate real matches, but is high enough to be useful in eliminating false positive (IBC) matches.  And I can tell you, there are just about as many opinions on what that threshold number should be as there are people giving opinions – and everyone seems to have one!  You can read more about this in the article, Concepts – CentiMorgans, SNPs and Pickin’ Crab.

Segment Survival

Let’s take a look and see how many of which size segments survived parental phasing.  Are some of those smaller segments legitimate matches, or did we lose them in phasing?

The chart below shows the results in segment size order, color coded as follows:

  • Red = segments that did not phase and were IBC
  • Teal = segments that match Mom only and may or may not be valid. We don’t have any way to know without additional matches.
  • Green = segments that phased and are IBD

Phased cMs by size

As you would expect, all of the larger segments phased, but surprisingly, so did several of the smaller segments, through three generations.

Given the fact that teal matches did not phase, for the most part, in the previous example, and given that the teal segments are mostly small, my suspicion would be that most of  these teal segments would not phase (with the probable exception of the 10.27 cm segment), if we have the opportunity to find out – which we don’t.

This example is for a non-endogamous line, or better stated, with distant endogamous groups in multiple lines. Endogamous results would probably be different.

Statistics

What do our statistics look like?

There were 58 matching segments between Denny, my child, me and my mother.

  Match To Whom # Segments # Phased %
Denny My Child 12 8 75
Denny Me 22 11 50
Denny Mother 24 Probably at least 11
Total 58

Of those 58 total matches, 16 were IBC meaning they did not match up through my mother.

  Total

Segment Matches

IBC (no phase) IBD (phase) Just Mother Match Groups 2 gen Groups 3 gen Groups
58 16 29 13 12 3 9
% 28% 50% 22% 25% 75%

Thirteen match just to mother (teal), of which one, on chromosome 12 for 10.27 centiMorgans, is the most likely to be legitimate, or IBD. The rest were smaller segments and none were passed to a the child, so they are less likely to be legitimate, or IBD.

There are a total of 12 matching groups, of which 3 are for only two generations, me and mother. In other words, not all of that DNA got passed on to my child, but at least some of it did 9 of those 12 times.

Does Size Matter?

I wanted to see how the small versus large segments faired in terms of three generations of parental phasing. Are smeller segments legitimate or not?  Do they stand up?  The “Phased cMs by Size” chart above was sorted in chromosome order, with teal being a match to mother only (so we don’t know if it phased), green meaning the segment DID phase and red meaning it DID NOT phase with the parent.

Removing the teal blocks, which match to mother only, meaning we don’t know if they would parentally phase or not, leaves us with the blocks that had the opportunity to phase, and whether they passed or failed. 100% of the blocks 3.57cM and above phased.  A natural dividing line seems to occur about the 3.5 cM level, shown below.

phased cms by size less teal

It’s interesting that all matches above 3.36 cM phased, several of them twice, through three generations or two transmission (inheritance) events. Of those, 9, or 43% were under the 10cM threshold suggested by some, and 7, or 33% were under the 7cM threshold.

Most of the segments 3.36 cM and below, did not pass phasing. Of those, 6 or 26% did pass phasing, while 17, or 74%, did not.  Note that this cM level is with the SNP threshold set to 500 SNPs, which is generally the lowest number I use.

Segment Size # of Segments # Segments Phased %
Larger than 3.5 cM 21 21 100
Smaller than 3.5 cM 23 6 26

Are these results a function of this particular family, or would this hold if more parental generational phasing studies were performed?

Let’s see. 

The Threshold Study

I was surprised by the seemingly low threshold of 3.5 cM that appeared to be the rough dividing line for cMs that passed parental phasing and those that did not. I undertook a small study of four additional 3 generation non-endogamous families.

I’ve included the Lore study that we discussed above in the first column.

I have also removed all duplicates in the results below, since the duplicates were an artifact of matching groups where we had three generations to match.

I completed 4 different three-generation studies in 4 unrelated non-endogamous families and noted the rough threshold for where matches seem to pass or fail phasing – in other words, the fall line. In all 4 examples below, the threshold was between 2.46 and 3.16 cM.  You could move it slightly higher, depending on what criteria you use for the “fall line,” which is why I’ve included the raw data.  In all cases, the SNP threshold was at 500 so you would not see any matches with fewer than 500 SNPs.

The black bar in the results below marks the location where the shift from fail to pass occurs in the various studies.

4 family phasing

Additionally, I have one 4-generation study available as well. The closest related of the 4 generations that were being matched against were first cousins, then first cousins once removed, then first cousins twice removed (equal to 2nd cousins) then 1st cousins three times removed (equal to second cousins once removed).

You can see, below, that the pass/fail threshold for this 4 generation, 3 transmission study was also at 3.69 cM for valid segments that survived. The segments labeled “2 match” mean that they did not get passed to the younger generations, so they only matched in the oldest two generations, 3 match the oldest 3 generations and 4 match meaning the match survived through all 4 generations.

It’s interesting that even some of the smaller segments held through all 4 generations.

4 gen phasing

Ethnicity Matters

Clearly, parental phasing is only successful when you have matches. Of the three data bases available for autosomal DNA comparisons today, Family Tree DNA and 23andMe likely have the largest representation of non-US participants, because the Ancestry.com test was not sold outside the US for quite some time.  The Family Tree DNA Family Finder test was sold in the most locations outside the US.

Family Tree DNA probably has the best representation of Jewish DNA of all of the data bases.

Family Tree DNA projects facilitate the grouping of individuals by self-selected interest which includes ethnic categories, making those relationships visible by virtue of project membership wherein they are not readily evident in other data bases.

Therefore, by virtue of who has tested, if your ancestry is not “US” meaning a melting pot type of environment who are not recent arrivals, then you are likely to have less matches, so less phased matches too.  If you have a high degree of any particular ethnicity, even if your ancestry is “US,” you may still have fewer matches.  For example, 3 of 4 of my mother’s grandparents were either German or Dutch, and she has 710 matches, or roughly half the matches that I have.  My father’s heritage was Appalachian, meaning Colonial American.

Here’s a quick chart showing the total matches as of April, 2016 for a number of individuals who contributed their match totals in Family Finder and who carry either no US heritage or a specific ethnicity.  For purposes of comparison, three individuals with typical mixed colonial US heritage are shown at the top.

Ethnicity match chart

People with high percentages of African heritage tend to have few matches today, as do those of purely European heritage. Unfortunately, not many Africans or African-Americans test their DNA and DNA testing is not as popular in Europe as it is in the US.  Many people in Europe are leary of DNA testing or don’t feel they need to test, because “we’ve always lived here.”   I’m hopeful that the sustained popularity of programs like Who Do You Think You Are and Finding Your Roots will encourage more people of all ethnicities and locations to test from around the globe.

People from highly endogamous populations have a different issue to deal with, as you can see from the very high number of Jewish matches in the chart above. Since these people descend from a common founder population, they share a lot of ancestral DNA that is identical by population, meaning they did receive it from an ancestor, so it’s not IBC, but they received that segment because that particular segment is very prevalent within that population.  Determining which ancestor contributed that piece of DNA is exceedingly difficult, if not impossible because several ancestors carried that same segment.

Therefore, while the segment is identical by descent, it’s probably not genealogically useful in a 100% endogamous scenario.

In an unpublished study, we discovered that while working with parentally phased Jewish results, it’s not unusual for up to half of the matches to not match the participant plus either parent on the same segments. Or conversely, they may match both parents, but the segments are comparatively small.  Matching to both parents in an endogamous population, without a known familial relationship, and without at least one relatively large segment, is an indicator of IBP, identical by population, matches.  For Jewish and other endogamous people, parental phasing is very promising, and will help them sort through irrelevant “diamond in the rough” matches indicated by no parent matches or smaller both parent matches to find the genealogically relevant gems.

In all parental phasing groups studied, no one lost less than 10% of their matches utilizing parental phasing and most people lost significantly more, up to half.  I would very much like to see these same kinds of 3 or 4 generation parental phasing studies done for groups of Jewish, other endogamous and African American families.  In order to do a study of one family, you need at least 3 generations who have tested and another known family member, like a first or second cousin perhaps, to match against.

In Summary

Dual parental phasing works wonderfully.  One parent phasing works pretty well too.  Even close relative phasing works, just not as well as parental phasing.  You can only work with the people you have available to test, so test every relative you can convince!

If you have one or both parents to test, by all means, do. You’ll be able to phase your matches against both of your parents individually and eliminate the majority of IBC matches.

If you have grandparents or their siblings available to test, do, and quickly so you don’t lose the opportunity. Test the oldest person/generation in each line that you can.

If you don’t have both parents, test your half and full siblings, all of them, the more the better, because they inherited parts of your parents DNA that you didn’t.

Find your closest relatives and test them, yes, all of them.

If you are testing parents, you don’t need to test their children too, because their children will only receive half of their parent’s DNA, and you already have the parents DNA.

Even if you can’t phase your matches utilizing your parents DNA, you can use the combination of your matches with other relatively close family members to assign or suggest matches to both sides of your family along family lines – creating match groups. For example, if your match matches you and your great-uncle Charlie on the same segment, then it’s very likely that match is from the common ancestral line shared by your common ancestor with great-uncle Charlie – your great-grandparents.  Triangulation, of course, will prove that.

Some of your relatives will be quite interested in DNA testing and others will be happy to test simply because it helps you, and they like to hear about the result of the genealogy research. I’ve discovered that providing a scholarship for the testing, especially for those people you really want to test, goes a very long way in convincing people that DNA testing for genealogy is something they might be interested in doing.  If you can’t personally afford a scholarship for everyone, try the old fashioned collection jar.  And no, I’m not kidding.  It works wonders and gives everyone an opportunity to participate and invest as well, as much as they can afford.

Ethnicity testing has a lot of sizzle for some folks too – so don’t just deliver the dry facts – be sure to talk about the sizzle too. Sizzle sells!  People get excited about the possibilities and of course, you’ll explain the result to them, so they get to visit with you a second time as well.  Something to look forward to at next summer’s picnic!

Be sure to take swab kits to family events; picnics, reunions, graduation parties, weddings and holiday gatherings. Believe me, I have a DNA kit in my purse or car at all times.  And maybe, if your extended family lives close by, resurrect the old-time Sunday afternoon tradition of “going calling.”  Not only can you collect DNA, you can collect family memories too and I guarantee, you’ll make a new discovery with every visit.  Take this opportunity to interview your relatives.

It’s amazing isn’t it, the things we do for this “DNA phase” that we’re all going through!

Acknowledgements

I want to thank Family Tree DNA for their ongoing support of projects and citizen scientists which makes these types of research studies possible. I also want to thank several individuals in the genetic genealogy community who provided their information and gave permission for me to incorporate their results into this article.  Without sharing and collaboration, these types of efforts would simply not be possible.

Autosomal DNA Matching Confidence Spectrum

Are you confused about DNA matches and what they mean…different kinds of matches…from different vendors and combined results between vendors.  Do you feel like lions and tigers and bears…oh my?  You’re not alone.

As the vendors add more tools, I’ve noticed recently that along with those tools has come a significant amount of confusion surrounding matches and what they mean.  Add to this issue confusion about the terminology being used within the industry to describe various kinds of matches.  Combined, we now have a verbiage or terminology issue and we have confusion regarding the actual matches and what they mean.  So, as people talk, what they mean, what they are trying to communicate and what they do say can be interpreted quite widely.  Is it any wonder so many people are confused?

I reached out within the community to others who I know are working with autosomal results on a daily basis and often engaged in pioneering research to see how they are categorizing these results and how they are referring to them.

I want to thank Jim Bartlett, Blaine Bettinger, Tim Janzen and David Pike (in surname alphabetical order) for their input and discussion about these topics.  I hope that this article goes a long way towards sorting through the various kinds of matches and what they can and do mean to genetic genealogists – and what they are being called.  To be clear, the article is mine and I have quoted them specifically when applicable.

But first, let’s talk about goals.

Goals

One thing that has become apparent over the past few months is that your goals may well affect how you interpret data.  For example, if you are an adoptee, you’re going to be looking first at your closest matches and your largest segments.  Distant matches and small segments are irrelevant at least until you work with the big pieces.  The theory of low hanging fruit, of course.

If your goal is to verify and generally validate your existing genealogy, you may be perfectly happy with Ancestry’s Circles.  Ancestry Circles aren’t proof, as many people think, but if you’re looking for low hanging fruit and “probably” versus “positively,” Ancestry Circles may be the answer for you.

If you didn’t stop reading after the last sentence, then I’m guessing that “probably” isn’t your style.

If your goal is to prove each ancestor and/or map their segments to your DNA, you’re not going to be at all happy with Ancestry’s lack of segment data – so your confidence and happiness level is going to be greatly different than someone who is just looking to find themselves in circles with other descendants of the same ancestor and go merrily on their way.

If you have already connected the dots on most of your ancestry for the past 4 or 5 generations, and you’re working primarily with colonial ancestors and those born before 1700, you may be profoundly interested in small segment data, while someone else decides to eliminate that same data on their spreadsheet to eliminate clutter.  One person’s clutter is another’s goldmine.

While, technically, the different types of tests and matches carry a different technical confidence level, your personal confidence ranking will be influenced by your own goals and by some secondary factors like how many other people match on a particular segment.

Let’s start by talking about the different kinds of matching.  I’ve been working with my Crumley line, so I’ll be utilizing examples from that project.

Individual Matching, Group Matching and Triangulation

There is a difference between individual matching, group matching and triangulation.  In fact, there is a whole spectrum of matching to be considered.

Individual Matching

Individual matching is when someone matches you.

confidence individual match

That’s great, but one match out of context generally isn’t worth much.  There’s that word, generally, because if there is one thing that is almost always true, it’s that there is an exception to every rule and that exception often has to do with context.  For example, if you’re looking for parents and siblings, then one match is all you need.

If this match happens to be to my first cousin, that alone confirms several things for me, assuming there is not a secondary relationship.  First, it confirms my relationship with my parent and my parent’s descent from their parents, since I couldn’t be matching my first cousin (at first cousin level) if all of the lines between me and the cousin weren’t intact.

confidence cousins

However, if the match is to someone I don’t know, and it’s not a close relative, like the 2nd to 4th cousins shown in the match above, then it’s meaningless without additional information.  Most of your matches will be more distant.  Let’s face it, you have a lot more distant cousins than close cousins.  Many ancestors, especially before about 1900, were indeed, prolific, at least by today’s standards.

So, at this point, your match list looks like this:

confidence match list

Bridget looks pretty lonely.  Let’s see what we can do about that.

Matching Additional People

The first question is “do you share a common ancestor with that individual?”  If yes, then that is a really big hint – but it’s not proof of anything – unless they are a close relative match like we discussed above.

Why isn’t a single match enough for proof?

You could be related to this person through more than one ancestral line – and that happens far more than I initially thought.  I did an analysis some time back and discovered that about 15% of the time, I can confirm a secondary genealogical line that is not related to the first line in my tree.  There were another 7% that were probable – meaning that I can’t identify a second common ancestor with certainty, but the surname and location is the same and a connection is likely.  Another 8% were from endogamous lines, like Acadians, so I’m sure there are multiple lines involved.  And of those matches (minus the Acadians), about 10% look to have 3 genealogical lines, not just two.  The message here – never assume.

When you find one match and identify one common genealogical line, you can’t assume that is how you are genetically related on the segment in question.

Ideally, at this point, you will find a third person who shares the common ancestor and their DNA matches, or triangulates, between you and your original match to prove the connection.  But, circumstances are not always ideal.

What is Triangualtion?

Triangulation on the continuum of confidence is the highest confidence level achievable, outside of close relative matching which is evident by itself without triangulation.

Triangulation is when you match two people who share a common ancestor and all three of you match each other on that same segment.  This means that segment descended to all three of you from that common ancestor.

This is what a match group would look like if Jerry matches both John and Bridget.

confidence example 1 match group

Example 1 – Match Group

The classic definition of triangulation is when three people, A, B and C all match each other on the same segment and share a known, identifiable common ancestor.  Above, we only have two.  We don’t know yet if John matches Bridget.

A matches B
A matches C
B matches C

This is what an exact triangulation group would look like between Jerry, John and Bridget.  Most triangulation matches aren’t exact, meaning the start and/or end segment might be different, but some are exact.

confidence example 2 triangulation group

Example 2 – Triangulation Group

It’s not always possible to prove all three.  Sometimes you can see that Jerry matches Bridget and Jerry matches John, but you have no access to John or Bridget’s kits to verify that they also match each other.  If you are at Family Tree DNA, you can run the ICW (in common with) tool to see if John and Bridget do match each other – but that tool does not confirm that they match on the same segment.

If the individuals involved have uploaded their kits to GedMatch, you have the ability to triangulate because you can see the kit numbers of your matches and you can then run them against each other to verify that they do indeed match each other as well.  Not everyone uploads their kits to GedMatch, so you may wind up with a hybrid combination of triangulated groups (like example 2, above) and matching groups (like example 1, above) on your own personal spreadsheet.

Matching groups (that are not triangulated) are referred to by different names within the community.  Tim Janzen refers to them as clusters of cousins, Blaine as pseudo triangulation and I have called them triangulation groups in the past if any three within the group are proven to be triangulated. Be careful when you’re discussing this, because matching groups are often misstated as triangulated groups.  You’ll want to clarify.

Creating a Match List

Sometimes triangulation options aren’t available to us.  For example, at Family Tree DNA, we can see who matches us, and we can see if they match each other utilizing the ICW tool, but we can’t see specifically where they match each other.  This is considered a match group.  This type of matching is also where a great deal of confusion is introduced because these people do match each other, but they are NOT (yet) triangulated.

What we know is that all of these people are on YOUR match list, but we don’t know that they are on each other’s match lists.  They could be matching you on different sides of your DNA or, if smaller segments, they might be IBC (identical by chance.)

You can run the ICW (in common with) tool at Family Tree DNA for every match you have.  The ICW tool is a good way to see who matches both people in question.  Hopefully, some of your matches will have uploaded trees and you can peruse for common ancestors.

The ICW tool is the little crossed arrows and it shows you who you and that person also match in common.

confidence match list ftdna

You can run the ICW tool in conjunction with the ancestral surname in question, showing only individuals who you have matches in common with who have the Crumley surname (for example) in their ancestral surname list.  This is a huge timesaver and narrows your scope of search immediately.  By clicking on the ICW tool for Ms. Bridget,  you see the list, below of those who match both the person whose account we are signed into and Ms. Bridget, below.

confidence icw ftdna

Another way to find common matches to any individual is to search by either the current surname or ancestral surnames.  The ancestral surname search checks the surnames entered by other participants and shows them in the results box.

In the example above, all of these individuals have Crumley listed in their surnames.  You can see that I’ve sorted by ancestral surname – as Crumley is in that search box.

Now, your match lists looks like this relative to the Crumley line.  Some people included trees and you can find your common ancestor on their tree, or through communications with them directly.  In other cases, no tree but the common surname appears in the surname match list.  You may want to note those results on your match list as well.

confidence match list 2

Of course, the next step is to compare these individuals in a matrix to see who matches who and the chromosome browser to see where they match you, which we’ll discuss momentarily.

Group Matching

The next type of matching is when you have a group of people who match each other, but not necessarily on the same segment of DNA.  These matching groups are very important, especially when you know there is a shared ancestor involved – but they don’t indicate that the people share the same segment, nor that all (or any) of their shared segments are from this particular ancestor.  Triangulation is the only thing that accomplishes proof positive.

This ICW matrix shows some of the Crumley participants who have tested and who matches whom.

confidence icw grid

You can display this grid by matching total cM or by known relationship (assuming the individuals have entered this information) or by predicted relationship range.  The total cMs shared is more important for me in evaluating how closely this person might be related to the other individual.

The Chromosome Browser

The chromosome browser at Family Tree DNA shows matches from the perspective of any one individual.  This means that the background display of the 22 Chromosomes (plus X) is the person all of the matches are comparing against. If you’re signed in to your account, then you are the black background chromosomes, and everyone is being compared against your DNA.  I’m only showing the first 6 chromosomes below.

confidence chromosome browser

You can see where up to 5 individuals match the person you’re comparing them to.  In this case, it looks like they may share a common segment on chromosome 2 among several descendants.  Of course, you’d need to check each of these individuals to insure that they match each other on this same segment to confirm that indeed, it did come from a common ancestor.  That’s triangulation.

When you see a grouping of matches of individuals known to descend from a common ancestor on the same chromosome, it’s very likely that you have a match group (cluster of cousins, pseudo triangulation group) and they will all match each other on that same segment if you have the opportunity to triangulate them, but it’s not absolute.

For example, below we have a reconstructed chromosome 8 of James Crumley, the common ancestor of a large group of people shown based on matches.  In other words, each colored segment represents a match between two people.  I have a lot more confidence in the matches shown with the arrows than the single or less frequent matches.

confidence chromosome 8 match group'

This pseudo triangulation is really very important, because it’s not just a match, and it’s not triangulation.  The more people you have that match you on this segment and that have the same ancestor, the more likely that this segment will triangulate.  This is also where much of the confusion is coming from, because matching groups of multiple descendants on the same segments almost always do triangulate so they have been being called triangulation groups, even when they have not all been triangulated to each other.  Very occasionally, you will find a group of several people with a common ancestor who triangulate to each other on this common segment, except one of a group doesn’t triangulate to one other, but otherwise, they all triangulate to others.

confidence triangulation issue

This situation has to be an error of some sort, because if all of these people match each other, including B, then B really must match D.  Our group discussed this, and Jim Bartlett pointed out that these problem matches are often near the vendor matching threshold (or your threshold if you’re using GedMatch) and if the threshold is lowered a bit, they continue to match.  They may also be a marginal match on the edge, so to speak or they may have a read error at a critical location in their kit.

What “in common with” matching does is to increase your confidence that these are indeed ancestral matches, a cousin cluster, but it’s not yet triangulation.

Ancestry Matches

Ancestry has added another level of matching into the mix.  The difference is, of course, that you can’t see any segment data at all, at Ancestry, so you don’t have anything other than the fact that you do match the other person and if you have a shakey leaf hint, you also share a common ancestor in your trees.

confidence ancestry matches

When three people match each other on any segment (meaning this does not infer a common segment match) and also share a common ancestor in a tree, they qualify to be a DNA Circle.  However, there is other criteria that is weighted and not every group of 3 individuals who match and share an ancestor becomes a DNA Circle.  However, many do and many Circles have significantly more than three individuals.

confidence Phoebe Crumley circle

This DNA Circle is for Phebe Crumley, one of my Crumley ancestors.  In this grouping, I match one close family group of 5 people, and one individual, Alyssa, all of whom share Phebe Crumley in their trees.  As luck would have it, the family group has also tested at Family Tree DNA and has downloaded their results to GedMatch, but as it stands here at Ancestry, with DNA Circle data only…the only thing I can do is to add them to my match list.

confidence match list 3

In case you’re wondering, the reason I only added three of the 5 family members of the Abija group to my match list is because two are children of one of the members and their Crumley DNA is represented through their parent.

While a small DNA Circle like Phebe Crumley’s can be incorrect, because the individuals can indeed be sharing the DNA of a different ancestor, a larger group gives you more confidence that the relationship to that group of people is actually through the common ancestor whose circle you are a member of.  In the example Circle shown below, I match 6 individuals out of a total of 21 individuals who are all interrelated and share Henry Bolton in their tree.

Confidence Henry Bolton circle

New Ancestor Discoveries

Ancestry introduced New Ancestor Discoveries (NADs) a few months ago.  This tool is, unfortunately, misnamed – and although this is a good concept for finding people whose DNA you share, but whose tree you don’t – it’s not mature yet.

The name causes people to misinterpret the “ancestors” given to them as genuinely theirs.  So far, I’ve had a total of 11 NADS and most have been easily proven false.

Here’s how NADs work.  Let’s say there is a DNA Circle, John Doe, of 3 people and you match two of them.  The assumption is that John Doe is also your ancestor because you share the DNA of his descendants.  This is a critically flawed assumption.  For example, in one case, my ancestors sister’s husband is shown as my “new ancestor discovery” because I share DNA with his descendants (through his wife, my ancestor’s sister.)  Like I said, not mature yet.

I have discussed this repeatedly, so let’s just suffice it to say for this discussion, that there is absolutely no confidence in NADs and they aren’t relevant.

Shared Matches

Ancestry recently added a Shared Matches function.

For each person that you match at Ancestry, that is a 4th cousin or closer and who has a high confidence match ranking, you can click on shared matches to see who you and they both match in common.

confidence ancestry shared matches

This does NOT mean you match these people through the same ancestor.  This does NOT mean you match them on the same segment.  I wrote about how I’ve used this tool, but without additional data, like segment data, you can’t do much more with this.

What I have done is to build a grid similar to the Family Tree DNA matrix where I’ve attempted to see who matches whom and if there is someone(s) within that group that I can identify as specifically descending from the same ancestor.  This is, unfortunately, extremely high maintenance for a very low return.  I might add someone to my match list if they matched a group (or circle) or people that match me, whose common ancestor I can clearly identify.

Shared Matches are the lowest item on the confidence chart – which is not to say they are useless.  They can provide hints that you can follow up on with more precise tools.

Let’s move to the highest confidence tool, triangulation groups.

Triangulation Groups

Of course, the next step, either at 23andMe, Family Tree DNA, through GedMatch, or some combination of each, is to compare the actual segments of the individuals involved.  This means, especially at Ancestry where you have no tools, that you need to develop a successful begging technique to convince your matches to download their data to GedMatch or Family Tree DNA, or both.  Most people don’t, but some will and that may be the someone you need.

You have three triangulation options:

  1. If you are working with the Family Inheritance Advanced at 23andMe, you can compare each of your matches with each other. I would still invite my matches to download to GedMatch so you can compare them with people who did not test at 23andMe.
  2. If you are working with a group of people at Family Tree DNA, you can ask them to run themselves against each other to see if they also match on the same segment that they both match you on. If you are a project administrator on a project where they are all members, you can do this cross-check matching yourself. You can also ask them to download their results to GedMatch.
  3. If your matches will download their results to GedMatch, you can run each individual against any other individual to confirm their common segment matches with you and with each other.

In reality, you will likely wind up with a mixture of matches on your match list and not everyone will upload to GedMatch.

Confirming that segments create a three way match when you share a common ancestor constitutes proof that you share that common ancestor and that particular DNA has been passed down from that ancestor to you.

confidence match list 4

I’ve built this confidence table relative to matches first found at Family Tree DNA, adding matches from Ancestry and following them to GedMatch.  Fortunately, the Abija group has tested at all 3 companies and also uploaded their results to GedMatch.  Some of my favorite cousins!

Spectrum of Confidence

Blaine Bettinger built this slide that sums up the tools and where they fall on the confidence range alone, without considerations of your goals and technical factors such as segment size.  Thanks Blaine for allowing me to share it here.

confidence level Blaine

These tools and techniques fall onto a spectrum of confidence, which I’ve tried to put into perspective, below.

confidence level highest to lowest

I really debated how to best show these.  Unfortunately, there is almost always some level of judgment involved. In some cases, like triangulation at the 3 vendors, the highest level is equivalent, but in other cases, like the medium range, it really is a spectrum from lowest to highest within that grouping.

Now, let’s take a look at our matches that we’ve added to our match list in confidence order.

confidence match list 5

As you would expect, those who triangulated with each other using some chromosome browser and share a common ancestor are the highest confidence matches – those 5 with a red Y.  These are followed by matches who match me and each other but not on the same segment (or at least we don’t know that), so they don’t triangulate, at least not yet.

I didn’t include any low confidence matches in this table, but of the lowest ones that are included, the shakey leaf matches at Ancestry that won’t answer inquiries and the matches at FTDNA who do share a common surname but didn’t download their information to be triangulated are the least confident of the group.  However, even those lower confidence matches on this chart are medium, meaning at Ancestry they are in a Circle and at FTDNA, they do match and share a common surname.  At Family Tree DNA, they may eventually fall into a triangulation group of other descendants who triangulate.

Caveats

As always, there are some gotchas.  As someone said in something I read recently, “autosomal DNA is messy.”

Endogamy

Endogamous populations are just a mess.  The problem is that literally, everyone is related to everyone, because the founder population DNA has just been passed around and around for generations with little or no new DNA being introduced.

Therefore, people who descend from endogamous populations often show to be much more closely related than they are in a genealogical timeframe.

Secondly, we have the issue pointed out by David Pike, and that is when you really don’t know where a particular segment came from, because the segment matches both the parents, or in some cases, multiple grandparents.  So, which grandparent did that actual segment that descended to the grandchild descend from?

For people who are from the same core population on both parent’s side, close matches are often your only “sure thing” and beyond that, hopefully you have your parents (at least one parent) available to match against, because that’s the only way of even beginning to sort into family groups.  This is known as phasing against your parents and while it’s a great tool for everyone to use – it’s essential to people who descend from endogamous groups. Endogamy makes genetic genealogy difficult.

In other cases, where you do have endogamy in your line, but only in one of your lines, endogamy can actually help you, because you will immediately know based on who those people match in addition to you (preferably on the same segment) which group they descend from.  I can’t tell you how many rows I have on my spreadsheet that are labeled with the word “Acadian,” “Brethren” and “Mennonite.”  I note the common ancestor we can find, but in reality, who knows which upstream ancestor in the endogamous population the DNA originated with.

Now, the bad news is that Ancestry runs a routine that removes DNA that they feel is too matchy in your results, and most of my Acadian matches disappeared when Ancestry implemented their form of population based phasing.

Identical by Population

There is sometimes a fine line between a match that’s from an ancestor one generation further back than you can go, and a match from generations ago via DNA found at a comparatively high percentage in a particular population.  You can’t tell the difference.  All you know is that you can’t assign that segment to an ancestor, and you may know it does phase against a parent, so it’s valid, meaning not IBC or identical by chance.

Yes, identical by population segment matching is a distinct problem with endogamy, but it can also be problematic with people from the same region of the world but not members of endogamous populations.  Endogamy is a term for the timeframe we’re familiar with.  We don’t know what happened before we know what happened.

From time to time, you’ll begin to see something “odd” happened where a group of segments that you already have triangulated to one ancestor will then begin to triangulate to a second ancestor.  I’m not talking about the normal two groups for every address – one from your Mom’s side and one from your Dad’s.  I’m talking, for example, when my Mom’s DNA in a particular area begins to triangulate to one ancestral group from Germany and one from France.  These clearly aren’t the same ancestors, and we know that one particular “spot” or segment range that I received from her DNA can only come from one ancestor.  But these segment matches look to be breaking that rule.

I created the example below to illustrate this phenomenon.  Notice that the top and bottom 3 all match nicely to me and to each other and share a common ancestor, although not the same common ancestor for the two groups.  However, the range significantly overlaps.  And then there is the match to Mary Ann in the middle whose common ancestor to me is unknown.

confidence IBP example

Generally, we see these on smaller segment groups, and this is indicative that you may be seeing an identical by population group.  Many people lump these IBP (identical by population) groups in with IBC, identical by chance, but they aren’t.  The difference is that the DNA in an IBP group truly is coming from your ancestors – it’s just that two distinct groups of ancestors have the same DNA because at some point, they shared a common ancestor.  This is the issue that “academic phasing” (as opposed to parental phasing) is trying to address.  This is what Ancestry calls “pileup areas” and attempts to weed out of your results.  It’s difficult to determine where the legitimate mathematical line is relative to genealogically useful matches versus ones that aren’t.  And as far as I’m concerned, knowing that my match is “European” or “Native” or “African” even if I can’t go any further is still useful.

Think about this, if every European has between 1 and 4% Neanderthal DNA from just a few Neanderthal individuals that lived more than 20,000 years ago in Europe – why wouldn’t we occasionally trip over some common DNA from long ago that found its way into two different family lines.

When I find these multiple groupings, which is actually relatively rare, I note them and just keep on matching and triangulating, although I don’t use these segments to draw any conclusions until a much larger triangulated segment match with an identified ancestor comes into play.  Confidence increases with larger segments.

This multiple grouping phenomenon is a hint of a story I don’t know – and may never know.  Just because I don’t quite know how to interpret it today doesn’t mean it isn’t valid.  In time, maybe its full story will be revealed.

ROH – Runs of Homozygosity

Autosomal DNA tests test someplace over 500,000 locations, depending on the vendor you select.  At each of those locations, you find a value of either T, A, C or G, representing a specific nucleotide.  Sometimes, you find runs of the same nucleotide, so you will find an entire group of all T, for example.  If either of your parents have all Ts in the same location, then you will match anyone with any combination of T and anything else.

confidence homozygosity example

In the example above, you can see that you inherited T from both your Mom and Dad.  Endogamy maybe?

Sally, although she will technically show as a match, doesn’t really “match” you.  It’s just a fluke that her DNA matches your DNA by hopping back and forth between her Mom’s and Dad’s DNA.  This is not a match my descent, but by chance, or IBC (identical by chance.)  There is no way for you to know this, except by also comparing your results to Sally’s parents – another example of parental phasing.  You won’t match Sally’s parents on this segment, so the segment is IBC.

Now let’s look at Joe.  Joe matches you legitimately, but you can’t tell by just looking at this whether Joe matches you on your Mom’s or Dad’s side.  Unfortunately, because no one’s DNA comes with a zipper or two sides of the street labeled Mom and Dad – the only way to determine how Joe matches you is to either phase against Joe’s parents or see who else Joe matches that you match, preferable on the same segment – in other words – create either a match or ICW group, or triangulation.

Segment Size

Everyone is in agreement about one thing.  Large segments are never IBC, identical by chance.  And I hate to use words like never, so today, interpret never to mean “not yet found.”  I’ve seen that large segment number be defined both 13cM and 15cM and “almost never” over 10cM.  There is currently discussion surrounding the X chromosome and false positives at about this threshold, but the jury is still out on this one.

Most medium segments hold true too.  Medium segment matches to multiple people with the same ancestors almost always hold true.  In fact, I don’t personally know of one that didn’t, but that isn’t to say it hasn’t happened.

By medium segments, most people say 7cM and above.  Some say 5cM and above with multiple matching individuals.

As the segment size decreases, the confidence level decreases too, but can be increased by either multiple matches on that segment from a common proven ancestor or, of course, triangulation.  Phasing against your parent also assures that the match is not IBD.  As you can see, there are tools and techniques to increase your confidence when dealing with small segments, and to eliminate IBC segments.

The issue of small segments, how and when they can be utilized is still unresolved.  Some people simply delete them.  I feel that is throwing the baby away with the bathwater and small segments that triangulate from a common ancestor and that don’t find themselves in the middle of a pileup region that is identical by population or that is known to be overly matchy (near the center of chromosome 6, for example) can be utilized.  In some cases, these segments are proven because that same small segment section is also proven against matches that are much larger in a few descendants.

Tim Janzen says that he is more inclined to look at the number of SNPs instead of the segment size, and his comfort number is 500 SNPs or above.

The flip side of this is, as David Pike mentioned, that the fewer locations you have in a row, the greater the chance that you can randomly match, or that you can have runs of heterozygosity.

No one in our discussion group felt that all small segments were useless, although the jury is still out in terms of consensus about what exactly defines a small segment and when they are legitimate and/or useful.  Everyone of us wants to work towards answers, because for those of us who are dealing with colonial ancestors and have already picked the available low hanging fruit, those tantalizing small segments may be all that is left of the ancestor we so desperately need to identify.

For example, I put together this chart detailing my matching DNA by generation. Interesting, I did a similar chart originally almost exactly three years ago and although it has seemed slow day by day, I made a lot of progress when a couple of brick walls fell, in particular, my Dutch wall thanks to Yvette Hoitink.

If you look at the green group of numbers, that is the amount of shared DNA to be expected at each level.  The number of shared cMs drops dramatically between the 5th and 6th generation from 13 cM which would be considered a reasonable matching level (according to the above discussion) at the 5th generation, and 3.32 cM at the 6th generation level, which is a small segment by anyone’s definition.

confidence segment size vs generation

The 6th generation was born roughly in 1760, and if you look to the white grouping to the right of the green group, you can see that my percentage of known ancestors is 84% in the 5th generation, 80% in the 6th generation, but drops quickly after that to 39, 22 and 3%, respectively.  So, the exact place where I need the most help is also the exact place where the expected amount of DNA drops from 13 to 3.32 cM.  This means, that if anyone ever wants to solve those genealogical puzzles in that timeframe utilizing genetic genealogy, we had better figure out how to utilize those small segments effectively – because it may well be all we have except for the occasional larger sticky segment that is passed intact from an ancestor many generations past.

From my perspective, it’s a crying shame that Ancestry gives us no segment data and it’s sad that 23andMe only gives us 5cM and above.  It’s a blessing that we can select our own threshold at GedMatch.  I’m extremely grateful that FTDNA shows us the small segment matches to 1cM and 500 SNPs if we also match on 20cM total and at least one segment over 7cM.  That’s a good compromise, because small segments are more likely to be legitimate if we have a legitimate match on a larger segment and a known ancestor.  We already discussed that the larger the matching segment, the more likely it is to be valid. I would like to see Family Tree DNA lower the matching threshold within projects.  Surname projects imply that a group of people will be expected to match, so I’d really like to be able to see those lower threshold matches.

I’m hopeful that Family Tree DNA will continue to provide small segment information to us.  People who don’t want to learn how to use or be bothered with small segments don’t have to.  Delete is perfectly legitimate option, but without the data, those of us who are interested in researching how to best utilize these segments, can’t.  And when we don’t have data to use, we all lose.  So, thank you Family Tree DNA.

Coming Full Circle

This discussion brings us full circle once again to goals.

Goals change over time.

My initial reason for testing, the first day an autosomal test could be ordered, was to see if my half-brother was my half-brother.  Obviously for that, I didn’t need matching to other people or triangulation.  The answer was either yes or no, we do match at the half-sibling level, or we don’t.

He wasn’t.  But by then, he was terminally ill, and I never told him.  It certainly explained why I wasn’t a transplant match for him.

My next goal, almost immediately, was to determine which if either my brother or I were the child of my father.  For that, we did need matching to other people, and preferably close cousins – the closer the better.  Autosomal DNA testing was new at that time, and I had to recruit cousins.  Bless those who took pity on me and tested, because I was truly desperate to know.

Suffice it to say that the wait was a roller coaster ride of emotion.

If I was not my father’s child, I had just done 30+ years of someone else’s genealogy – not a revelation I relished, at all.

I was my father’s child.  My brother wasn’t.  I was glad I never told him the first part, because I didn’t have to tell him this part either.

My goal at that point changed to more of a general interest nature as more cousins tested and we matched, verifying different lineages that has been unable to be verified by Y or mtDNA testing.

Then one day, something magical happened.

One of my Y lines, Marcus Younger, whose Y line is a result of a NPE, nonparental event, or said differently, an undocumented adoption, received amazing information.  The paternal Younger family line we believed Marcus descended from, he didn’t.  However, autosomal DNA confirmed that even though he is not the paternal child of that line, he is still autosomally related to that line, sharing a common ancestor – suggesting that he may have been born of a Younger female and given that surname, while carrying the Y DNA of his biological father, who remains unidentified.

Amazingly, the next day, a match popped up that matched me and another Younger relative.  This match descended not from the Younger line, but from Marcus Younger’s wife’s alleged surname family.  I suddenly realized that not only was autosomal DNA interesting for confirming your tree – it could also be used to break down long-standing brick walls.  That’s where I’ve been focused ever since.

That’s a very different goal from where I began, and my current goal utilizes the tools in a very different way than my earlier goals.  Confidence levels matter now, a great deal, where that first day, all I wanted was a yes or no.

Today, my goal, other than breaking down brick walls, is for genetic genealogy to become automated and much easier but without taking away our options or keeping us so “safe” that we have no tools (Ancestry).

The process that will allow us to refine genetic genealogy and group individuals and matches utilizing trees on our desktops will ultimately be the key to unraveling those distant connections.  The data is there, we just have to learn how to use it most effectively, and the key, other than software, is collaboration with many cousins.

Aside from science and technology, the other wonderful aspect of autosomal DNA testing is that is has the potential to unite and often, reunite families who didn’t even know they were families.  I’ve seen this over and over now and I still marvel at this miracle given to us by our ancestors – their DNA.

So, regardless of where you fall on the goals and matching confidence spectrum in terms of genetic genealogy, keep encouraging others to test and keep reaching out and sharing – because it takes a village to recreate an ancestor!  No one can do it alone, and the more people who test and share, the better all of our chances become to achieve whatever genetic genealogy goals we have.

Demystifying Autosomal DNA Matching

dna word cluster4

What, exactly, is an autosomal DNA match?

Answer:  It’s Relative

I’m sorry, I just had to say that.

But truthfully, it is.

I know this sounds like a very basic question, and it is, but the answer sometimes isn’t as straightforward as we would like for it to be.

Plus, there are differences in quality of matches and types of matches.  If you want to sigh right about now, it’s OK.

We’ve talked a lot about matching in various recent articles.  I have several people who follow this blog religiously, and who would rather read this than, say, do dishes (who wouldn’t).  One of our regulars recently asked me the question, “what, exactly, is a match and how do I tell?”

Darned good question and I wish someone had explained this to me so I wouldn’t have had to figure it out.

In the computer industry, where I spent many years, we have what we call flow charts or wernier diagrams which in essence are logic paths that lead to specific results or outcomes depending on the answers at different junctions.

flow chart

I had a really hard time deciding whether to use the beer decision-making flow chart or the procrastinator flow chart, but the procrastinator flow chart was just one big endless loop, so I decided on the beer.

What I’m going to do is to step you through the logic path of finding and evaluating a match, determining whether it’s valid, identical by descent or chance, when possible, and how to work with your matches and what they mean.

Let me also say that while I use and prefer Family Tree DNA, these matching techniques are universal and apply to results from 23andMe as well, but not for Ancestry who gives you no browser or tools to compare your DNA to anyone else.  So, you can’t compare your results at Ancestry.

Comparing DNA results is the lynchpin of genetic genealogy.  You’re dead in the water without it.  If you have tested at Ancestry, you can always transfer your results to Family Tree DNA, where you do have tools, and to GedMatch as well.  You’re always better, in terms of genealogy, to fish in as many ponds as possible.

Before we talk about how to work with matches, for those who need to figure out how to find matches at Family Tree DNA and 23andMe, I wrote about that in the Chromosome Browser War article.  This article focuses on working with matching DNA after you have found that you are a match to someone – and what those matches might mean.

Matching Thresholds

All autosomal DNA vendors have matching thresholds.  People who meet or exceed those thresholds will be shown on your match list.  People who do not meet the initial threshold will not be considered as a match to you, and therefore will not be on your match list.

Currently, at Family Tree DNA, their match threshold to be shown as a match is about 20cM of total matching DNA and a single segment of about 7.7cM with 500 SNPs or over. The words “about” are in there because there is some fuzziness in the rules based on certain situations.

After you meet that criteria and you are shown as a match to an individual, when you download your matching data, your matches to them on each chromosome will be shown to the 1cM and 500 SNP level

At 23andMe, the threshold is 7cMs/700 SNPs for the first segment.  However, 23andMe has an upper limit of people who can match you at about 1000 matches.  This can be increased by the number of people you are communicating or sharing with.  However, your smallest matches will be dropped from your list when you hit your threshold.  This means that it’s very likely that at least some of your matches are not showing if you have in excess of 1000 matches total.  This means that your personal effective cM/SNP match threshold at 23andMe may be much higher.

Step 1 – Downloading Your Matching Segments

For this comparison, I’m starting with two fresh files from Family Tree DNA, one file of my own matches and one of my mother’s matches.  My mother died before autosomal DNA testing was available, so her results are only at Family Tree DNA (and now downloaded to GedMatch,) because her DNA was archived there.  Thank you Family Tree DNA, 100,000 times thank you!!!

At Family Tree DNA, the option to download all matches with segment information is on the chromosome browser tab, at the top, at the right, shown below.

ftdna download button

If you have your parents DNA available to test and it hasn’t been tested, order a kit for them today.  If either or both parents have been tested, download their results into the same spreadsheet with yours and color code them in a way you will understand.

In my case, I only have my mother’s results, and I color coded my matches pink, because I’m the daughter.  However, if I had both parents, I might have colored coded Mother pink and Dad blue.

Whatever color coding you do, it’s forever in your master spreadsheet, so make a note of what it is.  In my case, it’s part of the match column header.  Why is it in my column header?  Because I screwed up once and reversed them in a download.

Step 2 – Preparing and Sorting Your Spreadsheet

In my master DNA spreadsheet, I have the following columns,

dna master header

The green cell matches are matches to me from 23andMe.  My cousin, Cheryl also tested at 23andMe before autosomal testing was offered at Family Tree DNA.

The Source column, in my spreadsheet, means any source other than FTDNA.  The Ignore column is an extraneous number generated at one time by downloads.  I could delete that column now.

The “Side” column is which side the match is from, Mom or Dad.  Mom’s I can identify easily, because I have her DNA to compare to.  I don’t identify a match as Dad’s without having identified an ancestral line, because I don’t have his DNA to compare to.

And no, you can’t just assume that if it doesn’t match Mom, it’s an automatic match to Dad because you may have some IBS, identical by chance, matches.

The Common Ancestors/Comments column is just that.  I include things like when I e-mailed someone, if the match is triangulated and if so, with whom, etc.

In my master spreadsheet, the first “name” column (of who tested) is deleted, but I’ve left it in the working spreadsheet (below) with my mother for illustration purposes.  That way, neither of us has to remember who is pink!

Step 3 – Reviewing IBD and IBS Guidelines

If you need a refresher on, phasing, IBD, identical by descent, IBS which can mean either identical by chance or identical by population, it would be a good time to read or reread the article titled How Phasing Works and Determining IBD Versus IBS Matches.

Let’s briefly review the IBD vs IBS guidelines, because we’ll be applying them in this article.

Identical by Chance – Can be determined if an individual you match does not match to one of your parents, if parents are available.  If parents are not available for matching, IBS by chance segments won’t triangulate with other known genealogical matches on a common segment.

Identical by Descent – Can be suggested if a common ancestor (or ancestral line) can be determined between any two people who are not known relatives. If the two people are known close relatives, and their DNA matches, identical by descent is proven.  IBD can be proven with previously unknown family or genealogical matches when any three people descending from that same ancestor or ancestral line all match each other on the same segment of DNA.  Three way matching is called triangulation.

Identical by Population – Can be determined when multiple people triangulate with you on a specific segment of DNA, but the triangulated groups are from proven different lineages and are not otherwise related.  This is generally found in smaller segments from similar regions of the world.  Identical by population is identical by descent, but the ancestors are so far back in time that they cannot be determined and may contribute the same DNA to multiple lineages.  This is particularly evident in Jewish genealogy and other endogamous groups.

Step 4 – Determining Parental Side and IBS by Chance

The first thing to do, if you have either or both parents, is to determine whether your matches phase to your parents or are IBS by chance.

In this context, phasing means determining whether a particular match is to your father’s side of the family or to your mother’s side of the family.

Remember, at every address in your DNA, you will have two valid matches to different lines, one from your mother and one from your father.  The address on your DNA consists of the chromosome number which equates to the street name, and then the start and end locations, which consists of a range of addresses on that street.  Think of it as the length of your property on the street.

First, let’s look at my situation with only my mother’s DNA for comparison.

It’s easy to tell one of three things.

  1. Do mother and I both match the person? If so, that means that DNA match is from mother’s side of the family. Mark it as such. They are green, below.
  2. If the individual does not match me and mother, both, and only matches me, then the match is either on my father’s side or it’s IBS by chance. Those matches are blue below. Because I don’t have my father’s DNA, I can’t tell any more at this step.
  3. Notice the matches that are Mom’s but not to me. That means that I did not receive that DNA from Mom, or I received a small part, but it’s not over the lowest matching threshold at Family Tree DNA of 1cM and 500 SNPs.

match mom

In this next scenario, you can see that mother and I both match the same individual, but not on all segments.  I selected this particular match between me, my mother and Alfred because it has some “problems” to work through.

match mom2

The segments shown in green above are segments that Mom carries that I don’t.  This means that I didn’t receive them from mother.  This also means they could be  matching to Alfred legitimately, or are IBS by chance.  I can’t tell anything more about them at this point, so I’ve just noted what they are.  I usually mark these as “mother only” in my master spreadsheet.

match mom3

The first of the two green rows above show a match but it’s a little unusual.  My segment is larger than my mothers.  This means that one of five things has happened.

  1. Part of this segment is a valid match.  At the end, where we don’t match, the match extends IBS by chance a bit at the end, in my case, when matching Alfred. The valid match portion would end where my mother’s segment ends, at 16,100,293
  2. There is a read error in one of the files.
  3. The boundary locations are fuzzy, meaning vendor calculations like ‘healing’ for no calls, etc..
  4. I also match to my father’s line.
  5. Recombination has occurred, especially possible in an endogamous population, reconnecting identical by population segments between me and Alfred at the end of the segment where I don’t match my mother’s segment, so from 16,100,293 to 16,250,884.

Given that this is a small segment, the most likely scenario would be the first, that this is partly valid and partly IBS by chance.  I just make the note by that row.

The second green segment above isn’t an exact match, but if my segment “fits within” the boundaries of my mother’s segments, then we know I inherited the entire segment from her.  Once again, my boundaries are off a bit from hers, but this time it’s the beginning.  The same criteria applies as in 1-5, above.

match mom4

The green segments above are where I match Alfred, but my mother does not.  This means that these segments are either IBS by chance or that they will match my father.  I don’t know which, so I simply label them.  Given that they are all small segments, they are likely IBS by chance, but we don’t know that.  If we had my father’s DNA, we would be able to phase against him, too, but we don’t.

Now, if I was to leave this discussion here, you might have the impression that all small segment matches have problems, but they don’t.  In fact, here’s a much more normal “rea life” situation where mother and I are both matching to our cousin, Cheryl, Mom’s first cousin.  These matches include both large and small segments.  Let’s take a look and see what we can tell about our matches.

match mom complete

Roberta and Barbara have a total of 83 DNA matches to Cheryl.

Some matches will be where Barbara matches Cheryl and Roberta doesn’t.  That’s normal, Barbara is Roberta’s mother and Roberta only inherits half of Barbara’s DNA.  These rows where only Barbara, the mother, matches Cheryl are not colorized in the Start, End, cM and SNP columns, so they show as white.

Some matches will be exact matches.  That too is normal.  In some cases, Barbara passes all of a particular segment of DNA to Roberta.  These matches are colored purple.

Some of these matches are partial matches where Roberta inherited part of the segment of DNA from Barbara.  These are colored green. There are two additional columns at right where the percentage of DNA that Roberta inherited from Barbara on these segments is calculated, both for cM and SNPs.

Some of the matches are where Roberta matches Cheryl and Barbara doesn’t.  Cheryl is not known to be related to Roberta on her father’s side, so assuming that statement is correct, these matches would be IBS, identical by state, meaning identical by chance and can be disregarded at legitimate matches.  These are colored rust.  Note that most of these are small segments, but one segment is 8.8cM and 2197 SNPs.  In this case, if this segment becomes important for any reason, I would be inclined to look at the raw data file of Barbara to see if there were no calls or a problem with reads in this region that would prevent an otherwise legitimate match.

Let’s look at how these matches stack up.

Number Percent (rounded) Comment
Exact Matches 26 31 100% of the DNA
Barbara Only 20 24 0% of the DNA
Partial Matches 29 35 11-98% of the actual DNA matches
Roberta Only (IBS by chance) 7 8 Not a valid match

I think it’s interesting to note that while, on the average, 50% of the DNA of any segment is passed to the child, in actuality, in this example of partial inheritance, meaning the green rows, inheritance was never actually 50%.  In fact, the SNP and cM percentages inherited for the same segment varied, and the actual amounts ranged from 11-98% of the DNA of the parent being inherited by the child.  The average of these events was 54.57143 (cM) and 54.21429 (SNPs) however.

On top of that, in 13 (26 rows) instances, Roberta inherited all of Barbara’s DNA in that sequence, and in 20 cases, Roberta inherited none of Barbara’s DNA in that sequence.

This illustrates that while the average of something may be 50%, none of the actual individual values may be 50% and the values themselves may include the entire range of possibilities.  In this case, 11-98% were the actual percentage ranges for partial matches.

Matching Both Parents

I don’t have my father’s DNA, but I’m creating this next example as if I did.

match both parents

Matches to mother are marked in green.

I have two matches where I match my father, so we can attribute those to his side, which I’ve done and marked in orange.

The third group of matches to me, at the bottom, to Julio, Anna, Cindy and George don’t match either parent, so they must be IBS by chance.

I label IBS by chance segments, but I don’t delete them because if I download again, I’ll have to go through this same analysis process if I don’t leave them in my spreadsheet

Step 5 – How Much of the DNA is a Match?

One person asked, “exactly how do I tell how much DNA is matching, especially between three people.”  That’s a very valid question, especially since triangulation requires matching of three people, on the same segment, proven to a common ancestral line.

Let’s look at the match of both me and my mother to Don, Cheryl and Robin.

match mom part

In this example, we know that Don, Cheryl and Robin all match me on my mother’s side, because they all three match me and my mother, both on the same segment.

How do we determine that we match on the same segment?

I have sorted this spreadsheet in order of end location, then start location, then chromosome number so that the entire spreadsheet is in chromosome order, then start location, then end location.

We can see that both mother and I match Cheryl partially on this segment of chromosome 1, but not exactly.  The start location is slightly different, but the end location matches exactly.

The area where we all three match, meaning me, Mom and Cheryl, begins at 176,231,846 and ends at the common endpoint of 178,453,336

On the chart below, you can see that mother and I also both match Don, Cheryl’s brother, on part of this same segment, but not all of the same segment.

match mom part2

The common matching areas between me, Mom and Don begins at 176,231,846 and ends at 178,453,336.

Next, let’s look at the third person, Robin.

Mom and I both match Robin on part of this same overlapping segment as well.  Note that my segment extends beyond Mom’s, but that does not invalidate the portion that does match between Robin, Mom and I.

match mom part3

Our common match area begins at the same location, but ends at 178,453,336, the same location as the common end area with Don and Cheryl

Step 6 – What Do Matches Mean? IBD vs IBS in Action

So, let’s look at various types of matches and what they tell us.

match mom example

Looking at our matching situation above, let’s apply the various IBD/IBS rules and guidelines and see what we have

1. Are these matches identical by chance?  No.  How do we know?

a. Because they all match both me and a parent.

2. Are these matches identical by descent? Yes. How do we know?

a. Because we all match each other on this segment, and we know the common ancestor of Cheryl, Don, Barbara and me is Hiram Ferverda and Evaline Miller.  We know that Robin descends from the same ancestral Miller line.

3. Are these matches identical by population.  We don’t know, but there is no reason at this point to think so. Why?

a. Because looking at my master spreadsheet, I see no evidence that these segments are also assigned to other lineages. These individuals are also triangulated on a large number of other, much larger, segments as well.

4. Are these matches triangulated, meaning they are proven to a common ancestor? Yes. How do we know?

a. Documented genealogy of Hiram Ferverda and Evaline Miller. Don, Barbara, Cheryl and me are known family since birth.
b. Documented genealogy of Robin to the same ancestral family, even though Robin was previously unknown before DNA matching.
c. Even without the documented genealogy, Robin matches a set of two triangulation groups of people documented to the same ancestral line, which means she has to descend from that same line as well.

In our case, clearly these individuals share a common ancestor and a common ancestral line.  Even though these are small segments on chromosome 1, there are much larger matching segments on other chromosomes, and the same rules still apply.  The difference might be at some point smaller segments are more likely to be identical by population than larger segments.  Larger segments, when available, are always safer to use to draw conclusions.  Larger groups of matching individuals with known common genealogy on the same segments are also the safest way to draw conclusions.

Step 7 – Matching With No Parents

Sometimes you’re just not that lucky.  Let’s say both of your parents have passed and you have no DNA from them.

That immediately eliminates phasing and the identical by chance test by comparing to your parents, so you’ll have to work with your matches, including your identical by chance segments.

A second way to “phase” part of your DNA to a side of your family is by matching with known cousins or any known family member.

In the situation above, matching to Cheryl, Don and Robin, let’s remove my mother and see what we have.

match no mom

In this case, I still match to both of my first cousins, once removed, Cheryl and Don.  Given that Cheryl and Don are both known cousins, since forever, I don’t feel the need for triangulation proof in this case – although the three of us are triangulated to our common ancestor.  In other words, the fact that my mother does match them at the expected 1st cousin level is proof enough in and of itself if we only had one cousin to test.  We know our common ancestor is Cheryl and Don’s grandparents, who are my great-grandparents, Hiram Ferverda and Evaline Miller.

When I looked at Robin’s pedigree chart and saw that Robin descended from Philip Jacob Miller and wife Magdalena, I knew that this segment was a Miller side match, not a Ferverda match.

Therefore, matching with someone whose genealogy goes beyond the common ancestor of Cheryl, Don and me proves this line through 4 more generations.  In other words, this DNA segment came through the following direct line to reach Me, Mother, Cheryl and Don.

  • Philip Jacob Miller and Magdalena
  • Daniel Miller
  • David Miller
  • John David Miller
  • Evaline Louise Miller who married Hiram Ferverda

Clearly, we know from the earlier chart that my mother carried this DNA too, but even if we didn’t know that, she obviously had to have carried this segment or I would not carry it today.

So, even though in this example, our parents aren’t directly available for IBS testing and elimination, we can determine that anyone who matches both me and Cheryl or me and Don will have also matched mother on that segment, so we have, in essence, phased those people by triangulation, not by direct parental matching.

Step 8 – Triangulation Groups

What else does this match group tell us?

It tells us that anyone else who matches me and any one of our triangulation group on that segment also descends from the Miller descendant clan, one way or another.

Why do they have to match me AND one of the triangulation group members on that segment?  Because I have two sides to my DNA, my Mom’s side and my Dad’s side.  Matching me plus another person from the triangulation group proves which side the match is on – Mom’s or Dad’s.

We were able to phase to eliminate any identical by chance segments people on Mom’s side, so we know matches to both of us are valid.

On Dad’s side, there are some IBS by chance people (or segments) thrown in for good measure because I don’t have my Dad’s DNA to eliminate them out of the starting gate.  Those IBS segments will have to be removed in time by not triangulating with proven triangulated groups they should triangulate with, if they were valid matches.

When you map matches on your chromosome spreadsheet, this is what you’re doing.  Over time, you will be able to tell when you receive a new match by who they match and where they fall on your spreadsheet which ancestral line they descend from.

GedMatch also includes a triangulation utility.  It’s a great tool, because it produces trios of people for your top 400 matches.  The results are two kits that triangulate to the third person whose kit number you are matching against.

The output, below, shows you the chromosome number followed by the two kit numbers (obscured) that triangulate at this location, and then the start and end location followed by the matching cMs.  The result is triangulation groups that “slide to the right.”

gedmatch triang group3

In the example above, all of the triangulation matches to me above the red arrow include either Mother, my Ferverda cousins or the Miller group that we discussed in the Just One Cousin article.  In other words they are all related via a common ancestor.

You can tell a great deal about triangulation groups by who is, and isn’t in them using deductive reasoning.  And once you’ve figured out the key to the group, you have the key to the entire group.

In this case, Mom is a member of the first triangulation group, so I know this group is from her side and not Dad’s side.  Both Ferverda cousins are there, so I know it’s Mom’s Dad’s side of the family.  The Miller cousins are there, so I know it’s the Miller side of Mom’s Dad’s side of the family.

Please also note that while this entire group triangulates within itself, that the group manages to slide right and the first triangulated group of 3 in the list may not overlap the DNA of the last triangulated group of 3.  In fact, because you can see the start and end points, you can tell that these two triangulated groups don’t overlap.  The multiple triangulation groups all do match some portion of the group above and below them (in this case,) and as a composite group, they slide to the right. Because each group overlaps with the group above and below them, they all connect together in a genetic chain.  Because there is an entire group that are triangulated together, in multiple ways, we know that it is one entire group.

This allows me to map that entire segment on my Mom’s side of my DNA, from 10,369,154 to 41,685,667 to this group because it is contiguously connected to me, triangulated and unbroken.  The most distant ancestor listed will vary based upon the known genealogy of the three people being triangulated  For example, part of this segment, may come from Philip Jacob Miller himself, the line’s founder,, but another part could come from his son’s wife, who is also my ancestor.  Therefore, the various pieces of this group segment may eventually be attributed to different ancestors from this particular line based upon the oldest common ancestor of the three people who have triangulated.

In our example above, the second group starts where the red arrow is pointing.  I have absolutely no idea which ancestor this second group comes from – except – I know it does not come from my mother’s side because her kit number isn’t there.

Neither are any of my direct line Estes or Vannoy relatives, so it’s probably not through that line either.  My Bolton cousins are also missing, so we’ve probably eliminated several possible lines, 3 of 4 great grandparents, based on who is NOT in the match group.  See the value of testing both close and distant cousins?  In this case, the family members not only have to test, they also have to upload their results to GedMatch.

Conversely, we could quickly identify at least a base group by the presence in the triangulation groups of at least one my known cousins or people with whom I’ve identified my common ancestor.  Two from the same line would be even better!!!

Endogamy

The last thing I want to show you is an example of what an endogamous group looks like when triangulated.

gedmatch endogamy

This segment of chromosome 9 is an Acadian matching group to my Mom – and the list doesn’t stop here – this is just the size of the screen shot.  These matches continue for pages.

How do I know this group is Acadian?  In part, because this group also triangulates with my known Lore cousin who also descends from the same Acadian ancestor, Antoine Lore, son of Honore Lore and Marie Lafaille.  Additionally, I’ve worked with some of these people and we have confirmed Honore Lore and Marie Lafaille as our common ancestor as well.  In other cases, we’ve confirmed upstream ancestors.

Unfortunately, the Acadians are so intermarried that it’s very difficult to sort through the most distant genetic ancestor because there tend to be multiple most distant ancestors in everyone’s trees.  There is a saying that if you’re related to one Acadian, you’re related to all Acadians and it’s the truth.  Just ask my cousin Paul who I’m related to 137 different ways.

Matches to endogamous groups tend to have very, very long lists of matches, even triangulated, which means proven, matches.

Oh, and by the way, just for the record, this lengthy group includes some of my proven Acadian matches that were trimmed, meaning removed, from my match list when Ancestry did their big purge due to their new and improved phasing.  So if there was ever any doubt that we did in fact lose at least some valid matches, the proof lies right here, in the triangulation of those exact same people at GedMatch

Summary

I hope this step by step article has helped take the Greek, or maybe the geek, out of matching.  Once you think of it in a step by step logical basis, it makes a lot of sense and allows you to reasonably judge the quality of your matches.

The rule of thumb has been that larger matches tend to be “legitimate” and smaller matches are often discarded en masse because they might be problematic.  However, we’ve seen situations where some larger matches may not be legitimate and some smaller matches clearly are.  In essence, the 50% average seldom applies exactly and rules of thumb don’t apply in individuals situations either.  Your situation is unique with every match and now you have tools and guidelines to help you through the matching maze.

And hey, since we made it to the end, I think we should celebrate with that beer!!!

beer