DNA Inherited from Grandparents and Great-Grandparents

Philip Gammon, our statistician friend has been working with crossover simulations again in order to tell us what we might expect relative to how much DNA we actually inherit from grandparents and great-grandparents.

We know that on average, we’re going to inherit 25% of our DNA from each grandparent – but we also know in reality that’s not what happens. We get more or less than exactly 25% from each person in a grandparent pair. It’s the total of the DNA of both grandparents that adds up to 50% for the couple.

How does this work, and does it make a difference whether we inherit our grandparent’s DNA through males or females?

Philip has answers for us as a result of his simulations.

DNA Inheritance from Grandparents

Philip Gammon:

When we consider the DNA that we inherit from our ancestors the only quantity that we can be certain of is that we receive half of our autosomal DNA from each parent. This is delivered to us in the form of the 22 segments (i.e. chromosomes) provided by our mothers in the ova and the 22 segments/chromosomes provided by our fathers in the sperm cell. Beyond parent-child relationships we tend to talk about averages. For instance, we receive an average of one quarter of our DNA from each of our four grandparents and an average of one-eighth of our DNA from each of our eight great-grandparents etc.

These figures vary because our parents didn’t necessarily pass on to us equal portions of the DNA that they received from their parents. The level of variation is driven by the number (and location) of crossover events that occur when the ova and the sperm cells are created.

The statistics relevant to the recombination process were discussed in detail in a previous article (Crossovers: Frequency and Inheritance Statistics – Male Versus Female Matters). With the availability these days of abundant real data from direct-to-consumer genetic testing companies (such as the 23andMe data utilised by Campbell et. al. in their paper titled “Escape from crossover interference increases with maternal age”) we can use this information as a basis for simulations that accurately mimic the crossover process. From these simulations we can measure the amount of variation that is expected to be observed in the proportions of DNA inherited from our ancestors. This is precisely what I have done in simulations run on my GAT-C model.

Before looking at the simulation results let’s anticipate what we expect to see. The previous article on crossover statistics revealed that there are an average of about 42 crossovers in female meiosis and about 27 in male meiosis. So, on the set of 22 chromosomes received from our mothers there will have been an average of 42 crossover locations where there was a switch between DNA she inherited from one parent to the other. That means that the DNA we inherit from our maternal grandparents typically comes in about 64 segments, but it won’t necessarily be 32 segments from each maternal grandparent. Chromosomes that experienced an odd number of crossovers contain an even number of segments (half originating from the grandmother, the other half from the grandfather) but chromosomes with an even number of crossovers (or zero!) have an odd number of segments so on these chromosomes you must receive one more segment from one grandparent than the other. And of course not all segments are the same size either. A single crossover occurring close to one end of the chromosome results in a small segment from one grandparent and a large segment from the other. All up there are quite a few sources of variation that can affect the amount of DNA inherited from grandparents. The only certainty here is that the amount inherited from the two maternal grandparents must add to 50%. If you inherit more than the average of 25% from one maternal grandparent that must be offset by inheriting less than 25% from the other maternal grandparent.

Gammon grandparents maternal percent.png

The above chart shows the results of 100,000 simulation runs. Excluding the bottom and top 1% of results, 98% of people will receive between 18.7% and 31.3% of their DNA from a maternal grandparent. The more darkly shaded region in the centre shows the people who receive a fairly even split of between 24% and 26% from the maternal grandparents. Only 28.8% of people are in this region and the remainder receive a less even contribution.

On the set of 22 chromosomes received from fathers there will have been an average of around 27 crossovers so the DNA received from the paternal grandparents has only been split into around 49 segments. It’s the same amount of DNA as received from mothers but just in larger chunks of the grandparent’s DNA. This creates greater opportunity for the father to pass on unequal amounts of DNA from the two grandparents so it would be expected that results from paternal inheritance will show more variation than from maternal inheritance.

Gammon grandparents paternal percent.png

The above chart shows the results of 100,000 simulated paternal inheritance events. They are more spread out than the maternal events with the middle 98% of people receiving between 16.7% and 33.3% of their DNA from a paternal grandparent. Only 21.9% of people receive a fairly even split of between 24% and 26% from each paternal grandparent as shown by the more darkly shaded region in the centre.

Gammon grandparents percent cM.png

To help with the comparison between maternal and paternal inheritance from grandparents the two distributions have been overlayed on the same scale in the chart above. And what are the chances of receiving a fairly even split of grandparents DNA from both your mother and your father? Only 6.3% of people can be expected to inherit an amount of between 24% and 26% of their DNA from all four grandparents.

Now I’ll extend the simulations out to the next generation and examine the variation in proportions of DNA inherited from the eight great-grandparents. There are effectively four groups of great-grandparents:

  • Mother’s maternal grandparents
  • Mother’s paternal grandparents
  • Father’s maternal grandparents
  • Father’s paternal grandparents

The DNA from group 1 has passed to you via two maternal recombination events, from your mother’s mother to your mother, then from your mother to you. On average there would have been 42 crossovers in each of these recombination events. Group 4 comprised two paternal recombination events averaging only 27 crossovers in each. The average amount of DNA received along each path is the same but along the group 1 path it would comprise of more numerous smaller segments than the group 4 path. Groups 2 and 3 would be somewhere between, both consisting of one maternal and one paternal recombination event.

Gammon greatgrandparents percent cM.png

The above chart shows the variation in the amount of DNA received from members of the four groups of great-grandparents. 25,000 simulations were performed. The average amount from any great-grandparent is 12.5% but there can be considerably more variation in the amount received from the father’s paternal grandparents than from the mother’s maternal grandparents. Groups 2 and 3 are between these two extremes and are equivalent. It doesn’t matter whether a paternal recombination follows a maternal one or vice versa – the end result is that both paths consist of the same average number of crossovers.

The table below shows the range in the amount of DNA that people receive from their great-grandparents. The bottom and top 1% of outcomes have been excluded. Note that these are based on a total of 3,418 cM for the 22 autosomes which is the length observed in the Campbell et. al. study. The average of 12.5% of total DNA is 854.5 cM:

Group 1st percentile 99th percentile
Mother’s maternal grandparents 522 cM 1219 cM
Mother’s paternal grandparents 475 cM 1282 cM
Father’s maternal grandparents 475 cM 1281 cM
Father’s paternal grandparents 426 cM 1349 cM

As a matter of interest, in each of the 25,000 simulations the amount of DNA received from the eight great-grandparents were sorted into order from the highest cM to the lowest cM. The averages of each of these eight amounts were then calculated and the results are below:

Gammon greatgrandparents average cM.png

On average, a person receives 1,129 cM from the great-grandparent that they inherited the most of their DNA from and only 600 cM from the great-grandparent that they received the least of their DNA from. But none of us are the result of 25,000 trials – we are each the product of recombination events that occurred once only. The above chart shows the average or typical variation in the amount of DNA received from the eight great-grandparents. Half of people will have experienced more variation than shown above and half of people will have experienced less variation.

Could you have received the same amount of DNA from all eight grandparents? Of course, it is possible, but it turns out that it is extremely unlikely. The average is 12.5% (854.5 cM) so anything between 12% (820.4 cM) and 13% (888.7 cM) could be considered as being close to this figure. The results reveal that this did not occur in any of the 25,000 simulations. Not one person received amounts between 12% and 13% from all eight great-grandparents.

Widening the criteria, I observe that there were 13 instances in the 25,000 simulations where people received between 11.5% and 13.5% of their DNA from all eight great-grandparents. That is still an extremely rare occurrence. Expanding the range further to between 11% and 14% saw a total of 126 instances, but this still only represents about half a percent of all observations. I think that we just have to face the fact that unless we are an extremely rare individual then we will not have inherited close to equal amounts of DNA from our eight great-grandparents.

Now, back to Roberta.

Thanks Philip.

Now we see why we might not inherit the same amount of DNA from our grandparents and great-grandparents.

We Don’t Have Equal Numbers of Matches on Tree Branches

This also might explain, at least in part, why people don’t have the same number of DNA matches on each branch of their tree.

Of course, other reasons include:

  • Uneven family sizes
  • Fewer or more cousins testing on different branches
  • Recent immigration meaning there are few people available to test
  • Family from a region where DNA testing and/or genealogy is not popular
  • Endogamy which dramatically increases the number of people you will match

Real Life Example

In our real-life example, two grandchildren are fortunate to have three grandparents and one great-grandparent available for matching.

For comparison purposes, let’s take a look at how many matches each grandchild has in common with their grandparents and great-grandparent.

The line of descent is as follows:

Gammon line of descent.png

Both end of line testers are female children.

The transmission path from their great-grandmother is:

  • Female to their paternal grandmother
  • Female to their father
  • Male to female tester

The transmission path from their maternal grandfather is:

  • Male to their mother
  • Female to female tester

The transmission path from their maternal grandmother is:

  • Female to their mother
  • Female to female tester

This first chart shows the number of common matches.

Matches Grand 1 Grand 2 GGF GGM Grand 3 Grand 4
Female 1 absent 1061 absent 238 529 1306
Female 2 absent 1225 absent 431 700 1064

It’s interesting that the matches in just 3 generations to the great-grandmother vary by 55%. The second tester has almost twice as many matches in common with her great-great-grandmother as she does the first tester. There a difference in the earlier generation, meaning matches to Grand 2, but only about 23%. That difference increased significantly in one generation.

The second chart shows the total number of matching cM with the matching family member.

Total cM Grand 1 Grand 2 GGF GGM Grand 3 Grand 4
Female 1 absent 1688 absent 713 1601 1818
Female 2 absent 1750 absent 852 1901 1511

We can see that the amount of DNA inherited from a grandparent does correlate with the number of matches to that grandparents. The more DNA shared, of course the better the chances of sharing that DNA with another person. However, multiple factors may be involved with why some people have more or fewer matches.

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Top 10 All-Time Favorite DNA Articles

Top 10

I’ve been writing about DNA is every shape and form for approaching 8 years now, offering more than 1200 free (key word seachable) articles.

First, thank you for being loyal subscribers or finding my articles and using them to boost your genealogy research with the power of DNA.

You may not know this, but many of my articles stem from questions that blog readers ask, plus my own genealogical research stumbling-blocks, of course.

DNAeXplain articles have accumulated literally millions and millions of page views, generating more than 38,000 approved comments. Yes, I read and approve (or not) every single comment. No, I do not have “staff” to assist. Staff consists of some very helpful felines who would approve any comment with the word catnip😊

More than twice that number of comments were relegated to spam. That’s exactly why I approve each one personally.

Old Faithful

Looking at your favorites, I’ve discovered that some of these articles have incredible staying power, meaning that people access them again and again. Given their popularity and usefulness, please feel free to share by linking or forwarding to your friends and genealogy groups.

Subscribe for FREE

Don’t forget, you can subscribe for free by clicking on the little grey “follow” box on the upper right hand side of the blog margin.

Top 10 subscribe

Just enter your e-mail address and click on follow. I don’t sell or share your e-mail, ever. I’ve never done a mass e-mailing either – so I’ll not be spamming you😊

You will receive each and every article, about 2 per week, in a nice handy e-mail, or RSS feed if you prefer.

Your Favorites

You didn’t realize it, but every time you click, you’re voting.

So, which articles are reader favorites? Remember that older articles have had more time to accumulate views.

I’ve noted the all-time ranking along with the 2019 ranking.

Starting with number 10, you chose:

  • Number 10 all-time, did not place in top 10 in 2019: Ethnicity Testing – A Conundrum – Published in 2016 – How ethnicity testing works – and why sometimes it doesn’t work like people expect it will.

Ethnicity results from DNA testing. Fascinating. Intriguing. Frustrating. Exciting. Fun. Challenging. Mysterious. Enlightening. And sometimes wrong. These descriptions all fit. Welcome to your personal conundrum! The riddle of you! If you’d like to understand why your ethnicity results might not have … Continue reading →

  • Number 9 all time and number 4 in 2019: How Much Indian Do I Have in Me? – Published in 2015 – This article explains how to convert that family story into an expected percentage.

I can’t believe how often I receive this question. Here’s today’s version from Patrick. “My mother had 1/8 Indian and my grandmother on my father’s side was 3/4, and my grandfather on my father’s side had 2/3. How much would … Continue reading →

  • Number 8 all-time, did not place in top 10 in 2019: 4 Kinds of DNA for Genetic Genealogy – Published in 2012 – Short, basic and THE article I refer people to most often to understand DNA for genealogy.

Let’s talk about the different “kinds” of DNA and how they can be used for genetic genealogy. It used to be simple. When this “industry” first started, in the year 2000, you could test two kinds of DNA and it was … Continue reading →

Yep, there’s a gene for these traits, and more. The same gene, named EDAR (short for Ectodysplasin receptor EDARV370A), it turns out, also confers more sweat glands and distinctive teeth and is found in the majority of East Asian people. This is one … Continue reading →

  • Number 6 all-time, did not place in top 10 in 2019: What is a Haplogroup? – Published in 2013 – One of the first questions people ask about Y and mitochondrial DNA is about haplogroups.

Sometimes we’ve been doing genetic genealogy for so long we forget what it’s like to be new. I’m reminded, sometimes humorously, by some of the questions I receive. When I do DNA Reports for clients, each person receives a form to … Continue reading

  • Number 5 all-time and number 10 in 2019: X Marks the Spot – Published in 2012 – This article explains how to use the X chromosome for genealogy and its unique inheritance path.

When using autosomal DNA, the X chromosome is a powerful tool with special inheritance properties. Many people think that mitochondrial DNA is the same as the X chromosome. It’s not. Mitochondrial DNA is inherited maternally, only. This means that mothers … Continue reading →

  • Number 4 all-time, did not place in top 10 in 2019: Ethnicity Results – True or Not? – Published in 2013 – Are your ethnicity results accurate? How can you know, and why might your percentages reflect something different than you expect?

I can’t even begin to tell you how many questions I receive that go something like this: “I received my ethnicity results from XYZ. I’m confused. The results don’t seem to align with my research and I don’t know what … Continue reading →

  • Number 3 all-time and number 1 in 2019: Concepts – Calculating Ethnicity Percentages – Published in 2017 – With the huge number of ethnicity testers, it’s no surprise that the most popular article discussed how those percentages are calculated.

There has been a lot of discussion about ethnicity percentages within the genetic genealogy community recently, probably because of the number of people who have recently purchased DNA tests to discover “who they are.” Testers want to know specifically if ethnicity percentages are right … Continue reading →

  • Number 2 all-time, did not place in top 10 in 2019: Which DNA Test is Best? – Published in 2017 – A comprehensive review of the tests and major vendors in the genetic genealogy testing space. The answer is that your testing goals determine which test is best. This article aligns goals with tests.

If you’re reading this article, congratulations. You’re a savvy shopper and you’re doing some research before purchasing a DNA test. You’ve come to the right place. The most common question I receive is asking which test is best to purchase. There is … Continue reading →

Every day, I receive e-mails very similar to this one. “My family has always said that we were part Native American.  I want to prove this so that I can receive help with money for college.” The reasons vary, and … Continue reading →

2019 Only

Five articles ranked in the top 10 in 2019 that aren’t in the top all-time 10 articles. Two were just published in 2019.

  • Number 8 for 2019: Migration Pedigree Chart – Published in 2016 – This fun article illustrates how to create a pedigree charting focused on the locations of your ancestors.

Paul Hawthorne started a bit of a phenomenon, whether he meant to or not, earlier this week on Facebook, when he created a migration map of his own ancestors using Excel to reflect his pedigree chart. You can view … Continue reading →

Just as they promised, and right on schedule, Family Tree DNA today announced X chromosome matching. They have fully integrated X matching into their autosomal Family Finder product matching. This will be rolling live today. Happy New Year from Family … Continue reading →

  • Number 6 for 2019: Full or Half Siblings – Published in April 2019 – Want to know how to determine the difference between full and half siblings? This is it.

Many people are receiving unexpected sibling matches. Every day on social media, “surprises” are being reported so often that they are no longer surprising – unless of course you’re the people directly involved and then it’s very personal, life-altering and you’re … Continue reading →

Ancestry’s new tool, ThruLines has some good features and a lot of potential, but right now, there are a crop of ‘gators in the swimmin’ hole – just waiting for the unwary. Here’s help to safely navigate the waters and … Continue reading →

One of the most common questions I receive, especially in light of the interest in ethnicity testing, is how much of an ancestor’s DNA someone “should” share. The chart above shows how much of a particular generation of ancestors’ DNA … Continue reading →

In Summary

Taking a look at a summary chart is interesting. From my perspective, I never expected the “Thick Hair, Small Boobs” article to be so popular.

“Which DNA Test is Best?” ranked #2 all time, but not in the 2019 top 10. I wonder if that is a function of the market softening a bit, or of fewer people researching before purchasing.

I was surprised that 5 of the top 10 all-time were not in the top 10 of 2019.

Conversely, I’m equally as surprised that 3 of the older 2019 articles not in the all-time top 10.

I’m very glad these older articles continue to be useful, and I do update them periodically, especially if I notice they are accessed often.

Article All-time Top 10 2019 Top 10
Ethnicity Testing – A Conundrum 10 0
How Much Indian Do I Have in Me? 9 4
4 Kinds of DNA for Genetic Genealogy 8 0
Thick Hair, Small Boobs, Shovel Shaped Teeth, and More 7 9
What is a Haplogroup? 6 0
X Marks the Spot 5 10
Ethnicity Results – True or Not? 4 0
Concepts – Calculating Ethnicity Percentages 3 1
Which DNA Test is Best? 2 0
Proving Native American Ancestry Using DNA 1 2
Migration Pedigree Chart 0 8
X Chromosome Matching at Family Tree DNA 0 7
Full or Half Siblings Published in 2019 6
Ancestry’s ThruLines Dissected: How to Use and Not get Bit by the ‘Gators Published in 2019 5
Ancestral DNA Percentages – How Much of Them is in You? 0 3

What Would You Like to See in 2020?

Given that your questions are often my inspiration, what articles would you like to see in 2020?

Are there topics you’d like to see covered? (Sorry, I don’t know the name of your great-great-grandfather’s goat.)

Burning questions you’d like to have answered? (No, I don’t know why there is air.)

Something you’ve been wishing for? (Except maybe for the 1890 census.)

Leave a comment and let me know. (Seriously😊)

I’m looking forward to a wonderful 2020 and hope you’ll come along!

_____________________________________________________________

Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

2019: The Year and Decade of Change

2019 ends both a year and a decade. In the genealogy and genetic genealogy world, the overwhelmingly appropriate word to define both is “change.”

Everything has changed.

Millions more records are online now than ever before, both through the Big 3, being FamilySearch, MyHeritage and Ancestry, but also through multitudes of other sites preserving our history. Everyplace from National Archives to individual blogs celebrating history and ancestors.

All you need to do is google to find more than ever before.

I don’t know about you, but I’ve made more progress in the past decade that in all of the previous ones combined.

Just Beginning?

If you’re just beginning with genetic genealogy, welcome! I wrote this article just for you to see what to expect when your DNA results are returned.

If you’ve been working with genetic genealogy results for some time, or would like a great review of the landscape, let’s take this opportunity to take a look at how far we’ve come in the past year and decade.

It’s been quite a ride!

What Has Changed?

EVERYTHING

Literally.

A decade ago, we had Y and mitochondrial DNA, but just the beginning of the autosomal revolution in the genetic genealogy space.

In 2010, Family Tree DNA had been in business for a decade and offered both Y and mitochondrial DNA testing.

Ancestry offered a similar Y and mtDNA product, but not entirely the same markers, nor full sequence mitochondrial. Ancestry subsequently discontinued that testing and destroyed the matching database. Ancestry bought the Sorenson database that included Y, mitochondrial and autosomal, then destroyed that data base too.

23andMe was founded in 2006 and began autosomal testing in 2007 for health and genealogy. Genealogists piled on that bandwagon.

Family Tree DNA added autosomal to their menu in 2010, but Ancestry didn’t offer an autosomal product until 2012 and MyHeritage not until 2016. Both Ancestry and MyHeritage have launched massive marketing and ad campaigns to help people figure out “who they are,” and who their ancestors were too.

Family Tree DNA

2019 FTDNA

Family Tree DNA had a banner year with the Big Y-700 product, adding over 211,000 Y DNA SNPs in 2019 alone to total more than 438,000 by year end, many of which became newly defined haplogroups. You can read more here. Additionally, Family Tree DNA introduced the Block Tree and public Y and public mitochondrial DNA trees.

Anyone who ignores Y DNA testing does so at their own peril. Information produced by Y DNA testing (and for that matter, mitochondrial too) cannot be obtained any other way. I wrote about utilizing mitochondrial DNA here and a series about how to utilize Y DNA begins in a few days.

Family Tree DNA remains the premier commercial testing company to offer high resolution and full sequence testing and matching, which of course is the key to finding genealogy solutions.

In the autosomal space, Family Tree DNA is the only testing company to provide Phased Family Matching which uses your matches on both sides of your tree, assuming you link 3rd cousins or closer, to assign other testers to specific parental sides of your tree.

Family Tree DNA accepts free uploads from other testing companies with the unlock for advanced features only $19. You can read about that here and here.

MyHeritage

MyHeritage, the DNA testing dark horse, has come from behind from their late entry into the field in 2016 with focused Europeans ads and the purchase of Promethease in 2019. Their database stands at 3.7 million, not as many as either Ancestry or 23andMe, but for many people, including me – MyHeritage is much more useful, especially for my European lines. Not only is MyHeritage a genealogy company, piloted by Gilad Japhet, a passionate genealogist, but they have introduced easy-to-use advanced tools for consumers during 2019 to take the functionality lead in autosomal DNA.

2019 MyHeritage.png

You can read more about MyHeritage and their 2019 accomplishments, here.

As far as I’m concerned, the MyHeritage bases-loaded 4-product “Home Run” makes MyHeritage the best solution for genetic genealogy via either testing or transfer:

  • Triangulation – shows testers where 3 or more people match each other. You can read more, here.
  • Tree Matching – SmartMatching for both DNA testers and those who have not DNA tested
  • Theories of Family Relativity – a wonderful new tool introduced in February. You can read more here.
  • AutoClusters – Integrated cluster technology helps you to visualize which groups of people match each other.

One of their best features, Theories of Family Relativity connects the dots between people you DNA match with disparate trees and other documents, such as census. This helps you and others break down long-standing brick walls. You can read more, here.

MyHeritage encourages uploads from other testing companies with basic functions such as matching for free. Advanced features cost either a one-time unlock fee of $29 or are included with a full subscription which you can try for free, here. You can read about what is free and what isn’t, here.

You can develop a testing and upload strategy along with finding instructions for how to upload here and here.

23andMe

Today, 23andMe is best known for health, having recovered after having had their wings clipped a few years back by the FDA. They were the first to offer Health results, leveraging the genealogy marketspace to attract testers, but have recently been eclipsed by both Family Tree DNA with their high end full Exome Tovana test and MyHeritage with their Health upgrade which provides more information than 23andMe along with free genetic counseling if appropriate. Both the Family Tree DNA and MyHeritage tests are medically supervised, so can deliver more results.

23andMe has never fully embraced genetic genealogy by adding the ability to upload and compare trees. In 2019, they introduced a beta function to attempt to create a genetic tree on your behalf based on how your matches match you and each other.

2019 23andMe.png

These trees aren’t accurate today, nor are they deep, but they are a beginning – especially considering that they are not based on existing trees. You can read more here.

The best 23andMe feature for genealogy, as far as I’m concerned, is their ethnicity along with the fact that they actually provide testers with the locations of their ethnicity segments which can help testers immensely, especially with minority ancestry matching. You can read about how to do this for yourself, here.

23andMe generally does not allow uploads, probably because they need people to test on their custom-designed medical chip. Very rarely, once that I know of in 2018, they do allow uploads – but in the past, uploaders do not receive all of the genealogy features and benefits of testing.

You can however, download your DNA file from 23andMe and upload elsewhere, with instructions here.

Ancestry

Ancestry is widely known for their ethnicity ads which are extremely effective in recruiting new testers. That’s the great news. The results are frustrating to seasoned genealogists who get to deal with the fallout of confused people trying to figure out why their results don’t match their expectations and family stories. That’s the not-so-great news.

However, with more than 15 million testers, many of whom DO have genealogy trees, a serious genealogist can’t *NOT* test at Ancestry. Testers do need to be aware that not all features are available to DNA testers who don’t also subscribe to Ancestry’s genealogy subscriptions. For example, you can’t see your matches’ trees beyond a 5 generation preview without a subscription. You can read more about what you do and don’t receive, here.

Ancestry is the only one of the major companies that doesn’t provide a chromosome browser, despite pleas for years to do so, but they do provide ThruLines that show you other testers who match your DNA and show a common ancestor with you in their trees.

2019 Ancestry.png

ThruLines will also link partial trees – showing you ancestral descendants from the perspective of the ancestor in question, shown above. You can read about ThruLines, here.

Of course, without a chromosome browser, this match is only as good as the associated trees, and there is no way to prove the genealogical connection. It’s possible to all be wrong together, or to be related to some people through a completely different ancestor. Third party tools like Genetic Affairs and cluster technology help resolve these types of issues. You can read more, here.

You can’t upload DNA files from other testing companies to Ancestry, probably due to their custom medical chip. You can download your file from Ancestry and upload to other locations, with instructions here.

Selling Customers’ DNA

Neither Family Tree DNA, MyHeritage nor Gedmatch sell, lease or otherwise share their customers’ DNA, and all three state (minimally) they will not in the future without prior authorization.

All companies utilize their customers’ DNA internally to enhance and improve their products. That’s perfectly normal.

Both Ancestry and 23andMe sell consumers DNA to both known and unknown partners if customers opt-in to additional research. That’s the purpose of all those questions.

If you do agree or opt-in, and for those who tested prior to when the opt-in began, consumers don’t know who their DNA has been sold to, where it is or for what purposes it’s being utilized. Although anonymized (pseudonymized) before sale, autosomal results can easily be identified to the originating tester (if someone were inclined to do so) as demonstrated by adoptees identifying parents and law enforcement identifying both long deceased remains and criminal perpetrators of violent crimes. You can read more about re-identification here, although keep in mind that the re-identification frequency (%) would be much higher now than it was in 2018.

People are widely split on this issue. Whatever you decide, to opt-in or not, just be sure to do your homework first.

Always read the terms and conditions fully and carefully of anything having to do with genetics.

Genealogy

The bottom line to genetic genealogy is the genealogy aspect. Genealogists want to confirm ancestors and discover more about those ancestors. Some information can only be discovered via DNA testing today, distant Native heritage, for example, breaking through brick walls.

This technology, as it has advanced and more people have tested, has been a godsend for genealogists. The same techniques have allowed other people to locate unknown parents, grandparents and close relatives.

Adoptees

Not only are genealogists identifying people long in the past that are their ancestors, but adoptees and those seeking unknown parents are making discoveries much closer to home. MyHeritage has twice provided thousands of free DNA tests via their DNAQuest program to adoptees seeking their biological family with some amazing results.

The difference between genealogy, which looks back in time several generations, and parent or grand-parent searches is that unknown-parent searches use matches to come forward in time to identify parents, not backwards in time to identify distant ancestors in common.

Adoptee matching is about identifying descendants in common. According to Erlich et al in an October 2018 paper, here, about 60% of people with European ancestry could be identified. With the database growth since that time, that percentage has risen, I’m sure.

You can read more about the adoption search technique and how it is used, here.

Adoptee searches have spawned their own subculture of sorts, with researchers and search angels that specialize in making these connections. Do be aware that while many reunions are joyful, not all discoveries are positively received and the revelations can be traumatic for all parties involved.

There’s ying and yang involved, of course, and the exact same techniques used for identifying biological parents are also used to identify cold-case deceased victims of crime as well as violent criminals, meaning rapists and murderers.

Crimes Solved

The use of genetic genealogy and adoptee search techniques for identifying skeletal remains of crime victims, as well as identifying criminals in order that they can be arrested and removed from the population has resulted in a huge chasm and division in the genetic genealogy community.

These same issues have become popular topics in the press, often authored by people who have no experience in this field, don’t understand how these techniques are applied or function and/or are more interested in a sensational story than in the truth. The word click-bait springs to mind although certainly doesn’t apply equally to all.

Some testers are adamantly pro-usage of their DNA in order to identify victims and apprehend violent criminals. Other testers, not so much and some, on the other end of the spectrum are vehemently opposed. This is a highly personal topic with extremely strong emotions on both sides.

The first such case was the Golden State Killer, which has been followed in the past 18 months or so by another 100+ solved cases.

Regardless of whether or not people want their own DNA to be utilized to identify these criminals and victims, providing closure for families, I suspect the one thing we can all agree on is that we are grateful that these violent criminals no longer live among us and are no longer preying on innocent victims.

I wrote about the Golden State Killer, here, as well as other articles here, here, here and here.

In the genealogy community, various vendors have adopted quite different strategies relating to these kinds of searches, as follows:

  • Ancestry, 23andMe and MyHeritage – have committed to fight all access attempts by law enforcement, including court ordered subpoenas.
  • MyHeritage, Family Tree DNA and GedMatch allow uploads, so forensic kits, meaning kits from deceased remains or rape kits could be uploaded to search for matches, the same as any other kit. Law Enforcement uploads violate the MyHeritage terms of service. Both Family Tree DNA and GEDmatch have special law enforcement procedures in place. All three companies have measures in place to attempt to detect unauthorized forensic uploads.
  • Family Tree DNA has provided a specific Law Enforcement protocol and guidelines for forensic uploads, here. All EU customers were opted out earlier in 2019, but all new or existing non-EU customers need to opt out if they do not want their DNA results available for matching to law enforcement kits.
  • GEDmatch was recently sold to Verogen, a DNA forensics company, with information, here. Currently GEDMatch customers are opted-out of matching for law enforcement kits, but can opt-in. Verogen, upon purchase of GEDmatch, required all users to read the terms and conditions and either accept the terms or delete their kits. Users can also delete their kits or turn off/on law enforcement matching at any time.

New Concerns

Concerns in late 2019 have focused on the potential misuse of genetic matching to potentially target subsets of individuals by despotic regimes such as has been done by China to the Uighurs.

You can read about potential risks here, here and here, along with a recent DoD memo here.

Some issues spelled out in the papers can be resolved by vendors agreeing to cryptographically sign their files when customers download. Of course, this would require that everyone, meaning all vendors, play nice in the sandbox. So far, that hasn’t happened although I would expect that the vendors accepting uploads would welcome cryptographic signatures. That pretty much leaves Ancestry and 23andMe. I hope they will step up to the plate for the good of the industry as a whole.

Relative to the concerns voiced in the papers and by the DoD, I do not wish to understate any risks. There ARE certainly risks of family members being identified via DNA testing, which is, after all, the initial purpose even though the current (and future) uses were not foreseen initially.

In most cases, the cow has already left that barn. Even if someone new chooses not to test, the critical threshold is now past to prevent identification of individuals, at least within the US and/or European diaspora communities.

I do have concerns:

  • Websites where the owners are not known in the genealogical community could be collecting uploads for clandestine purposes. “Free” sites are extremely attractive to novices who tend to forget that if you’re not paying for the product, you ARE the product. Please be very cognizant and leery. Actually, just say no unless you’re positive.
  • Fearmongering and click-bait articles in general will prevent and are already causing knee-jerk reactions, causing potential testers to reject DNA testing outright, without doing any research or reading terms and conditions.
  • That Ancestry and 23andMe, the two major vendors who don’t accept uploads will refuse to add crypto-signatures to protect their customers who download files.

Every person needs to carefully make their own decisions about DNA testing and participating in sharing through third party sites.

Health

Not surprisingly, the DNA testing market space has cooled a bit this past year. This slowdown is likely due to a number of factors such as negative press and the fact that perhaps the genealogical market is becoming somewhat saturated. Although, I suspect that when vendors announce major new tools, their DNA kit sales spike accordingly.

Look at it this way, do you know any serious genealogists who haven’t DNA tested? Most are in all of the major databases, meaning Ancestry, 23andMe, FamilyTreeDNA, MyHeritage and GedMatch.

All of the testing companies mentioned above (except GEDmatch who is not a testing company) now have a Health offering, designed to offer existing and new customers additional value for their DNA testing dollar.

23andMe separated their genealogy and health offering years ago. Ancestry and MyHeritage now offer a Health upgrade. For existing customers, FamilyTreeDNA offers the Cadillac of health tests through Tovana.

I would guess it goes without saying here that if you really don’t want to know about potential health issues, don’t purchase these tests. The flip side is, of course, that most of the time, a genetic predisposition is nothing more and not a death sentence.

From my own perspective, I found the health tests to be informative, actionable and in some cases, they have been lifesaving for friends.

Whoever knew genealogy might save your life.

Innovative Third-Party Tools

Tools, and fads, come and go.

In the genetic genealogy space, over the years, tools have burst on the scene to disappear a few months later. However, the last few years have been won by third party tools developed by well-known and respected community members who have created tools to assist other genealogists.

As we close this decade, these are my picks of the tools that I use almost daily, have proven to be the most useful genealogically and that I feel I just “couldn’t live without.”

And yes, before you ask, some of these have a bit of a learning curve, but if you are serious about genealogy, these are all well worthwhile:

  • GedMatch – offers a wife variety of tools including triangulation, half versus fully identical segments and the ability to see who your matches also match. One of the tools I utilize regularly is segment search to see who else matches me on a specific segment, attached to an ancestor I’m researching. GedMatch, started by genealogists, has lasted more than a decade prior to the sale in December 2019.
  • Genetic Affairs – a barn-burning newcomer developed by Evert-Jan Blom in 2018 wins this years’ “Best” award from me. Genetic Affairs offers clustering, tree building between your matches even when YOU don’t have a tree. You can read more here.

2019 genetic affairs.png

Just today, Genetic Affairs released a new cluster interface with DNAPainter, example shown above.

  • DNAPainter – THE chromosome painter created by Jonny Perl just gets better and better, having added pedigree tree construction this year and other abilities. I wrote a composite instructional article, here.
  • DNAGedcom.com and Genetic.Families, affiliated with DNAAdoption.org – Rob Warthen in collaboration with others provides tools like clustering combined with triangulation. My favorite feature is the gathering of all direct ancestors of my matches’ trees at the various vendors where I’ve DNA tested which allows me to search for common surnames and locations, providing invaluable hints not otherwise available.

Promising Newcomer

  • MitoYDNA – a non-profit newcomer by folks affiliated with DNAAdoption and DNAGedcom is designed to replace YSearch and MitoSearch, both felled by the GDPR ax in 2018. This website allows people to upload their Y and mitochondrial DNA results and compare the values to each other, not just for matching, which you can do at Family Tree DNA, but also to see the values that do and don’t match and how they differ. I’ll be taking MitoYDNA for a test drive after the first of the year and will share the results with you.

The Future

What does the future hold? I almost hesitate to guess.

  • Artificial Intelligence Pedigree Chart – I think that in the not-too-distant future we’ll see the ability to provide testers with a “one and done” pedigree chart. In other words, you will test and receive at least some portion of your genealogy all tidily presented, red ribbon untied and scroll rolled out in front of you like you’re the guest on one of those genealogy TV shows.

Except it’s not a show and is a result of DNA testing, segment triangulation, trees and other tools which narrow your ancestors to only a few select possibilities.

Notice I said, “the ability to.” Just because we have the ability doesn’t mean a vendor will implement this functionality. In fact, just think about the massive businesses built upon the fact that we, as genealogists, have to SEARCH incessantly for these elusive answers. Would it be in the best interest of these companies to just GIVE you those answers when you test?

If not, then these types of answers will rest with third parties. However, there’s a hitch. Vendors generally don’t welcome third parties offering advanced tools and therefore block those tools, even though they are being used BY the customer or with their explicit authorization to massage their own data.

On the other hand, as a genealogist, I would welcome this feature with open arms – because as far as I’m concerned, the identification of that ancestor is just the first step. I get to know them by fleshing out their bones by utilizing those research records.

In fact, I’m willing to pony up to the table and I promise, oh-so-faithfully, to maintain my subscription lifelong if one of those vendors will just test me. Please, please, oh pretty-please put me to the test!

I guess you know what my New Year’s Wish is for this and upcoming years now too😊

What About You?

What do you think the high points of 2019 have been?

How about the decade?

What do you think the future holds?

Do you care to make any predictions?

Are you planning to focus on any particular goal or genealogy problem in 2020?

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Genealogy Research

Fun DNA Stuff

  • Celebrate DNA – customized DNA themed t-shirts, bags and other items

Are You DNA Testing the Right People?

We often want to purchase DNA kits for relatives, especially during the holidays when there are so many sales. (There are links for free shipping on tests in addition to sale prices at the end of this article. If you already know who to test, pop on down to the Sales section, now.)

Everyone is on a budget, so who should we test to obtain results that are relevant to our genealogy?

We tell people to test as many family members as possible – but what does that really mean?

Testing everyone may not be financially viable, nor necessary for genealogy, so let’s take a look at how to decide where to spend YOUR testing dollars to derive the most benefit.

It’s All Relative😊

When your ancestors had children, those children inherited different pieces of your ancestors’ DNA.

Therefore, it’s in your best interest to test all of the direct descendants generationally closest to the ancestor that you can find.

It’s especially useful to test descendants of your own close ancestors – great-great-grandparents or closer – where there is a significant possibility that you will match your cousins.

All second cousins match, and roughly 90% (or more) of third cousins match.

Percent of cousins match.png

This nifty chart compiled by ISOGG shows the probability statistics produced by the major testing companies regarding cousin matching relationships.

My policy is to test 4th cousins or closer. The more, the merrier.

Identifying Cousins

  • First cousins share grandparents.
  • Second cousins share great-grandparents.
  • Third cousins share great-great-grandparents.

The easiest way for me to see who these cousins might be is to open my genealogy software on my computer, select my great-great-grandparent, and click on descendants. Pretty much all software has a similar function.

The resulting list shows all of the descendants of that ancestor that I’ve entered in my software. Most genealogists already have or could construct this information with relative ease. These are the cousins you need to be talking to anyway, because they will have photos and stories that you don’t. If you don’t know them, there’s never been a better time to reach out and introduce yourself.

Who to test descendants software

Click to enlarge

People You Already Know

Sometimes it’s easier to start with the family you already know and may see from time to time. Those are the people who will likely be the most beneficial to your genealogy.

Who to test 1C.png

Checking my tree at FamilyTreeDNA, Hiram Ferverda and Evaline MIller are my great-grandparents. All of their children are deceased, but I have a relationship with the children born to their son, Roscoe. Both Cheryl and her brother carry parts of Hiram and Eva’s DNA their son John Ferverda (my grandfather) didn’t inherit, and therefore that I can’t carry.

Therefore, it’s in my best interest to gift my cousin, Cheryl and her brother, both, with DNA kits. Turns out that I already have and my common matches with both Cheryl and her brother are invaluable because I know that people who match me plus either one of them descend from the Ferverda or Miller lines. This relationship and linking them on my tree, shown above, allows Family Tree DNA to perform phased Family Matching which is their form of triangulation.

It’s important to test both siblings, because some people will match me plus one but not the other sibling.

Who’s Relevant?

Trying to convey the concept of who to test and not to test, and why, is sometimes confusing.

Many family members may want to test, but you may only be willing to pay for those tests that can help your own genealogy. We need to know who can best benefit our genealogy in order to make informed decisions.

Let’s look at example scenarios – two focused on grandparents and two on parents.

In our example family, a now-deceased grandmother and grandfather have 3 children and multiple grandchildren. Let’s look at when we test which people, and why.

Example 1: Grandparents – 2 children deceased, 1 living

In our first example, Jane and Barbara, my mother, are deceased, but their sibling Harold is living. Jane has a living daughter and my mother had 3 children, 2 of which are living. Who should we test to discover the most about my maternal grandparents?

Please note that before making this type of a decision, it’s important to state the goal, because the answer will be different depending on your goal at hand. If I wanted to learn about my father’s family, for example, instead of my maternal grandparents, this would be an entirely different question, answer, and tree.

Descendant test

Click to enlarge

The people who are “married in” but irrelevant to the analysis are greyed out. In this case, all of the spouses of Jane, Barbara and Harold are irrelevant to the grandmother and grandfather shown. We are not seeking information about those spouses or their families.

The people I’ve designated with the red stars should be tested. This is the “oldest” generation available. Harold can be tested, so his son, my first cousin, does not need to test because the only part of the grandparent’s DNA that Harold’s son can inherit is a portion of what his father, Harold, carries and gave to him.

Unfortunately, Jane is deceased but her daughter, Liz, is available to test, so Liz’s son does not need to.

I need to test, as does my living brother and the children of my deceased brother in order to recover as much as possible of my mother’s DNA. They will all carry pieces of her DNA that I don’t.

The children of anyone who has a red star do NOT need to test for our stated genealogical purpose because they only carry a portion of thier parent’s DNA, and that parent is already testing.

Those children may want to test for their own genealogy given that they also have a parent who is not relevant to the grandfather and grandmother shown. In my case, I’m perfectly happy to facilitate those tests, but not willing to pay for the children’s tests if the relevant parent is living. I’m only willing to pay for tests that are relevant to my genealogical goals – in this case, my grandparents’ heritage.

In this scenario, I’m providing 5 tests.

Of course, you may have other family factors in play that influence your decision about how many tests to purchase for whom. Family dynamics might include things like hurt feelings and living people who are unwilling or unable to test. I’ve been known to purchase kits for non-biologically related family members so that people could learn how DNA works.

Example 2: Grandparents – 2 children living, one deceased

For our second example, let’s change this scenario slightly.

Descendant test 2

Click to enlarge

From the perspective of only my grandparents’ genealogy, if my mother is alive, there’s no reason to test her children.

Barbara and Harold can test. Since Jane is deceased, and she had only one child, Liz is the closest generationally and can test to represent Jane’s line. Liz’s son does not need to test since his mother, the closest relative generationally to the grandparents is available to test.

In this scenario, I’m providing 3 tests.

Example 3: My Immediate Family – both parents living

In this third example, I’m looking from strictly MY perspective viewing my maternal grandparents (as shown above) AND my immediate family meaning the genealogical lines of both of my parents. In other words, I’ve combined two goals. This makes sense, especially if I’m going to be seeing a group of people at a family gathering. We can have a swab party!

Descendants - parents alive

Click to enlarge

In the situation where my parents are both living, I’m going to test them in addition to Harold and Liz.

I’m testing myself because I want to work using my own DNA, but that’s not really necessary. My parents will both have twice as many matches to other people as I do – because I only inherited half of each parent’s DNA.

In this scenario, I’m providing 5 tests.

Example 4: My Immediate Family – one parent living, one deceased

Descendants - father deceased

Click to enlarge

In our last example, my mother is living but my father is deceased. In addition to Harold and Liz who reflect the DNA of my maternal grandparents, I will test myself, my mother my living brother and my deceased brother’s child.

Because my father is deceased, testing as many of my father’s descendants as possible, in addition to myself, is the only way for me to obtain some portion of his DNA. My siblings will have pieces of my parent’s DNA that I don’t.

I’m not showing my father’s tree in this view, but looking at his tree and who is available to test to provide information about his side of the family would be the next logical step. He may have siblings and cousins that are every bit as valuable as the people on my mother’s side.

Applying this methodology to your own family, who is available to test?

Multiple Databases

Now that you know WHO to test, the next step is to make sure your close family members test at each of the major providers where your DNA is as well.

I test everyone at Family Tree DNA because I have been testing family members there for 19 years and many of the original testers are deceased now. The only way new people can compare to those people is to be in the FamilyTreeDNA data base.

Then, with permission of course, I transfer all kits, for free, to MyHeritage. Matching is free, but if you don’t have a subscription, there’s an unlock fee of $29 to access advanced tools. I have a full subscription, so all tools are entirely free for the kits I transfer and manage in my account.

Transferring to Family Tree DNA and matching there is free too. There’s an unlock fee of $19 for advanced tools, but that’s a good deal because it’s substantially less than a new test.

Neither 23andMe nor Ancestry accept transfers, so you have to test at each of those companies.

The great news is that both Ancestry and 23andMe tests can be transferred to  MyHeritage and FamilyTreeDNA.

Before purchasing tests, check first by asking your relatives or testing there yourself to be sure they aren’t already in those databases. If they took a “spit in a vial” test, they are either at 23andMe or Ancestry. If they took a swab test, it’s MyHeritage or FamilyTreeDNA.

I wrote about creating a testing and transfer strategy in the article, DNA Testing and Transfers – What’s Your Strategy? That article includes a handy dandy chart about who accepts which versions of whose files.

Sales

Of course, everything is on sale since it’s the holidays.

Who are you planning to test?

______________________________________________________________

Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Genealogy Research

Fun DNA Stuff

  • Celebrate DNA – customized DNA themed t-shirts, bags and other items

Duplicate Copies of Parental Chromosomes – Uniparental Disomy

Recently, three articles were been published that discuss a phenomenon where unsuspecting individuals have two copies one parent’s chromosome, and no copy of the other parent’s chromosome. This is called Uniparental Disomy.

Since then, online I’ve seen this phenomenon being offered as a reason for all kinds of things – which just isn’t the case.

I’m sure in part it’s because people either haven’t actually read the articles, or they don’t understand what’s being said.

I’m going to explain this briefly and then tell you how you can find out if this situation actually DOES apply to you.

Uniparental Disomy in Brief

Here are a few summary bullet points about uniparental disomy:

  • Uniparental disomy is found on ONLY ONE CHROMOSOME in roughly 1 in 2000 people in the reference samples utilized at 23andMe.
  • This is not a new discovery, per se. It was known and previously believed to occur in 1 of 3,500 births, but that frequency has been updated to 1 in 2,000 in the paper.
  • Uniparental disomy was found in 1 of 50,000 people on TWO CHROMOSOMES.
  • This is NOT the reason you have more maternal or paternal matches, in general. Legitimate reasons for more matches on one parent’s line include the fact that one family or another historically has more or fewer descendants, more or fewer dead ends, recent immigrants, ancestors from regions where DNA testing is not popular and/or endogamous populations.
  • The people included in the research were trios where the tester and their parents have all 3 tested.
  • Many/most people with uniparental disomy have no known health issues.
  • The testers have in some cases been associated with some conditions, as described in the paper and supplemental information.
  • Of the people who carry this condition, more people carry a double maternal chromosome than a double paternal chromosome.
  • Uniparental disomy occurs more on chromosome 16 than any other chromosome, twice as often as the second highest, chromosome 7, with 40 and 20 occurrences each, respectively. Chromosome 18 had none. No, no one knows why.
  • It’s not necessary for the entire chromosome to be duplicated. In some cases, only part of the chromosome is improperly combined.

Articles

This Atlantic article provides an overview:

This academic paper in Cell is referenced in The Atlantic article and is where the meat of the information is found. Be sure to look at the supplemental files too.

Much of the data for the article was from 23andMe who discussed this study in their blog here.

What About You?

Do you have a chromosome that has experienced uniparental disomy? Probably not, but there’s a very easy way for you to find out.

If you have a duplicate chromosome, or portion of a chromosome from one parent, the genetic genealogy “indicator” that you’ll see is called ROH, or Run of Homozygosity. This condition occurs in situations where you have a duplicate chromosome, or where your parents are related to each other

  1. The first question to ask yourself is whether or not your parents are related to each other. If so, you will have some ROH segments.
  2. The second question is whether you have an entire duplicated chromosome when your parents aren’t related.

In order to answer both questions, we use the tool at GedMatch called “Are your parents related?”

Are Your Parents Related to Each Other?

You’ll need to establish an account at GedMatch and upload your DNA results from one of the testing vendors.

Here are instructions for how to download from the various vendors:

Using the “Are your parents related” Tool

To use this tool at GedMatch, after your uploaded kit is finished processing, click on “Are your parents related?” and enter the kit number of the person you want to evaluate. I’m assuming for this discussion that person is you.

Parents related.png

Normally, we use this tool to determine if someone’s parents are related to each other. We find this occurring in endogamous populations or where cousins married in the past few generations, as happened rather routinely in history.

In those situations, across all of a person’s chromosomes (not just one), we find relatively small segments of common DNA inherited by the person on both their maternal and paternal copies of each chromosome.

Parents are related.png

These matching areas are called ROH or “runs of homozygosity” meaning that the DNA is identical on both chromosomes for short segments, as shown above in the regions where the top bars are solid green and the bottom bar is solid blue.

The legend for reading the graphic is shown below.

Parents related legend.png

The chromosomes of a person whose parents are not related is shown below. Notice that there are no significant green bars on top, and no blue bars on the bottom.

Parents not related.png

Simple chance alone is responsible for tiny segments that are identical, like those tiny green slivers, but not larger segments over 7cM as shown in the first example and marked by blue on the bottom.

For someone that has a fully duplicated chromosome, meaning uniparental disomy, we see something different.

A Duplicate Chromosome

For someone that has a duplicate parental chromosome, all of their chromosomes look normal except that one entire chromosome, or a very large segment, is entirely identical.

Below is an example of a person whose chromosome 7 is duplicated. The rest of this person’s chromosomes looked like the image above with only tiny green slivers.

Parents uniparental disomy.png

If you have a duplicate chromosome, you’re rare, one in every 2,000 people in the populations studied.

If you have two identical chromosomes, you’re hen’s teeth rare – 1 in 50,000.

If you have uniparental disomy, you probably have no idea. You can also experience uniparental disomy when most of, but not all of a single chromosome is duplicated.

If you have duplicate parental chromosomes, you’ll match people on both sides of your family normally on all of your OTHER non-duplicate chromosomes. On your duplicate chromosome, you’ll only match people from the parent whose chromosome is duplicated.

In other words, this is NOT why you seem to be missing matches from one side of your family generally. You’ll need to look at other reasons to explain that.

If you have a duplicate chromosome, or large segment of a duplicate chromosome, leave a comment.

______________________________________________________________

Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

 

 

Hit a Genetic Genealogy Home Run Using Your Double-Sided Two-Faced Chromosomes While Avoiding Imposters

Do you want to hit a home run with your DNA test, but find yourself a mite bewildered?

Yep, those matches can be somewhat confusing – especially if you don’t understand what’s going on. Do you have a nagging feeling that you might be missing something?

I’m going to explain chromosome matching, and its big sister, triangulation, step by step to remove any confusion, to help you sort through your matches and avoid imposters.

This article is one of the most challenging I’ve ever written – in part because it’s a concept that I’m so familiar with but can be, and is, misinterpreted so easily. I see mistakes and confusion daily, which means that resulting conclusions stand a good chance of being wrong.

I’ve tried to simplify these concepts by giving you easy-to-use memory tools.

There are three key phrases to remember, as memory-joggers when you work through your matches using a chromosome browser: double-sided, two faces and imposter. While these are “cute,” they are also quite useful.

When you’re having a confusing moment, think back to these memory-jogging key words and walk yourself through your matches using these steps.

These three concepts are the foundation of understanding your matches, accurately, as they pertain to your genealogy. Please feel free to share, link or forward this article to your friends and especially your family members (including distant cousins) who work with genetic genealogy. 

Now, it’s time to enjoy your double-sided, two-faced chromosomes and avoid those imposters:)

Are you ready? Grab a nice cup of coffee or tea and learn how to hit home runs!

Double-Sided – Yes, Really

Your chromosomes really are double sided, and two-faced too – and that’s a good thing!

However, it’s initially confusing because when we view our matches in a chromosome browser, it looks like we only have one “bar” or chromosome and our matches from both our maternal and paternal sides are both shown on our one single bar.

How can this be? We all have two copies of chromosome 1, one from each parent.

Chromosome 1 match.png

This is my chromosome 1, with my match showing in blue when compared to my chromosome, in gray, as the background.

However, I don’t know if this blue person matches me on my mother’s or father’s chromosome 1, both of which I inherited. It could be either. Or neither – meaning the dreaded imposter – especially that small blue piece at left.

What you’re seeing above is in essence both “sides” of my chromosome number 1, blended together, in one bar. That’s what I mean by double-sided.

There’s no way to tell which side or match is maternal and which is paternal without additional information – and misunderstanding leads to misinterpreting results.

Let’s straighten this out and talk about what matches do and don’t mean – and why they can be perplexing. Oh, and how to discover those imposters!

Your Three Matches

Let’s say you have three matches.

At Family Tree DNA, the example chromosome browser I’m using, or at any vendor with a chromosome browser, you select your matches which are viewed against your chromosomes. Your chromosomes are always the background, meaning in this case, the grey background.

Chromosome 1-4.png

  • This is NOT three copies each of your chromosomes 1, 2, 3 and 4.
  • This is NOT displaying your maternal and paternal copies of each chromosome pictured.
  • We CANNOT tell anything from this image alone relative to maternal and paternal side matches.
  • This IS showing three individual people matching you on your chromosome 1 and the same three people matching you in the same order on every chromosome in the picture.

Let’s look at what this means and why we want to utilize a chromosome browser.

I selected three matches that I know are not all related through the same parent so I can demonstrate how confusing matches can be sorted out. Throughout this article, I’ve tried to explain each concept in at least two ways.

Please note that I’m using only chromsomes 1-4 as examples, not because they are any more, or less, important than the other chromosomes, but because showing all 22 would not add any benefit to the discussion. The X chromosome has a separate inheritance path and I wrote about that here.

Let’s start with a basic question.

Why Would I Want to Use a Chromosome Browser?

Genealogists view matches on chromosome browsers because:

  • We want to see where our matches match us on our chromosomes
  • We’d like to identify our common ancestor with our match
  • We want to assign a matching segment to a specific ancestor or ancestral line, which confirmed those ancestors as ours
  • When multiple people match us on the same location on the chromosome browser, that’s a hint telling us that we need to scrutinize those matches more closely to determine if those people match us on our maternal or paternal side which is the first step in assigning that segment to an ancestor

Once we accurately assign a segment to an ancestor, when anyone else matches us (and those other people) on that same segment, we know which ancestral line they match through – which is a great head start in terms of identifying our common ancestor with our new match.

That’s a genetic genealogy home run!

Home Runs 

There are four bases in a genetic genealogy home run.

  1. Determine whether you actually match someone on the same segment
  2. Which is the first step in determining that you match a group of people on the same segment
  3. And that you descend from a common ancestor
  4. The fourth step, or the home run, is to determine which ancestor you have in common, assigning that segment to that ancestor

If you can’t see segment information, you can’t use a chromosome browser and you can’t confirm the match on that segment, nor can you assign that segment to a particular ancestor, or ancestral couple.

The entire purpose of genealogy is to identify and confirm ancestors. Genetic genealogy confirms the paper trail and breaks down even more brick walls.

But before you can do that, you have to understand what matches mean and how to use them.

The first step is to understand that our chromosomes are double-sided and you can’ t see both of your chromosomes at once!

Double Sided – You Can’t See Both of Your Chromosomes at Once

The confusing part of the chromosome browser is that it can only “see” your two chromosomes blended as one. They are both there, but you just can’t see them separately.

Here’s the important concept:

You have 2 copies of chromosomes 1 through 22 – one copy that you received from your mother and one from your father, but you can’t “see” them separately.

When your DNA is sequenced, your DNA from your parents’ chromosomes emerges as if it has been through a blender. Your mother’s chromosome 1 and your father’s chromosome 1 are blended together. That means that without additional information, the vendor can’t tell which matches are from your father’s side and which are from your mother’s side – and neither can you.

All the vendor can tell is that someone matches you on the blended version of your parents. This isn’t a negative reflection on the vendors, it’s just how the science works.

Chromosome 1.png

Applying this to chromosome 1, above, means that each segment from each person, the blue person, the red person and the teal person might match you on either one of your chromosomes – the paternal chromosome or the maternal chromosome – but because the DNA of your mother and father are blended – there’s no way without additional information to sort your chromosome 1 into a maternal and paternal “side.”

Hence, you’re viewing “one” copy of your combined chromosomes above, but it’s actually “two-sided” with both maternal and paternal matches displayed in the chromosome browser.

Parent-Child Matches

Let’s explain this another way.

Chromosome parent.png

The example above shows one of my parents matching me. Don’t be deceived by the color blue which is selected randomly. It could be either parent. We don’t know.

You can see that I match my parent on the entire length of chromosome 1, but there is no way for me to tell if I’m looking at my mother’s match or my father’s match, because both of my parents (and my children) will match me on exactly the same locations (all of them) on my chromosome 1.

Chromosome parent child.png

In fact, here is a combination of my children and my parents matching me on my chromosome 1.

To sort out who is matching on paternal and maternal chromosomes, or the double sides, I need more information. Let’s look at how inheritance works.

Stay with me!

Inheritance Example

Let’s take a look at how inheritance works visually, using an example segment on chromosome 1.

Chromosome inheritance.png

In the example above:

  • The first column shows addresses 1-10 on chromosome 1. In this illustration, we are only looking at positions, chromosome locations or addresses 1-10, but real chromosomes have tens of thousands of addresses. Think of your chromosome as a street with the same house numbers on both sides. One side is Mom’s and one side is Dad’s, but you can’t tell which is which by looking at the house numbers because the house numbers are identical on both sides of the street.
  • The DNA pieces, or nucleotides (T, A, C or G,) that you received from your Mom are shown in the column labeled Mom #1, meaning we’re looking at your mother’s pink chromosome #1 at addresses 1-10. In our example she has all As that live on her side of the street at addresses 1-10.
  • The DNA pieces that you received from your Dad are shown in the blue column and are all Cs living on his side of the street in locations 1-10.

In other words, the values that live in the Mom and Dad locations on your chromosome streets are different. Two different faces.

However, all that the laboratory equipment can see is that there are two values at address 1, A and C, in no particular order. The lab can’t tell which nucleotide came from which parent or which side of the street they live on.

The DNA sequencer knows that it found two values at each address, meaning that there are two DNA strands, but the output is jumbled, as shown in the First and Second read columns. The machine knows that you have an A and C at the first address, and a C and A at the second address, but it can’t put the sequence of all As together and the sequence of all Cs together. What the sequencer sees is entirely unordered.

This happens because your maternal and paternal DNA is mixed together during the extraction process.

Chromosome actual

Click to enlarge image.

Looking at the portion of chromosome 1 where the blue and teal people both match you – your actual blended values are shown overlayed on that segment, above. We don’t know why the blue and the teal people are matching you. They could be matching because they have all As (maternal), all Cs (paternal) or some combination of As and Cs (a false positive match that is identical by chance.)

There are only two ways to reassemble your nucleotides (T, A, C, and G) in order and then to identify the sides as maternal and paternal – phasing and matching.

As you read this next section, it does NOT mean that you must have a parent for a chromosome browser to be useful – but it does mean you need to understand these concepts.

There are two types of phasing.

Parental Phasing

  • Parental Phasing is when your DNA is compared against that of one or both parents and sorted based on that comparison.

Chromosome inheritance actual.png

Parental phasing requires that at least one parent’s DNA is available, has been sequenced and is available for matching.

In our example, Dad’s first 10 locations (that you inherited) on chromosome 1 are shown, at left, with your two values shown as the first and second reads. One of your read values came from your father and the other one came from your mother. In this case, the Cs came from your father. (I’m using A and C as examples, but the values could just as easily be T or G or any combination.)

When parental phasing occurs, the DNA of one of your parents is compared to yours. In this case, your Dad gave you a C in locations 1-10.

Now, the vendor can look at your DNA and assign your DNA to one parent or the other. There can be some complicating factors, like if both your parents have the same nucleotides, but let’s keep our example simple.

In our example above, you can see that I’ve colored portions of the first and second strands blue to represent that the C value at that address can be assigned through parental phasing to your father.

Conversely, because your mother’s DNA is NOT available in our example, we can’t compare your DNA to hers, but all is not lost. Because we know which nucleotides came from your father, the remaining nucleotides had to come from your mother. Hence, the As remain after the Cs are assigned to your father and belong to your mother. These remaining nucleotides can logically be recombined into your mother’s DNA – because we’ve subtracted Dad’s DNA.

I’ve reassembled Mom, in pink, at right.

Statistical/Academic Phasing

  • A second type of phasing uses something referred to as statistical or academic phasing.

Statistical phasing is less successful because it uses statistical calculations based on reference populations. In other words, it uses a “most likely” scenario.

By studying reference populations, we know scientifically that, generally, for our example addresses 1-10, we either see all As or all Cs grouped together.

Based on this knowledge, the Cs can then logically be grouped together on one “side” and As grouped together on the other “side,” but we still have no way to know which side is maternal or paternal for you. We only know that normally, in a specific population, we see all As or all Cs. After assigning strings or groups of nucleotides together, the algorithm then attempts to see which groups are found together, thereby assigning genetic “sides.” Assigning the wrong groups to the wrong side sometimes happens using statistical phasing and is called strand swap.

Once the DNA is assigned to physical “sides” without a parent or matching, we still can’t identify which side is paternal and which is maternal for you.

Statistical or academic phasing isn’t always accurate, in part because of the differences found in various reference populations and resulting admixture. Sometimes segments don’t match well with any population. As more people test and more reference populations become available, statistical/academic phasing improves. 23andMe uses academic phasing for ethnicity, resulting in a strand swap error for me. Ancestry uses academic phasing before matching.

By comparison to statistical or academic phasing, parental phasing with either or both parents is highly accurate which is why we test our parents and grandparents whenever possible. Even if the vendor doesn’t use our parents’ results, we certainly can!

If someone matches you and your parent too, you know that match is from that parent’s side of your tree.

Matching

The second methodology to sort your DNA into maternal and paternal sides is matching, either with or without your parents.

Matching to multiple known relatives on specific segments assigns those segments of your DNA to the common ancestor of those individuals.

In other words, when I match my first cousin, and our genealogy indicates that we share grandparents – assuming we match on the appropriate amount of DNA for the expected relationship – that match goes a long way to confirming our common ancestor(s).

The closer the relationship, the more comfortable we can be with the confirmation. For example, if you match someone at a parental level, they must be either your biological mother, father or child.

While parent, sibling and close relationships are relatively obvious, more distant relationships are not and can occur though unknown or multiple ancestors. In those cases, we need multiple matches through different children of that ancestor to reasonably confirm ancestral descent.

Ok, but how do we do that? Let’s start with some basics that can be confusing.

What are we really seeing when we look at a chromosome browser?

The Grey/Opaque Background is Your Chromosome

It’s important to realize that you will see as many images of your chromosome(s) as people you have selected to match against.

This means that if you’ve selected 3 people to match against your chromosomes, then you’ll see three images of your chromosome 1, three images of your chromosome 2, three images of your chromosome 3, three images of your chromosome 4, and so forth.

Remember, chromosomes are double-sided, so you don’t know whether these are maternal or paternal matches (or imposters.)

In the illustration below, I’ve selected three people to match against my chromosomes in the chromosome browser. One person is shown as a blue match, one as a red match, and one as a teal match. Where these three people match me on each chromosome is shown by the colored segments on the three separate images.

Chromosome 1.png

My chromosome 1 is shown above. These images are simply three people matching to my chromosome 1, stacked on top of each other, like cordwood.

The first image is for the blue person. The second image is for the red person. The third image is for the teal person.

If I selected another person, they would be assigned a different color (by the system) and a fourth stacked image would occur.

These stacked images of your chromosomes are NOT inherently maternal or paternal.

In other words, the blue person could match me maternally and the red person paternally, or any combination of maternal and paternal. Colors are not relevant – in other words colors are system assigned randomly.

Notice that portions of the blue and teal matches overlap at some of the same locations/addresses, which is immediately visible when using a chromosome browser. These areas of common matching are of particular interest.

Let’s look closer at how chromosome browser matching works.

What about those colorful bars?

Chromosome Browser Matching

When you look at your chromosome browser matches, you may see colored bars on several chromosomes. In the display for each chromosome, the same color will always be shown in the same order. Most people, unless very close relatives, won’t match you on every chromosome.

Below, we’re looking at three individuals matching on my chromosomes 1, 2, 3 and 4.

Chromosome browser.png

The blue person will be shown in location A on every chromosome at the top. You can see that the blue person does not match me on chromosome 2 but does match me on chromosomes 1, 3 and 4.

The red person will always be shown in the second position, B, on each chromosome. The red person does not match me on chromosomes 2 or 4.

The aqua person will always be shown in position C on each chromosome. The aqua person matches me on at least a small segment of chromosomes 1-4.

When you close the browser and select different people to match, the colors will change and the stacking order perhaps, but each person selected will always be consistently displayed in the same position on all of your chromosomes each time you view.

The Same Address – Stacked Matches

In the example above, we can see that several locations show stacked segments in the same location on the browser.

Chromosome browser locations.png

This means that on chromosome 1, the blue and green person both match me on at least part of the same addresses – the areas that overlap fully. Remember, we don’t know if that means the maternal side or the paternal side of the street. Each match could match on the same or different sides.

Said another way, blue could be maternal and teal could be paternal (or vice versa,) or both could be maternal or paternal. One or the other or both could be imposters, although with large segments that’s very unlikely.

On chromosome 4, blue and teal both match me on two common locations, but the teal person extends beyond the length of the matching blue segments.

Chromosome 3 is different because all three people match me at the same address. Even though the red and teal matching segments are longer, the shared portion of the segment between all three people, the length of the blue segment, is significant.

The fact that the stacked matches are in the same places on the chromosomes, directly above/below each other, DOES NOT mean the matches also match each other.

The only way to know whether these matches are both on one side of my tree is whether or not they match each other. Do they look the same or different? One face or two? We can’t tell from this view alone.

We need to evaluate!

Two Faces – Matching Can be Deceptive!

What do these matches mean? Let’s ask and answer a few questions.

  • Does a stacked match mean that one of these people match on my mother’s side and one on my father’s side?

They might, but stacked matches don’t MEAN that.

If one match is maternal, and one is paternal, they still appear at the same location on your chromosome browser because Mom and Dad each have a side of the street, meaning a chromosome that you inherited.

Remember in our example that even though they have the same street address, Dad has blue Cs and Mom has pink As living at that location. In other words, their faces look different. So unless Mom and Dad have the same DNA on that entire segment of addresses, 1-10, Mom and Dad won’t match each other.

Therefore, my maternal and paternal matches won’t match each other either on that segment either, unless:

  1. They are related to me through both of my parents and on that specific location.
  2. My mother and father are related to each other and their DNA is the same on that segment.
  3. There is significant endogamy that causes my parents to share DNA segments from their more distant ancestors, even though they are not related in the past few generations.
  4. The segments are small (segments less than 7cM are false matches roughly 50% of the time) and therefore the match is simply identical by chance. I wrote about that here. The chart showing valid cM match percentages is shown here, but to summarize, 7-8 cMs are valid roughly 46% of the time, 8-9 cM roughly 66%, 9-10 cM roughly 91%, 10-11 cM roughly 95, but 100 is not reached until about 20 cM and I have seen a few exceptions above that, especially when imputation is involved.

Chromosome inheritance match.png

In this inheritance example, we see that pink Match #1 is from Mom’s side and matches the DNA I inherited from pink Mom. Blue Match #2 is from Dad’s side and matches the DNA I inherited from blue Dad. But as you can see, Match #1 and Match #2 do not match each other.

Therefore, the address is only half the story (double-sided.)

What lives at the address is the other half. Mom and Dad have two separate faces!

Chromosome actual overlay

Click to enlarge image

Looking at our example of what our DNA in parental order really looks like on chromosome 1, we see that the blue person actually matches on my maternal side with all As, and the teal person on the paternal side with all Cs.

  • Does a stacked match on the chromosome browser mean that two people match each other?

Sometimes it happens, but not necessarily, as shown in our example above. The blue and teal person would not match each other. Remember, addresses (the street is double-sided) but the nucleotides that live at that address tell the real story. Think two different looking faces, Mom’s and Dad’s, peering out those windows.

If stacked matches match each other too – then they match me on the same parental side. If they don’t match each other, don’t be deceived just because they live at the same address. Remember – Mom’s and Dad’s two faces look different.

For example, if both the blue and teal person match me maternally, with all As, they would also match each other. The addresses match and the values that live at the address match too. They look exactly the same – so they both match me on either my maternal or paternal side – but it’s up to me to figure out which is which using genealogy.

Chromosome actual maternal.png

Click to enlarge image

When my matches do match each other on this segment, plus match me of course, it’s called triangulation.

Triangulation – Think of 3

If my two matches match each other on this segment, in addition to me, it’s called triangulation which is genealogically significant, assuming:

  1. That the triangulated people are not closely related. Triangulation with two siblings, for example, isn’t terribly significant because the common ancestor is only their parents. Same situation with a child and a parent.
  2. The triangulated segments are not small. Triangulation, like matching, on small segments can happen by chance.
  3. Enough people triangulate on the same segment that descends from a common ancestor to confirm the validity of the common ancestor’s identity, also confirming that the match is identical by descent, not identical by chance.

Chromosome inheritance triangulation.png

The key to determining whether my two matches both match me on my maternal side (above) or paternal side is whether they also match each other.

If so, assuming all three of the conditions above are true, we triangulate.

Next, let’s look at a three-person match on the same segment and how to determine if they triangulate.

Three Way Matching and Identifying Imposters

Chromosome 3 in our example is slightly different, because all three people match me on at least a portion of that segment, meaning at the same address. The red and teal segments line up directly under the blue segment – so the portion that I can potentially match identically to all 3 people is the length of the blue segment. It’s easy to get excited, but don’t get excited quite yet.

Chromosome 3 way match.png

Given that three people match me on the same street address/location, one of the following three situations must be true:

  • Situation 1- All three people match each other in addition to me, on that same segment, which means that all three of them match me on either the maternal or paternal side. This confirms that we are related on the same side, but not how or which side.

Chromosome paternal.png

In order to determine which side, maternal or paternal, I need to look at their and my genealogy. The blue arrows in these examples mean that I’ve determined these matches to all be on my father’s side utilizing a combination of genealogy plus DNA matching. If your parent is alive, this part is easy. If not, you’ll need to utilize common matching and/or triangulation with known relatives.

  • Situation 2 – Of these three people, Cheryl, the blue bar on top, matches me but does not match the other two. Charlene and David, the red and teal, match each other, plus me, but not Cheryl.

Chromosome maternal paternal.png

This means that at least either my maternal or paternal side is represented, given that Charlene and David also match each other. Until I can look at the identity of who matches, or their genealogy, I can’t tell which person or people descend from which side.

In this case, I’ve determined that Cheryl, my first cousin, with the pink arrow matches me on Mom’s side and Charlene and David, with the blue arrows, match me on Dad’s side. So both my maternal and paternal sides are represented – my maternal side with the pink arrow as well as my father’s side with the blue arrows.

If Cheryl was a more distant match, I would need additional triangulated matches to family members to confirm her match as legitimate and not a false positive or identical by chance.

  • Situation 3 – Of the three people, all three match me at the same addresses, but none of the three people match each other. How is this even possible?

Chromosome identical by chance.png

This situation seems very counter-intuitive since I have only 2 chromosomes, one from Mom and one from Dad – 2 sidesof the street. It is confusing until you realize that one match (Cheryl and me, pink arrow) would be maternal, one would be paternal (Charlene and me, blue arrow) and the third (David and me, red arrows) would have DNA that bounces back and forth between my maternal and paternal sides, meaning the match with David is identical by chance (IBC.)

This means the third person, David, would match me, but not the people that are actually maternal and paternal matches. Let’s take a look at how this works

Chromosome maternal paternal IBC.png

The addresses are the same, but the values that live at the addresses are not in this third scenario.

Maternal pink Match #1 is Cheryl, paternal blue Match #2 is Charlene.

In this example, Match #3, David, matches me because he has pink and blue at the same addresses that Mom and Dad have pink and blue, but he doesn’t have all pink (Mom) nor all blue (Dad), so he does NOT match either Cheryl or Charlene. This means that he is not a valid genealogical match – but is instead what is known as a false positive – identical by chance, not by descent. In essence, a wily genetic imposter waiting to fool unwary genealogists!

In his case, David is literally “two-faced” with parts of both values that live in the maternal house and the paternal house at those addresses. He is a “two-faced imposter” because he has elements of both but isn’t either maternal or paternal.

This is the perfect example of why matching and triangulating to known and confirmed family members is critical.

All three people, Cheryl, Charlene and David match me (double sided chromosomes), but none of them match each other (two legitimate faces – one from each parent’s side plus one imposter that doesn’t match either the legitimate maternal or paternal relatives on that segment.)

Remember Three Things

  1. Double-Sided – Mom and Dad both have the same addresses on both sides of each chromosome street.
  2. Two Legitimate Faces – The DNA values, nucleotides, will have a unique pattern for both your Mom and Dad (unless they are endogamous or related) and therefore, there are two legitimate matching patterns on each chromsome – one for Mom and one for Dad. Two legitimate and different faces peering out of the houses on Mom’s side and Dad’s side of the street.
  3. Two-Faced Imposters – those identical by chance matches which zig-zag back and forth between Mom and Dad’s DNA at any given address (segment), don’t match confirmed maternal and paternal relatives on the same segment, and are confusing imposters.

Are you ready to hit your home run?

What’s Next?

Now that we understand how matching and triangulation works and why, let’s put this to work at the vendors. Join me for my article in a few days, Triangulation in Action at Family Tree DNA, MyHeritage, 23andMe and GedMatch.

We will step through how triangulation works at each vendor. You’ll have matches at each vendor that you don’ t have elsewhere. If you haven’t transferred your DNA file yet, you still have time with the step by step instructions below:

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Thank you so much.

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Phoebe: Board of Trustee Member at 16 – 52 Ancestors #257

Phoebe JCF Photo.jpg

I’m just going to have to ask your forbearance. This is my granddaughter, Phoebe, who at the age of 16 has just been appointed to an advisory board of trustees for a nonprofit organization, Jackson Community Foundation. No, that’s not a typo. She’s only 16, and it’s no small nonprofit.

I’m proud as punch, as you’ve already figured out, I’m sure.

I’m the grandma and that’s my job.

However, Phoebe truly is remarkable. I know every grandma thinks that, so this is exactly why I’m asking forbearance.

You see, this almost wasn’t a happy story. In fact, it almost never happened at all.

We Nearly Lost Her

I’m holding Phoebe, my first grandchild, in the photo below, immediately after she was born, just before I realized she was turning blue. Actually, her hands already look blue in this photo. The nurse was unconcerned and told me this was “normal,” but I knew otherwise and let’s just say I became very assertive very quickly. By the time I waylaid a nurse, any nurse, Phoebe’s lips were blue.

There was no time to lose. When that second nurse realized what was happening, Phoebe was quickly whisked away into neo-natal intensive care where she spent the next week or so. She was not absorbing oxygen and nearly died.

Phoebe born.jpg

We were terrified.

This was a tough time for our family, in many ways. For her parents and me too. I had already lost one newborn baby, and this was eerily similar – way too close for comfort. Years before, I held my own baby as she passed away.

Thankfully, Phoebe improved and clearly survived, but that wouldn’t have been the case without modern medical care. A few decades ago, she would only have been one of those anonymous blank spaces in the census – a child only suggested by their absence and not known by their presence. Except, for us, as for those families, she would never have been anonymous. She would always have been a hole in our hearts.

Homecoming

A week or so later, she came home from the hospital.

Phoebe newborn quilt.jpg

Here’s Phoebe being held by her aunt the day she came home from the hospital – with her “welcome to the world” quilt from Grandma.

I made each of my grandchildren a quilt when they were born. That’s just the first of many quilts I’ve made them. I’m so glad they love grandma’s quilts – and now they like to quilt with grandma too.

I started quilting when I was young with scraps from making my own clothes when I was about the age Phoebe is now.

Phoebe and me as teen.png

Here are photos of Phoebe and me at about the same age. I fought to straighten my hair. Phoebe embraces her lovely curls.

My first professional photo wouldn’t be taken until I was 26 and out of college.

Phoebe is light years ahead of me and just sparkles with energy and enthusiasm!

Phoebe with daughter.png

Phoebe with my daughter at about the same age.

The Wedding

When Phoebe was three months old, my daughter made Phoebe a tiny dress to match the wedding décor, and Phoebe was in her grandmother’s wedding.

Phoebe at my wedding.jpg

Of course, Phoebe has no memory of that day, but I surely do!

Phoebe wedding 3 months.jpg

Fortunately, we took photos, because this wedding photo would be the only full family photo we would ever have.

Phoebe family wedding photo.jpg

These pictures make me cry today, for the loss, but also for the love. My mother and brother are both gone now.

Phoebe my wedding dress.png

This spring, Phoebe standing in the bedroom with my mother’s furniture, trying my wedding gown on.

Phoebe my wedding dress with sister.png

Someday, it will be hers to wear if she chooses.

Phoebe and Mawmaw

In our family, until this generation, grandmothers were called Mawmaw. Sadly, Phoebe also has no memory of my mother, Mawmaw.

Phoebe with Mawmaw.jpg

This is one of only a couple photos of Phoebe with my mother. This was Phoebe’s first Christmas and the only one with her great-grandmother.

Here’s Phoebe’s photo beside my mom’s high school graduation picture.

Phoebe with Mom.png

Making Memories

As Phoebe began to grow up, we started making family memories, like this one at Disney World.

Phoebe at Disney.jpg

And yes, as any good grandparent would do, Phoebe went to the Bippity-Bop Boutique and magically became transformed into a Princess. That boutique is a goldmine designed to mine the bank accounts of grandparents which it does VERY successfully, I might add.

Our family events seem to be punctuated by quilts.

Phoebe Princess quilt.jpg

I finished this quilt for Phoebe at Disney so she could have her very own special princess quilt to go with the one-of-a-kind special princess dress I made for her to wear at Disney. I was concerned that she would be upset that she didn’t have a more traditional princess dress like the other young princesses, but she wasn’t, and loved her unique “grandma princess dress.”

Phoebe Tinkerbell dress.jpg

What a great adventure.

Phoebe fountain.jpg

Even if it was beastly hot.

Phoebe facepaint.jpg

Phoebe got to wear both lipstick and nail polish for the first time! She was so excited, and then facepainting too.

Phoebe grandpa shark.jpg

There are just no words for some things, but grandpa makes scary things not so much!

Phoebe Disney family.jpg

I’m not sure who these other family members are. I must have missed something in my genealogy.

Grandma’s Princess

Planning for college or not, she’s still my Princess – even though she’s old enough to drive the chariot now. How did that happen anyway?

Princess Phoebe.jpg

For the next couple of years after Disney, we had princess everything!

Phoebe with princess jewelry.jpg

At least that made gift shopping easy.

Phoebe princess hat.jpg

Now that’s some hat. Even the English would be jealous!

But something was in the offing that was even better than being a princess.

Becoming a Big Sister

Phoebe big sister.jpg

Phoebe became a big sister!

Phoebe grandpa big sister.jpg

We nearly lost this baby too, for an entirely different reason. We didn’t realize it at the time, but this child was in constant pain for months.

Phoebe with baby sister.jpg

Phoebe loves her sister, even though her sister didn’t always love to be carried around like a baby doll!

Phoebe sister first steps.jpg

A year and a risky, life-saving surgery later, Phoebe was there for her sister’s first steps, with Dad and Grandpa. What an exciting red-letter day.

Phoebe with Disney dress.jpg

After that, Grandma made Disney dresses and goodies for both girls.

Phoebe sister with Disney dress.jpg

It was difficult to take photos of Phoebe’s sister, because once she started walking, and running, she never slowed down!

Phoebe bedtime yoga.png

The girls are inseparable. Here, they are doing “bedtime yoga” to quiet down before bedtime, under grandma’s quilts. I love it that their parents share these wonderful photos with me!

Sports

Phoebe began to engage in sports from a young age. She ran her first (partial) race with her dad when she was 3.

Phoebe first marathon.jpg

He’s pinning her runner identification on. A rite of passage in this family. Phoebe was so excited.

Phoebe first run.jpg

You can see her in the brightly colored clothing right up front, in the center. Unfortunately, she got run over by another runner, fell and bumped her head on the concrete, but got back up, crying, but carried on. Her Dad picked her up, which made her unhappy.

Phoebe with Dad.jpg

Dad carried her part of the way, first in his arms, then on his shoulders as he ran. She was on top of the world there.

Sometimes, it’s not about winning but being present in the moment.

Phoebe and gymnastics.jpg

Phoebe has always loved all kinds of sports. Gymnastics, horseback riding, volleyball, soccer, basketball, karate,swimming and I’m sure I’ve forgotten something.

Phoebe and soccer.jpg

I love the look of intensity on her face. She’s a dedicated athlete.

Phoebe and kids.jpg

Phoebe has always been a team player and enjoys working with young people, volunteering her time at various camps and events including coaching soccer.

Essential Lessons

Phoebe jewelry.jpg

Grandma teaching Phoebe the essentials of life. How to select jewelry. Next, we moved on to chocolate and dessert😊

Phoebe dessert.jpg

Hey, a grandma’s gotta do what a grandma’s gotta do!

Phoebe missing tooth

And you’ve got to show grandma your missing tooth.

Not only that, but she lost that first tooth after tripping over another dancer at a recital. Afterwards, she proudly rushed off the stage displaying her prize tooth gripped tightly in her hand! She didn’t miss a beat dancing! No one would ever have known what happened – but she also didn’t lose the tooth. Great recovery!

Phoebe recital.jpg

Who can resist those eyes? Not me, that’s for sure.

Phoebe red shoes.jpg

Not sure exactly how, but somehow she wound up in Kansas. You don’t suppose she clicked do you?

Phoebe fabric shopping.jpg

We’ve now graduated to fabric shopping for quilts with grandma! Yes!

Phoebe, Nora and Quilts

My mother only quilted at Missionary Circle, but this quilt made by her grandmother, Nora Kirsch Lore, represented the State of Indiana in the 1933 Chicago World’s fair.

climbing vine quilt

Nora is Phoebe’s 3 times great-grandmother.

Phoebe with Nora.png

Here’s Phoebe beside Nora at age 22 in 1888 when she was married.

Maintaining the family tradition, Phoebe likes to quilt with Grandma now.

Phoebe planning college quilt.jpg

Sometimes the hardest part of quilting is making decisions. Here, Phoebe’s planning blocks for a college quilt.

Farms are Fun

Phoebe and goat.jpg

Phoebe has lots of interests, farm animals among them. Somehow, I think that runs in her blood.

Peewee.jpg

My daughter with our orphan goat, Peewee, when my kids were growing up. Peewee wore diapers in the house and wore a yellow sweater to town for walks on a leash.

Phoebe pumpkins.jpg

Phoebe doesn’t know it, but on the farm at home, my dad used to plant pumpkins every year just so the grandkids could grow and select their own pumpkin for carving. She would have loved that, and him. I’m sure he’s watching over her now.

Phoebe and sister in labyrinth.jpg

Grandma doesn’t exactly have a farm, but I do have a labyrinth.

Phoebe buckets.jpg

Our ancestors carried water and also maple sap in buckets like these.

Phoebe sawing.jpg

I think she’s moved on to chain saws now.

Phoebe horse and boots.jpg

Perhaps Phoebe has her grandmother’s “boot” gene.

Phoebe and unicorn.jpg

Phoebe is no one-trick pony, um, I mean, unicorn, though. Not one bit.

Music

Phoebe Mississippi.jpg

Phoebe loves music. All kinds of music.

Phoebe drums.jpg

Phoebe and the family drum corps.

From a very young age, she was attracted to any musical instrument.

Phoebe tongue.jpg

You know, how you hold your tongue really DOES matter!

Phoebe guitar.jpg

Phoebe plays a number of instruments, but loves to play the piano. For hours on end.

Phoebe piano with sister.jpg

Alone or with someone. Sometimes her sister sings along.

Phoebe and piano.jpg

Phoebe was playing with the Jackson Symphony Orchestra and winning state-wide championships before she was 12. The first year she won, she was actually competing in the youngest category that began at 13 – and they didn’t know exactly what to do because she was actually “too young” to win. The prize was money and a scholarship.

Phoebe and Dad by piano.jpg

Sometimes her dad had to come directly from work to be at her recitals and events. I love this picture of them together!

Phoebe piano professional.jpg

This was probably actually Phoebe’s first “professional” picture.

Phoebe piano competition.jpg

I have miles and miles of footage of Phoebe playing soul-searing, breathtaking music. Songs were even composed for her to play at university competitions.

Phoebe award.jpg

Phoebe accepting a state-wide award with her teacher.

Phoebe trophy.jpg

You’ll excuse me if I call Phoebe a child prodigy, because she is – and I am, after all, the grandmother. I will, however, spare you the videos, although you’d probably enjoy them😊

Phoebe did not get her musical talent from me.

Phoebe with Edith.png

Phoebe’s great-great-grandmother, Edith Lore Ferverda played the piano beautifully, accompanying a great many dance recitals as my mother performed.

Genetics

PHoebe swabbing.jpg

As Phoebe has continued to mature, she developed an interest in science. Here, she’s swabbing for DNA testing.

I have NO IDEA where she got the idea to do something like that😊

Granddaughter DNA 2016

Next, Phoebe wanted to sequence DNA. Here, she’s in the lab at Michigan State University doing just that with strawberries.

We’ve spent hours reviewing where her DNA segments originated – because she is lucky enough to have the autosomal DNA of 3 grandparents and one great-grandparent, plus several aunts and uncles.

Phoebe’s DNA as compared to mine. The blue areas on her chromosomes are what she inherited from me.

Phoebe me DNA

Nothing makes genetics personal like your own family members and the power of visual examples.

Just a Normal Teen

Phoebe easter eggs.jpg

Amid all of this serious stuff, Phoebe is just a normal fun-loving teen.

Phoebe balloons.jpg

Cutting up with her friends.

Phoebe dinosaur.jpg

Petting dinosaurs.

Phoebe chickens.jpg

Making friends with chickens!

Phoebe snow.jpg

Playing in the snow. Her sister is hidden behind the tree and just caused it to dump on Phoebe.

Phoebe rock.jpg

This young woman perseveres and conquers what she sets her mind on.

Phoebe victory rock.jpg

Phoebe Branches Out

Now in the second half of her teen years, Phoebe is branching out and finding her wings – or maybe her voice.

Phoebe tree.jpg

Yes, Phoebe still hikes and climbs trees. One of my favorite photos, a lucky shot.

However, when on the ground, Phoebe has taken a shine to the stage. She has danced for years, but the theater bug has bitten her recently.

Phoebe play.jpg

I was convinced that Phoebe was going to be a geneticist, but she has since developed an interest in the arts, aside from piano performances. She also sings, dances and now acts in community theater.

Phoebe stage.jpg

Of course, my mother performed professionally – so maybe Phoebe comes by that ability naturally.

Barbara Ferverda dancing 1944 2 pro

Must have “skipped a generation,” or two, because I guarantee you, I have absolutely no talent there.

Phoebe Mom DNA.png

Is Phoebe’s dancing and theatrical ability handed down on the red segments above, passed down to Phoebe from my mother, through my blue segments? If so, those genes didn’t express in my generation.

Public Service

While Phoebe was recently appointed to the board of trustees, this is not her first time working as a public servant.

Phoebe volunteers at the Dahlem Outdoor Environmental Education Center and has been a volunteer assistant camp counselor since she was 13. She has been attending since she was 5. It’s one of her favorite places.

Phoebe moose.jpg

Phoebe’s on the committee for the annual Goblin Walk Fundraiser. She’s a moose, above, in brown, and a hummingbird in the blue/green sweatshirt, below.

PHoebe hummingbird.jpg

Beauty

Phoebe sees beauty everyplace and in everything.

Phoebe photographer.jpg

She has a great eye for color and detail and enjoys photography in grandma’s garden.

Phoebe taller than grandma.jpg

Phoebe was quite pleased with herself the day she realized she was taller than grandma.

What Phoebe doesn’t realize is that the white and purple phlox blooming beside us is from her great-grandparent’s farm. Yes, Mawmaw and Pawpaw are with us in subtle ways.

I dug the Phlox and brought it home the day Dad passed away. A few years later, it moved along with me to a new house and is now migrating to my children’s gardens a quarter century later.

Our ancestors are with us, not only in our DNA, abilities and appearance but in other subtle ways too.

Someday, I hope these same plants, or their descendants, will grow in Phoebe’s own garden. In the mean time, I’ll be the steward of the plants because she has a lot of cultivating to do.

The future is bright and full of promise. Whatever Phoebe’s life choices, I’m privileged to witness this remarkable young woman develop her potential, find her grounding, fledge the nest and fly on her own.

I have no doubt that Phoebe will leave this earth a better place than she found it.

Phoebe 6 generations.png

Her ancestors would be very, very proud of her. This one already is!

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Lineage Societies: Requirements and DNA

I’ve been hesitant to rock this boat, hoping this ship would right itself, but I’ve decided that this vessel needs to be swayed a bit with the hope of providing encouragement and perhaps positive motivation for change.

Based on my ancestors, I qualify to join multiple lineage societies, including both the DAR and the Mayflower Society.

I checked the qualifications for both, and did not apply to the DAR, but did inquire about membership to the Mayflower Association for several reasons:

  • 2020 is the 400th anniversary of Plymouth Colony, meaning there should be lots going on next year.
  • I descend from Pilgrims; William Brewster, Patience Brewster, William’s wife Mary Brewster, Stephen Hopkins and Gyles Hopkins.
  • I felt that my expertise might be beneficial to the organization, in multiple ways, especially given the upcoming opportunities to recruit new members in 2020.

The first thing I ran into was a brick wall, not an ancestral brick wall, but an organizational one.

Birth Certificates

Lineage societies require your birth certificate.

Birth certificates are the most personal document you will ever have. Birth certificates are utilized for passports and are the premier document, meaning the most highly prized, for identity theft. Once compromised, you can never obtain a different birth certificate. It’s not like a credit card that you can cancel and have reissued.

Furthermore, you don’t actually need a birth certificate if you have tested the appropriate parent – and I have.

In fact, here’s my predicted relationship to my deceased mother at Family Tree DNA.

Lineage me mother.png

My mother is deceased, so her identity can no longer be compromized. I don’t have any problem providing her birth and death certificates in addition to an obituary that states that I’m her daughter – plus the genetic evidence of course. In fact, I could join the Mayflower DNA Project, and as administrators, they could see that relationship for themselves.

Furthermore, birth certificates are sometimes wrong – very wrong.

When Birth Certificates are Wrong

Birth certificates are wrong or misleading in the following circumstances:

  • People who are adopted and don’t know it
  • People who are adopted and know who their relevant biological parent is but have no access to a birth certificate showing their biological parents
  • People whose parent is not who they believe it is

In some circumstances, the child’s birth certificate isn’t incorrect, but the lineage may be incorrect when people’s ancestors beyond their parents are not the recorded individuals. Yes, I’m referring to the dreaded NPE, non-paternal event or not parent expected. You can read more about that here.

Aside from the issues above, there’s the issue of security when storing the birth certificate and privacy associated with the parents named on the birth certificate, especially if they are living.

Security and Privacy

Let’s take the issue of privacy first. Let’s say, for example, that an applicant’s parents weren’t married. The relevant parent is the applicant’s mother, not the father, so the identity of the father (or lack thereof) is irrelevant for lineage society membership.

The father’s privacy is compromised, along with the fact that the society now knows that the applicant’s parents weren’t married at the time the applicant was born. That’s entirely irrelevant to the application, and an invasion of the privacy of all 3 people involved.

Requiring applicants to submit a birth certificate, especially when genetic forms of identification are now readily available, forces the applicant to disclose information not relevant to joining a lineage society.

Frankly, anything beyond confirming an applicant’s connection to the relevant parent is none of anyone’s business.

Second, the applicant has absolutely no idea who is going to have access to their birth certificate in the future, once submitted, where it will be stored and security precautions taken, if any.

When inquiring about birth certificates at the Mayflower Society, I was told then are kept in locked cabinets but would probably be scanned soon.

While I’m sure this was supposed to make me feel better, it struck terror into my heart.

Often, organizations are slow to adopt technology as a whole, and when they do, they often aren’t aware of and don’t utilize safety and security precautions. Organizations owe it to their membership to stay current with security requirements and maintain up-do-date security measures. So, while I was already concerned enough about who has access to the filing cabinet key, I’m terrified about savvy hackers taking blatant advantage of an ill-secured or unsecured computer.

The sad part is that today, this is really a moot point because with DNA, many times we don’t need birth certificates for proof – and the only reason to continue doing what has always been done is ignorance, inertia and resistance to change.

Adoptees

Because birth certificates without genetic evidence are considered as the only accepted proof of a relationship to the applicant’s parents, this means that many adoptees have joined believing they are a linear descendant of the ancestor in question. Legally, they are.

Each organization needs to consider whether they want to honor linear paper descent as membership criteria or whether they are looking for linear biological descent. Or perhaps both.

Today, some adoptees who discover their biological parents would be eligible if they had not been adopted – but they are not eligible for membership because they don’t have a birth certificate with the biological parent’s name as their parent.

This creates an awkward situation, at best.

People who should be able to join, can’t, because of the birth certificate issue. And some people who are not biological descendants can join with no problem.

Is this the intention?

This is not small consideration. According to the University of Oregon, 5 million living people in the US are adopted, with 2-4% of all families having adopted, and 2.5% of children under the age of 18 being adoptees.

Y DNA

The DAR requires direct linear descent from a Revolutionary War Veteran. Like with the Mayflower Society, I won’t provide my birth certificate, so I’m not eligible to join.

The DAR has for many years accepted Y DNA at 37 markers as a portion of proof. According to this document, one close relative of the application must match the Y DNA of a descendant of an already “proven” patriot exactly at 37 markers.

This protocol is flawed in multiple ways.

Let’s say we have 2 men who descend from a common patrilineal ancestor, but we’re not sure which ancestor.

Today the Y DNA of these men matches at some level. STR mutations do not occur on a schedule and the reality of when/how often mutations occur varies widely. It’s certainly possible, and even likely, that in the roughly 9 generations, using a 25-year generation, since that patriot was born, that a marker mutation occurred. That would disqualify the applicant from using DNA evidence.

Conversely, if I’m a male Estes applicant and I want to apply to the DAR based on my descent from George Estes, my Y DNA may match the descendants of George at some level whether or not I’m descended from George or George’s brother, father or uncle. Y DNA really can only disprove a direct paternal relationship, not prove it.

In other words, there’s no or little analysis involved, simply a rule that doesn’t make sense.

Lineage chart

Click to enlarge

Let’s take a look at this example.

George Estes is the patriot, born in 1761. George had 3 brothers, Josiah, Bartlett and Winston.

George’s father, Moses II, had two brothers, John and William, who also had sons.

I’ve shown only one son’s line for both John and William, and I’ve named each man’s descendants the same name as his – for clarity.

John R. Estes, descendant of George was our original tester, and therefore, every other person who applies and submits Y DNA MUST match John R. Estes exactly at 37 markers.

George’s other descendant, George, comes along, but he does not match John R. exactly, having had one mutation someplace in the line between the patriot and George the tester’s birth. Therefore, George the tester’s Y DNA cannot be used – even though he is a descendant of George the patriot.

Based on my experience, it’s more likely that they won’t match at 37 markers, after 8 or 9 generations, than they will. That’s certainly the case in the Estes surname project.

In reality, in colonial families, everyone named their sons after their father, grandfather and often, brothers – so the names in all of these generations are likely to be the same, meaning John, William, George and Moses would likely be sprinkled in each generation of every line – causing confusion when attempting to genealogically connect back to the right Estes ancestor.

We see in our example chart, that by chance, William actually does match John R. exactly at 37 markers, even though George doesn’t. Therefore, if William was trying to use DNA to prove descent from George, even though that’s inaccurate, the Y DNA evidence would be allowed. So would Winston, descendant of George’s brother.

The only three that were accurate, based on the full 37 match rule is John, who does not descend from George, Josiah who was adopted and Bartlett who does descend from the same Estes line, but has too many mutations at that level to be considered a match to John R. Estes at all.

In other words, the only real descendant of the patriot is excluded, where 2 men not descended from the patriot would be included if they thought they descended from George.

Furthermore, one can be descended from George through a daughter and still qualify for DAR membership. If I believed, due to the Estes surname and other evidence, like a mention of a grandchild by name in George’s estate, that I descended from George’s son, but I actually descend through George’s daughter who was not married and gave her child the Estes surname – I would still technically qualify to join but the non-matching Y DNA would disqualify me today.

Another issue is if the original tester had been adopted or descended from a non-Estes male, every future tester would be compared to the wrong Y DNA and while the incorrect Y DNA would continue to be the reference sample for the patriot – even after it could be proven that was inaccurate due to multiple matching tests from multiple sons of George.

Rules without thoughtful analysis simply don’t work well. We know a whole lot more today than when these rules were put in place.

Parental Autosomal DNA is Definitive

Parental autosomal DNA is definitive unless you are dealing with an identical twin.

In addition to the actual match itself, you can see that parents and children match on the entire length of every chromosome.

Lineage parent child chromosome browser.png

Here’s my Mom’s chromosome browser match with me. There is no question that we are parent and child. Furthermore, looking at DNAPainter’s shared cM project tool, we can see that there is no other relationship that has the same match level as a parent/child relationship. My match with my mother is 3384 cM.

Lineage DNAPainter.png

Could someone go to a great deal of trouble to change a siblings name to their name or change their child’s name to their parent’s name to “fake” the identities of the people involved? Yes, they could if they had proper access to all accounts.

However, I can do exactly the same thing with a paper birth certificate, even with a seal.

My DNA test matching my mother, in conjunction with my mother’s birth and death certificates, in addition to her obituary identifying me as a child is about the most definitive evidence you could ever produce – far, far, more reliable than a birth certificate which would state that my mother is my mother even if I’m adopted.

This scenario works for adoptees as well in multiple scenarios, such as full siblings who clearly share both parents. In this case, if the non-adopted sibling is a lineage society member, then based on a DNA match at the full sibling level, the adopted individual should qualify for membership too. This isn’t the only example, just the first one that came to mind.

Thoughtful analysis and understanding of DNA is required.

Distant DNA is Not Black and White

While a parent-child autosomal relationship is evident, other autosomal relationships require analysis by someone experienced with that type of evaluation.

Furthermore, Y DNA can be deceptive as well, because the extent of what Y DNA can tell you is that two men descend from a common ancestor, not which common ancestor, nor how long ago, with very few exceptions. The exception would be when the actual Revolutionary War veteran experienced a SNP mutation that his sons have, but his brothers don’t.

However, no lineage societies that I know of utilize Y DNA SNP or even autosomal DNA evidence – even at the most basic level of parent/child.

With increasingly advanced testing, analysis versus line-in-the-sand rules needs to be implemented.

If lineage societies are going to utilize DNA testing, they need to stay current with technology and utilize best practices of genetic evidence.

Lineage Society Suggestions

Lineage societies need to re-evaluate their goals with applicants’ privacy and security in mind, in addition to how they can utilize genetic and other evidence to replace the existing birth certificate requirement – both in terms of traditional applicants like myself, as well as adoptees.

I have the following suggestions to be implemented as steps in a comprehensive solution:

  • Decide as a matter of policy whether applicants are allowed to join based on their paper trail descendancy, or their biological descendancy, or both. Paper trail only, meaning no additional evidence would be considered, would allow membership by children adopted into descendant families, but not children adopted out of descendant families. If genetic descendants are accepted, this allows children adopted out of descendant families to join once the relationship is discovered. If both types of membership are embraced, that avoids the issue of how to handle people who have already joined and subsequently discover they or their ancestors are/were adopted.
  • Determine the course of action when a line discovers that their Y DNA does not match that of the ancestor in question, especially given that the person could still potentially be a linear descendant through a female who gave the child her (the patriot’s) surname.
  • Obsolete the requirement for birth certificates at all when possible. If a DNA test proving a relationship can be substituted in lieu of a birth certificate, accept that as the preferred form of evidence.
  • Obsolete the requirement to physically submit any applicant’s birth certificate. Two individuals viewing a certificate with the relevant parent’s information exposed, and the non-relevant parent obscured, should suffice when no other avenue can be utilized. This eliminates the storage and privacy issues and requirements.
  • Implement a system that records the fact that current members and applicants have submitted a paper birth certificate that includes the parent of interest, then shred the existing birth certificates for anyone living. Without proof of death, this is presumed to be anyone under 100 years of age.
  • Allow additional proofs like parents’ obituaries instead of children’s birth certificates. This can easily be verified using publicly available sources such as Newspapers.com., etc.
  • Utilize Y DNA primarily to eliminate a line, and only when the descendants don’t match at 111 markers or are a completely different base haplogroup, such as haplogroup C versus R. Evaluate Y DNA matches along with other evidence, specifically looking for a mutation trail, if appropriate.
  • Remove the out-of-date requirement for future descendants to be required to match the Y DNA of an already “paper proven” ancestor. Paper can easily be wrong.
  • Revamp the DNA policies and procedures to incorporate qualified analysis. Provide guidelines instead of rules.
  • Retain a competent genetic genealogist to analyze applications that include DNA evidence, understanding that a CG, certified genealogist, certificate has no bearing on or evidence of the competence of that individual in DNA analysis. There is no genetic genealogy certification and many people who consult in the autosomal space are not experienced in the Y and mitochondrial DNA arenas.

The Alternate Future

Many older genealogical organizations are struggling for life. For the Mayflower Society, 2020 is a banner year. I hope they take advantage of the opportunity by not hobbling themselves with out-of-date requirements that are unnecessarily risky to applicants.

Younger people won’t join otherwise. Out of date and unreasonably burdensome membership requirements will cause membership to shrink over time until the organization shrivels and dies, going the way of the dinosaurs.

I would like to join multiple lineage organizations, but that won’t happen until the organizations update their policies to utilize widely and inexpensively available technology, along with associated best practices.

If you’d like to see these suggested changes implemented, and especially if you would be willing to help, make your voices heard to lineage societies, especially if you are already a member.

These organizations play an important role in the preservation of the records and information of our ancestors. I hope they choose to adapt.

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

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Crossovers: Frequency and Inheritance Statistics – Male Versus Female Matters

Recently, a reader asked if I had any crossover statistics.

They were asking about the number of crossovers, meaning divisions on each chromosome, of the parent’s DNA when a child is created. In other words, how many segments of your maternal and paternal grandparent’s DNA do you inherit from your mother and father – and are those numbers somehow different?

Why would someone ask that question, and how is it relevant for genealogists?

What is a Crossover and Why is it Important?

We know that every child receives half of their autosomal DNA from their father, and half from their mother. Conversely that means that each parent can only give their child half of their own DNA that they received from their parents. Therefore, each parent has to combine some of the DNA from their father’s chromosome and their mother’s chromosome into a new chromosome that they contribute to their child.

Crossovers are breakpoints that are created when the DNA of the person’s parents is divided into pieces before being recombined into a new chromosome and passed on to the person’s child.

I’m going to use the following real-life scenario to illustrate.

Crossover pedigree.png

The colors of the people above are reflected on the chromosome below where the DNA of the blue daughter, and her red and green parents are compared to the DNA of the tester. The tester is shown as the gray background chromosomes in the chromosome browser. The backgroud person is whose results we are looking at.

My granddaughter has tested her DNA, as have her parents and 3 of her 4 grandparents along with 2 great-grandparents, shown as red and green in the diagram above.

Here’s an example utilizing the FamilyTreeDNA chromosome browser.

Crossover example chr 1.png

On my granddaughter’s chromosome 1, on the chromosome brower above, we see two perfect examples of crossovers.

There’s no need to compare her DNA against that of her parent, the son in the chart above, because we already know she matches the full length of every chromosome with both of her parents.

However, when comparing my granddaughter’s DNA against the grandmother (blue) and her grandmother’s parents, the great-grandmother shown in red and great-grandfather shown in green, we can see that the granddaughter received her blue segments from the grandmother.

The grandmother had to receive that entire blue segment from either her mother, in red, or her father, in green. So, every blue segment must have an exactly matching red segment, green segment or combination of both.

The first red box at left shows that the blue segment was inherited partially from the grandmother’s red mother and green father. We know that because the tester matches the red great-grandmother on part of that blue segment and the green great-grandfather on a different part of the entire blue segment that the tester inherited from her blue grandmother.

The middle colored region, not boxed, shows the entire blue segment was inherited from the red great-grandmother and the blue grandmother passed that intact through her son to her granddaughter.

The third larger red boxed area encompassing the entire tested region to the right of the centromere was inherited by the granddaughter from her grandmother (blue segment) but it was originally from the blue grandmother’s red mother and green father.

The Crossover

The areas on this chromosome where the blue is divided between the red and green, meaning where the red and green butt up against each other is called a crossover. It’s literally where the DNA of the blue daughter crosses over between DNA contributed by her red mother and green father.

Crossover segments.png

In other words, the crossover where the DNA divided between the blue grandmother’s parents when the grandmother’s son was created is shown by the dark arrows above. The son gave his daughter that exact same segment from his mother and it’s only by comparing the tester’s DNA against her great-grandparents that we can see the crossover.

Crossover 4 generations.png

What we’re really seeing is that the segments inherited by the grandmother from her parents two different chromosomes were combined into one segment that the grandmother gave to her son. The son inherited the green piece and the red piece on his maternal chromosome, which he gave intact to his daughter, which is why the daughter matches her grandmother on that entire blue segment and matches her great-grandparents on the red and green pieces of their individual DNA.

Inferred Matching Segments

Crossover untested grandfather.png

The entirely uncolored regions are where the tester does not match her blue grandmother and where she would match her grandfather, who has not tested, instead of her blue grandmother.

The testers father only received his DNA from his mother and father, and if his daughter does not match his mother, then she must match his untested father on that segment.

Looking at the Big Inheritance Picture

The tester’s full autosomal match between the blue grandmother, red great-grandmother and green great-grandfather is shown below.

Crossover autosomes.png

In light of the discussion that follows, it’s worth noting that chromosomes 4 and 20 (orange arrows) were passed intact from the blue grandmother to the tester through two meiosis (inheritance) events. We know this because the tester matches the green great-grandfather’s DNA entirely on these two chromosomes that he passed to his blue daughter, her son and then the tester.

Let’s track this for chromosomes 4 and 20:

  • Meiosis 1 –The tester matches her blue grandmother, so we know that there was no crossover on that segment between the father and the tester.
  • Meiosis 2 – The tester matches her green great-grandfather along the entire chromosome, proving that it was passed intact from the grandmother to the tester’s father, her son.
  • What we don’t know is whether there were any crossovers between the green great-grandfather when he passed his parent or parents DNA to the blue grandmother, his daughter. In order to determine that, we would need at least one of the green great-grandfather’s parents, which we don’t have. We don’t know if the green great-grandfather passed on his maternal or paternal copy of his chromosome, or parts of each to the blue great-grandmother, his daughter.

Meiosis Events and the Tree

So let’s look at these meiosis or inheritance events in a different way, beginning at the bottom with the pink tester and counting backwards, or up the tree.

Crossover meiosis events.png

By inference, we know that chromosomes 11, 16 and 22 (purple arrows) were also passed intact, but not from the blue grandmother. The tester’s father passed his father’s chromosome intact to his daughter. That’s the untested grandfather again. We know this because the tester does not match her blue grandmother at all on either of these three chromosomes, so the tester must match her untested grandfather instead, because those are the only two sources of DNA for the tester’s father.

A Blip, or Not?

If you’ve noticed that chromosome 14 looks unusual, in that the tester matches her grandmother’s blue segment, but not either of her great-grandparents, which is impossible, give yourself extra points for your good eye.

In this case, the green great-grandfather’s kit was a transfer kit in which that portion of chromosome 14 was not included or did not read accurately. Given that the red great-grandmother’s kit DID read in that region and does not match the tester, we know that chromosome 14 would actually have a matching green segment exactly the size of the blue segment.

However, in another situation where we didn’t know of an issue with the transfer kit, it is also possible that the granddaughter matched a small segment of the blue grandmother’s DNA where they were identical by chance. In that case, chromosome 14 would actually have been passed to the tester intact from her father’s father, who is untested.

Every Segment has a Story

Looking at this matching pattern and our ability to determine the source of the DNA back several generations, originating from great-grandparents, I hope you’re beginning to get a sense of why understanding crossovers better is important to genealogists.

Every single segment has a story and that story is comprised of crossovers where the DNA of our ancestors is combined in their offspring. Today, we see the evidence of these historical genetic meiosis or division/recombination events in the start and end points of matches to our genetic cousins. Every start and end point represents a crossover sometime in the past.

What else can we tell about these events and how often they occur?

Of the 22 autosomes, not counting the X chromosome which has a unique inheritance pattern, 17 chromosomes experienced at least one crossover.

What does this mean to me as a genealogist and how can I interpret this type of information?

Philip Gammon

You may remember our statistician friend Philip Gammon. Philip and I have collaborated before authoring the following articles where Philip did the heavy lifting.

I discussed crossovers in the article Concepts – DNA Recombination and Crossovers, also in collaboration with Philip, and showed several examples in a Four Generation Inheritance Study.

If you haven’t read those articles, now might be a good time to do so, as they set the stage for understanding the rest of this article.

The frequency of chromosome segment divisions and their resulting crossovers are key to understanding how recombination occurs, which is key to understanding how far back in time a common ancestor between you and a match can expect to be found.

In other words, everything we think we know about relationships, especially more distant relationships, is predicated on the rate that crossovers occur.

The Concepts article references the Chowdhury paper and revealed that females average about 42 crossovers per child and males average about 27 but these quantities refer to the total number of crossovers on all 22 autosomes and reveal nothing about the distribution of the number of crossovers at the individual chromosome level.

Philip Gammon has been taking a closer look at this particular issue and has done some very interesting crossover simulations by chromosome, which are different sizes, as he reports beginning here.

Crossover Statistics by Philip Gammon

For chromosomes there is surprisingly little information available regarding the variation in the number of crossovers experienced during meiosis, the process of cell division that results in the production of ova and sperm cells. In the scientific literature I have been able to find only one reference that provides a table showing a frequency distribution for the number of crossovers by chromosome.

The paper Broad-Scale Recombination Patterns Underlying Proper Disjunction in Humans by Fledel-Alon et al in 2009 contains this information tucked away at the back of the “Supplementary methods, figures, and tables” section. It was likely not produced with genetic genealogists in mind but could be of great interest to some. The columns X0 to X8 refer to the number of crossovers on each chromosome that were measured in parental transmissions. Separate tables are shown for male and female transmissions because the rates between the two sexes differ significantly. Note that it’s the gender of the parent that matters, not the child. The sample size is quite small, containing only 288 occurrences for each gender.

A few years ago I stumbled across a paper titled Escape from crossover interference increases with maternal age by Campbell et al 2015. This study investigated the properties of crossover placement utilising family groups contained within the database of the direct-to-consumer genetic testing company 23andMe. In total more than 645,000 well-supported crossover events were able to be identified. Although this study didn’t directly report the observed frequency distribution of crossovers per chromosome, it did produce a table of parameters that accurately described the distribution of inter-crossover distances for each chromosome.

By introducing these parameters into a model that I had developed to implement the equations described by Housworth and Stahl in their 2003 paper Crossover Interference in Humans I was able to derive tables depicting the frequency of crossovers. The following results were produced for each chromosome by running 100,000 simulations in my crossover model:

Crossover transmissions from female to child.png

Transmissions from female parent to child, above.

Crossover transmissions male to child.png

Transmissions from male parent to child.

To be sure that we understand what these tables are revealing let’s look at the first row of the female table. The most frequent outcome for chromosome #1 is that there will be three crossovers and this occurs 27% of the time. There were instances when up to 10 crossovers were observed in a single meiosis but these were extremely rare. Cells that are blank recorded no observations in the 100,000 simulations. On average there are 3.36 crossovers observed on chromosome #1 in female to child transmissions i.e. the female chromosome #1 is 3.36 Morgans (336 centimorgans) in genetic length.

Blaine Bettinger has since examined crossover statistics using crowdsourced data in The Recombination Project: Analyzing Recombination Frequencies Using Crowdsourced Data, but only for females. His sample size was 250 maternal transmissions and Table 2 in the report presents the results in the same format as the tables above. There is a remarkable degree of conformity between Blaine’s measurements and the output from my simulation model and also to the earlier Fledel-Alon et al study.

The diagrams below are a typical representation of the chromosomes inherited by a child.

Crossovers inherited from mother.jpg

The red and orange (above) are the set of chromosomes inherited from the mother and the aqua and green (below) from the father. The locations where the colours change identify the crossover points.

It’s worth noting that all chromosomes have a chance of being passed from parent to child without recombination. These probabilities are found in the column for zero crossovers.

In the picture above the mother has passed on two red chromosomes (#14 and #20) without recombination from one of the maternal grandparents. No yellow chromosomes were passed intact.

Similarly, below, the father has passed on a total of five chromosomes that have no crossover points. Blue chromosomes #15, #18 and #21 were passed on intact from one paternal grandparent and green chromosomes #4 and #20 from the other.

Crossovers inherited from father.jpg

It’s quite a rare event for one of the larger chromosomes to be passed on without recombination (only a 1.4% probability for chromosome #1 in female transmissions) but occurs far more frequently in the smaller chromosomes. In fact, the male chromosome #21 is passed on intact more often (50.6% of the time) than containing DNA from both of the father’s parents.

However, there is nothing especially significant about chromosome #21.

The same could be said for any region of similar genetic length on any of the autosomes i.e. the first 52 cM of chromosome #1 or the middle 52 cM of chromosome #10 etc. From my simulations I have observed that on average 2.8 autosomes are passed down from a mother to child without a crossover and an average of 5.1 autosomes from a father to child.

In total (from both parents), 94% of offspring will inherit between 4 and 12 chromosomes containing DNA exclusively from a single grandparent. In the 100,000 simulations the child always inherited at least one chromosome without recombination.

Back to Roberta

If you have 3 generations who have tested, you can view the crossovers in the grandchild as compared to either one or two grandparents.

If the child doesn’t match one grandparent, even if their other grandparent through that parent hasn’t tested, you can certainly infer that any DNA where the grandchild doesn’t match the available grandparent comes from the non-tested “other” grandparent on that side.

Let’s Look at Real-Life Examples

Using the example of my 2 granddaughters, both of their parents and 3 of their 4 grandparents have tested, so I was able to measure the crossovers that my granddaughters experienced from all 4 of their grandparents.

Maternal Crossovers Granddaughter 1 Granddaughter 2 Average
Chromosome 1 6 2 3.36
Chromosome 2 4 2 3.17
Chromosome 3 3 2 2.71
Chromosome 4 2 2 2.59
Chromosome 5 2 1 2.49
Chromosome 6 4 2 2.36
Chromosome 7 3 1 2.23
Chromosome 8 2 2 2.11
Chromosome 9 3 1 1.95
Chromosome 10 4 2 2.08
Chromosome 11 3 0 1.93
Chromosome 12 3 3 2.00
Chromosome 13 1 1 1.52
Chromosome 14 3 1 1.38
Chromosome 15 4 1 1.44
Chromosome 16 2 2 1.58
Chromosome 17 2 2 1.53
Chromosome 18 2 0 1.40
Chromosome 19 2 1 1.18
Chromosome 20 0 1 1.19
Chromosome 21 0 1 0.74
Chromosome 22 1 0 0.78
Total 56 30 41.71

Looking at these results, it’s easy to see just how different inheritance between two full siblings can be. Granddaughter 1 has 56 crossovers through her mother, significantly more than the average of 41.71. Granddaughter 2 has 30, significantly less than average.

The average of the 2 girls is 43, very close to the total average of 41.71.

Note that one child received 2 chromosomes intact from her mother, and the other received 3.

Paternal Crossovers Granddaughter 1 Granddaughter 2 Average
Chromosome 1 2 2 1.98
Chromosome 2 3 2 1.85
Chromosome 3 2 2 1.64
Chromosome 4 0 1 1.46
Chromosome 5 1 2 1.46
Chromosome 6 2 1 1.41
Chromosome 7 1 2 1.36
Chromosome 8 1 1 1.23
Chromosome 9 1 3 1.26
Chromosome 10 3 2 1.30
Chromosome 11 0 1 1.20
Chromosome 12 1 1 1.32
Chromosome 13 2 1 1.02
Chromosome 14 1 0 0.97
Chromosome 15 1 2 1.01
Chromosome 16 0 1 1.02
Chromosome 17 0 0 1.06
Chromosome 18 1 1 0.98
Chromosome 19 1 1 1.00
Chromosome 20 0 0 0.99
Chromosome 21 0 0 0.52
Chromosome 22 0 0 0.63
Total 23 26 26.65

Granddaughter 2 had slightly more paternal crossovers than did granddaughter 1.

One child received 7 chromosomes intact from her father, and the other received 5.

Chromosome Granddaughter 1 Maternal Granddaughter 1 Paternal
Chromosome 1 6 2
Chromosome 2 4 3
Chromosome 3 3 2
Chromosome 4 2 0
Chromosome 5 2 1
Chromosome 6 4 2
Chromosome 7 3 1
Chromosome 8 2 1
Chromosome 9 3 1
Chromosome 10 4 3
Chromosome 11 3 0
Chromosome 12 3 1
Chromosome 13 1 2
Chromosome 14 3 1
Chromosome 15 4 1
Chromosome 16 2 0
Chromosome 17 2 0
Chromosome 18 2 1
Chromosome 19 2 1
Chromosome 20 0 0
Chromosome 21 0 0
Chromosome 22 1 0
Total 56 23

Comparing each child’s maternal and paternal crossovers side by side, we can see that Granddaughter 1 has more than double the number of maternal as compared to paternal crossovers, while Granddaughter 2 only had slightly more.

Chromosome Granddaughter 2 Maternal Granddaughter 2 Paternal
Chromosome 1 2 2
Chromosome 2 2 2
Chromosome 3 2 2
Chromosome 4 2 1
Chromosome 5 1 2
Chromosome 6 2 1
Chromosome 7 1 2
Chromosome 8 2 1
Chromosome 9 1 3
Chromosome 10 2 2
Chromosome 11 0 1
Chromosome 12 3 1
Chromosome 13 1 1
Chromosome 14 1 0
Chromosome 15 1 2
Chromosome 16 2 1
Chromosome 17 2 0
Chromosome 18 0 1
Chromosome 19 1 1
Chromosome 20 1 0
Chromosome 21 1 0
Chromosome 22 0 0
Total 30 26

Granddaughter 2 has closer to the same number of maternal and paternal of crossovers, but about 8% more maternal.

Comparing Maternal and Paternal Crossover Rates

Given that males clearly have a much, much lower crossover rate, according to the Philip’s chart as well as the evidence in just these two individual cases, over time, we would expect to see the DNA segments significantly LESS broken up in male to male transmissions, especially an entire line of male to male transmissions, as compared to female to female linear transmissions. This means we can expect to see larger intact shared segments in a male to male transmission line as compared to a female to female transmission line.

  G1 Mat G2 Mat Mat Avg G1 Pat G2 Pat Pat Avg
Gen 1 56 30 41.71 23 26 26.65
Gen 2 112 60 83.42 46 52 53.30
Gen 3 168 90 125.13 69 78 79.95
Gen 4 224 120 166.84 92 104 106.60

Using the Transmission rates for Granddaughter 1, Granddaughter 2, and the average calculated by Philip, it’s easy to see the cumulative expected average number of crossovers vary dramatically in every generation.

By the 4th generation, the maternal crossovers seen in someone entirely maternally descended at the rate of Grandchild 1 would equal 224 crossovers meaning that the descendant’s DNA would be divided that many times, while the same number of paternal linear divisions at 4 generations would only equal 92.

Yet today, we would never look at 2 people’s DNA, one with 224 crossovers compared to one with 92 crossovers and even consider the possibility that they are both only three generations descended from an ancestor, counting the parents as generation 1.

What Does This Mean?

The number of males and females in a specific line clearly has a direct influence on the number of crossovers experienced, and what we can expect to see as a result in terms of average segment size of inherited segments in a specific number of generations.

Using Granddaughter 1’s maternal crossover rate as an example, in 4 generations, chromosome 1 would have incurred a total of 24 crossovers, so the DNA would be divided into in 25 pieces. At the paternal rate, only 8 crossovers so the DNA would be in 9 pieces.

Chromosome 1 is a total of 267 centimorgans in length, so dividing 267 cM by 25 would mean the average segment would only be 10.68 cM for the maternal transmission, while the average segment divided by 9 would be 29.67 cM in length for the paternal transmission.

Given that the longest matching segment is a portion of the estimated relationship calculation, the difference between a 10.68 cM maternal linear segment match and a 29.67 paternal linear cM segment match is significant.

While I used the highest and lowest maternal and paternal rates of the granddaughters, the average would be 19 and 29, respectively – still a significant difference.

Maternal and Paternal Crossover Average Segment Size

Each person has an autosomal total of 3374 cM on chromosomes 1-22, excluding the X chromosome, that is being compared to other testers. Applying these calculations to all 22 autosomes using the maternal and paternal averages for 4 generations, dividing into the 3374 total we find the following average segment centiMorgan matches:

Crossovers average segment size.png

Keep in mind, of course, that the chart above represents 3 generations in a row of either maternal or paternal crossovers, but even one generation is significant.

The average size segment of a grandparent’s DNA that a child receives from their mother is 80.89 cM where the average segment of a grandparent’s DNA inherited from their father is 1.57 times larger at 126.6 cM.

Keep the maternal versus paternal inheritance path in mind as you evaluate matches to cousins with identified common ancestors, especially if the path is entirely or mostly maternal or paternal.

For unknown matches, just keep in mind that the average that vendors calculate and use to predict relationships, because they can’t and don’t have “inside knowledge” about the inheritance path, may or may not be either accurate or average. They do the best they can do with the information they have at hand.

Back to Philip again who provides us with additional information.

Maternal Versus Paternal Descent

Along a predominantly maternal path the DNA is likely to be inherited in more numerous smaller segments while along a predominantly paternal path it will likely be in fewer but larger segments. So matches who descend paternally from a common ancestor and carry the surname are not likely to carry more DNA from that common male ancestor than someone who descends from a mixed or directly maternal line. In fact, someone descending from an ancestor down an all-male path is more likely to inherit no DNA at all from that ancestor than someone descending down an all-female path. This is because the fewer segments there are the higher the risk is that a person won’t pass on any of them. Of course, there’s also a greater chance that all of the segments could be passed on. Fewer segments leads to more variation in the amount of DNA inherited but not a higher average amount of DNA inherited.

Gammon 3X great-grandparents.png

The chart above shows the spread in the amount of DNA inherited from a 3xgreat-grandparent, down all-maternal, all-paternal and down all possible paths. The average in each case is 3.125% i.e. 1 part in 32 but as expected the all-paternal path shows much more variation. Compared to the all-maternal path, on the all-paternal you are more likely to inherit either less than 2.0% or more than 5.0%. In 50,000 simulations there were 14 instances where a 3xgreat-grandchild did not inherit any DNA down the all-paternal path. There were no cases of zero DNA inherited down the all-maternal path.

One way to think about this is to consider a single chromosome. If at least one crossovers occurs in the meiosis some DNA from each grandparent will be passed down to the grandchild but when it is passed on without recombination, as occurs more frequently in paternal than maternal meiosis, all of the DNA from one grandparent is passed on but none at all from the other. When this happens, there is no bias toward either the grandfather’s or the grandmother’s chromosome being passed on. It’s just as likely that the segment coming down the all-paternal path will be lost entirely as it is that it will be passed on in full.

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

Mitochondrial DNA Resources – Everything You Need to Know

Mitochondrial DNA Resources

Recently, I wrote a multi-part series about mitochondrial DNA – start to finish – everything you need to know.

I’ve assembled several articles in one place, and I’ll add any new articles here as well.

Please feel free to share this resource or any of the links to individual articles with friends, genealogy groups or on social media.

What the Difference Between Mitochondrial and Other Types of DNA?

Mitochondrial DNA is inherited directly from your matrilineal line, only, meaning your mother’s mother’s mother’s mother – on up your family tree until you run out of direct line mothers that you’ve identified. The great news is even if you don’t know the identities of those people in your tree, you carry their mitochondrial DNA which can help identify them.

Here’s a short article about the different kinds of DNA that can be used for genealogy.

Why Mitochondrial DNA?

Let’s start out with why someone might want to test their mitochondrial DNA.

After you purchase a DNA test, swab, return the kit and when the lab finishes processing your test, you’ll receive your results on your personal page at FamilyTreeDNA, the only company that tests mitochondrial DNA at the full sequence level and provides matching with tens of thousands of other testers.

What About Those Results?

People want to understand how to use all of the different information provided to testers. These articles provide a step-by-step primer.

Mitochondrial DNA personal page update

Sign in to your Family Tree DNA account and use these articles as a guideline to step through your results on your personal page.

We begin with an overview. What is mitochondrial DNA, how it is inherited and why is it useful for genealogy?

Next, we look at your results and decode what all the numbers mean. It’s easy, really!

Our ancestors lived in clans, and our mitochondrial DNA has its own versions of clans too – called haplogroups. Your full haplogroup can be very informative.

Sometimes there’s more than meets the eye. Here are my own tips and techniques for more than doubling the usefulness of your matches.

You’ll want to wring every possible advantage out of your tests, so be sure to join relevant projects and use them to their fullest extent.

Do you know how to utilize advanced matching? It’s a very powerful tool. If not, you will after these articles.

Mitochondrial DNA Information for Everyone

FamilyTreeDNA maintains an extensive public mitochondrial DNA tree, complete with countries of origin for all branches. You don’t need to have tested to enjoy the public tree.

However, if you have tested, take a look to see where the earliest known ancestors of your haplogroup matches are located based on the country flags.

Mitochondrial resources haplotree

These are mine. Where are yours?

What Can Mitochondrial DNA Do for You?

Some people mistakenly think that mitochondrial DNA isn’t useful for genealogy. I’m here to testify that it’s not only useful, it’s amazing! Here are three stories from my own genealogy about how I’ve used mitochondrial DNA to learn more about my ancestors and in some cases, break right through brick walls.

It’s not only your own mitochondrial DNA that’s important, but other family members too.

My cousin tested her mitochondrial DNA to discover that her direct matrilineal ancestor was Native American, much to her surprise. The great news is that her ancestor is my ancestor too!

Searching for Native American Ancestors?

If you’re searching for Native American or particular ancestors, mitochondrial DNA can tell you specifically if your mitochondrial DNA, or that of your ancestors (if you test a direct matrilineal descendant,) is Native, African, European, Jewish or Asian. Furthermore, your matches provide clues as to what country your ancestor might be from and sometimes which regions too.

Did you know that people from different parts of the world have distinctive haplogroups?

You can discover your ancestors’ origins through their mitochondrial DNA.

You can even utilize autosomal segment information to track back in time to the ancestor you seek. Then you can obtain that ancestor’s mitochondrial DNA by selectively testing their descendants or finding people who have already tested that descend from that ancestor. Here’s how.

You never know what you’re going to discover when you test your mitochondrial DNA. I discovered that although my earliest known matrilineal ancestor is found in Germany, her ancestors were from Scandinavia. My cousin discovered that our common ancestor is Mi’kmaq.

What secrets will your mitochondrial DNA reveal?

You can test or upgrade your mitochondrial DNA by clicking here.

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research