DNA: In Search of…Signs of Endogamy

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

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

After introductions, we will be covering the following topics:

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

What Is Endogamy and Why Does It Matter?

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

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

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

This Article

This article serves two purposes.

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

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

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

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

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

I’ve previously written about endogamy in the articles:

Let’s start with definitions.

Pedigree Collapse and Endogamy

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

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

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

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

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

Pedigree Collapse and Endogamy is NOT the Same

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

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

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

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

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

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

Endogamy Doesn’t Necessarily Indicate Recent Pedigree Collapse

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

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

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

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

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

Endogamous Groups

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

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

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

Native American (Indigenous) People – all indigenous peoples found in North and South America before European colonization descended from a small number of original founders who probably arrived at multiple times.

Indigenous Pacific Islanders – Including indigenous peoples of Australia, New Zealand, and Hawaii prior to colonization. They are probably equally as endogamous as Native American people, but I don’t have specific examples to share.

Villages – European or other villages with little inflow or whose residents were restricted from leaving over hundreds of years.

Other groups may have significant multiple lines of pedigree collapse and therefore become endogamous over time. Some people from Newfoundland, French Canadians, and Mormons (Church of Jesus Christ of Latter-Day Saints) come to mind.

Endogamy is a process that occurs over time.

Endogamy and Unknown Relatives

If you know who your relatives are, you may already know you’re from an endogamous population, but if you’re searching for close relatives, it’s helpful to be able to determine if you have endogamous heritage, at least in recent generations.

If you know nothing about either parent, some of these tools won’t help you, at least not initially, but others will. However, as you add to your knowledge base, the other tools will become more useful.

If you know the identity of one parent, this process becomes at least somewhat easier.

In future articles, we will search specifically for parents and each of your four grandparents. In this article, I’ll review each of the diagnostic tools and techniques you can use to determine if you have endogamy, and perhaps pinpoint the source.

The Challenge

People with endogamous heritage are related in multiple, unknown ways, over many generations. They may also be related in known ways in recent generations.

If both of your parents share the SAME endogamous culture or group of relatives:

  • You may have significantly more autosomal DNA matches than people without endogamy, unless that group of people is under-sampled. Jewish people have significantly more matches, but Native people have fewer due to under-sampling.
  • You may experience a higher-than-normal cM (centiMorgan) total for estimated relationships, especially more distant relationships, 3C and beyond.
  • You will have many matches related to you on both your maternal and paternal sides.
  • Parts of your autosomal DNA will be the same on both your mother’s and father’s sides, meaning your DNA will be fully identical in some locations. (I’ll explain more in a minute.)

If either (or both) of your parents are from an endogamous population, you:

  • Will, in some cases, carry identifying Y and mitochondrial DNA that points to a specific endogamous group. This is true for Native people, can be true for Jewish people and Pacific Islanders, but is not true for Anabaptist people.

One Size Does NOT Fit All

Please note that there is no “one size fits all.”

Each or any of these tools may provide relevant hints, depending on:

  • Your heritage
  • How many other people have tested from the relevant population group
  • How many close or distant relatives have tested
  • If your parents share the same heritage
  • Your unique DNA inheritance pattern
  • If your parents, individually, were fully endogamous or only partly endogamous, and how far back generationally that endogamy occurred

For example, in my own genealogy, my maternal grandmother’s father was Acadian on his father’s side. While I’m not fully endogamous, I have significantly more matches through that line proportionally than on my other lines.

I have Brethren endogamy on my mother’s side via her paternal grandmother.

Endogamous ancestors are shown with red stars on my mother’s pedigree chart, above. However, please note that her maternal and paternal endogamous ancestors are not from the same endogamous population.

However, I STILL have fewer matches on my mother’s side in total than on my father’s side because my mother has recent Dutch and recent German immigrants which reduces her total number of matches. Neither of those lines have had as much time to produce descendants in the US, and Europe is under-sampled when compared with the US where more people tend to take DNA tests because they are searching for where they came from.

My father’s ancestors have been in the US since it was a British Colony, and I have many more cousins who have tested on his side than mother’s.

If you looked at my pedigree chart and thought to yourself, “that’s messy,” you’d be right.

The “endogamy means more matches” axiom does not hold true for me, comparatively, between my parents – in part because my mother’s German and Dutch lines are such recent immigrants.

The number of matches alone isn’t going to tell this story.

We are going to need to look at several pieces and parts for more information. Let’s start with ethnicity.

Ethnicity and Populations

Ethnicity can be a double-edged sword. It can tell you exactly nothing you couldn’t discern by looking in the mirror, or, conversely, it can be a wealth of information.

Ethnicity reveals the parts of the world where your ancestors originated. When searching for recent ancestors, you’re most interested in majority ethnicity, meaning the 50% of your DNA that you received from each of your parents.

Ethnicity results at each vendor are easy to find and relatively easy to understand.

This individual at FamilyTreeDNA is 100% Ashkenazi Jewish.

If they were 50% Jewish, we could then estimate, and that’s an important word, that either one of their parents was fully Jewish, and not the other, or that two of their grandparents were Jewish, although not necessarily on the same side.

On the other hand, my mother’s ethnicity, shown below, has nothing remarkable that would point to any majority endogamous population, yet she has two.

The only hint of endogamy from ethnicity would be her ~1% Americas, and that isn’t relevant for finding close relatives. However, minority ancestry is very relevant for identifying Native ancestors, which I wrote about, here.

You can correlate or track your ethnicity segments to specific ancestors, which I discussed in the article, Native American & Minority Ancestors Identified Using DNAPainter Plus Ethnicity Segments, here.

Since I wrote that article, FamilyTreeDNA has added the feature of ethnicity or population Chromosome Painting, based on where each of your populations fall on your chromosomes.

In this example on chromosome 1, I have European ancestry (blue,) except for the pink Native segment, which occurs on the following segment in the same location on my mother’s chromosome 1 as well.

Both 23andMe, and FamilyTreeDNA provide chromosome painting AND the associated segment information so you can identify the relevant ancestors.

Ancestry is in the process of rolling out an ethnicity painting feature, BUT, it has no segment or associated matching information. While it’s interesting eye candy, it’s not terribly useful beyond the ethnicity information that Ancestry already provides. However, Jonny Perl at DNAPainter has devised a way to estimate Ancestry’s start and stop locations, here. Way to go Jonny!

Now all you need to do is convince your Ancestry matches to upload their DNA file to one of the three databases, FamilyTreeDNA, MyHeritage, and GEDMatch, that accept transfers, aka uploads. This allows matching with segment data so that you can identify who matches you on that segment, track your ancestors, and paint your ancestral segments at DNAPainter.

I provided step-by-step instructions, here, for downloading your raw DNA file from each vendor in order to upload the file to another vendor.

Ethnicity Sides

Three of the four DNA testing vendors, 23andMe, FamilyTreeDNA, and recently, Ancestry, attempt to phase your ethnicity DNA, meaning to assign it to one parental “side” or the other – both in total and on each chromosome.

Here’s Ancestry’s SideView, where your DNA is estimated to belong to parent 1 and parent 2. I detailed how to determine which side is which, here, and while that article was written specifically pertaining to Ancestry’s SideView, the technique is relevant for all the vendors who attempt to divide your DNA into parents, a technique known as phasing.

I say “attempt” because phasing may or may not be accurate, meaning the top chromosome may not always be parent 1, and the bottom chromosome may not always be chromosome 2.

Here’s an example at 23andMe.

See the two yellow segments. They are both assigned as Native. I happen to know one is from the mother and one is from the father, yet they are both displayed on the “top” chromosome, which one would interpret to be the same parent.

I am absolutely positive this is not the case because this is a close family member, and I have the DNA of the parent who contributed the Native segment on chromosome 1, on the top chromosome. That parent does not have a Native segment on chromosome 2 to contribute. So that Native segment had to be contributed by the other parent, but it’s also shown on the top chromosome.

The DNA segments circled in purple belong together on the same “side” and were contributed to the tester by the same parent. The Native segment on chromosome 2 abuts a purple African segment, suggesting perhaps that the ancestor who contributed that segment was mixed between those ethnicities. In the US, that suggests enslavement.

The other African segments, circled, are shown on the second chromosome in each pair.

To be clear, parent 1 is not assigned by the vendors to either mother or father and will differ by person. Your parent 1, or the parent on the top chromosome may be your mother and another person’s parent 1 may be their father.

As shown in this example, parents can vary by chromosome, a phenomenon known as “strand swap.” Occasionally, the DNA can even be swapped within a chromosome assignment.

You can, however, get an idea of the division of your DNA at any specific location. As shown above, you can only have a maximum of two populations of DNA on any one chromosome location.

In our example above, this person’s majority ancestry is European (blue.) On each chromosome where we find a minority segment, the opposite chromosome in the same location is European, meaning blue.

Let’s look at another example.

At FamilyTreeDNA, the person whose ethnicity painting is shown below has a Native American (pink) ancestor on their father’s side. FamilyTreeDNA has correctly phased or identified their Native segments as all belonging to the second chromosome in each pair.

Looking at chromosome 18, for example, most of their father’s chromosome is Native American (pink). The other parent’s chromosome is European (dark blue) at those same locations.

If one of the parents was of one ethnicity, and the other parent is a completely different ethnicity, then one bar of each chromosome would be all pink, for example, and one would be entirely blue, representing the other ethnicity.

Phasing ethnicity or populations to maternal and paternal sides is not foolproof, and each chromosome is phased individually.

Ethnicity can, in some cases, give you a really good idea of what you’re dealing with in terms of heritage and endogamy.

If someone had an Ashkenazi Jewish father and European mother, for example, one copy of each chromosome would be yellow (Ashkenazi Jewish), and one would be blue (European.)

However, if each of their parents were half European Jewish and half European (not Jewish), then their different colored segments would be scattered across their entire set of chromosomes.

In this case, both of the tester’s parents are mixed – European Jewish (green) and Western Europe (blue.) We know both parents are admixed from the same two populations because in some locations, both parents contributed blue (Western Europe), and in other locations, both contributed Jewish (green) segments.

Both MyHeritage and Ancestry provide a secondary tool that’s connected to ethnicity, but different and generally in more recent times.

Ancestry’s DNA Communities

While your ethnicity may not point to anything terribly exciting in terms of endogamy, Genetic Communities might. Ancestry says that a DNA Community is a group of people who share DNA because their relatives recently lived in the same place at the same time, and that communities are much smaller than ethnicity regions and reach back only about 50-300 years.

Based on the ancestors’ locations in the trees of me and my matches, Ancestry has determined that I’m connected to two communities. In my case, the blue group is clearly my father’s line. The orange group could be either parent, or even a combination of both.

My endogamous Brethren could be showing up in Maryland, Pennsylvania, and Ohio, but it’s uncertain, in part, because my father’s ancestral lines are found in Virginia, West Virginia, and Maryland too.

These aren’t useful for me, but they may be more useful for fully endogamous people, especially in conjunction with ethnicity.

My Acadian cousin’s European ethnicity isn’t informative.

However, viewing his DNA Communities puts his French heritage into perspective, especially combined with his match surnames.

I wrote about DNA Communities when it was introduced with the name Genetic Communities, here.

MyHeritage’s Genetic Groups

MyHeritage also provides a similar feature that shows where my matches’ ancestors lived in the same locations as mine.

One difference, though, is that testers can adjust their ethnicity results confidence level from high, above, to low, below where one of my Genetic Groups overlaps my ethnicity in the Netherlands.

You can also sort your matches by Genetic Groups.

The results show you not only who is in the group, but how many of your matches are in that group too, which provides perspective.

I wrote about Genetic Groups, here.

Next, let’s look at how endogamy affects your matches.

Matches

The number of matches that a person has who is from an entirely endogamous community and a person with no endogamy may be quite different.

FamilyTreeDNA provides a Family Matching feature that triangulates your matches and assigns them to your paternal or maternal side by using known matches that you have linked to their profile cards in your tree. You must link people for the Family Matching feature known as “bucketing” to be enabled.

The people you link are then processed for shared matches on the same chromosome segment(s). Triangulated individuals are then deposited in your maternal, paternal, and both buckets.

Obviously, your two parents are the best people to link, but if they haven’t tested (or uploaded their DNA file from another vendor) and you have other known relatives, link them using the Family Tree tab at the top of your personal page.

I uploaded my Ancestry V4 kit to use as an example for linking. Let’s pretend that’s my sister. If I had not already linked my Ancestry V4 kit to “my sister’s” profile card, I’d want to do that and link other known individuals the same way. Just drag and drop the match to the correct profile card.

Note that a full or half sibling will be listed as such at FamilyTreeDNA, but an identical twin will show as a potential parent/child match to you. You’re much more likely to find a parent than an identical twin, but just be aware.

I’ve created a table of FamilyTreeDNA bucketed match results, by category, comparing the number of matches in endogamous categories with non-endogamous.

Total Matches Maternal Matches Paternal Matches Both % Both % DNA Unassigned
100% Jewish 34,637 11,329 10,416 4,806 13.9 23.3
100% Jewish 32,973 10,700 9,858 4,606 14 23.7
100% Jewish 32,255 9,060 10,970 3,892 12 25.8
75% Jewish 24,232 11,846 Only mother linked Only mother linked Only mother linked
100% Acadian 8093 3826 2299 1062 13 11
100% Acadian 7828 3763 1825 923 11.8 17
Not Endogamous 6760 3845 1909 13 0.19 14.5
Not Endogamous 7723 1470 3317 6 0.08 38
100% Native American 1,115 Unlinked Unlinked Unlinked
100% Native American 885 290 Unknown Can’t calculate without at least one link on both sides

The 100% Jewish, Acadian, and Not Endogamous testers both have linked their parents, so their matches, if valid (meaning not identical by chance, which I discussed here,) will match them plus one or the other parent.

One person is 75% Jewish and has only linked their Jewish mother.

The Native people have not tested their parents, and the first Native person has not linked anyone in their tree. The second Native person has only linked a few maternal matches, but their mother has not tested. They are seeking their father.

It’s very difficult to find people who are fully Native as testers. Furthermore, Native people are under-sampled. If anyone knows of fully Native (or other endogamous) people who have tested and linked their parents or known relatives in their trees, and will allow me to use their total match numbers anonymously, please let me know.

As you can see, Jewish, Acadian, and Native people are 100% endogamous, but many more Jewish people than Native people have tested, so you CAN’T judge endogamy by the total number of matches alone.

In fact, in order:

  • Fully Jewish testers have about 4-5 times as many matches as the Acadian and Non-endogamous testers
  • Acadian and Non-endogamous testers have about 5-6 times as many matches as the Native American testers
  • Fully Jewish people have about 30 times more matches than the Native American testers

If a person’s endogamy with a particular population is only on their maternal or paternal side, they won’t have a significant number of people related to both sides, meaning few people will fall into the “Both” bucket. People that will always be found in the ”Both” bucket are full siblings and their descendants, along with descendants of the tester, assuming their match is linked to their profiles in the tester’s tree.

In the case of our Jewish testers, you can easily see that the “Both” bucket is very high. The Acadians are also higher than one would reasonably expect without endogamy. A non-endogamous person might have a few matches on both sides, assuming the parents are not related to each other.

A high number of “Both” matches is a very good indicator of endogamy within the same population on both parents’ sides.

The percentage of people who are assigned to the “Both” bucket is between 11% and 14% in the endogamous groups, and less than 1% in the non-endogamous group, so statistically not relevant.

As demonstrated by the Native people compared to the Jewish testers, the total number of matches can be deceiving.

However, being related to both parents, as indicated by the “Both” bucket, unless you have pedigree collapse, is a good indicator of endogamy.

Of course, if you don’t know who your relatives are, you can’t link them in your tree, so this type of “hunt” won’t generally help people seeking their close family members.

However, you may notice that you’re matching people PLUS both of their parents. If that’s the case, start asking questions of those matches about their heritage.

A very high number of total matches, as compared to non-endogamous people, combined with some other hints might well point to Jewish heritage.

I included the % DNA Unassigned category because this category, when both parents are linked, is the percentage of matches by chance, meaning the match doesn’t match either of the tester’s parents. All of the people with people listed in “Both” categories have linked both of their parents, not just maternal and paternal relatives.

Matching Location at MyHeritage

MyHeritage provides a matching function by location. Please note that it’s the location of the tester, but that may still be quite useful.

The locations are shown in the most-matches to least-matches order. Clicking on the location shows the people who match you who are from that location. This would be the most useful in situations where recent immigration has occurred. In my case, my great-grandfather from the Netherlands arrived in the 1860s, and my German ancestors arrived in the 1850s. Neither of those groups are endogamous, though, unless it would be on a village level.

AutoClusters

Let’s shift to Genetic Affairs, a third-party tool available to everyone.

Using their AutoCluster function, Genetic Affairs clusters your matches together who match both each other and you.

This is an example of the first few clusters in my AutoCluster. You can see that I have several colored clusters of various sizes, but none are huge.

Compare that to the following endogamous cluster, sample courtesy of EJ Blom at Genetic Affairs.

If your AutoCluster at Genetic Affairs looks something like this, a huge orange blob in the upper left hand corner, you’re dealing with endogamy.

Please also note that the size of your cluster is also a function of both the number of testers and the match threshold you select. I always begin by using the defaults. I wrote about using Genetic Affairs, here.

If you tested at or transferred to MyHeritage, they too license AutoClusters, but have optimized the algorithm to tease out endogamous matches so that their Jewish customers, in particular, don’t wind up with a huge orange block of interrelated people.

You won’t see the “endogamy signature” huge cluster in the corner, so you’re less likely to be able to discern endogamy from a MyHeritage cluster alone.

The commonality between these Jewish clusters at MyHeritage is that they all tend to be rather uniform in size and small, with lots of grey connecting almost all the blocks.

Grey cells indicate people who match people in two colored groups. In other words, there is often no clear division in clusters between the mother’s side and the father’s side in Jewish clusters.

In non-endogamous situations, even if you can’t identify the parents, the clusters should still fall into two sides, meaning a group of clusters for each parent’s side that are not related to each other.

You can read more about Genetic Affairs clusters and their tools, here. DNAGedcom.com also provides a clustering tool.

Endogamous Relationships

Endogamous estimated relationships are sometimes high. Please note the word, “sometimes.”

Using the Shared cM Project tool relationship chart, here, at DNAPainter, people with heavy endogamy will discover that estimated relationships MAY be on the high side, or the relationships may, perhaps, be estimated too “close” in time. That’s especially true for more distant relationships, but surprisingly, it’s not always true. The randomness of inheritance still comes into play, and so do potential unknown relatives. Hence, the words “may” are bolded and underscored.

Unfortunately, it’s often stated as “conventional wisdom” that Jewish matches are “always” high, and first cousins appear as siblings. Let’s see what the actual data says.

At DNAPainter, you can either enter the amount of shared DNA (cM), or the percent of shared DNA, or just use the chart provided.

I’ve assembled a compilation of close relationships in kits that I have access to or from people who were generous enough to share their results for this article.

I’ve used Jewish results, which is a highly endogamous population, compared with non-endogamous testers.

The “Jewish Actual” column reports the total amount of shared DNA with that person. In other words, someone to their grandparent. The Average Range is the average plus the range from DNAPainter. The Percent Difference is the % difference between the actual number and the DNAPainter average.

You’ll see fully Jewish testers, at left, matching with their family members, and a Non-endogamous person, at right, matching with their same relative.

Relationship Jewish Actual Percent Difference than Average Average -Range Non-endogamous Actual Percent Difference than Average
Grandparent 2141 22 1754 (984-2482) 1742 <1 lower
Grandparent 1902 8.5 1754 (984-2482) 1973 12
Sibling 3039 16 2613 (1613-3488) 2515 3.5 lower
Sibling 2724 4 2613 (1613-3488) 2761 5.5
Half-Sibling 2184 24 1759 (1160-2436) 2127 21
Half-Sibling 2128 21 1759 (1160-2436) 2352 34
Aunt/Uncle 2066 18.5 1741 (1201-2282) 1849 6
Aunt/Uncle 2031 16.5 1741 (1201-2282) 2097 20
1C 1119 29 866 (396-1397) 959 11
1C 909 5 866 (396-1397) 789 9 lower
1C1R 514 19 433 (102-980) 467 8
1C1R 459 6 433 (102-980) 395 9 lower

These totals are from FamilyTreeDNA except one from GEDMatch (one Jewish Half-sibling).

Totals may vary by vendor, even when matching with the same person. 23andMe includes the X segments in the total cMs and also counts fully identical segments twice. MyHeritage imputation seems to err on the generous side.

However, in these dozen examples:

  • You can see that the Jewish actual amount of DNA shared is always more than the average in the estimate.
  • The red means the overage is more than 100 cM larger.
  • The percentage difference is probably more meaningful because 100 cM is a smaller percentage of a 1754 grandparent connection than compared to a 433 cM 1C1R.

However, you can’t tell anything about endogamy by just looking at any one sample, because:

  • Some of the Non-Endogamous matches are high too. That’s just the way of random inheritance.
  • All of the actual Jewish match numbers are within the published ranges, but on the high side.

Furthermore, it can get more complex.

Half Endogamous

I requested assistance from Jewish genealogy researchers, and a lovely lady, Sharon, reached out, compiled her segment information, and shared it with me, granting permission to share with you. A HUGE thank you to Sharon!

Sharon is half-Jewish via one parent, and her half-sibling is fully Jewish. Their half-sibling match to each other at Ancestry is 1756 cM with a longest segment of 164 cM.

How does Jewish matching vary if you’re half-Jewish versus fully Jewish? Let’s look at 21 people who match both Sharon and her fully Jewish half-sibling.

Sharon shared the differences in 21 known Jewish matches with her and her half-sibling. I’ve added the Relationship Estimate Range from DNAPainter and colorized the highest of the two matches in yellow. Bolding in the total cM column shows a value above the average range for that relationship.

Total Matching cMs is on the left, with Longest Segment on the right.

While this is clearly not a scientific study, it is a representative sample.

The fully Jewish sibling carries more Jewish DNA, which is available for other Jewish matches to match as a function of endogamy (identical by chance/population), so I would have expected the fully Jewish sibling to match most if not all Jewish testers at a higher level than the half-Jewish sibling.

However, that’s not universally what we see.

The fully Jewish sibling is not always the sibling with the highest number of matches to the other Jewish testers, although the half-Jewish tester has the larger “Longest Segment” more often than not.

Approximately two-thirds of the time (13/21), the fully Jewish person does have a higher total matching cM, but about one-third of the time (8/21), the half-Jewish sibling has a higher matching cM.

About one-fourth of the time (5/21), the fully Jewish sibling has the longest matching segment, and about two-thirds of the time (13/21), the half-Jewish sibling does. In three cases, or about 14% of the time, the longest segment is equal which may indicate that it’s the same segment.

Because of endogamy, Jewish matches are more likely to have:

  • Larger than average total cM for the specific relationship
  • More and smaller matching segments

However, as we have seen, neither of those are definitive, nor always true. Jewish matches and relationships are not always overestimated.

Ancestry and Timber

Please note that Ancestry downweights some matches by removing some segments using their Timber algorithm. Based on my matches and other accounts that I manage, Ancestry does not downweight in the 2-3rd cousin category, which is 90 cM and above, but they do begin downweighting in the 3-4th cousin category, below 90 cM, where my “Extended Family” category begins.

If you’ve tested at Ancestry, you can check for yourself.

By clicking on the amount of DNA you share with your match on your match list at Ancestry, shown above, you will be taken to another page where you will be able to view the unweighted shared DNA with that match, meaning the amount of DNA shared before the downweighting and removal of some segments, shown below.

Given the downweighting, and the information in the spreadsheet provided by Sharon, it doesn’t appear that any of those matches would have been in a category to be downweighted.

Therefore, for these and other close matches, Timber wouldn’t be a factor, but would potentially be in more distant matches.

Endogamous Segments

Endogamous matches tend to have smaller and more segments. Small amounts of matching DNA tend to skew the total DNA cM upwards.

How and why does this happen?

Ancestral DNA from further back in time tends to be broken into smaller segments.

Sometimes, especially in endogamous situations, two smaller segments, at one time separated from each other, manage to join back together again and form a match, but the match is only due to ancestral segments – not because of a recent ancestor.

Please note that different vendors have different minimum matching cM thresholds, so smaller matches may not be available at all vendors. Remember that factors like Timber and imputation can affect matching as well.

Let’s take a look at an example. I’ve created a chart where two ancestors have their blue and pink DNA broken into 4 cM segments.

They have children, a blue child and a pink child, and the two children, shown above, each inherited the same blue 4 cM segment and the same pink 4 cM segment from their respective parents. The other unlabeled pink and blue segments are not inherited by these two children, so those unlabeled segments are irrelevant in this example.

The parents may have had other children who inherited those same 4 cM labeled pink and blue segments as well, and if not, the parents’ siblings were probably passing at least some of the same DNA down to their descendants too.

The blue and pink children had children, and their children had children – for several generations.

Time passed, and their descendants became an endogamous community. Those pink and blue 4 cM segments may at some time be lost during recombination in the descendants of each of their children, shown by “Lost pink” and “Lost blue.”

However, because there is only a very limited amount of DNA within the endogamous community, their descendants may regain those same segments again from their “other parent” during recombination, downstream.

In each generation, the DNA of the descendant carrying the original blue or pink DNA segment is recombined with their partner. Given that the partners are both members of the same endogamous community, the two people may have the same pink and/or blue DNA segments. If one parent doesn’t carry the pink 4 cM segment, for example, their offspring may receive that ancestral pink segment from the other parent.

They could potentially, and sometimes do, receive that ancestral segment from both parents.

In our example, the descendants of the blue child, at left, lost the pink 4 cM segment in generation 3, but a few generations later, in generation 11, that descendant child inherited that same pink 4 cM segment from their other parent. Therefore, both the 4 cM blue and 4 cM pink segments are now available to be inherited by the descendants in that line. I’ve shown the opposite scenario in the generational inheritance at right where the blue segment is lost and regained.

Once rejoined, that pink and blue segment can be passed along together for generations.

The important part, though, is that once those two segments butt up against each other again during recombination, they aren’t just two separate 4 cM segments, but one segment that is 8 cM long – that is now equal to or above the vendors’ matching threshold.

This is why people descended from endogamous populations often have the following matching characteristics:

  • More matches
  • Many smaller segment matches
  • Their total cM is often broken into more, smaller segments

What does more, smaller segments, look like, exactly?

More, Smaller Segments

All of our vendors except Ancestry have a chromosome browser for their customers to compare their DNA to that of their matches visually.

Let’s take a look at some examples of what endogamous and non-endogamous matches look like.

For example, here’s a screen shot of a random Jewish second cousin match – 298 cM total, divided into 12 segments, with a longest segment of 58 cM,

A second Jewish 2C with 323 cM total, across 19 segments, with a 69 cM longest block.

A fully Acadian 2C match with 600 cM total, across 27 segments, with a longest segment of 69 cM.

A second Acadian 2C with 332 cM total, across 20 segments, with a longest segment of 42 cM.

Next, a non-endogamous 2C match with 217 cM, across 7 segments, with a longest segment of 72 cM.

Here’s another non-endogamous 2C example, with 169 shared cM, across 6 segments, with a longest segment of 70 cM.

Here’s the second cousin data in a summary table. The take-away from this is the proportion of total segments

Tester Population Total cM Longest Block Total Segments
Jewish 2C 298 58 12
Jewish 2C 323 69 19
Acadian 2C 600 69 27
Acadian 2C 332 42 20
Non-endogamous 2C 217 72 7
Non-endogamous 2C 169 70 6

You can see more examples and comparisons between Native American, Jewish and non-endogamous DNA individuals in the article, Concepts – Endogamy and DNA Segments.

I suspect that a savvy mathematician could predict endogamy based on longest block and total segment information.

Lara Diamond, a mathematician, who writes at Lara’s Jewnealogy might be up for this challenge. She just published compiled matching and segment information in her Ashkenazic Shared DNA Survey Results for those who are interested. You can also contribute to Laura’s data, here.

Endogamy, Segments, and Distant Relationships

While not relevant to searching for close relatives, heavily endogamous matches 3C and more distant, to quote one of my Jewish friends, “dissolve into a quagmire of endogamy and are exceedingly difficult to unravel.”

In my own Acadian endogamous line, I often simply have to label them “Acadian” because the DNA tracks back to so many ancestors in different lines. In other words, I can’t tell which ancestor the match is actually pointing to because the same DNA segments or segments is/are carried by several ancestors and their descendants due to founder effect.

The difference with the Acadians is that we can actually identify many or most of them, at least at some point in time. As my cousin, Paul LeBlanc, once said, if you’re related to one Acadian, you’re related to all Acadians. Then he proceeded to tell me that he and I are related 137 different ways. My head hurts!

It’s no wonder that endogamy is incredibly difficult beyond the first few generations when it turns into something like multi-colored jello soup.

“Are Your Parents Related?” Tool

There’s another tool that you can utilize to determine if your parents are related to each other.

To determine if your parents are related to each other, you need to know about ROH, or Runs of Homozygosity (ROH).

ROH means that the DNA on both strands or copies of the same chromosome is identical.

For a few locations in a row, ROH can easily happen just by chance, but the longer the segment, the less likely that commonality occurs simply by chance.

The good news is that you don’t need to know the identity of either of your parents. You don’t need either of your parent’s DNA tests – just your own. You’ll need to upload your DNA file to GEDmatch, which is free.

Click on “Are your parents related?”

GEDMatch analyzes your DNA to see if any of your DNA, above a reasonable matching threshold, is identical on both strands, indicating that you inherited the exact same DNA from both of your parents.

A legitimate match, meaning one that’s not by chance, will include many contiguous matching locations, generally a minimum of 500 SNPs or locations in a row. GEDmatch’s minimum threshold for identifying identical ancestral DNA (ROH) is 200 cM.

Here’s my result, including the graphic for the first two chromosomes. Notice the tiny green bars that show identical by chance tiny sliver segments.

I have no significant identical DNA, meaning my parents are not related to each other.

Next, let’s look at an endogamous example where there are small, completely identical segments across a person’s chromosome

This person’s Acadian parents are related to each other, but distantly.

Next, let’s look at a Jewish person’s results.

You’ll notice larger green matching ROH, but not over 200 contiguous SNPs and 7 cM.

GEDMatch reports that this Jewish person’s parents are probably not related within recent generations, but it’s clear that they do share DNA in common.

People whose parents are distantly related have relatively small, scattered matching segments. However, if you’re seeing larger ROH segments that would be large enough to match in a genealogical setting, meaning multiple greater than 7 cM and 500 SNPs,, you may be dealing with a different type of situation where cousins have married in recent generations. The larger the matching segments, generally, the closer in time.

Blogger Kitty Cooper wrote an article, here, about discovering that your parents are related at the first cousin level, and what their GEDMatch “Are Your Parents Related” results look like.

Let’s look for more clues.

Surnames

There MAY be an endogamy clue in the surnames of the people you match.

Viewing surnames is easier if you download your match list, which you can do at every vendor except Ancestry. I’m not referring to the segment data, but the information about your matches themselves.

I provided instructions in the recent article, How to Download Your DNA Match Lists and Segment Files, here.

If you suspect endogamy for any reason, look at your closest matches and see if there is a discernable trend in the surnames, or locations, or any commonality between your matches to each other.

For example, Jewish, Acadian, and Native surnames may be recognizable, as may locations.

You can evaluate in either or both of two ways:

  • The surnames of your closest matches. Closest matches listed first will be your default match order.
  • Your most frequently occurring surnames, minus extremely common names like Smith, Jones, etc., unless they are also in your closest matches. To utilize this type of matching, sort the spreadsheet in surname order and then scan or count the number of people with each surname.

Here are some examples from our testers.

Jewish – Closest surname matches.

  • Roth
  • Weiss
  • Goldman
  • Schonwald
  • Levi
  • Cohen
  • Slavin
  • Goodman
  • Sender
  • Trebatch

Acadian – Closest surname matches.

  • Bergeron
  • Hebert
  • Bergeron
  • Marcum
  • Muise
  • Legere
  • Gaudet
  • Perry
  • Verlander
  • Trombley

Native American – Closest surname matches.

  • Ortega
  • Begay
  • Valentine
  • Hayes
  • Montoya
  • Sun Bear
  • Martin
  • Tsosie
  • Chiquito
  • Yazzie

You may recognize these categories of surnames immediately.

If not, Google is your friend. Eliminate common surnames, then Google for a few together at a time and see what emerges.

The most unusual surnames are likely your best bets.

Projects

Another way to get some idea of what groups people with these surnames might belong to is to enter the surname in the FamilyTreeDNA surname search.

Go to the main FamilyTreeDNA page, but DO NOT sign on.

Scroll down until you see this image.

Type the surname into the search box. You’ll see how many people have tested with that surname, along with projects where project administrators have included that surname indicating that the project may be of interest to at least some people with that surname.

Here’s a portion of the project list for Cohen, a traditional Jewish surname.

These results are for Muise, an Acadian surname.

Clicking through to relevant surname projects, and potentially contacting the volunteer project administrator can go a very long way in helping you gather and sift information. Clearly, they have an interest in this topic.

For example, here’s the Muise surname in the Acadian AmerIndian project. Two great hints here – Acadian heritage and Halifax, Nova Scotia.

Repeat for the balance of surnames on your list to look for commonalities, including locations on the public project pages.

Locations

Some of the vendor match files include location information. Each person on your match list will have the opportunity at the vendor where they tested to include location information in a variety of ways, either for their ancestors or themselves.

Where possible, it’s easiest to sort or scan the download file for this type of information.

Ancestry does not provide or facilitate a match list, but you can still create your own for your closest 20 or 30 matches in a spreadsheet.

MyHeritage provides common surname and ancestral location information for every match. How cool is that!

Y DNA, Mitochondrial DNA, and Endogamy

Haplogroups for both Y and mitochondrial DNA can indicate and sometimes confirm endogamy. In other cases, the haplogroup won’t help, but the matches and their location information just might.

FamilyTreeDNA is the only vendor that provides Y DNA and mitochondrial DNA tests that include highly granular haplogroups along with matches and additional tools.

23andMe provides high-level haplogroups which may or may not be adequate to pinpoint a haplogroup that indicates endogamy.

Of course, only males carry Y DNA that tracks to the direct paternal (surname) line, but everyone carries their mother’s mitochondrial DNA that represents their mother’s mother’s mother’s, or direct matrilineal line.

Some haplogroups are known to be closely associated with particular ethnicities or populations, like Native Americans, Pacific Islanders, and some Jewish people.

Haplogroups reach back in time before genealogy and can give us a sense of community that’s not available by either looking in the mirror or through traditional records.

This Native American man is a member of high-level haplogroup Q-M242. However, some men who carry this haplogroup are not Native, but are of European or Middle Eastern origin.

I entered the haplogroup in the FamilyTreeDNA Discover tool, which I wrote about, here.

Checking the information about this haplogroup reveals that their common ancestor descended from an Asian man about 30,000 years ago.

The migration path in the Americans explains why this person would have an endogamous heritage.

Our tester would receive a much more refined haplogroup if he upgraded to the Big Y test at FamilyTreeDNA, which would remove all doubt.

However, even without additional testing, information about his matches at FamilyTreeDNA may be very illuminating.

The Q-M242 Native man’s Y DNA matches men with more granular haplogroups, shown above, at left. On the Haplogroup Origins report, you can see that these people have all selected the “US (Native American)” country option.

Another useful tool would be to check the public Y haplotree, here, and the public mitochondrial tree here, for self-reported ancestor location information for a specific haplogroup.

Here’s an example of mitochondrial haplogroup A2 and a few subclades on the public mitochondrial tree. You can see that the haplogroup is found in Mexico, the US (Native,) Canada, and many additional Caribbean, South, and Central American countries.

Of course, Y DNA and mitochondrial DNA (mtDNA) tell a laser-focused story of one specific line, each. The great news, if you’re seeking information about your mother or father, the Y is your father’s direct paternal (surname) line, and mitochondrial is your mother’s direct matrilineal line.

Y and mitochondrial DNA results combined with ethnicity, autosomal matching, and the wide range of other tools that open doors, you will be able to reveal a great deal of information about whether you have endogamous heritage or not – and if so, from where.

I’ve provided a resource for stepping through and interpreting your Y DNA results, here, and mitochondrial DNA, here.

Discover for Y DNA Only

If you’re a female, you may feel left out of Y DNA testing and what it can tell you about your heritage. However, there’s a back door.

You can utilize the Y DNA haplogroups of your closest autosomal matches at both FamilyTreeDNA and 23andMe to reveal information

Haplogroup information is available in the download files for both vendors, in addition to the Family Finder table view, below, at FamilyTreeDNA, or on your individual matches profile cards at both 23andMe and FamilyTreeDNA.

You can enter any Y DNA haplogroup in the FamilyTreeDNA Discover tool, here.

You’ll be treated to:

  • Your Haplogroup Story – how many testers have this haplogroup (so far), where the haplogroup is from, and the haplogroup’s age. In this case, the haplogroup was born in the Netherlands about 250 years ago, give or take 200 years. I know that it was 1806 or earlier based on the common ancestor of the men who tested.
  • Country Frequency – heat map of where the haplogroup is found in the world.
  • Notable Connections – famous and infamous (this haplogroup’s closest notable person is Leo Tolstoy).
  • Migration Map – migration path out of Africa and through the rest of the world.
  • Ancient Connections – ancient burials. His closest ancient match is from about 1000 years ago in Ukraine. Their shared ancestor lived about 2000 years ago.
  • Suggested Projects – based on the surname, projects that other matches have joined, and haplogroups.
  • Scientific Details – age estimates, confidence intervals, graphs, and the mutations that define this haplogroup.

I wrote about the Discover tool in the article, FamilyTreeDNA DISCOVER Launches – Including Y DNA Haplogroup Ages.

Endogamy Tools Summary Tables

Endogamy is a tough nut sometimes, especially if you’re starting from scratch. In order to make this topic a bit easier and to create a reference tool for you, I’ve created three summary tables.

  • Various endogamy-related tools available at each vendor which will or may assist with evaluating endogamy
  • Tools and their ability to detect endogamy in different groups
  • Tools best suited to assist people seeking information about unknown parents or grandparents

Summary of Endogamy Tools by Vendor

Please note that GEDMatch is not a DNA testing vendor, but they accept uploads and do have some tools that the testing vendors do not.

 Tool 23andMe Ancestry FamilyTreeDNA MyHeritage GEDMatch
Ethnicity Yes Yes Yes Yes Use the vendors
Ethnicity Painting Yes + segments Yes, limited Yes + segments Yes
Ethnicity Phasing Yes Partial Yes No
DNA Communities No Yes No No
Genetic Groups No No No Yes
Family Matching aka Bucketing No No Yes No
Chromosome Browser Yes No Yes Yes Yes
AutoClusters Through Genetic Affairs No Through Genetic Affairs Yes, included Yes, with subscription
Match List Download Yes, restricted # of matches No Yes Yes Yes
Projects No No Yes No
Y DNA High-level haplogroup only No Yes, full haplogroup with Big Y, matching, tools, Discover No
Mitochondrial DNA High-level haplogroup only No Yes, full haplogroup with mtFull, matching, tools No
Public Y Tree No No Yes No
Public Mito Tree No No Yes No
Discover Y DNA – public No No Yes No
ROH No No No No Yes

Summary of Endogamous Populations Identified by Each Tool

The following chart provides a guideline for which tools are useful for the following types of endogamous groups. Bolded tools require that both parents be descended from the same endogamous group, but several other tools give more definitive results with higher amounts of endogamy.

Y and mitochondrial DNA testing are not affected by admixture, autosomal DNA or anything from the “other” parent.

Tool Jewish Acadian Anabaptist Native Other/General
Ethnicity Yes No No Yes Pacific Islander
Ethnicity Painting Yes No No Yes Pacific Islander
Ethnicity Phasing Yes, if different No No Yes, if different Pacific Islander, if different
DNA Communities Yes Possibly Possibly Yes Pacific Islander
Genetic Groups Yes Possibly Possibly Yes Pacific Islander
Family Matching aka Bucketing Yes Yes Possibly Yes Pacific Islander
Chromosome Browser Possibly Possibly Yes, once segments or ancestors identified Possibly Pacific Islander, possibly
Total Matches Yes, compared to non-endogamous No No No No, unknown
AutoClusters Yes Yes Uncertain, probably Yes Pacific Islander
Estimated Relationships High Not always Sometimes No Sometimes Uncertain, probably
Relationship Range High Possibly, sometimes Possibly Possibly Possibly Pacific Islander, possibly
More, Smaller Segments Yes Yes Probably Yes Pacific Islander, probably
Parents Related Some but minimal Possibly Uncertain Probably similar to Jewish Uncertain, Possibly
Surnames Probably Probably Probably Not Possibly Possibly
Locations Possibly Probably Probably Not Probably Probably Pacific Islander
Projects Probably Probably Possibly Possibly Probably Pacific Islander
Y DNA Yes, often Yes, often No Yes Pacific Islander
Mitochondrial DNA Yes, often Sometimes No Yes Pacific Islander
Y public tree Probably not alone No No Yes Pacific Islander
MtDNA public tree Probably not No No Yes Pacific Islander
Y DNA Discover Yes Possibly Probably not, maybe projects Yes Pacific Islander

Summary of Endogamy Tools to Assist People Seeking Unknown Parents and Grandparents

This table provides a summary of when each of the various tools can be useful to:

  • People seeking unknown close relatives
  • People who already know who their close relatives are, but are seeking additional information or clues about their genealogy

I considered rating these on a 1 to 10 scale, but the relative usefulness of these tools is dependent on many factors, so different tools will be more or less useful to different people.

For example, ethnicity is very useful if someone is admixed from different populations, or even 100% of a specific endogamous population. It’s less useful if the tester is 100% European, regardless of whether they are seeking close relatives or not. Conversely, even “vanilla” ethnicity can be used to rule out majority or recent admixture with many populations.

Tools Unknown Close Relative Seekers Known Close Relatives – Enhance Genealogy
Ethnicity Yes, to identify or rule out populations Yes
Ethnicity Painting Yes, possibly, depending on population Yes, possibly, depending on population
Ethnicity Phasing Yes, possibly, depending on population Yes, possibly, depending on population
DNA Communities Yes, possibly, depending on population Yes, possibly, depending on population
Genetic Groups Possibly, depending on population Possibly, depending on population
Family Matching aka Bucketing Not if parents are entirely unknown, but yes if one parent is known Yes
Chromosome Browser Unlikely Yes
AutoClusters Yes Yes, especially at MyHeritage if Jewish
Estimated Relationships High Not No
Relationship Range High Not reliably No
More, Smaller Segments Unlikely Unlikely other than confirmation
Match List Download Yes Yes
Surnames Yes Yes
Locations Yes Yes
Projects Yes Yes
Y DNA Yes, males only, direct paternal line, identifies surname lineage Yes, males only, direct paternal line, identifies and correctly places surname lineage
Mitochondrial DNA Yes, both sexes, direct matrilineal line only Yes, both sexes, direct matrilineal line only
Public Y Tree Yes for locations Yes for locations
Public Mito Tree Yes for locations Yes for locations
Discover Y DNA Yes, for heritage information Yes, for heritage information
Parents Related – ROH Possibly Less useful

Acknowledgments

A HUGE thank you to several people who contributed images and information in order to provide accurate and expanded information on the topic of endogamy. Many did not want to be mentioned by name, but you know who you are!!!

If you have information to add, please post in the comments.

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Concepts: Chromosome Browser – What Is It, How Do I Use It, and Why Do I Care?

The goal of genetic genealogy is to utilize DNA matches to verify known ancestors and identify unknown ancestors.

A chromosome browser is a tool that allows testers to visualize and compare their DNA on each chromosome with that of their genetic matches. How to utilize and interpret that information becomes a little more tricky.

I’ve had requests for one article with all the information in one place about chromosome browsers:

  • What they are
  • How and when to use them
  • Why you’d want to

I’ve included a feature comparison chart and educational resource list at the end.

I would suggest just reading through this article the first time, then following along with your own DNA results after you understand the basic landscape. Using your own results is the best way to learn anything.

What Does a Chromosome Browser Look Like?

Here’s an example of a match to my DNA at FamilyTreeDNA viewed on their chromosome browser.

browser example.png

On my first 16 chromosomes, shown above, my 1C1R (first cousin once removed,) Cheryl, matches me where the chromosomes are painted blue. My chromosome is represented by the grey background, and her matching portion by the blue overlay.

Cheryl matches me on some portion of all chromosomes except 2, 6, and 13, where we don’t match at all.

You can select any one person, like Cheryl, from your match list to view on a chromosome browser to see where they match you on your chromosomes, or you can choose multiple matches, as shown below.

browser multiple example.png

I selected my 7 closest matches that are not my immediate family, meaning not my parents or children. I’m the background grey chromosome, and each person’s match is painted on top of “my chromosome” in the location where they match me. You see 7 images of my grey chromosome 1, for example, because each of the 7 people being compared to me are shown stacked below one another.

Everyplace that Cheryl matches me is shown on the top image of each chromosome, and our matching segment is shown in blue. The same for the second red copy of the chromosome, representing Don’s match to me. Each person I’ve selected to match against is shown by their own respective color.

You’ll note that in some cases, two people match me in the same location. Those are the essential hints we are looking for. We’ll be discussing how to unravel, interpret, and use matches in the rest of this article.

browser MyHeritage example.png

The chromosome browser at MyHeritage looks quite similar. However, I have a different “top 7” matches because each vendor has people who test on their platform who don’t test or transfer elsewhere.

Each vendor that supports chromosome browsers (FamilyTreeDNA, MyHeritage, 23andMe, and GedMatch) provides their own implementation, of course, but the fundamentals of chromosome browsers, how they work and what they are telling us is universal.

Why Do I Need a Chromosome Browser?

“But,” you might say, “I don’t need to compare my DNA with my matches because the vendors already tell me that I match someone, which confirms that we are related and share a common ancestor.”

Well, not exactly. It’s not quite that straightforward.

Let’s take a look at:

  • How and why people match
  • What matches do and don’t tell you
  • Both with and without a chromosome browser

In part, whether you utilize a chromosome browser or not depends on which of the following you seek:

  • A broad-brush general answer; yes or no, I match someone, but either I don’t know how are related, or have to assume why. There’s that assume word again.
  • To actually confirm and prove your ancestry, getting every ounce of value out of your DNA test.

Not everyone’s goals are the same. Fortunately, we have an entire toolbox with a wide range of tools. Different tools are better suited for different tasks.

People seeking unknown parents should read the article, Identifying Unknown Parents and Individuals Using DNA Matching because the methodology for identifying unknown parents is somewhat different than working with genealogy. This article focuses on genealogy, although the foundation genetic principles are the same.

If you’re just opening your DNA results for the first time, the article, First Steps When Your DNA Results are Ready – Sticking Your Toe in the Genealogy Water would be a great place to start.

Before we discuss chromosome browsers further, we need to talk about DNA inheritance.

Your Parents

Every person has 2 copies of each of their 22 chromosomes – one copy contributed by their mother and one copy contributed by their father. A child receives exactly half of the autosomal DNA of each parent. The DNA of each parent combines somewhat randomly so that you receive one chromosome’s worth of DNA from each of your parents, which is half of each parent’s total.

On each chromosome, you receive some portion of the DNA that each parent received from their ancestors, but not exactly half of the DNA from each individual ancestor. In other words, it’s not sliced precisely in half, but served up in chunks called segments.

Sometimes you receive an entire segment of an ancestor’s DNA, sometimes none, and sometimes a portion that isn’t equal to half of your parent’s segment.

browser inheritance.png

This means that you don’t receive exactly half of the DNA of each of your grandparents, which would be 25% each. You might receive more like 22% from one maternal grandparent and 28% from the other maternal grandparent for a total of 50% of the DNA you inherit from your parents. The other 50% of your DNA comes from the other parent, of course. I wrote about that here.

There’s one tiny confounding detail. The DNA of your Mom and Dad is scrambled in you, meaning that the lab can’t discern scientifically which side is which and can’t tell which pieces of DNA came from Mom and which from Dad. Think of a genetic blender.

Our job, using genetic genealogy, is to figure out which side of our family people who match us descend from – which leads us to our common ancestor(s).

Parallel Roads

For the purposes of this discussion, you’ll need to understand that the two copies you receive of each chromosome, one from each parent, have the exact same “addresses.” Think of these as parallel streets or roads with identical addresses on each road.

browser street.png

In the example above, you can see Dad’s blue chromosome and Mom’s red chromosome as compared to me. Of course, children and parents match on the full length of each chromosome.

I’ve divided this chromosome into 6 blocks, for purposes of illustration, plus the centromere where we generally find no addresses used for genetic genealogy.

In the 500 block, we see that the address of 510 Main (red bar) could occur on either Dad’s chromosome, or Mom’s. With only an address and nothing more, you have no way to know whether your match with someone at 510 Main is on Mom’s or Dad’s side, because both streets have exactly the same addresses.

Therefore, if two people match you, at the same address on that chromosome, like 510 Main Street, they could be:

  • Both maternal matches, meaning both descended from your mother’s ancestors, and those two people will also match each other
  • Both paternal matches, meaning both descended from your father’s ancestors, and those two people will also match each other
  • One maternal and one paternal match, and those two people will not match each other

Well then, how do we know which side of the family a match descends from, and how do we know if we share a common ancestor?

Good question!

Identical by Descent

If you and another person match on a reasonably sized DNA segment, generally about 7 cM or above, your match is probably “identical by descent,” meaning not “identical by chance.” In this case, then yes, a match does confirm that you share a common ancestor.

Identical by descent (IBD) means you inherited the piece of DNA from a common ancestor, inherited through the relevant parent.

Identical by chance (IBC) means that your mom’s and dad’s DNA just happens to have been inherited by you randomly in a way that creates a sequence of DNA that matches that other person. I wrote about both IBD and IBC here.

MMB stats by cM 2

This chart, courtesy of statistician Philip Gammon, from the article Introducing the Match-Maker-Breaker Tool for Parental Phasing shows the percentage of time we expect matches of specific segment sizes to be valid, or identical by descent.

Identical by Chance

How does this work?

How is a match NOT identical by descent, meaning that it is identical by chance and therefore not a “real” or valid match, a situation also known as a false positive?

browser inheritance grid.png

The answer involves how DNA is inherited.

You receive a chromosome with a piece of DNA at every address from both parents. Of course, this means you have two pieces of DNA at each address. Therefore people will match you on either piece of DNA. People from your Dad’s side will match you on the pieces you inherited from him, and people from your Mom’s side will match you on the pieces you inherited from her.

However, both of those matches have the same address on their parallel streets as shown in the illustration, above. Your matches from your mom’s side will have all As, and those from your dad’s side will have all Ts.

The problem is that you have no way to know which pieces you inherited from Mom and from Dad – at least not without additional information.

You can see that for 10 contiguous locations (addresses), which create an example “segment” of your DNA, you inherited all As from your Mom and all Ts from your Dad. In order to match you, someone would either need to have an A or a T in one of their two inherited locations, because you have an A and a T, both. If the other person has a C or a G, there’s no match.

Your match inherited a specific sequence from their mother and father, just like you did. As you can see, even though they do match you because they have either an A or a T in all 10 locations – the As and Ts did not all descend from either their mother or father. Their random inheritance of Ts and As just happens to match you.

If your match’s parents have tested, you won’t match either of their parents nor will they match either of your parents, which tells you immediately that this match is by chance (IBC) and not by descent (IBD), meaning this segment did not come from a common ancestor. It’s identical by chance and, therefore, a false positive.

If We Match Someone Else In Common, Doesn’t That Prove Identical by Descent?

Nope, but I sure wish it did!

The vendors show you who else you and your match both match in common, which provides a SUGGESTION as to your common ancestor – assuming you know which common ancestor any of these people share with you.

browser icw.png

However, shared matches are absolutely NOT a guarantee that you, your match, and your common matches all share the same ancestor, unless you’re close family. Your shared match could match you or your match through different ancestors – or could be identical by chance.

How can we be more confident of what matching is actually telling us?

How can we sort this out?

Uncertainties and Remedies

Here’s are 9 things you DON’T know, based on matching alone, along with tips and techniques to learn more.

  1. If your match to Person A is below about 20cM, you’ll need to verify that it’s a legitimate IBD match (not IBC). You can achieve this by determining if Person A also matches one of your parents and if you match one of Person A’s parents, if parents have tested.

Not enough parents have tested? An alternative method is by determining if you and Person A both match known descendants of the candidate ancestors ON THE SAME SEGMENT. This is where the chromosome browser enters the picture.

In other words, at least three people who are confirmed to descend from your presumptive common ancestor, preferably through at least two different children, must match on a significant portion of the same segment.

Why is that? Because every segment has its own unique genealogical history. Each segment can and often does lead to different ancestors as you move further back in time.

In this example, I’m viewing Buster, David, and E., three cousins descended from the same ancestral couple, compared to me on my chromosome browser. I’m the background grey, and they show in color. You can see that all three of them match me on at least some significant portion of the same segment of chromosome 15.

browser 3 cousins.png

If those people also match each other, that’s called triangulation. Triangulation confirms descent from a common ancestral source.

In this case, I already know that these people are related on my paternal side. The fact that they all match my father’s DNA and are therefore all automatically assigned to my paternal matching tab at Family Tree DNA confirms my paper-trail genealogy.

I wrote detailed steps for triangulation at Family Tree DNA, here. In a nutshell, matching on the same segment to people who are bucketed to the same parent is an automated method of triangulation.

Of course, not everyone has the luxury of having their parents tested, so testing other family members, finding common segments, and assigning people to their proper location in your tree facilitates confirmation of your genealogy (and automating triangulation.)

The ONLY way you can determine if people match you on the same segment, and match each other, is having segment information available to you and utilizing a chromosome browser.

browser MyHeritage triangulation.png

In the example above, the MyHeritage triangulation tool brackets matches that match you (the background grey) and who are all triangulated, meaning they all also match each other. In this case, the portion where all three people match me AND each other is bracketed. I wrote about triangulation at MyHeritage here.

  1. If you match several people who descend from the same ancestor, John Doe, for example, on paper, you CANNOT presume that your match to all of those people is due to a segment of DNA descended from John Doe or his wife. You may not match any of those people BECAUSE OF or through segments inherited from John Doe or his wife. You need segment information and a chromosome browser to view the location of those matches.

Assuming these are legitimate IBD matches, you may share another common line, known or unknown, with some or all of those matches.

It’s easy to assume that because you match and share matches in common with other people who believe they are descended from that same ancestor:

  • That you’re all matching because of that ancestor.
  • Even on the same segments.

Neither of those presumptions can be made without additional information.

Trust me, you’ll get yourself in a heap o’ trouble if you assume. Been there, done that. T-shirt was ugly.

Let’s look at how this works.

browser venn.png

Here’s a Venn diagram showing me, in the middle, surrounded by three of my matches:

  • Match 1 – Periwinkle, descends from Lazarus Estes and Elizabeth Vannoy
  • Match 2 – Teal, descends from Joseph Bolton and Margaret Claxton
  • Match 3 – Mustard, descends from John Y. Estes and Rutha Dodson

Utilizing a chromosome browser, autocluster software, and other tools, we can determine if those matches also match each other on a common segment, which means they triangulate and confirm common ancestral descent.

Of course, those people could match each other due to a different ancestor, not necessarily the one I share with them nor the ancestors I think we match through.

If they/we do all match because they descend from a common ancestor, they can still match each other on different segments that don’t match me.

I’m in the center. All three people match me, and they also match each other, shown in the overlap intersections.

Note that the intersection between the periwinkle (Match 1) and teal (Match 2) people, who match each other, is due to the wives of the children of two of my ancestors. In other words, their match to each other has absolutely nothing to do with their match to me. This was an “aha’ moment for me when I first realized this was a possibility and happens far more than I ever suspected.

The intersection of the periwinkle (Match 1) and mustard (Match 3) matches is due to the Dodson line, but on a different segment than they both share with me. If they had matched each other and me on the same segment, we would be all triangulated, but we aren’t.

The source of the teal (Match 2) to mustard (Match 3) is unknown, but then again, Match 3’s tree is relatively incomplete.

Let’s take a look at autocluster software which assists greatly with automating the process of determining who matches each other, in addition to who matches you.

  1. Clustering technology, meaning the Leeds method as automated by Genetic Affairs and DNAGedcom help, but don’t, by themselves, resolve the quandary of HOW people match you and each other.

People in a colored cluster all match you and each other – but not necessarily on the same segment, AND, they can match each other because they are related through different ancestors not related to your ancestor. The benefit of autocluster software is that this process is automated. However, not all of your matches will qualify to be placed in clusters.

browser autocluster.png

My mustard cluster above includes the three people shown in the chromosome browser examples – and 12 more matches that can be now be researched because we know that they are all part of a group of people who all match me, and several of whom match each other too.

My matches may not match each other for a variety of reasons, including:

  • They are too far removed in time/generations and didn’t inherit any common ancestral DNA.
  • This cluster is comprised of some people matching me on different (perhaps intermarried) lines.
  • Some may be IBC matches.

Darker grey boxes indicate that those people should be in both clusters, meaning the red and mustard clusters, because they match people in two clusters. That’s another hint. Because of the grid nature of clusters, one person cannot be associated with more than 2 clusters, maximum. Therefore, people like first cousins who are closely related to the tester and could potentially be in many clusters are not as useful in clusters as they are when utilizing other tools.

  1. Clusters and chromosome browsers are much less complex than pedigree charts, especially when dealing with many people. I charted out the relationships of the three example matches from the Venn diagram. You can see that this gets messy quickly, and it’s much more challenging to visualize and understand than either the chromosome browser or autoclusters.

Having said that, the ultimate GOAL is to identify how each person is related to you and place them in their proper place in your tree. This, cumulatively with your matches, is what identifies and confirms ancestors – the overarching purpose of genealogy and genetic genealogy.

Let’s take a look at this particular colorized pedigree chart.

Browser pedigree.png

click to enlarge

The pedigree chart above shows the genetic relationship between me and the three matches shown in the Venn diagram.

Four descendants of 2 ancestral couples are shown, above; Joseph Bolton and Margaret Claxton, and John Y. Estes and Rutha Dodson. DNA tells me that all 3 people match me and also match each other.

The color of the square (above) is the color of DNA that represents the DNA segment that I received and match with these particular testers. This chart is NOT illustrating how much DNA is passed in each generation – we already know that every child inherits half of the DNA of each parent. This chart shows match/inheritance coloring for ONE MATCHING SEGMENT with each match, ONLY.

Let’s look at Joseph Bolton (blue) and Margaret Claxton (pink). I descend through their daughter, Ollie Bolton, who married William George Estes, my grandfather. The DNA segment that I share with blue Match 2 (bottom left) is a segment that I inherited from Joseph Bolton (blue). I also carry inherited DNA from Margaret Claxton too, but that’s not the segment that I share with Match 2, which is why the path from Joseph Bolton to me, in this case, is blue – and why Match 2 is blue. (Just so you are aware, I know this segment descends from Joseph Bolton, because I also match descendants of Joseph’s father on this segment – but that generation/mtach is not shown on this pedigree chart.)

If I were comparing to someone else who I match through Margaret Claxton, I would color the DNA from Margaret Claxton to me pink in that illustration. You don’t have to DO this with your pedigree chart, so don’t worry. I created this example to help you understand.

The colored dots shown on the squares indicate that various ancestors and living people do indeed carry DNA from specific ancestors, even though that’s not the segment that matches a particular person. In other words, the daughter, Ollie, of Joseph Bolton and Margaret Claxton carries 50% pink DNA, represented by the pink dot on blue Ollie Bolton, married to purple William George Estes.

Ollie Bolton and William George Estes had my father, who I’ve shown as half purple (Estes) and half blue (Bolton) because I share Bolton DNA with Match 2, and Estes DNA with Match 1. Obviously, everyone receives half of each parent’s DNA, but in this case, I’m showing the path DNA descended for a specific segment shared with a particular match.

I’ve represented myself with the 5 colors of DNA that I carry from these particular ancestors shown on the pedigree chart. I assuredly will match other people with DNA that we’ve both inherited from these ancestors. I may match these same matches shown with DNA that we both inherited from other ancestors – for example, I might match Match 2 on a different segment that we both inherited from Margaret Claxton. Match 2 is my second cousin, so it’s quite likely that we do indeed share multiple segments of DNA.

Looking at Match 3, who knows very little about their genealogy, I can tell, based on other matches, that we share Dodson DNA inherited through Rutha Dodson.

I need to check every person in my cluster, and that I share DNA with on these same segment addresses to see if they match on my paternal side and if they match each other.

  1. At Family Tree DNA, I will be able to garner more information about whether or not my matches match each other by using the Matrix tool as well as by utilizing Phased Family Matching.

At Family Tree DNA, I determined that these people all match in common with me and Match 1 by using the “In Common With” tool. You can read more about how to use “In Common With” matching, here.

browser paternal.png

Family Matching phases the matches, assigning or bucketed them maternally or paternally (blue and red icons above), indicating, when possible, if these matches occur on the same side of your family. I wrote about the concept of phasing, here, and Phased Family Matching here and here.

Please note that there is no longer a limit on how distantly related a match can be in order to be utilized in Phased Family Matching, so long as it’s over the phase-matching threshold and connected correctly in your tree.

browser family tree dna link tree.png

Bottom line, if you can figure out how you’re related to someone, just add them into your tree by creating a profile card and link their DNA match to them by simply dragging and dropping, as illustrated above.

Linking your matches allows Family Matching to maternally or paternally assign other matches that match both you and your tree-linked matches.

If your matches match you on the same segment on the same parental side, that’s segment triangulation, assuming the matches are IBD. Phased Family Matching does this automatically for you, where possible, based on who you have linked in your tree.

For matches that aren’t automatically bucketed, there’s another tool, the Matrix.

browser matrix.png

In situations where your matches aren’t “bucketed” either maternally or paternally, the Matrix tool allows you to select matches to determine whether your matches also match each other. It’s another way of clustering where you can select specific people to compare. Note that because they also match each other (blue square) does NOT mean it’s on the same segment(s) where they match you. Remember our Venn diagram.

browser matrix grid.png

  1. Just because you and your matches all match each other doesn’t mean that they are matching each other because of the same ancestor. In other words, your matches may match each other due to another or unknown ancestor. In our pedigree example, you can see that the three matches match each other in various ways.
browser pedigree match.png

click to enlarge

  • Match 1 and Match 2 match each other because they are related through the green Jones family, who is not related to me.
  • Match 2 and Match 3 don’t know why they match. They both match me, but not on the same segment they share with each other.
  • Match 1 and Match 3 match through the mustard Dodson line, but not on the same segment that matches me. If we all did match on the same segment, we would be triangulated, but we wouldn’t know why Match 3 was in this triangulation group.
  1. Looking at a downloaded segment file of your matches, available at all testing vendors who support segment information and a chromosome browser, you can’t determine without additional information whether your matches also match each other.

browser chr 15.png

Here’s a group of people, above, that we’ve been working with on chromosome 15.

My entire match-list shows many more matches on that segment of chromosome 15. Below are just a few.

browser chr 15 all

Looking at seven of these people in the chromosome browser, we can see visually that they all overlap on part of a segment on chromosome 15. It’s a lot easier to see the amount of overlap using a browser as opposed to the list. But you can only view 7 at a time in the browser, so the combination of both tools is quite useful. The downloaded spreadsheet shows you who to select to view for any particular segment.

browser chr 15 compare.png

The critical thing to remember is that some matches will be from tyour mother’s side and some from your father’s side.

Without additional information and advanced tools, there’s no way to tell the difference – unless they are bucketed using Phased Family Matching at Family Tree DNA or bracketed with a triangulation bracket at MyHeritage.

At MyHeritage, this assumes you know the shared ancestor of at least one person in the triangulation group which effectively assigns the match to the maternal or paternal side.

Looking at known relatives on either side, and seeing who they also match, is how to determine whether these people match paternally or maternally. In this example below, the blue people are bucketed paternally through Phased Family Matching, the pink maternally, and the white rows aren’t bucketed and therefore require additional evaluation.

browser chr 15 maternal paternal.png

Additional research shows that Jonathan is a maternal match, but Robert and Adam are identical by chance because they don’t match either of my parents on this segment. They might be valid matches on other segments, but not this one.

browser chr 15 compare maternal paternal.png

  1. Utilizing relatives who have tested is a huge benefit, and why we suggest that everyone test their closest upstream relatives (meaning not children or grandchildren.) Testing all siblings is recommended if both parents aren’t available to test, because every child received different parts of their parents’ DNA, so they will match different relatives.

After deleting segments under 7 cM, I combine the segment match download files of multiple family members (who agree to allow me to aggregate their matches into one file for analysis) so that I can create a master match file for a particular family group. Sorting by match name, I can identify people that several of my cousins’ match.

browser 4 groups.png

This example is from a spreadsheet where I’ve combined the results of about 10 collaborating cousins to determine if we can break through a collective brick wall. Sorted by match name, this table shows the first 4 common matches that appear on multiple cousin’s match lists. Remember that how these people match may have nothing to do with our brick wall – or it might.

Note that while the 4 matches, AB, AG, ag, and A. Wayne, appear in different cousins’ match lists, only one shares a common segment of DNA: AB triangulates with Buster and Iona. This is precisely WHY you need segment information, and a chromosome browser, to visualize these matches, and to confirm that they do share a common DNA segment descended from a specific ancestor.

These same people will probably appear in autocluster groups together as well. It’s worth noting, as illustrated in the download example, that it’s much more typical for “in common with” matches to match on different segments than on the same segment. 

  1. Keep in mind that you will match both your mother and father on every single chromosome for the entire length of each chromosome.

browser parent matching.png

Here’s my kit matching with my father, in blue, and mother, in red on chromosomes 1 and 2.

Given that I match both of my parents on the full chromosome, inheriting one copy of my chromosome from each parent, it’s impossible to tell by adding any person at random to the chromosome browser whether they match me maternally or paternally. Furthermore, many people aren’t fortunate enough to have parents available for testing.

To overcome that obstacle, you can compare to known or close relatives. In fact, your close relatives are genetic genealogy gold and serve as your match anchor. A match that matches you and your close relatives can be assigned either maternally or paternally. I wrote about that here.

browser parent plus buster.png

You can see that my cousin Buster matches me on chromosome 15, as do both of my parents, of course. At this point, I can’t tell from this information alone whether Buster matches on my mother’s or father’s side.

I can tell you that indeed, Buster does match my father on this same segment, but what if I don’t have the benefit of my father’s DNA test?

Genealogy tells me that Buster matches me on my paternal side, through Lazarus Estes and Elizabeth Vannoy. Given that Buster is a relatively close family member, I already know how Buster and I are related and that our DNA matches. That knowledge will help me identify and place other relatives in my tree who match us both on the same segment of DNA.

To trigger Phased Family Matching, I placed Buster in the proper place in my tree at Family Tree DNA and linked his DNA. His Y DNA also matches the Estes males, so no adoptions or misattributed parental events have occurred in the direct Estes patrilineal line.

browser family tree dna tree.png

I can confirm this relationship by checking to see if Buster matches known relatives on my father’s side of the family, including my father using the “in common with” tool.

Buster matches my father as well as several other known family members on that side of the family on the same segments of DNA.

browser paternal bucket.png

Note that I have a total of 397 matches in common with Buster, 140 of which have been paternally bucketed, 4 of which are both (my children and grandchildren), and 7 of which are maternal.

Those maternal matches represent an issue. It’s possible that those people are either identical by chance or that we share both a maternal and paternal ancestor. All 7 are relatively low matches, with longest blocks from 9 to 14 cM.

Clearly, with a total of 397 shared matches with Buster, not everyone that I match in common with Buster is assigned to a bucket. In fact, 246 are not. I will need to take a look at this group of people and evaluate them individually, their genealogy, clusters, the matrix, and through the chromosome browser to confirm individual matching segments.

There is no single perfect tool.

Every Segment Tells a Unique History

I need to check each of the 14 segments that I match with Buster because each segment has its own inheritance path and may well track back to different ancestors.

browser buster segments.png

It’s also possible that we have unknown common ancestors due to either adoptions, NPEs, or incorrect genealogy, not in the direct Estes patrilineal line, but someplace in our trees.

browser buster paint.png

The best way to investigate the history and genesis of each segment is by painting matching segments at DNAPainter. My matching segments with Buster are shown painted at DNAPainter, above. I wrote about DNAPainter, here.

browser overlap.png

By expanding each segment to show overlapping segments with other matches that I’ve painted and viewing who we match, we can visually see which ancestors that segment descends from and through.

browser dnapainter walk back.png

These roughly 30 individuals all descend from either Lazarus Estes and Elizabeth Vannoy (grey), Elizabeth’s parents (dark blue), or her grandparents (burgundy) on chromosome 15.

As more people match me (and Buster) on this segment, on my father’s side, perhaps we’ll push this segment back further in time to more distant ancestors. Eventually, we may well be able to break through our end-of-line brick wall using these same segments by looking for common upstream ancestors in our matches’ trees.

Arsenal of Tools

This combined arsenal of tools is incredibly exciting, but they all depend on having segment information available and understanding how to use and interpret segment and chromosome browser match information.

One of mine and Buster’s common segments tracks back to end-of-line James Moore, born about 1720, probably in Virginia, and another to Charles Hickerson born about 1724. It’s rewarding and exciting to be able to confirm these DNA segments to specific ancestors. These discoveries may lead to breaking through those brick walls eventually as more people match who share common ancestors with each other that aren’t in my tree.

This is exactly why we need and utilize segment information in a chromosome browser.

We can infer common ancestors from matches, but we can’t confirm segment descent without specific segment information and a chromosome browser. The best we can do, otherwise, is to presume that a preponderance of evidence and numerous matches equates to confirmation. True or not, we can’t push further back in time without knowing who else matches us on those same segments, and the identity of their common ancestors.

The more evidence we can amass for each ancestor and ancestral couple, the better, including:

  • Matches
  • Shared “In Common With” Matches, available at all vendors.
  • Phased Family Matching at Family Tree DNA assigns matches to maternal or paternal sides based on shared, linked DNA from known relatives.
  • The Matrix, a Family Tree DNA tool to determine if matches also match each other. Tester can select who to compare.
  • ThruLines from Ancestry is based on a DNA match and shared ancestors in trees, but no specific segment information or chromosome browser. I wrote about ThruLines here and here.
  • Theories of Family Relativity, aka TOFR, at MyHeritage, based on shared DNA matches, shared ancestors in trees and trees constructed between matches from various genealogical records and sources. MyHeritage includes a chromosome browser and triangulation tool. I wrote about TOFR here and here.
  • Triangulation available through Phased Family Matching at Family Tree DNA and the integrated triangulation tool at MyHeritage. Triangulation between only 3 people at a time is available at 23andMe, although 23andMe does not support trees. See triangulation article links in the Resource Articles section below.
  • AutoClusters at MyHeritage (cluster functionality included), at Genetic Affairs (autoclusters plus tree reconstruction) and at DNAGedcom (including triangulation).
  • Genealogical information. Please upload your trees to every vendor site.
  • Y DNA and mitochondrial DNA confirmation, when available, through Family Tree DNA. I wrote about the 4 Kinds of DNA for Genetic Genealogy, here and the importance of Y DNA confirmation here, and how not having that information can trip you up.
  • Compiled segment information at DNAPainter allows you to combine segment information from various vendors, paint your maternal and paternal chromosomes, and visually walk segments back in time. Article with DNAPainter instructions is found here.

Autosomal Tool Summary Table

In order to help you determine which tool you need to use, and when, I’ve compiled a summary table of the types of tools and when they are most advantageous. Of course, you’ll need to read and understand about each tool in the sections above. This table serves as a reminder checklist to be sure you’ve actually utilized each relevant tool where and how it’s appropriate.

Family Tree DNA MyHeritage Ancestry 23andMe GedMatch
DNA Matches Yes Yes Yes Yes, but only highest 2000 minus whoever does not opt -in Yes, limited matches for free, more with subscription (Tier 1)
Download DNA Segment Match Spreadsheet Yes Yes No, must use DNAGedcom for any download, and no chromosome segment information Yes Tier 1 required, can only download 1000 through visualization options
Segment Spreadsheet Benefits View all matches and sort by segment, target all people who match on specific segments for chromosome browser View all matches and sort by segment, target all people who match on specific segments for chromosome browser No segment information but matches might transfer elsewhere where segment information is available View up to 2000 matches if matches have opted in. If you have initiated contact with a match, they will not drop off match list. Can download highest 1000 matches, target people who match on specific segments
Spreadsheet Challenges Includes small segments, I delete less than 7cM segments before using No X chromosome included No spreadsheet and no segment information Maximum of 2000 matches, minus those not opted in Download limited to 1000 with Tier 1, download not available without subscription
Chromosome Segment Information Yes Yes No, only total and longest segment, no segment address Yes Yes
Chromosome Browser Yes, requires $19 unlock if transfer Yes, requires $29 unlock or subscription if transfer No Yes Yes, some features require Tier 1 subscription
X Chromosome Included Yes No No Yes Yes, separate
Chromosome Browser Benefit Visual view of 7 or fewer matches Visual view of 7 or fewer matches, triangulation included if ALL people match on same portion of common segment No browser Visual view of 5 or fewer matches Unlimited view of matches, multiple options through comparison tools
Chromosome Browser Challenges Can’t tell whether maternal or paternal matches without additional info if don’t select bucketed matches Can’t tell whether maternal or paternal without additional info if don’t triangulate or you don’t know your common ancestor with at least one person in triangulation group No browser Can’t tell whether maternal or paternal without other information Can’t tell whether maternal or paternal without other information
Shared “In Common With” Matches Yes Yes Yes Yes, if everyone opts in Yes
Triangulation Yes, Phased Family Matching, plus chromosome browser Yes, included in chromosome browser if all people being compared match on that segment No, and no browser Yes, but only for 3 people if “Shared DNA” = Yes on Relatives in Common Yes, through multiple comparison tools
Ability to Know if Matches Match Each Other (also see autoclusters) Yes, through Matrix tool or if match on common bucketed segment through Family Matching Yes, through triangulation tool if all match on common segment No Yes, can compare any person to any other person on your match list Yes, through comparison tool selections
Autoclusters Can select up to 10 people for Matrix grid, also available for entire match list through Genetic Affairs and DNAGedcom which work well Genetic Affairs clustering included free, DNAGedcom has difficulty due to timeouts No, but Genetic Affairs and DNAGedcom work well No, but Genetic Affairs and DNAGedcom work well Yes, Genetic Affairs included in Tier 1 for selected kits, DNAGedcom is in beta
Trees Can upload or create tree. Linking you and relatives who match to tree triggers Phased Family Matching Can upload or create tree. Link yourself and kits you manage assists Theories of Family Relativity Can upload or create tree. Link your DNA to your tree to generate ThruLines. Recent new feature allows linking of DNA matches to tree. No tree support but can provide a link to a tree elsewhere Upload your tree so your matches can view
Matching and Automated Tree Construction of DNA Matches who Share Common Ancestors with You Genetic Affairs for matches with common ancestors with you Not available Genetic Affairs for matches with common ancestors with you No tree support Not available
Matching and Automated Tree Construction for DNA Matches with Common Ancestors with Each Other, But Not With You Genetic Affairs for matches with common ancestors with each other, but not with you Not available Genetic Affairs for matches with common ancestors with each other, but not with you No tree support Not available
DNAPainter Segment Compilation and Painting Yes, bucketed Family Match file can be uploaded which benefits tester immensely. Will be able to paint ethnicity segments soon. Yes No segment info available, encourage your matches to upload elsewhere Yes, and can paint ethnicity segments from 23andMe, Yes, but only for individually copied matches or highest 1000.
Y DNA and Mitochondrial Matching Yes, both, includes multiple tools, deep testing and detailed matching No No No, base haplogroup only, no matching No, haplogroup only if field manually completed by tester when uploading autosomal DNA file

Transfer Your DNA

Transferring your DNA results to each vendor who supports segment information and accepts transfers is not only important, it’s also a great way to extend your testing collar. Every vendor has strengths along with people who are found there and in no other database.

Ancestry does not provide segment information nor a chromosome browser, nor accept uploads, but you have several options to transfer your DNA file for free to other vendors who offer tools.

23andMe does provide a chromosome browser but does not accept uploads. You can download your DNA file and transfer free to other vendors.

I wrote detailed upload/download and transfer instructions for each vendor, here.

Two vendors and one third party support transfers into their systems. The transfers include matching. Basic tools are free, but all vendors charge a minimal fee for unlocking advanced tools, which is significantly less expensive than retesting:

Third-party tools that work with your DNA results include:

All vendors provide different tools and have unique strengths. Be sure that your DNA is working as hard as possible for you by fishing in every pond and utilizing third party tools to their highest potential.

Resource Articles

Explanations and step by step explanations of what you will see and what to do, when you open your DNA results for the first time.

Original article about chromosomes having 2 sides and how they affect genetic genealogy.

This article explains what triangulation is for autosomal DNA.

Why some matches may not be valid, and how to tell the difference.

This article explains the difference between a match group, meaning a group of people who match you, and triangulation, where that group also matches each other. The concepts are sound, but this article relies heavily on spreadsheets, before autocluster tools were available.

Parental phasing means assigning segment matches to either your paternal or maternal side.

Updated, introductory article about triangulation, providing the foundation for a series of articles about how to utilize triangulation at each vendor (FamilyTreeDNA, MyHeritage, 23andMe, GEDmatch, DNAPainter) that supports triangulation.

These articles step you through triangulation at each vendor.

DNAPainter facilitates painting maternally and paternally phased, bucketed matches from FamilyTreeDNA, a method of triangulation.

Compiled articles with instructions and ideas for using DNAPainter.

Autoclustering tool instructions.

How and why The Leeds Method works.

Step by step instructions for when and how to use FamilyTreeDNA’s chromosome browser.

Close family members are the key to verifying matches and identifying common ancestors.

This article details how much DNA specific relationships between people can expect to share.

Overview of transfer information and links to instruction articles for each vendor, below.

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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

DNAPainter: Painting “Bucketed” Family Tree DNA Maternal and Paternal Family Finder Matches in One Fell Swoop

DNAPainter has done it again, providing genealogists with a wonderful tool that facilitates separating your matches into maternal and paternal categories so that they can be painted on the proper chromosome – in one fell swoop no less.

Of course, the entire purpose of painting your chromosomes is to identify segments that descend from specific ancestors in order to push those lines back further in time genealogically. Identifying segments, confirming and breaking down brick walls is the name of the game.

DNA Painter New Import Tool

The new DNAPainter tool relies on Family Tree DNA’s Phased Family Matching which assigns your matches to maternal and paternal buckets. On your match list, at the top, you’ll see the following which indicates how many matches you have in total and how many people are assigned to each bucket.

DNAPainter FF import.png

Note that these are individual matches, not total matching segments – that number would be higher.

In order for Family Tree DNA to create bucketed matches for you, you’ll need to:

  • Either create a tree or upload a GEDCOM file
  • Attach your DNA kit to “you” in your tree
  • Attach all 4th cousins and closer with whom you match to their proper location on your tree

Yes, it appears that Family Tree DNA is now using 4th cousins, not just third cousins and closer, which provides for additional bucketed matches.

How reliable is bucketing?

Quite. Occasionally one of two issues arise which becomes evident if you actually compare the matches’ segments to the parent with whom they are bucketed:

  • One or more of your matches’ segments do match you and your parent, but additionally, one or more segments match you, but not your parent
  • The X chromosome is particularly susceptible to this issue, especially with lower cM matches
  • Occasionally, a match that is large enough to be bucketed isn’t, likely because no known, linked cousin shares that segment

Getting Started

Get started by creating or uploading your tree at Family Tree DNA.

DNAPainter mytree.png

After uploading your GEDCOM file or creating your tree at Family Tree DNA, click on the “matches” icon at the top of the tree to link yourself and your relatives to their proper places on your tree. Your matches will show in the box below the helix icon.

DNAPainter FF matches.png

I created an example “twin” for myself to use for teaching purposes by uploading a file from Ancestry, so I’m going to attach that person to my tree as my “Evil Twin.” (Under normal circumstances, I do not recommend uploading duplicate files of anyone.)

DNAPainter FF matches link.png

Just drag and drop the person on your match list on top of their place on the tree.

DNAPainter Ff sister.png

Here I am as my sister, Example Adoptee.

I’ve wished for a very, very long time that there was a way to obtain a list of segment matches sorted by maternal and paternal bucket without having to perform spreadsheet gymnastics, and now there is, at DNAPainter.

DNAPainter does the heavy-lifting so you don’t have to.

What Does DNAPainter Do with Bucketed Matches?

When you are finished uploading two files at DNAPainter, you’ll have:

  • Maternal groups of triangulated matches
  • Paternal groups of triangulated matches
  • Matches that could not be assigned based on the bucketing. Some (but not all) of these matches will be identical by chance – typically roughly 15-20% of your match list. You can read about identical by chance, here.

I’ll walk you through the painting process step by step.

First, you need to be sure your relatives are connected to your tree at Family Tree DNA so that you have matches assigned to your maternal and paternal buckets. The more relatives you connect, per the instructions in the previous section, the more matching people will be able to be placed into maternal or paternal buckets.

Painting Bucketed Matches at DNAPainter

I wrote basic articles about how to use DNAPainter here. If you’re unfamiliar with how to use DNAPainter or it’s new to you, now would be a good time to read those articles. This next section assumes that you’re using DNAPainter. If not, go ahead, register, and set up a profile. One profile is free for everyone, but multiple profiles require a subscription.

First, make a duplicate of the profile that you’re working with. This DNAPainter upload tool is in beta.

DNAPainter duplicate profile.png

Since I’m teaching and experimenting, I am using a fresh, new profile for this experiment. If it works successfully, I’ll duplicate my working profile, just in case something goes wrong or doesn’t generate the results I expect, and repeat these steps there.

Second, at Family Tree DNA, Download a fresh copy of your complete matching segment file. This “Download Segments” link is found at the top right of the chromosome browser page.

DNAPainter ff download segments.png

Third, download your matches at the bottom left of the actual matches page. This file hold information about your matches, such as which ones are bucketed, but no segment information. That’s in the other file.

DNAPainter csv.png

Name both of these files something you can easily identify and that tells them apart. I called the first one “Segments” in front of the file name and the second one “Matches” in front of the file name.

Fourth, at DNAPainter, you’ll need to import your entire downloaded segment file that you just downloaded from Family Tree DNA. I exclude segments under 7cM because they are about 50% identical by chance.

DNAPainter import instructions

click to enlarge

Select the segment file you just named and click on import.

DNAPainter both.png

At this point, your chromosomes at DNAPainter will look like this, assuming you’re using a new profile with nothing else painted.

Let’s expand chromosome 1 and see what it looks like.

DNAPainter chr 1 both.png

Note that all segments are painted over both chromosomes, meaning both the maternal and paternal copies of chromosome 1, partially shown above, because at this point, DNAPainter can’t tell which people match on the maternal and which people match on the paternal sides. The second “matches” file from Family Tree DNA has not yet been imported into DNAPainter, which tells DNAPainter which matches are on the maternal and which are on the paternal chromosomes.

If you’re not working with a new profile, then you’ll also see the segments you’ve already painted. DNAPainter attempts to NOT paint segments that appear to have previously been painted.

Fifth, at DNAPainter, click on the “Import mat/pat info from ftDNA” link on the left which will provide you with a page to import the matches file information. This is the file that has maternal and paternal sides specified for bucketed matches. DNAPainter needs both the segment file, which you already imported, and the matches file.

DNAPainter import bucket

click to enlarge

After the second import, the “matches” file, my matches are magically redistributed onto their appropriate chromosomes based on the maternal and paternal bucketing information.

I love this tool!

At this point, you will have three groups of matches, assuming you have people assigned to your maternal and paternal buckets.

  • A “Shared” group for people who are related to both of your parents, or who aren’t designated as a bucketed match to either parent
  • Maternal group (pink chromosome)
  • Paternal group (blue chromosome)

It’s Soup!!!

I’m so excited. Now my matches are divided into maternal and paternal chromosome groups.

DNAPainter import complete.png

Just so you know, I changed the colors of my legend at DNAPainter using “edit group,” because all three groups were shades of pink after the import and I wanted to be able to see the difference clearly.

DNAPainter legend.png

Your Painted Chromosomes

Let’s take a look at what we have.

DNAPainter both, mat, pat.png

There’s still pink showing, meaning undetermined, which gets painted over both the maternal and paternal chromosomes, but there’s also a lot of magenta (maternal) and blue (paternal) showing now too as a result of bucketing.

Let’s look at chromosome 1.

DNAPainter chr 1 all.png

This detail, which is actually a summary, shows that the bucketed maternal (magenta) and paternal (blue) matches have actually covered most of the chromosome. There are still a few areas without coverage, but not many.

For a genealogist, this is beautiful!!!

How many matches were painted?

DNAPainter paternal total.png

DNAPainter maternal total.png

Expanding chromosome 1, and scrolling to the maternal portion, I can now see that I have several painted maternal segments, and almost the entire chromosome is covered.

Here’s the exciting part!

DNAPainter ch1 1 mat expanded.png

I starred the relatives I know, on the painting, above and on the pedigree chart, below. The green group descends through Hiram Ferverda and Eva Miller, the yellow group through Antoine Lore and Rachel Hill. The blue group is Acadian, upstream of Antoine Lore.

DNAPainter maternal pedigree.png

Those ancestors are shown by star color on my pedigree chart.

I can now focus on the genealogies of the other unstarred people to see if their genealogy can push those segments back further in time to older ancestors.

On my Dad’s side, the first part of chromosome 1 is equally as exciting.

DNAPainter chr 1 pat expanded.png

The yellow star only pushed this triangulated group back only to my grandparents, but the green star is from a cousin descended from my great-grandparents. The red star matches are even more exciting, because my common ancestor with Lawson is my brick wall – Marcus Younger and his wife, Susanna, surname unknown, parents of Mary Younger.

DNAPainter paternal pedigree.png

I need to really focus hard on this cluster of 12 people because THEIR common ancestors in their trees may well provide the key I need to push back another generation – through the brick wall. That is, after all, the goal of genetic genealogy.

Woohoooo!

Manual Spreadsheet Compare

Because I decided to torture myself one mid-winter day, and night, I wanted to see how much difference there is between the bucketed matches that I just painted and actual matches that I’ve identified by downloading my parents’ segment match files and mine and comparing them manually against each other. I removed any matches in my file that were not matches to my parent, in addition to me, then painted the rest.

I’ll import the resulting manual spreadsheet into the same experimental DNAPainter profile so we can view matches that were NOT painted previously. DNAPainter does not paint matches previously painted, if it can tell the difference. Since both of these files are from downloads, without the name of the matches being in any way modified, DNAPainter should be able to recognize everyone and only paint new segment matches.

Please note here that the PERSON unquestionably belongs bucketed to the parental side in question, but not all SEGMENTS necessarily match you and your parent. Some will not, and those are the segments that I removed from my spreadsheet.

DNAPainter manual spreadsheet example.png

Here’s a made-up example where I’ve combined my matches and my mother’s matches in one spreadsheet in order to facilitate this comparison. I colored my Mom’s matches green so they are easy to see when comparing to my own, then sorting by the match name.

Person 1 matches me and Mom both, at 10 cM on chromosome 1. Person 1 is assigned to my maternal side due to the matches above 9 cM, the lowest threshold at Family Tree DNA for bucketing.

In this example, we can see that Person 1 matches me and Mom (colored green), both, on the segment on chromosome 1. That match, bracketed by red, is a valid, phased, match and should be painted.

However, Person 1 also matches me, but NOT Mom on chromosome 2. Because Person 1 is bucketed to mother, this segment on chromosome 2 will also be painted to my maternal chromosome 2 using the DNAPainter import. The only way to sort this out is to do the comparison manually.

The same holds true for the X match shown. The two segments shown in red should NOT be painted, but they will be unless you are willing to compare you and your parents’ matches manually, you will just have to evaluate segments individually when you see that you’re working in a cluster where matches have been assigned through the mass import tool.

If you choose to compare the spreadsheets manually to assure that you’re not painting segments like the red ones above, DNAPainter provides instructions for you to create your own mass upload template, which is what I did after removing any segment matches of people that were not “in common” between me and mother on the same chromosomal segment, like the red ones, above.

Please note that if you delete the erroneous segments and later reimport your bucketed matches, they will appear again. I’m more inclined to leave them, making a note.

I did not do a manual comparison of my father’s side of the tree after discovering just how little difference was found on my mother’s side, and how much effort was involved in the manual comparison.

Creating a Mass Upload Template and File

DNAPainter custom mass upload.png

The instructions for creating your own mass upload file are provided by DNAPainter – please follow them exactly.

In my case, after doing the manual spreadsheet compare with my mother, only a total of 18 new segments were imported that were not previously identified by bucketing.

Three of those segments were over 15cM, but the rest were smaller. I expected there would be more. Family Tree DNA is clearly doing a great job with maternal and paternal bucketing assignments, but they can’t do it without known relatives that have also tested and are linked to your tree. The very small discrepancy is likely due to matches with cousins that I have not been able to link on my tree.

The great news is that because DNAPainter recognizes already-painted segments, I can repeat this anytime and just paint the new segments, without worrying about duplicates.

  • The information above pertains to segments that should have been painted, but weren’t.
  • The information below pertains to segments that were painted, but should not have been.

I did not keep track of how many segments I deleted that would have erroneously been painted. There were certainly more than 18, but not an overwhelming number. Enough though to let me know to be careful and confirm the segment match individually before using any of the mass uploaded matches for hypothesis or conclusions.

Given that this experiment went well, I created a copy of my “real” profile in order to do the same import and see what discoveries are waiting!

Before and After

Before I did the imports into my “real” file (after making a copy, of course,) I had painted 82% of my DNA using 1700 segments. Of course, each one of those segments in my original profile is identified with an ancestor, even if they aren’t very far back in time.

Although I didn’t paint matches in common with my mother before this mass import, each of my matches in common with my mother are in common with one or the other of my maternal grandparents – and by using other known matches I can likely push the identity of those segments further back in time.

Status Percent Segments Painted
Before mass Phased Family Match bucketed import 82 1700
After mass Phased Family Match bucketed import 88 7123
After additional manual matches with my mother added 88 7141

While I did receive 18 additional matching segments by utilizing the manually intensive spreadsheet matching and removal process, I did not receive enough more matches to justify the hours and hours of work. I won’t be doing that anymore with Family Tree DNA files since they have so graciously provided bucketing and DNAPainter can leverage that functionality.

Those hours will be much better spent focusing on unraveling the ancestors whose stories are told in clusters of triangulated matches.

I Love The Import Tool, But It’s Not Perfect

Keep in mind that the X chromosome needs a match of approximately twice the size of a regular chromosome to be as reliable. In other words, a 14 cM threshold for the X chromosome is roughly equivalent to a 7 cM match for any other chromosome. Said another way, a 7 cM match on the X is about equal to a 3.5 cM match on any other chromosome.

X matches are not created equal.

The SNP density on the X chromosome is about half that of the other chromosomes, making it virtually impossible to use the same matching criteria. I don’t encourage using matches of less than 500 SNPs unless you know you’re in a triangulated group and WITH at least a few larger, proven matches on that segment of the X chromosome.

Having said that, X matches, due to their unique inheritance path can persist for many generations and be extremely useful. You can read about working with the X chromosome here and here.

I noticed when I was comparing segments in the manual spreadsheet that I had to remove many X matches with people who had identical matches on other chromosomes with me and my mother. In other words, just because they matched my mother and me exactly on one chromosome, that phasing did not, by default, extend to matching on other segments.

I checked my manually curated file and discovered that I had a total of seven X matches that should have been, and were, painted because they matched me and Mom both.

DNAPainter X spreadsheet example.png

However, there were many that didn’t match me and Mom both, matching only me, that were painted because that person was bucketed (assigned) to my maternal side because a different segment phased to mother correctly.

On the X chromosome, here’s what happened.

DNAPainter maternal X.png

You can see that a lot more than 7 bright red matches were painted – 26 more to be exact. That’s because if an individual is bucketed on your maternal or paternal side, it’s presumed that all of the matching segments come from the same ancestor and are legitimate, meaning identical by descent and not by chance. They aren’t. Every single segment has an inheritance path and story of its own – and just because one segment triangulates does NOT mean that other segments that match that person will triangulate as well.

The X chromosome is the worst case scenario of course, because these 7 cM segments are actually as reliable as roughly 3.5 cM segments on any other chromosome, which is to say that more than 50% of them will be incorrect. However, some will be accurate and those will match me and mother both. 21% of the X matches to people who phased and triangulated on other chromosomes were accurate – 79% were not. Thankfully, we have phasing, bucketing and tools like this to be able to tell the difference so we can utilize the 21% that are accurate. No one wants to throw the baby out with the bath water, nor do we want to chase after phantoms.

Keep in mind that Phased Family Matching, like any other tool, is just that, a tool and needs some level of critical analysis.

Every Segment Has Its Own Story

We know that every single DNA segment has an independent inheritance path and story of its own. (Yes, I’ve said that several time now because it’s critically important so that you don’t wind up barking up the wrong tree, literally, pardon the pun.)

In the graphic above of my painted X chromosome matches, only the six matches with green stars are on the hand-curated match list. One had already been painted previously. The balance of the bright red matches were a part of the mass import and need to be deleted. Additionally, one of the accurate matches did not upload for some reason, so I’ll add that one manually.

I suggest that you go ahead and paint your bucketed segments, but understand that you may have a red herring or two in your crop of painted segment matches.

As you begin to work with these clusters of matches, check your matching segments with your parents (or other family members who were used in bucketing) and make sure that all the segments that have been painted by bulk upload actually match on all of the same segments.

If you have a parent that tested, there is no need to see if you and your match match other relatives on that same side. If your match does not match you and your parent on some significant overlapping portion of that same segment, the match is invalid. DNA does not “skip generations.”

If you don’t have a parent that has tested, your known relatives are your salvation, and the key to bucketed matches.

The great news is that you can easily see that a bulk match was painted from the coloring of the batch import. As you discover the relevant genealogy and confirm that all segments actually match your parent (or another family member, if you don’t have parents to test,) move the matching person to the appropriately colored ancestral group.

I further recommend that you hand curate the X chromosome using a spreadsheet. The nature of the X makes depending on phased matching too risky, especially with a tool like DNAPainter that can’t differentiate between a legitimate and non-legitimate match. The X chromosome matches are extraordinarily valuable because they can be useful in ways that other chromosomes can’t be due to the X’s unique inheritance path.

What About You?

If you don’t have your DNA at Family Tree DNA and you have tested elsewhere, you can transfer your DNA file for free, allowing you to see your matches and use many of the Family Tree DNA tools. However, to access the chromosome browser, which you’ll need for DNA painting, you’ll need to purchase the unlock for $19, but that’s still a lot less than retesting.

Here are transfer instructions for transferring your DNA file from 23andMe, Ancestry or MyHeritage.

If you have not purchased a Family Finder test at Family Tree DNA and don’t have a DNA file to transfer, you can order a test 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 Products and Services

Genealogy Research

Fun DNA Stuff

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

Native American & Minority Ancestors Identified Using DNAPainter Plus Ethnicity Segments

Ethnicity is always a ticklish subject. On one hand we say to be leery of ethnicity estimates, but on the other hand, we all want to know who our ancestors were and where they came from. Many people hope to prove or disprove specific theories or stories about distant ancestors.

Reasons to be cautious about ethnicity estimates include:

  • Within continents, like Europe, it’s very difficult to discern ethnicity at the “country” level because of thousands of years of migration across regions where borders exist today. Ethnicity estimates within Europe can be significantly different than known and proven genealogy.
  • “Countries,” in Europe, political constructs, are the same size as many states in the US – and differentiation between those populations is almost impossible to accurately discern. Think of trying to figure out the difference between the populations of Indiana and Illinois, for example. Yet we want to be able to tell the difference between ancestors that came from France and Germany, for example.

Ethnicity states over Europe

  • All small amounts of ethnicity, even at the continental level, under 2-5%, can be noise and might be incorrect. That’s particularly true of trace amounts, 1% or less. However, that’s not always the case – which is why companies provide those small percentages. When hunting ancestors in the distant past, that small amount of ethnicity may be the only clue we have as to where they reside at detectable levels in our genome.

Noise in this case is defined as:

  • A statistical anomaly
  • A chance combination of your DNA from both parents that matches a reference population
  • Issues with the reference population itself, specifically admixture
  • Perhaps combinations of the above

You can read about the challenges with ethnicity here and here.

On the Other Hand

Having restated the appropriate caveats, on the other hand, we can utilize legitimate segments of our DNA to identify where our ancestors came from – at the continental level.

I’m actually specifically referring to Native American admixture which is the example I’ll be using, but this process applies equally as well to other minority or continental level admixture as well. Minority, in this sense means minority ethnicity to you.

Native American ethnicity shows distinctly differently from African and European. Sometimes some segments of DNA that we inherit from Native American ancestors are reported as Asian, specifically Siberian, Northern or Eastern Asian.

Remember that the Native American people arrived as a small group via Beringia, a now flooded land bridge that once connected Siberia with Alaska.

beringia map

By Erika Tamm et al – Tamm E, Kivisild T, Reidla M, Metspalu M, Smith DG, et al. (2007) Beringian Standstill and Spread of Native American Founders. PLoS ONE 2(9): e829. doi:10.1371/journal.pone.0000829. Also available from PubMed Central., CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=16975303

After that time, the Native American/First Nations peoples were isolated from Asia, for the most part, and entirely from Europe until European exploration resulted in the beginning of sustained European settlement, and admixture beginning in the late 1400s and 1500s in the Americas.

Family Inheritance

Testing multiple family members is extremely useful when working with your own personal minority heritage. This approach assumes that you’d like to identify your matches that share that genetic heritage because they share the same minority DNA that you do. Of course, that means you two share the same ancestor at some time in the past. Their genealogy, or your combined information, may hold the clue to identifying your ancestor.

In my family, my daughter has Native American segments that she inherited from me that I inherited from my mother.

Finding the same segment identified as Native American in several successive generations eliminates the possibility that the chance combination of DNA from your father and mother is “appearing” as Native, when it isn’t.

We can use segment information to our benefit, especially if we don’t know exactly who contributed that DNA – meaning which ancestor.

We need to find a way to utilize those Native or other minority segments genealogically.

23andMe

Today, the only DNA testing vendor that provides consumers with a segment identification of our ethnicity predictions is 23andMe.

If you have tested at 23andMe, sign in and click on Ancestry on the top tab, then select Ancestry Composition.

Minority ethnicity ancestry composition.png

Scroll down until you see your painted chromosomes.

Minority ethnicity chromosome painting.png

By clicking on the region at left that you want to see, the rest of the regions are greyed out and only that region is displayed on your chromosomes, at right.

Minority ethnicity Native.png

According to 23andMe, I have two Native segments, one each on chromosomes 1 and 2. They show these segments on opposite chromosomes, meaning one (the top for example) would be maternal or paternal, and the bottom one would be the opposite. But 23andMe apparently could not tell for sure because neither my mother nor father have tested there. This placement also turned out to be incorrect. The above image was my initial V3 test at 23andMe. My later V4 results were different.

Versions May Differ

Please note that your ethnicity predictions may be different based on which test you took which is dictated by when you took the test. The image above is my V3 test that was in use at 23andMe between 2010 and November 2013, and the image below is my V4 test in use between November 2013 and August 2017.

23andMe apparently does not correct original errors involving what is known as “strand swap” where the maternal and paternal segments are inverted during analysis. My V4 test results are shown below, where the strands are correctly portrayed.

Minority ethnicity Native V4.png

Note that both Native segments are now on the lower chromosome “side” of the pair and the position on the chromosome 1 segment has shifted visually.

Minority ethnicity sides.png

I have not tested at 23andMe on the current V5 GSA chip, in use since August 9, 2017, but perhaps I should. The results might be different yet, with the concept being that each version offers an improvement over earlier versions as science advances.

If your parents have tested, 23andMe makes adjustments to your ethnicity estimates accordingly.

Although my mother can’t test at 23andMe, I happen to already know that these Native segments descend from my mother based on genealogical and genetic analysis, combined. I’m going to walk you through the process.

I can utilize my genealogy to confirm or refute information shown by 23andMe. For example, if one of those segments comes from known ancestors who were living in Germany, it’s clearly not Native, and it’s noise of some type.

We’re going to utilize DNAPainter to determine which ancestors contributed your minority segments, but first you’ll need to download your ethnicity segments from 23andMe.

Downloading Ethnicity Segment Data

Downloading your ethnicity segments is NOT THE SAME as downloading your raw DNA results to transfer to another vendor. Those are two entirely different files and different procedures.

To download the locations of your ethnicity segments at 23andMe, scroll down below your painted ethnicity segments in your Ancestry Composition section to “View Scientific Details.”

MInority ethnicity scientific details.png

Click on View Scientific Details and scroll down to near the bottom and then click on “Download Raw Data.” I leave mine at the 50% confidence level.

Minority ethnicity download raw data.png

Save this spreadsheet to your computer in a known location.

In the spreadsheet, you’ll see columns that provide the name of the segment, the chromosome copy number (1 or 2) and the chromosome number with start and end locations.

Minority ethnicity download.png

You really don’t care about this information directly, but DNAPainter does and you’ll care a lot about what DNAPainter does for you.

DNAPainter

I wrote introductory articles about DNAPainter:

If you’re not familiar with DNAPainter, you might want to read these articles first and then come back to this point in this article.

Go ahead – I’ll wait!

Getting Started

If you don’t have a DNAPainter account, you’ll need to create one for free. Some features, such as having multiple profiles are subscription based, but the functionality you’ll need for one profile is free.

I’ve named this example profile “Ethnicity Demo.” You’ll see your name where mine says “Ethnicity Demo.”

Minority ethnicity DNAPainter.png

Click on “Import 23andme ancestry composition.”

You will copy and paste all the spreadsheet rows in the entire downloaded 23andMe ethnicity spreadsheet into the DNAPainter text box and make your selection, below. The great news is that if you discover that your assumption about copy 1 being maternal or paternal is incorrect, it’s easy to delete the ethnicity segments entirely and simply repaint later. Ditto if 23andMe changes your estimate over time, like they have mine.

Minority ethnicity DNAPainter sides.png

I happen to know that “copy 2” is maternal, so I’ve made that selection.

You can then see your ethnicity chromosome segments painted, and you can expand each one to see the detail. Click on “Save Segments.”

MInority ethnicity DNAPainter Native painting

Click to enlarge

In this example, you can see my Native segments, called by various names at different confidence levels at 23andMe, on chromosome 1.

Depending on the confidence level, these segments are called some mixture of:

  • East Asian & Native American
  • North Asian & Native American
  • Native American
  • Broadly East Asian & Native American

It’s exactly the same segment, so you don’t really care what it’s called. DNAPainter paints all of the different descriptions provided by 23andMe, at all confidence levels as you can see above.

The DNAPainter colors are different from 23andMe colors and are system-selected. You can’t assign the colors for ethnicity segments.

Now, I’m moving to my own profile that I paint with my ancestral segments. To date, I have 78% of my segments painted by identifying cousins with known common ancestors.

On chromosomes 1 and 2, copy 2, which I’ve determined to be my mother’s “side,” these segments track back to specific ancestors.

Minority ethnicity maternal side

Click to enlarge

Chromosome 1 segments, above, track back to the Lore family, descended from Antoine (Anthony) Lore (Lord) who married Rachel Hill. Antoine Lore was Acadian.

Minority ethnicity chromosome 1.png

Clicking on the green segment bar shows me the ancestors I assigned when I painted the match with my Lore family member whose name is blurred, but whose birth surname was Lore.

The Chromosome 2 segment, below, tracks back to the same family through a match to Fred.

Minority ethnicity chromosome 2.png

My common ancestors with Fred are Honore Lore and Marie Lafaille who are the parents of Antoine Lore.

Minority ethnicity common ancestor.png

There are additional matches on both chromosomes who also match on portions of the Native segments.

Now that I have a pointer in the ancestral direction that these Native American segments arrived from, what can traditional genealogy and other DNA information tell me?

Traditional Genealogy Research

The Acadian people were a mixture of English, French and Native American. The Acadians settled on the island of Nova Scotia in 1609 and lived there until being driven out by the English in 1755, roughly 6 or 7 generations later.

Minority ethnicity Acadian map.png

The Acadians intermarried with the Mi’kmaq people.

It had been reported by two very qualified genealogists that Philippe Mius, born in 1660, married two Native American women from the Mi’kmaq tribe given the name Marie.

The French were fond of giving the first name of Marie to Native women when they were baptized in the Catholic faith which was required before the French men were allowed to marry the Native women. There were many Native women named Marie who married European men.

Minority ethnicity Native mitochondrial tree

Click to enlarge

This Mius lineage is ancestral to Antoine Lore (Lord) as shown on my pedigree, above.

Mitochondrial DNA has revealed that descendants from one of Philippe Mius’s wives, Marie, carry haplogroup A2f1a.

However, mitochondrial tests of other descendants of “Marie,” his first wife, carry haplogroup X2a2, also Native American.

Confusion has historically existed over which Marie is the mother of my ancestor, Francoise.

Karen Theroit Reader, another professional genealogist, shows Francoise Mius as the last child born to the first Native wife before her death sometime after 1684 and before about 1687 when Philippe remarried.

However, relative to the source of Native American segments, whether Francoise descends from the first or second wife doesn’t matter in this instance because both are Native and are proven so by their mitochondrial DNA haplogroups.

Additionally, on Antoine’s mother’s side, we find a Doucet male, although there are two genetic male Doucet lines, one of European origin, haplogroup R-L21, and one, surprisingly, of Native origin, haplogroup C-P39. Both are proven by their respective haplogroups but confusion exists genealogically over who descends from which lineage.

On Antoine’s mother’s side, there are several unidentified lineages, any one or multiples of which could also be Native. As you can see, there are large gaps in my tree.

We do know that these Native segments arrived through Antoine Lore and his parents, Honore Lore and Marie LaFaille. We don’t know exactly who upstream contributed these segments – at least not yet. Painting additional matches attributable to specific ancestral couples will eventually narrow the candidates and allow me to walk these segments back in time to their rightful contributor.

Segments, Traditional Research and DNAPainter

These three tools together, when using continent-level segments in combination with painting the DNA segments of known cousins that match specific lineages create a triangulated ethnicity segment.

When that segment just happens to be genealogically important, this combination can point the researchers in the right direction knowing which lines to search for that minority ancestor.

If your cousins who match you on this segment have also tested with 23andMe, they should also be identified as Native on this same segment. This process does not apply to intracontinental segments, meaning within Europe, because the admixture is too great and the ethnicity predictions are much less reliable.

When identifying minority admixture at the continental level, adding Y and mitochondrial DNA testing to the mix in order to positively identify each individual ancestor’s Y and mitochondrial DNA is very important in both eliminating and confirming what autosomal DNA and genealogy records alone can’t do. The base haplogroup as assigned at 23andMe is a good start, but it’s not enough alone. Plus, we only carry one line of mitochondrial DNA and only males carry Y DNA, and only their direct paternal line.

We need Y and mitochondrial DNA matching at FamilyTreeDNA to verify the specific lineage. Additionally, we very well may need the Y and mitochondrial DNA information that we don’t directly carry – but other cousins do. You can read about Y and mitochondrial DNA testing, here.

I wrote about creating a personal DNA pedigree chart including your ancestors’ Y and mitochondrial DNA here. In order to find people descended from a specific ancestor who have DNA tested, I utilize:

  • WikiTree resources and trees
  • Geni trees
  • FamilySearch trees
  • FamilyTreeDNA autosomal matches with trees
  • AncestryDNA autosomal matches and their associated trees
  • Ancestry trees in general, meaning without knowing if they are related to a DNA match
  • MyHeritage autosomal matches and their trees
  • MyHeritage trees in general

At both MyHeritage and Ancestry, you can view the trees of your matches, but you can also search for ancestors in other people’s trees to see who might descend appropriately to provide a Y or mitochondrial DNA sample. You will probably need a subscription to maximize these efforts. My Heritage offers a free trial subscription here.

If you find people appropriately descended through WikiTree, Geni or FamilySearch, you’ll need to discuss DNA testing with them. They may have already tested someplace.

If you find people who have DNA tested through your DNA matches with trees at Ancestry and MyHeritage, you’ll need to offer a Y or mitochondrial DNA test to them if they haven’t already tested at FamilyTreeDNA.

FamilyTreeDNA is the only vendor who provides the Y DNA and mitochondrial DNA tests at the higher resolution level, beyond base haplogroups, required for matching and for a complete haplogroup designation.

If the person has taken the Family Finder autosomal test at FamilyTreeDNA, they may have already tested their Y DNA and mtDNA, or you can offer to upgrade their test.

Projects

Checking projects at FamilyTreeDNA can be particularly useful when trying to discover if anyone from a specific lineage has already tested. There are many, special interest projects such as the Acadian AmerIndian Ancestry project, the American Indian project, haplogroup projects, surname projects and more.

You can view projects alphabetically here or you can click here to scroll down to enter the surname or topic you are seeking.

Minority ethnicity project search.png

If the topic isn’t listed, check the alphabetic index under Geographical Projects.

23andMe Maternal and Paternal Sides

If possible, you’ll want to determine which “side” of your family your minority segments originate come from, unless they come from both. you’ll want to determine whether chromosome side one 1 or 2 is maternal, because the other one will be paternal.

23andMe doesn’t offer tree functionality in the same way as other vendors, so you won’t be able to identify people there descended from your ancestors without contacting each person or doing other sleuthing.

Recently, 23andMe added a link to FamilySearch that creates a list of your ancestors from their mega-shared tree for 7 generations, but there is no tree matching or search functionality. You can read about the FamilySearch connection functionality here.

So, how do you figure out which “side” is which?

Minority ethnicity minority segment.png

The chart above represents the portion of your chromosomes that contains your minority ancestry. Initially, you don’t know if the minority segment is your mother’s pink chromosome or your father’s blue chromosome. You have one chromosome from each parent with the exact same addresses or locations, so it’s impossible to tell which side is which without additional information. Either the pink or the blue segment is minority, but how can you tell?

In my case, the family oral history regarding Native American ancestry was from my father’s line, but the actual Native segments wound up being from my mother, not my father. Had I made an assumption, it would have been incorrect.

Fortunately, in our example, you have both a maternal and paternal aunt who have tested at 23andMe. You match both aunts on that exact same segment location – one from your father’s side, blue, and one from your mother’s side, pink.

You compare your match with your maternal aunt and verify that indeed, you do match her on that segment.

You’ll want to determine if 23andMe has flagged that segment as Native American for your maternal aunt too.

You can view your aunt’s Ancestry Composition by selecting your aunt from the “Your Connections” dropdown list above your own ethnicity chromosome painting.

Minority ethnicity relative connections.png

You can see on your aunt’s chromosomes that indeed, those locations on her chromosomes are Native as well.

Minority ethnicity relative minority segments.png

Now you’ve identified your minority segment as originating on your maternal side.

Minority ethnicity Native side.png

Let’s say you have another match, Match 1, on that same segment. You can easily tell which “side” Match 1 is from. Since you know that you match your maternal aunt on that minority segment, if Match 1 matches both you and your maternal aunt, then you know that’s the side the match is from – AND that person also shares that minority segment.

You can also view that person’s Ancestry Composition as well, but shared matching is more reliable,especially when dealing with small amounts of minority admixture.

Another person, Match 2, matches you on that same segment, but this time, the person matches you and your paternal aunt, so they don’t share your minority segment.

Minority ethnicity match side.png

Even if your paternal aunt had not tested, because Match 2 does not match you AND your maternal aunt, you know Match 2 doesn’t share your minority segment which you can confirm by checking their Ancestry Composition.

Download All of Your Matches

Rather than go through your matches one by one, it’s easiest to download your entire match list so you can see which people match you on those chromosome locations.

Minority ethnicity download aggregate data.png

You can click on “Download Aggregate Data” at 23andMe, at the bottom of your DNA Relatives match list to obtain all of your matches who are sharing with you. 23andMe limits your matches to 2000 or less, the actual number being your highest 2000 matches minus the people who aren’t sharing. I have 1465 matches showing and that number decreases regularly as new testers at 23andMe are focused on health and not genealogy, meaning lower matches get pushed off the list of 2000 match candidates.

You can quickly sort the spreadsheet to see who matches you on specific segments. Then, you can check each match in the system to see if that person matches you and another known relative on the minority segments or you can check their Ancestry Composition, or both.

If they share your minority segment, then you can check their tree link if they have one, included in the download, their Family Search information if included on their account, or reach out to them to see if you might share a known ancestor.

The key to making your ethnicity segment work for you is to identify ancestors and paint known matches.

Paint Those Matches

When searching for matches whose DNA you can attribute to specific ancestors, be sure to check at all 4 places that provide segment information that you can paint:

At GedMatch, you’ll find some people who have tested at the other various vendors, including Ancestry, but unfortunately not everyone uploads. Ancestry doesn’t provide segment information, so you won’t be able to paint those matches directly from Ancestry.

If your Ancestry matches transfer to GedMatch, FamilyTreeDNA or MyHeritage you can view your match and paint your common segments. At GedMatch, Ancestry kit numbers begin with an A. I use my Ancestry kit matches at GedMatch to attempt to figure out who that match is at Ancestry in order to attempt to figure out the common ancestor.

To Paint, You Must Test

Of course, in order to paint your matches that you find in various databases, you need to be in those data bases, meaning you either need to test there or transfer your DNA file.

Transfers

If you’d like to test your DNA at one vendor and download the file to transfer to another vendor, or GedMatch, that’s possible with both FamilyTreeDNA and MyHeritage who both accept uploads.

You can transfer kits from Ancestry and 23andMe to both FamilyTreeDNA and MyHeritage for free, although the chromosome browsers, advanced tools and ethnicity require an unlock fee (or alternatively a subscription at MyHeritage). Still, the free transfer and unlock for $19 at FamilyTreeDNA or $29 at MyHeritage is less than the cost of testing.

Here’s a quick cheat sheet.

DNA vendor transfer cheat sheet 2019

From time to time, as vendor file formats change, the ability to transfer is temporarily interrupted, but it costs nothing to try a transfer to either MyHeritage or FamilyTreeDNA, or better yet, both.

In each of these articles, I wrote about how to download your data from a specific vendor and how to upload from other vendors if they accept uploads.

Summary Steps

In order to use your minority ethnicity segments in your genealogy, you need to:

  1. Test at 23andMe
  2. Identify which parental side your minority ethnicity segments are from, if possible
  3. Download your ethnicity segments
  4. Establish a DNAPainter account
  5. Upload your ethnicity segments to DNAPainter
  6. Paint matches of people with whom you share known common ancestors utilizing segment information from 23andMe, FamilyTreeDNA, MyHeritage and AncestryDNA matches who have uploaded to GedMatch
  7. If you have not tested at either MyHeritage or FamilyTreeDNA, upload your 23andMe file to either vendor for matching, along with GedMatch
  8. Focus on those minority segments to determine which ancestral line they descend through in order to identify the ancestor(s) who provided your minority admixture.

Have fun!

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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

Concepts – Sorting Spreadsheets for Autosomal DNA

This article covers both sorting in Excel and how to identify an overlapping segment, and what that means to you as a genetic genealogist.

I swore I wasn’t going to teach Excel, but there have been so many questions about sorting Excel spreadsheets that I am going to a very basic “how to sort and not hurt yourself” article. This does NOT replace actually understanding how to use Excel, but it will at least get you through the knothole of sorting for genetic genealogy.

I wrote more about sorting and filtering in the concepts article about assigning parental sides.

There are some advanced ways to accomplish the same thing, and I’m not discussing those. If you already know how to use Excel those are fine, but this article provides the basics for those who don’t.

Sorting

I am going to use, as an example, my matches to only a few people which gives us enough information to sort, but isn’t overwhelming.

When you download your results from Family Tree DNA, your spreadsheet will be in match name order, like the spreadsheet below.

SS Raw

I want you to notice that while the primary order is by match, there is a secondary order too (chromosome), and a third (start location) and fourth (end location) as well.

Within each match, the order is by chromosome, and then by start and end location.

What this means that you can look at Alice and see that chromosome 1 is first, and that the lowest value start location is shown first within chromosome order.

That’s not the order you’ll likely be working with all the time, so let’s take a look at how to sort the spreadsheet in a different way.

The row highlighted in red contain column headers.

SS column headers

When you sort an individual column you will select the header for that column, shown below, if you’re going to sort the Matching SNPs column.

SS Column select

The cell on your spreadsheet won’t be red, but I’ve colored it red here so you can see that I’m selecting this column header and only this column header.

When you select a column header, you put the cursor on that cell and click once.

SS column select 2

The cell you’ve selected will be bordered in black.  A screen shot of my spreadsheet is shown above.

I want you to watch what happens to these two rows colored green when I sort in Matching SNP order.

SS rows green

At this point, you will click on the sort and filter button on the upper right hand side of the toolbar.

SS sort dropdown

Here’s a closeup.

SS sort dropdown closeup

Selecting the “Sort A to Z” option sorts the contents of the entire spreadsheet in Matching SNP order, smallest to largest, because that’s the column header and sort option combination you selected. I use lowest to highest (A-Z) but you can also sort in reverse order, highest to lowest (Z-A) but that isn’t terribly useful for what we will be doing.

SS SNP column sorted

Notice that all of the rows are sorted into smallest to larger order by the Matching SNP column. So while the two green rows were originally together, now the rows all appear in order by the Matching SNPs column values.

The first green row match to Alice on chromosome 3 with 1300 cMs falls between the SNP value of 850 and 1458.  The second green row with a value of 2000 falls between 1638 and 2355.  This is exactly as it should be.  The contents of the entire spreadsheet are sorted by the values in the Matching SNPs column.

The statement “sorts the contents of the entire spreadsheet” is very important, because if you perform this task incorrectly, you will bollux up your entire spreadsheet, as in irrecoverably and forever.  What follows is an example of what NOT TO DO.

DO NOT DO THIS

DO NOT, and I repeat, DO NOT select the entire column to sort.

SS - Do Not Sort

This is an example of WHAT NOT TO DO.

If you select the entire column, as shown above, then sort, here’s what happens.

SS example bad sort

Notice that the green rows are now split apart – in other words they no longer form a row from left to right. That means that ONLY the data in the Matching cM column was sorted, but not rest of the data which is still in the same location on the spreadsheet as it was before the sort. Therefore, Alice’s green row Matching cM value of 1300 is no longer with Alice, since only the data in the Matching SNPs column was sorted. Now Alice’s 1300 cMs connected to Stacy’s red row on chromosome 4. Alice now has 500 SNPs instead, which as you can see, clearly isn’t accurate.

This is what I meant by selecting the entire column instead of just the header will forever ruin your data. If you do this, there is no recovery, unless you JUST did it, SS undo
realize the error, and can selecte the blue backarrow on the top of the toolbar on the left to “undo” your action. If you’re beyond that, the only recovery is to download your data again, or move to a backup if you have one.

What’s even worse if you do this and don’t realize it, so you’re working with incorrect data trying to find overlapping segments.  Of course, everything will be wrong.  I periodically do a sanity check and look at a couple people in the chromosome browser just to make sure that everything is as it should be on my spreadsheet and I haven’t done something like this.

To Sort Correctly – DO This

To use this spreadsheet effectively for genetic genealogy, we need the spreadsheet to be sorted in this viewing order:

  • Chromosome number
  • Start location
  • End location

In other words, we need the spreadsheet to look like this with all of the green cells remaining in their row with their match:

SS example good sort

You’ll notice that all matches on each chromosome are grouped together, with the smallest start location first, as illustrated by the red groupings of chromsomes 1 and 6. I do realize these are small segments, but the process is the same for large or small segments, so for our sorting example, just ignore any genealogical relevance associated with segment size.

You will be looking for overlapping segments. Notice that you have to be cognizatnt of the end location. In the case of chromsome 1, above, there are no overlapping segments for the two chromsome one matches, so they can’t match each other on this segment.

However, on chromsome 6, we have a different situation. Stacy’s segment match with me is quite long, 104cM. Stacy’s segment overlaps with everyone else’s on chromsone 6 that matches to me, either fully or part way. She matches Alice on all of the segments fully except for the last one. Stacy’s match to me ends at 108,000,000. Alice’s last segment matches to me from 107,779,220 which is included in Stacy’s match, but Alice’s match extends beyond Stacys, to 110,175,307.

Keep in mind that we don’t know at this point whether or not Stacy and Alice are from my mother or father’s side, based on matching. In other words, to draw any conclusions, we also have to know if Stacy and Alice match each other on this segment which we can’t tell from this spreadsheet.

Because I have access to Stacy’s account, I can indeed tell you that Stacy and Alice do not match each other on this segment, so they would be from different sides of my family tree. Stacy is a known relative from my father’s side and Alice does match my mother as well, so we now know that Stacy and Alice don’t match each other.

If you don’t have access to the accounts to see if your matches match each other, two tools at Family Tree DNA are partial substitutes.

  • The ICW tool tells you if two of your matches match each other, just not on which segments.
  • The maternal/paternal Family Matching tool, if you have connected the DNA of relatives who have tested, tell you which side your matches are from, maternal or paternal.

You can read about how to use those tools here.

If there are multiple matches with the smallest start location then they will be in order by the smallest end location first, shown in the yellow cells.

Sort Order

The sort order is exactly the opposite of the viewing order. If you want to SEE the data in this order:

  • Chromosome
  • Start
  • End

Then you must sort in this order:

  • End
  • Start
  • Chromosome

The last column you sort will be the primary viewing order.

Let’s look at our spreadsheet utilizing these three steps, in order.

Step 1 – First Sort

Selecting End Location to sort:

SS sort end location

After sorting by end location, below.

SS end location sorted

You will notice that all of the data is now in order by the values in the End Location column – smallest at the top, largest at the bottom.

The data in the other columns is not in any particular order at all.

Step 2 – Second Sort

Now selecting Start Location to sort that column in order, shown below.

SS sort by start location

Having sorted by Start Location, below:

SS sorted by start location

You will notice that now all of the data is sorted by start location. In the case where there is a common start location between two rows, highlighted in red, the end row with the lower end location will show first, noted in yellow, because you sorted first by end location in smallest to largest order.

Step 3 – Third Sort

Last, you’ll select the Chromosome column header to sort in chromosome order.

Sort by chromosome

Below, the result of sorting the third time in chromsome order.  After sorting, I bordered all segments on the same chromosome.

Sorted by chromosome

You can see that the entire spreadsheet is grouped by chromsome, and within chromsome number, the Start Location is grouped smallest to largest. If there are multiple people with the same start location, then the End Location comes into play, with the smallest end location listed first, as shown in the red and yellow rows.

If you want to sort your spreadsheet in another order for some reason, you can do so using the same methodology. Once you understand about sorting spreadsheets, you understand about sorting all spreadsheets.

Now, you’re ready to look for your overlapping segments.

What is an Overlap?

An overlap is two segments of your matches that are partially or completely overlapping each other.  When you have overlapping segments, assuming they are of decent size, that indicates that the two people who match you on your spreadsheet potentially match each other too.  Remember, there are three matching possibilities:

  • Your matches will either match each other, in addition to you, because you and both of them share a common ancestor or…
  • They both match you, but they won’t match each other because one is from your mother’s side and one is from your father’s side or…
  • One or both are identical by chance.  In you need a refresher on what identical by chance, descent and population mean, click here.

Ss no overlap

In this first example, above, there is no overlap between these two people on chromosome 17.  One begins at 31,000,000 and ends at 36,000,000 while the second person’s match with you doesn’t begin until 40,000,000, which is clearly beyond the end of 36,000,000, so there is no possibility of overlaps between these two individuals.  In other words, they cannot match each other on these segments.  However, clearly they both match you because they are both on your matching spreadsheet.

SS overlap 1

In the example above, the overlapping portion of the segment is from 38,000,000 – 40,000,000.  The second person’s match with you extends to 53,000,000, but the area between 40,000,000 and 53,000,000 does not overlap.

SS overlap 2

In the example above, the start number is lower for the top row than the second row, so the overlapping area is still from 38,000,000 – 40,000,000, because the matches don’t match from 36,000,000 to 38,000,000.

SS overlap 3

Occasionally, you have an overlap that is fairly miniscule, which I generally ignore unless they are in a group that has a larger overlap that overlaps or covers both smaller matches, as in the example above. You can see that our red and yellow rows have a very small overlap from 39,500,000 – 40,000,000. However, the top row includes the entire areas of both red and yellow rows, reaching from 33,000,000 to 55,000,000 which begins before either red/yellow row and ends after both red/yellow rows.  So either all 3 individuals will match each other, indicating a common ancestor, or the top row will match one of the red/yellow rows and not the other.

Combining Spreadsheets From Different Sources

The good news is that you can download your matches into a spreadsheet format from  23andMe, Family Tree DNA and GedMatch, but you do need to understand something about the basics of sorting and how to stay out of spreadsheet trouble. I am careful about combining spreadsheets sources for a couple of reasons.

  • First, the formatting is not exactly the same, so you may need to move columns to be in the correct order for your spreadsheet before actually combining them.
  • Second, there may be overlapping people between 23andMe, Family Tree DNA and GedMatch. You’ll need to figure out how you want to deal with that, especially on an ongoing basis when you need to add to or update your spreadsheet without overwriting or eliminating your matching work and notes relative to common ancestors and ancestral lines in the columns you’ll be adding.

I always make a backup file with a date name in the file name before doing combinations, and sometimes before sorting as well.

Learning Excel

If you want to learn more about how to use Excel, here are some additional resources to utilize.

I found some training videos for Excel including “Twenty with Tessa, Tips and Suggestions for Spreadsheets” which is focused on using spreadsheets with one name studies and genetic genealogy, but the principles are the same.  https://www.youtube.com/watch?v=Ll_cfhOZTl0&feature=youtu.be

When discussing this online, one person mentioned that they joined www.lynda.com and took the basic Excel class which she found very useful.

Kitty Cooper has instructions on her blog for how to make a matches spreadsheet as well.

www.DNAadoption.com has some good courses.  Their DNA for beginners covers using spreadsheets and is not just for adoptees!

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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