DNA: In Search of…Full and Half-Siblings

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

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

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

All Parties Need to Test

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

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

My first questions when someone comments in this vein are:

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

Sibling Scenarios

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

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

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

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

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

Full and Half-Siblings

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

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

Caution

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

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

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

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

On the other hand, it may.

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

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

Congratulations, You Have a Sibling!

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

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

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

Let’s start with DNAPainter.

DNAPainter

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

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

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

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

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

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

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

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

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

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

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

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

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

Relationship Probability Calculator

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

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

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

Vendors

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

Sibling Matches at Ancestry

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

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

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

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

Ancestry never stipulates full or half.

The following relationship is a half-sibling at Ancestry.

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

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

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

Sibling Matches at 23andMe

23andMe does identify full versus half-siblings.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

GEDMatch shows both half and fully identical regions.

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

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

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

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

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

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

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

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

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

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

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

Sibling Matches at FamilyTreeDNA

FamilyTreeDNA does identify full siblings.

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

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

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

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

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

Sibling Matches at MyHeritage

MyHeritage indicates brother or sister for full siblings

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

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

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

View Close Known Relationships

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

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

Let’s start with the simplest situation first.

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

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

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

Here’s an example.

Close Relationships at FamilyTreeDNA

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

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

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

Now let’s make this a little more difficult.

No Parents, No Problem

Let’s say neither of your parents has tested.

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

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

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

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

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

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

Close Relationships at Ancestry

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

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

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

Close Relationships at MyHeritage

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

Now, THIS is interesting.

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

Close Relationships at 23andMe

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

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

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

More Tools Are Available

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

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

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

X Matching

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

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

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

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

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

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

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

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

Men pass no X chromosome to sons.

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

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

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

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

The full siblings, Melody, and Cinderella:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Here’s a summary chart for sibling X matching.

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

Here’s the information presented in a different way.

DOES match X summary:

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

Does NOT match X summary:

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

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

X Matching at FamilyTreeDNA

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

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

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

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

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

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

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

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

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

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

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

Y DNA and Mitochondrial DNA

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

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

Y DNA

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

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

Y DNA at FamilyTreeDNA

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Y DNA at 23andMe

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

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

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

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

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

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

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

Mitochondrial DNA

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

Mitochondrial DNA at 23andMe

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

Mitochondrial DNA at FamilyTreeDNA

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

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

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

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

I wrote about heteroplasmies, here.

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

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

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

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

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

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

Sibling Summary and Checklist

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

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

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

Additional Resources

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

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

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

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

Strategy

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

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

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

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

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

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

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

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

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

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

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DNA: In Search of…Signs of Endogamy

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

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

After introductions, we will be covering the following topics:

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

What Is Endogamy and Why Does It Matter?

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

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

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

This Article

This article serves two purposes.

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

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

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

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

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

I’ve previously written about endogamy in the articles:

Let’s start with definitions.

Pedigree Collapse and Endogamy

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

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

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

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

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

Pedigree Collapse and Endogamy is NOT the Same

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

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

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

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

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

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

Endogamy Doesn’t Necessarily Indicate Recent Pedigree Collapse

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

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

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

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

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

Endogamous Groups

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

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

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

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

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

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

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

Endogamy is a process that occurs over time.

Endogamy and Unknown Relatives

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

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

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

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

The Challenge

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

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

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

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

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

One Size Does NOT Fit All

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

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

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

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

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

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

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

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

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

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

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

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

Ethnicity and Populations

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

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

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

This individual at FamilyTreeDNA is 100% Ashkenazi Jewish.

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

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

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

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

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

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

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

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

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

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

Ethnicity Sides

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

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

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

Here’s an example at 23andMe.

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

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

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

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

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

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

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

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

Let’s look at another example.

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

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

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

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

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

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

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

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

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

Ancestry’s DNA Communities

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

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

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

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

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

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

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

MyHeritage’s Genetic Groups

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

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

You can also sort your matches by Genetic Groups.

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

I wrote about Genetic Groups, here.

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

Matches

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

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

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

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

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

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

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

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

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

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

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

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

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

In fact, in order:

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

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

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

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

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

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

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

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

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

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

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

Matching Location at MyHeritage

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

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

AutoClusters

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

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

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

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

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

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

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

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

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

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

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

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

Endogamous Relationships

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

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

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

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

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

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

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

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

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

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

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

However, in these dozen examples:

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

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

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

Furthermore, it can get more complex.

Half Endogamous

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

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

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

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

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

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

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

However, that’s not universally what we see.

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

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

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

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

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

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

Ancestry and Timber

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

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

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

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

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

Endogamous Segments

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

How and why does this happen?

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

More, Smaller Segments

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

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

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

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

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

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

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

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

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

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

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

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

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

Endogamy, Segments, and Distant Relationships

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

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

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

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

“Are Your Parents Related?” Tool

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

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

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

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

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

Click on “Are your parents related?”

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

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

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

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

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

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

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

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

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

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

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

Let’s look for more clues.

Surnames

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

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

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

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

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

You can evaluate in either or both of two ways:

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

Here are some examples from our testers.

Jewish – Closest surname matches.

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

Acadian – Closest surname matches.

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

Native American – Closest surname matches.

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

You may recognize these categories of surnames immediately.

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

The most unusual surnames are likely your best bets.

Projects

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

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

Scroll down until you see this image.

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

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

These results are for Muise, an Acadian surname.

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

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

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

Locations

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

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

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

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

Y DNA, Mitochondrial DNA, and Endogamy

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Discover for Y DNA Only

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

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

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

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

You’ll be treated to:

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

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

Endogamy Tools Summary Tables

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

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

Summary of Endogamy Tools by Vendor

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

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

Summary of Endogamous Populations Identified by Each Tool

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

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

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

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

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

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

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

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

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

Acknowledgments

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

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

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Identify Your Ancestors – Follow Nested Ancestral Segments

I don’t think that we actively think about our DNA segments as nested ancestors, like Russian Matryoshka dolls, but they are.

That’s exactly why segment information is critical for genealogists. Every segment, and every portion of a segment, has an incredibly important history. In fact, you could say that the further back in time we can track a segment, the more important it becomes.

Let’s see how to unveil nested segments. I’ll use my chromosome 20 as an example because it’s a smaller chromosome. But first, let’s start with my pedigree chart.

Pedigree

Click images to enlarge.

Before we talk about nested segments that originated with specific ancestors, it’s important to take a look at the closest portion of my maternal pedigree chart. My DNA segments came from and through these people. I’ll be working with the first 5 generations, beginning with my mother as generation #1.

Generation 1 – Parents

In the first generation, we receive a copy of each chromosome from each parent. I have a copy of chromosome 20 from my mother and a copy from my father.

At FamilyTreeDNA, you can see that I match my mother on the entire tested region of each chromosome.

Therefore, the entire length of each of my chromosomes is assigned to both mother and father because I received a copy from each parent. I’m fortunate that my mother’s DNA was able to be tested before she passed away.

We see that each copy of chromosome 20 is a total of 110.20 cM long with 17,695 SNPs.

Of course, my mother inherited the DNA on her chromosome 20 from multiple ancestors whose DNA combined in her parents, a portion of which was inherited by my mother. Mom received one chromosome from each of her parents.

I inherited only one copy of each chromosome (In this case, chromosome 20) from Mom, so the DNA of her two parents was divided and recombined so that I inherited a portion of my maternal chromosome 20 from both of my maternal grandparents.

Identifying Maternal and Paternal Matches

Associating matches with your maternal or paternal side is easy at FamilyTreeDNA because their Family Finder matching does it automatically for you if you upload (or create) a tree and link matches that you can identify to their proper place in your tree.

FamilyTreeDNA then uses that matching segment information from known, identified relatives in your tree to place people who match you both on at least one significant-sized segment in the correct maternal, paternal, (or both) buckets. That’s triangulation, and it happens automatically. All you have to do is click on the Maternal tab to view your triangulated maternal matches. As you can see, I have 1432 matches identified as maternal. 

Some other DNA testing companies and third-party tools provide segment information and various types of triangulation information, but they aren’t automated for your entire match list like Family Finder matching at FamilyTreeDNA.

You can read about triangulation in action at MyHeritage, here, 23andMe, here, GEDmatch, here, and DNAPainter, which we’ll use, here. Genetic Affairs AutoKinship tool incorporates triangulation, as does their AutoSegment Triangulation Cluster Tool at GEDmatch. I’ve compiled a reference resource for triangulation, here.

Every DNA testing vendor has people in their database that haven’t tested anyplace else. Your best strategy for finding nested segments and identifying matches to specific ancestors is to test at or transfer your DNA file to every vendor plus GEDmatch where people who test at Ancestry sometimes upload for matching. Ancestry does not provide segment information or a chromosome browser so you’ll sometimes find Ancestry testers have uploaded to GEDmatch, FamilyTreeDNA  or MyHeritage where segment information is readily available. I’ve created step-by-step download/upload instructions for all vendors, here.

Generation 2 – Grandparents

In the second generation, meaning that of my grandparents, I inherited portions of my maternal and paternal grandmother’s and grandfather’s chromosomes.

My maternal and paternal chromosomes can be divided into two pieces or groups each, one for each grandparent.

Using DNAPainter, we can see my father’s chromosome 20 on top and my mother’s on the bottom. I have previously identified segments assigned to specific ancestors which are represented by different colors on these chromosomes. You can read more about how to use DNAPainter, here.

We can divide the DNA inherited from each parent into the DNA inherited from each grandparent based on the trees of people we match. If we test cousins from each side, assigning segments maternally or paternally becomes much, much easier. That’s exactly why I’ve tested several.

For the rest of this article, I’m focusing only on my mother’s side because the concepts and methods are the same regardless of whether you’re working on your maternal side or your paternal side.

Using DNAPainter, I expanded my mother’s chromosome 20 in order to see all of the people I’ve painted on my mother’s side.

DNAPainter allows us to paint matching segments from multiple testing vendors and assign them to specific ancestors as we identify common ancestors with our matches.

Based on these matches, I’ve divided these maternal matches into two categories:

  • Maternal grandmother, meaning my mother’s mother, bracketed in red boxes
  • Maternal grandfather, meaning my mother’s father, bracketed in black boxes.

The text and arrows in these graphics refer to the colors of the brackets/boxes, and NOT the colors of the segments beside people’s names. For example, if you look at the large black box at far right, you’ll see several people, with their matching segments identified by multiple colored bars. The different colored segments (bars) mean I’ve associated the match with different ancestors in multiple or various levels of generations.

Generation 3 – Great-grandparents

Within those maternal and paternal grandparent segments, more nested information is available.

The black Ferverda grandfather segments are further divided into black, from Hiram Ferverda, and gold from his wife Eva Miller. The same concept applies to the red grandmother segments which are now divided into red representing Nora Kirsch and purple representing Curtis Lore, her husband.

While I have only been able to assign the first four segments (at the top) to one person/ancestor, there’s an entire group of matches who share the grouping of segments at right, in gold, descended through Eva Miller. The Miller line is Brethren and Mennonite with lots of testers, so this is a common pattern in my DNA matches.

Eva Miller, the gold ancestor, has two parents, Margaret Elizabeth Lentz and John David Miller, so her segments would come from those two sides.

Generation 4 and 5 – Fuschia Segment

I was able to track the segment shown in fuschia indicated by the blue arrow to Jacob Lentz and his wife Fredericka Ruhle, German immigrant ancestors. Other people in this same match (triangulation) group descend from Margaret Elizabeth Lentz and John David Miller – but that fuschia match is the one that shows us where that segment originated. This allows us to assign that entire gold/blue bracketed set of segments to a specific ancestor or ancestral couple because they triangulate, meaning they all match me and each other.

Therefore, all of the segments that match with the fuschia segment also track back to Jacob Lentz and Fredericka Ruhle, or to their ancestors. We would need people who descend from Jacob’s parents and/or Fredericka’s parents to determine the origins of that segment.

In other words, we know all of these people share a common source of that segment, even if we don’t yet know exactly who that common ancestor was or when they lived. That’s what the process of tracking back discovers.

To be very clear, I received that segment through Jacob and Fredericka, but some of those matches who I have not been able to associate with either Jacob or Fredericka may descend from either Jacob or Fredericka’s ancestors, not Jacob and Fredericka themselves. Connecting the dots between Jacob/Fredericka and their ancestors may be enlightening as to the even older source of that segment.

Let’s take a look at nested segments on my pedigree chart.

Nested Pedigree

Click to enlarge.

You can see the progression of nesting on my pedigree chart, using the same colors for the brackets/boxes. The black Ferverda box at the grandparent level encompasses the entire paternal side of my mother’s ancestry, and the red includes her mother’s entire side. This is identical to the DNAPainter graphic, just expressed on my pedigree chart instead of my chromosome 20.

Then the black gets broken into smaller nested segments of black, gold and fuschia, while the red gets broken into red and purple.

If I had more matches that could be assigned to ancestors, I would have even more nested levels. Of course, if I was using all of my chromosomes, not just 20, I would be able to go back further as well.

You can see that as we move further back in time, the bracketed areas assigned to each color become smaller and smaller, as do the actual segments as viewed on my DNAPainter chromosomes.

Segments Get Progressively Smaller

You can see in the pedigree chart and segment painting above that the segments we inherit from specific ancestors divide over time. As we move further and further back in our tree, the segments inherited from any specific ancestor get smaller and smaller too.

Dr. Paul Maier in the MyOrigins 3.0 White Paper provides this informative graphic that shows the reduction in segments and the number of ancestors whose DNA we carry reaching back in time.

I refer to this as a porcupine chart.

Eventually, we inherit no segments from red ancestors, and the pieces of DNA that we inherit from the distant blue ancestors become so small and fragmented that they cannot be positively identified as coming from a specific ancestor when compared to and matched with other people. That’s why vendors don’t show small segment matches, although different vendors utilize different segment thresholds.

The debate about how small is too small continues, but the answer is not simply segment size alone. There is no one-size-fits-all answer.

As segments become smaller, the probability, or chances that we match another person by chance (IBC) increases. Proof that someone shares a specific ancestor, especially when dealing with increasingly smaller segments is a function of multiple factors, such as tree completeness for both people, shared matches, parental match confirmation, and more. I wrote about What Constitutes Proof, here.

In the Family Finder Matching White Paper, Dr. Maier provides this chart reflecting IBD (Identical By Descent) and IBC (Identical By Chance) segments and the associated false positivity rate. That means how likely you are to match someone on a segment of that size by chance and NOT because you both share the DNA from a common ancestor.

I wrote Concepts: Identical by Descent, State, Population and Chance to help you better understand how this works.

In the chart below, I’ve combined the generations, relationships, # of ancestors, assuming no duplicates, birth year range based on an approximate 30-year generation, percent of DNA assuming exactly half of each ancestor’s DNA descends in each generation (which we know isn’t exactly accurate), and the average amount of total inherited cMs using that same assumption.

Note that beginning with the 7th generation, on average, we can expect to inherit less than 1% of the DNA of an ancestor, or approximately 55 total cM which may be inherited in multiple segments.

The amount of actual cMs inherited in each generation can vary widely and explains why, beginning with third cousins, some people won’t share DNA from a common ancestor above the various vendor matching thresholds. Yet, other cousins several generations removed will match. Inheritance is random.

Parallel Inheritance

In order to match someone else descended from that 11th generation ancestor, BOTH you AND your match will need to have inherited the exact SAME DNA segment, across 11 generations EACH in order to match. This means that 11 transmission events for each person will need to have taken place in parallel with that identical segment being passed from parent to child in each line. For 22 rolls of the genetic dice in a row, the same segment gets selected to be passed on.

You can see why we all need to work to prove that distant matches are valid.

The further back in time we work, the more factors we must take into consideration, and the more confirming proof is needed that a match with another individual is a result of a shared ancestor.

Having said that, shared distant matches ARE the key to breaking through brick-wall ancestors. We just need to be sure we are chasing the real deal and not a red herring.

Exciting Possibilities

The most exciting possibility is that some segments are actually passed intact for several generations, meaning those segments don’t divide into segments too small for matching.

For example, the 22 cM fuschia segment that tracks through generations 4 and 5 to Jacob Lentz and Fredericka Ruhle has been passed either intact or nearly intact to all of those people who stack up and match each other and me on that segment. 22 cM is definitely NOT a small segment and we know that it descended from either Jacob or Fredericka, or perhaps combined segments from each. In any case, if someone from the Lentz line in Germany tested and matched me on that segment (and by inference, the rest of these people too), we would know that segment descended to me from Jacob Lentz – or at least the part we match on if we don’t match on the entire segment.

This is exactly what nested segments are…breadcrumbs to ancestors.

Part of that 22cM segment could be descended from Jacob and part from Fredericka. Then of Jacob’s portion, for example, pieces could descend from both his mother and father.

This is why we track individual segments back in time to discern their origin.

The Promise of the Future

The promise of the future is when a group of other people triangulate on a reasonably sized segment AND know where it came from. When we match that triangulation group, their identified segment may well help break down our brick walls because we match all of them on that same segment.

It is exactly this technique that has helped me identify a Womack segment on my paternal line. I still haven’t identified our common ancestor, but I have confirmed that the Womacks and my Moore/Rice family interacted as neighbors 8 generations ago and likely settled together in Amelia county, migrating from eastern Virginia. In time, perhaps I’ll be able to identify the common Womack ancestor and the link into either my Moore or Rice lines.

I’m hoping for a similar breakthrough on my mother’s side for Philip Jacob Miller’s wife, Magdalena, 7 generations back in my tree. We know Magdalena was Brethren and where they lived when they took up housekeeping. We don’t know who her parents were. However, there are thousands of Miller descendants, so it’s possible that eventually, we will be able to break down that brick wall by using nested segments – ours and people who descend from Magdalena’s siblings, aunts, and uncles.

Whoever those people were, at least some of their descendants will likely match me and/or my cousins on at least one nested Miller segment that will be the same segment identified to their ancestors.

Genealogy is a team sport and solving puzzles using nested segments requires that someone out there is working on identifying triangulated segments that track to their common ancestors – which will be my ancestors too. I have my fingers crossed that someone is working on that triangulation group and I find them or they find me. Of course, I’m working to triangulate and identify my segments to specific ancestors – hoping for a meeting in the middle – that much-desired bridge to the past.

By the time you’ve run out of other records, nested segments are your last chance to identify those elusive ancestors. 

Do you have genealogical brick walls that nested segments could solve?

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Thank you so much.

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DNA for Native American Genealogy – Hot Off the Press!

Drum roll please…my new book, DNA for Native American Genealogy, was just released today, published by Genealogical.com.

I’m so excited! I expected publication around the holidays. What a pleasant surprise.

This 190-page book has been a labor of love, almost a year in the making. There’s a lot.

  • Vendor Tools – The book incorporates information about how to make the best use of the autosomal DNA tools offered by all 4 of the major testing vendors; FamilyTreeDNA, MyHeritage, Ancestry, and 23andMe.
  • Chromosome Painting – I’ve detailed how to use DNAPainter to identify which ancestor(s) your Native heritage descends from by painting your population/ethnicity segments provided by FamilyTreeDNA and 23andMe.
  • Y and Mitochondrial DNA – I’ve described how and when to utilize the important Y and mitochondrial DNA tests, for you and other family members.
  • Maps – Everyone wants to know about ancient DNA. I’ve included ancient DNA information complete with maps of ancient DNA sites by major Native haplogroups, gathered from many academic papers, as well as mapped contemporary DNA locations.
  • Haplogroups – Locations in the Americas, by haplogroup, where individual haplogroups and subgroups are found. Some haplogroups are regional in nature. If you happen to have one of these haplogroups, that’s a BIG HINT about where your ancestor lived.
  • Tribes – Want to know, by tribe, which haplogroups have been identified? Got you covered there too.
  • Checklist – I’ve provided a checklist type of roadmap for you to follow, along with an extensive glossary.
  • Questions – I’ve answered lots of frequently asked questions. For example – what about joining a tribe? I’ve explained how tribes work in the US and Canada, complete with links for relevant forms and further information.

But wait, there’s more…

New Revelations!!!

There is scientific evidence suggesting that two haplogroups not previously identified as Native are actually found in very low frequencies in the Native population. Not only do I describe these haplogroups, but I provide their locations on a map.

I hope other people will test and come forward with similar results in these same haplogroups to further solidify this finding.

It’s important to understand the criteria required for including these haplogroups as (potentially) Native. In general, they:

  • Must be found multiple times outside of a family group
  • Must be unexplained by any other scenario
  • Must be well-documented both genetically as well as using traditional genealogical records
  • Must be otherwise absent in the surrounding populations

This part of the research for the book was absolutely fascinating to me.

Description

Here’s the book description at Genealogical.com:

DNA for Native American Genealogy is the first book to offer detailed information and advice specifically aimed at family historians interested in fleshing out their Native American family tree through DNA testing.

Figuring out how to incorporate DNA testing into your Native American genealogy research can be difficult and daunting. What types of DNA tests are available, and which vendors offer them? What other tools are available? How is Native American DNA determined or recognized in your DNA? What information about your Native American ancestors can DNA testing uncover? This book addresses those questions and much more.

Included are step-by-step instructions, with illustrations, on how to use DNA testing at the four major DNA testing companies to further your genealogy and confirm or identify your Native American ancestors. Among the many other topics covered are the following:

    • Tribes in the United States and First Nations in Canada
    • Ethnicity
    • Chromosome painting
    • Population Genetics and how ethnicity is assigned
    • Genetic groups and communities
    • Y DNA paternal direct line male testing for you and your family members
    • Mitochondrial DNA maternal direct line testing for you and your family members
    • Autosomal DNA matching and ethnicity comparisons
    • Creating a DNA pedigree chart
    • Native American haplogroups, by region and tribe
    • Ancient and contemporary Native American DNA

Special features include numerous charts and maps; a roadmap and checklist giving you clear instructions on how to proceed; and a glossary to help you decipher the technical language associated with DNA testing.

Purchase the Book and Participate

I’ve included answers to questions that I’ve received repeatedly for many years about Native American heritage and DNA. Why Native DNA might show in your DNA, why it might not – along with alternate ways to seek that information.

You can order DNA for Native American Genealogy, here.

For customers in Canada and outside the US, you can use the Amazon link, here, to reduce the high shipping/customs costs.

I hope you’ll use the information in the book to determine the appropriate tests for your situation and fully utilize the tools available to genealogists today to either confirm those family rumors, put them to rest – or maybe discover a previously unknown Native ancestor.

Please feel free to share this article with anyone who might be interested.

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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 Uploads

Genealogy Products and Services

My Book

Genealogy Books

Genealogy Research

DNA Beginnings: How Many DNA Matches Do I Have?

People often want to know how many DNA matches they have.

Sounds simple, right?

At some vendors, the answer to this question is easy to find, and at others, not so much.

How do you locate this information at each of the four major vendors?

What else do you need to know?

I’ve written handy step-by-step instructions for each company!

Matches at FamilyTreeDNA

Sign on at FamilyTreeDNA and under autosomal results, click on Family Finder Matches.

At the top of the next page, you’ll see your total number of matches along with matches that FamilyTreeDNA has been able to assign maternally or paternally based on creating/uploading a tree and linking known matches to that tree in their proper place.

Your parents do NOT need to have tested for the maternal/paternal bucketing functionality, but you DO need to identify some relatives and link their tests to their place in your tree. It’s that easy. Instructions for linking can be found in the “Linking Matches on Your Tree” section of this article (click here), along with information about how that helps you, or here.

Obviously, if your parents have tested, that’s the best scenario. For people who don’t have that option, FamilyTreeDNA is the ONLY vendor that offers this type of feature if your parents have NOT tested.

At FamilyTreeDNA, I have 7313 total matches of which 3169 are paternal, 1402 are maternal and 6 are related to both parents.

Hint – your siblings, their children, your children, grandchildren, etc. will be related to you on both your paternal and maternal sides.

If you don’t have an autosomal DNA test at FamilyTreeDNA, you can upload one from Ancestry, 23andMe, or MyHeritage for free. Click here for instructions.

Matches at MyHeritage

At MyHeritage, sign on and click on DNA, then DNA Matches.

At the top of your matches page, you’ll see your total number of matches.

At MyHeritage, I have 14,082 matches.

Matches are not broken down maternally and paternally automatically, but I can filter my matches in a wide variety of ways, including shared matches with either parent if they have tested, or other relatives.

If you don’t have an autosomal DNA test at MyHeritage, you can transfer one from Ancestry, 23andMe, or FamilyTreeDNA for free. Click here to begin your upload to MyHeritage.

Click here for instructions about how to download a copy of your DNA file from other vendors.

Matches at Ancestry

At Ancestry, sign on and click on DNA, then DNA Matches.

On your matches page, at the top, you’ll see a number of function widgets. Look for “Shared DNA.”

Click the down arrow to expand the Shared DNA box and you’ll see the total number of matches, along with the breakdown between 4th cousins or closer and distant matches.

Sometimes the number of matches doesn’t show up which means Ancestry’s servers are too busy to calculate the number of matches. Refresh your screen or try again in a few minutes. This happens often to me and always makes me question my sanity:)

I have 53,435 matches at Ancestry, of which 4,102 are estimated to be 4th cousins or closer and 49,333 are more distant.

For close matches only, if your parents have tested at Ancestry, when possible, Ancestry tells you on each match if that person is associated with your father’s side or your mother’s side.

You can’t upload DNA files from other vendors to Ancestry, but you can download a copy of your DNA file from Ancestry and upload to either FamilyTreeDNA or MyHeritage. Click here for instructions.

You can also download a copy of your tree from Ancestry and upload it to either of those vendors, along with your DNA file for best results.

Matches at 23andMe

23andMe functions differently from the other vendors. They set a hard limit on the number of matches you receive.

That maximum number differs based on the test version you took and if you pay for a membership subscription that provides enhanced medical information along with advanced filters and the ability to have a maximum of 5000 matches.

In order to purchase the membership subscription, you need to take their most current V5 test. If you tested with an earlier product, you will need to repurchase, retest or upgrade your current test which means you’ll need to spit in the vial again.

Please note the words, “up to 5000 relatives,” in the 23andMe verbiage. They also say that’s “over 3 times what you get” with their test without a subscription.

23andMe handles things differently from any other vendor in the industry. They made changes recently which created quite a stir because they removed some capabilities from existing customers and made those functions part of their subscription model. You can read about that here and here.

The match limit on the current 23andMe V5 test, WITHOUT the subscription, is 1500. If you tested previously on earlier kits, V2-V4, 23andMe has reinstated your prior maximum match limit which was 2000.

So, here’s the maximum match summary for 23andMe:

  • Earlier kits (V2-V4) – 2000 maximum matches
  • Current V5 kit with no subscription – 1500 maximum matches
  • Current V5 kit with subscription – 5000 maximum matches

Except, that’s NOT the number of matches you’ll actually see.

23andMe handles matching differently too.

23andMe matches you with their other customers up to your maximum, whatever that is, then subtracts the people who have not opted-in to genealogy matching. Remember, 23andMe focuses on health, not genealogy, so not all of their customers want matching.

Therefore, you’ll NEVER see your total number of allowed matches, which is why 23andMe cleverly says you “get access to up to 5000 relatives.”

Let’s look at my V4 test at 23andMe. Sign on and click on Ancestry, then DNA Relatives. (Please note, Ancestry is not Ancestry the company, but at 23andMe means genealogy results as opposed to medical/health results.)

At the top of your DNA Relatives page, you’ll see your total number of matches, before any sorting filters are applied.

23andMe does not automatically assign matches maternally or paternally, but if your parents have tested AND opt-in to matching, then you can filter by people who also match either parent.

I have 1796 matches at 23andMe, which means that 204 or 11% of my matches have not opted-in to matching.

You can’t upload DNA files from other vendors to 23andMe, but you can download a copy of your DNA file from 23andMe and upload to either FamilyTreeDNA or MyHeritage where you will assuredly receive more matches. Click here for instructions.

Summary

Each vendor has its own unique set of features and operates differently. It’s not so much the number of matches you have, but if you have the RIGHT match to break through a particular brick wall or provide you with a previously unknown photo of a cherished family member.

I encourage everyone to fish in all 4 of these ponds by testing or uploading your DNA. Uploading and matching are both free. Advanced tools require a small one-time unlock fee, but it’s significantly less than testing again. You can find step-by-step instructions to walk you through the process, here.

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 Products and Services

Books

Genealogy Research

DNA Beginnings: What is a Match?

Before we evaluate matches at each of the four major vendors, FamilyTreeDNA, MyHeritage, Ancestry and 23andMe, let’s discuss what a DNA match is, what it means, and what it does NOT mean.

A Match to Another Person

Each of the four major vendors, but not some other vendors, provide matches to you and other individuals in their database.

This example from FamilyTreeDNA shows my mother’s match list listing me as her closest match, along with a kit I uploaded from Ancestry when I was recently updating upload/download article instructions for my readers. You don’t need to upload multiple kits to vendors.

Every vendor’s match list looks different, as is the information they provide. We will cover each vendor’s match list individually in future articles in this DNA Beginnings series.

Each vendor has different criteria for matching, but in essence, using that vendor’s match criteria – your DNA and the DNA of a person you match are identical on a section of DNA of a vendor-defined length.

Each of those vendors identifies the people who match each other and opt-in to matching in one way or another,

When you sign on to your account at each vendor, you’ll see a match list. Each of those people on that list match your DNA:

  • At or above the vendor-defined centiMorgan (cM) threshold. You can read more about centiMorgans here.
  • At or above the vendor-defined SNP threshold, meaning the number individual contiguous matching locations.

Each vendor has their own thresholds and internal algorithms that define matches. For example, a match of 8 cM with 1500 SNPs refers to both the length of the match (cM) and the density of locations within that segment of DNA that match between two people. Only matches above each vendor’s threshold appear on your match list.

Matches smaller than or beneath those vendor thresholds are considered less likely to be valid matches, so are excluded and do not appear on your match list.

Imputation Affects Matching

Different vendors test their customers’ DNA on different DNA chips:

  • Different chips test a different amount of DNA, but generally roughly 700,000 SNP locations
  • That 700K locations of DNA can be in different locations in your genome

In other words, just because two vendors both test 700,000 locations doesn’t mean they test the same 700,000 locations.

Even the same vendor will, over time, implement different DNA testing chips or modify the SNP locations tested on the same chip.

These different chips, chip versions and SNP locations are not fully compatible with each other, so the vendors use a technique known as imputation to level the playing field between non-identical files.

This is particularly relevant for vendors that accept uploads from other vendors.

In this example, we have 3 vendors and 10 different SNPs, or DNA locations.

  • Vendor 1, on their first Version 1 chip, tested locations 1-8.
  • Vendor 1, on their second V2 chip, tested locations 3-10.

Therefore only 6 locations, 3-8, were “common” between those two different chips used by the same vendor.

  • Vendor 2, on yet a different DNA testing chip version (V3) tested locations 1-4 and 7-10.
  • Vendor 3 on chip version V4 tested locations 2-5, 7, 8 and 10.

There are only 4 locations out of 10 tested by all the vendors’ chips.

If the vendor’s match criteria is that 10 locations in a row must match, then none of these people will match each other.

Sometimes differences occur because of chip differences, and sometimes a difference occurs because a location doesn’t read well for some reason.

In order to compensate for the differences in DNA locations tested/reported, a technique called imputation is widely used.

Imputation uses scientific probability techniques to fill in the blanks based on DNA that typically neighbors or “travels with” the nucleotides or DNA values, (T, A, C or G), found in the customer being tested.

Imputation allows all of those blanks to be filled in for all customers for each of those 10 locations, assuming the “missing DNA” is close to tested DNA locations.

It’s thanks to imputation that customers can download their raw DNA files from one vendor and upload to another for matching, even though the vendors don’t use the same exact chip.

Sometimes imputation is incorrect. Matching can be affected in both directions, meaning that some people will be on each other’s match lists who actually don’t match on a particular segment. Others would actually match if all of those locations were tested.

The highest quality matches are between people who tested at the same vendor, on the same chip or at two different vendors who use exactly the same chip. However, that’s often not possible and isn’t within the control of the customer.

False Positive Matches

This translates to, “You’re a match but not really” and is a headache for genealogists.

False positive matches show as a match between two people on their match lists, but they aren’t actually valid matches for genealogy.

  • A false positive match could occur as a result of imputation, of course.
  • A false positive match could also occur because the two people match because part of the DNA of their mother and part of the DNA of their father at those locations just happens to combine to appear as a match.

For purposes of these examples, presume that each of these matches exceeds the vendor’s match criteria so would be shown on your match list.

In our example, Person 1 and Person 2 match at all 10 locations, so they would appear on each other’s match lists.

However, if we could see the DNA of Person 2’s parents, we would see that Person 2 DOES match Person 1, but is NOT a valid match. Person 3 inherited the first 5 DNA locations from their mother and the second 5 DNA locations from their father.

While Person 2 technically is a match to Person 1, they aren’t a legitimate match because the segment of DNA that matches does not descend from the same parent. This means that the DNA did not descend in one piece from ONE ancestor, but clearly descended in pieces from two ancestors – one maternal and one paternal.

Therefore a technical match that is not a genealogical match because the DNA is inherited in part from both parents is known as a false positive and is said to be Identical by Chance, or IBC. You can read about IBC matches here.

False Negative Matches

A false negative match is just the opposite. False negatives occur when two people are NOT reported on each other’s match lists when they actually would match if all of the DNA at the various required locations were tested, read, and reported accurately. In other words, if imputation were not necessary.

  • False negatives can be caused by imputation not working as accurately as we would hope. Imputation is a probability tool, and it’s not perfect.
  • False negatives can also be caused by differing match thresholds at different vendors.

For example, if one vendor reports matches at 6 cM and above, and a second vendor reports matches at 8 cM and above, the same two people who match at 7 cM will match at the first vendor, but not at the second.

The only way you would ever know about a false negative match, because they aren’t reported, is if you simply happen to match at a vendor who allows smaller thresholds.

Also, keep in mind that each vendor creates their own imputations algorithms, so two different vendors using imputation on the same file may produce different results.

Determining Valid Matches

So, how might you determine which matches are actually valid matches?

That’s a great question.

There are useful “hints:”

  • If your parents have tested, a valid match will match one of your parents on that same segment of DNA. If your match does NOT match one of your parents, it’s a false positive match and invalid for genealogy.
  • If only one of your parents has tested, and your match does NOT match the tested parent, you can’t presume that person automatically matches your other, non-tested parent. That match could match your non-tested parent, or could be IBC.
  • If neither of your parents have tested, check to see if your match also matches close relatives who have tested, but not your descendants. For example, if a match also matches your aunt or uncle, or first cousins, that increases the probability that the match is probably valid.
  • The larger the match, the more likely it is to be a valid match. For example, matches in the 6-7 cM level are IBC about half the time. By the time you’re evaluating matches at the 20 cM level for a single segment, they are accurate almost all the time.

Keep in mind that each matching segment must be confirmed separately, and not every vendor shares the locations of the segments that match.

So What Is a Match?

  • A match is a person who is found on your match list at one of the major vendors.
  • A match at one vendor may not be on your match list if you both have DNA at another common vendor due to various reasons including the vendor’s match criteria, imputation, or file compatibility issues.
  • A match may be false positive, or IBC which means that person is not an accurate match for genealogy. This is especially true for smaller segment matches.
  • A false positive match can occur because of erroneous reads, imputation, or because your match is identical by chance.
  • The larger a matching segment of DNA, the more likely it is to be an accurate match meaning you and your match share a common ancestor.
  • The best way to tell if your match is valid is to compare your match to both of your parents as well.

A match is not a guarantee that you share a common ancestor unless you are matching to close relatives. You won’t match a close relative if the match is not valid.

What About You?

What is your plan to verify that your matches are valid?

Have your parents tested their DNA? Either of both parents?

If so, ask for your parents to upload their DNA with you to each vendor where you upload your own results.

At each vendor, you’ll have different matches. That’s exactly why we fish in multiple ponds.

I always work with my closest matches first, because I’m the most likely to be able to easily identify our common ancestor.

Locate your closest known relatives from both your mother’s side and your father’s side at each vendor. These people will be extremely helpful for our next article about shared matches.

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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.

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What is a Heteroplasmy and Why Do I Care?

Most people have never heard of a heteroplasmy – but you might have one.

You Might Have a Heteroplasmy If…

…You have no exact matches at the full sequence mitochondrial DNA level.

A heteroplasmy is one of the first things I think of when someone tells me they have no exact full sequence matches but several that are a genetic distance of 1, meaning one mutation difference.

That phenomenon usually means the tester has a rare mutation that no one else has, at least no one who has tested their mitochondrial DNA (yet) – and that mutation just might be a heteroplasmy.

Heteroplasmies are generally (but not always) quite recent mutations. Actually, heteroplasmies are mutations caught in the act of mutating – kind of like an insect in genetic amber – frozen in time in your generation.

By Anders L. Damgaard – http://www.amber-inclusions.dk – Baltic-amber-beetle CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=16792582

Let’s say you might have a heteroplasmy. Or maybe you want to see if you do. Even if YOU don’t have a heteroplasmy, other people’s heteroplasmies can and will affect matching.

Here’s everything you ever wanted to know about heteroplasmies but didn’t know to ask😊

Heteroplasmies are Fascinating

A heteroplasmy is actually quite interesting because it’s a genetic mutation in progress.

This means you have two versions of a DNA sequence showing in your mitochondrial DNA at a specific location.

Said another way, at a specific genetic location, you show both of two separate nucleotides. Amounts detected of a second nucleotide greater than 20% are considered a heteroplasmy. Amounts below 20% are ignored. Generally, within a few generations, the mutation will resolve in one direction or the other – although some heteroplasmies persist for several generations and can sometimes define family branches.

If you’d like to read more about mitochondrial DNA, I wrote a series of step-by-step articles and combined them into one resource page, here.

Show Me!

You can easily check to see if you have a heteroplasmy by signing on to your FamilyTreeDNA account. Hopefully, you’ve taken the full sequence test.

Today, new testers, thankfully, can only purchase full sequence tests, so HVR1 results don’t present quite the same challenges when combined with heteroplasmies as they used to. We’ll talk about that in a minute.

If you have only taken the HVR1 or HVR1+HVR2 “Plus” test, as opposed to the Full Sequence, you can upgrade by signing on here and clicking on the “Full” button on the Maternal Ancestry section of your personal page.

These buttons will be pink if you’ve taken that test already, and grey if you need to upgrade. If you have an account at FamilyTreeDNA, you can add a mitochondrial DNA test to that same account by clicking on “Add Ons and Upgrades” at the top of your personal page. You can order a test if you’re a new customer, here.

How Do I Know if I Have a Heteroplasmy?

Your mitochondrial DNA has a total of 16,569 locations that you can think of as addresses. If your DNA at those locations is normal, meaning no mutations, they won’t be listed in your results.

Mutations are shown in your mitochondrial DNA results by a different letter at the end of the location.

For example, here are my mutations for my HVR1 region. Each of these locations in the HVR1 region has a mutation.

For locations that are shown in your results, meaning those where you have a mutation, you’ll see, in order:

  • A letter, either T, A, C or G
  • The location number
  • A different letter, typically another one of T, A, C or G, but sometimes a small d

For the first mutation, C16069T, the location address is 16069, the normal value is C, the mutation that occurred is T.

Heteroplasmies are shown in your mitochondrial DNA results by letters other than T, A, C, G or d at the end of the location.

I don’t have any heteroplasmies, so I’m switching to the results of a cousin who has a heteroplasmic mutation at location T16362Y to use as an example. The trailing Y means they have a heteroplasmy at location 16362.

But first, what do those letters mean?

The Letters

The letters stand for the nucleotide bases that comprise DNA, as follows:

  • T – Thymine
  • A – Adenine
  • C – Cytosine
  • G – Guanine
  • d – a deletion has occurred. There is no nucleotide at this location.

For location T16362Y, the first letter, T, is the “normal” value found at this location. If a mutation has occurred, the second letter is the mutated value. Normally, this is one of the other nucleotides, A, C or G.

Any other letter after the location has a specific meaning; in this case, Y means that both a C and a T were found, per the chart below.

Note – if you have a small letter t, a, c or g, it’s not a heteroplasmy, and I wrote about small letters and what they mean in the article, Mitochondrial DNA Part 2: What Do Those Numbers Mean?

Check Your Results

On your FamilyTreeDNA personal page in the mtDNA section, click on the Mutations tab.

If you’ve taken the full sequence test, you’ll see Extra Mutations. You’re looking for any mutation that ends in any letter other than T, A, C, G or d.

If you haven’t taken the full sequence test, you don’t have “Extra” mutations listed, but you can still view your mutations for the HVR1 and HVR2 regions.

Look for any value that has any letter other than T, A, C, G or lower case d at the end of the location.

The Y tells us that this location is a heteroplasmy.

Heteroplasmy Matching

Ok, let’s look at a heteroplasmy mutation at location 16326. A heteroplasmy can occur at any mitochondrial location. I’ve selected this location because it occurs in the HVR1 region of the mitochondrial DNA, so even people who haven’t tested at the full sequence level will see results for this location. Plus, the location at which the heteroplasmy occurs affects matching in different ways.

Using the example of T16362Y, the Y tells us that both nucleotides C and T were found. This location should match against anyone carrying the following values in the same location:

  • Y (letter indicating a C/T heteroplasmy)
  • T (standard or normal value)
  • C (mutated value)

However, currently at Family Tree DNA, the heteroplasmy only counts as a match to anyone with a Y, the specific heteroplasmy indicator, and the “normal” value of T, but not the mutated value of C.

This table shows how heteroplasmies are counted at FamilyTreeDNA. For heteroplasmy T16362Y, based on the value your potential match has at this location, you either will or will not be considered a match at that location.

Scenario Other Person’s Value Your Result – T16362Y
1 T16362Y – heteroplasmy indicator Match to you at this location
2 T16362T – normal value, not a mutation Match to you at this location
3 T16362C – mutated value Not counted as match to you at this location
  • If your match has a value of Y, the heteroplasmic C/T value, they are counted as a match to you, so no problem.
  • If your match has a value of T, the normal value, this location won’t be shown on their mutation list at all. They WILL be counted as a match to you so there’s no issue.
  • If your match has a value of C, the mutated value, in my opinion they should also be counted as a match to you, but they aren’t today. The logic, I believe, was that the most likely value is the standard or normal value and that the mutated value is much less likely to be accurate. Regardless, I’ve requested this change and am hoping for a matching adjustment in a future release for heteroplasmies.

Heteroplasmies do affect matching at the different levels.

Viewing Your Matches

Mitochondrial DNA, for testing purposes, is broken into three regions, HVR1 (hyper-variable region 1), HVR2 and the Coding Region.

At FamilyTreeDNA, you can view your matches at each level. The matches are cumulative, meaning that the HVR2 level includes the HVR1 level information, and the Coding Region level includes the HVR1 and HVR2 regions. That highest level which includes all three regions shows information from your entire your entire full mitochondrial DNA sequence.

Heteroplasmy Effects on Matching

If you otherwise match someone exactly, but one of you has a heteroplasmy and the other person carries the mutated value, you will be counted as a mismatch of 1 at the full sequence level.

A mismatch has different effects when it occurs in the HVR1, HVR2 or Coding Regions, respectively.

GD is an abbreviation for Genetic Distance which is how mutations are counted. A GD of 1 means the two people have one mutation difference between them.

In the following chart, the effects of you having a nonmatch, heteroplasmic or otherwise, in each of the regions is shown at each level. The region in which the mismatch occurs is shown in the first column, at left, and the effect the mismatch has on matching in each region is shown in columns 2-4.

The red sections are not counted as matches.

Mismatch Occurs in this Region HVR1 Level Match to Someone Else HVR2 Level Match to Someone Else Coding Region Level Match to Someone Else
HVR1 region nonmatch GD of 1 means no match GD of 1 means no match GD of 1 is a match
HVR2 region nonmatch Does not affect HVR1 – so you are a match GD of 1 means no match GD of 1 is a match
Coding Region nonmatch Does not affect HVR1 – so you are a match Does not affect HVR2 – so you are a match GD of 1 is a match

For purposes of this discussion, we’re assuming our two people being compared in the chart above match exactly on every other location so matching is not otherwise affected.

  • If your heteroplasmic nonmatch occurs in the HVR1 region – in other words, scenario 3 – you’ll fall into the HVR1 nonmatch row. That means you won’t be shown as a match at the HVR1 or HVR1+HVR2 levels, but you WILL be shown as a full sequence match.
  • If your heteroplasmic nonmatch is in the HVR2 region of addresses, it won’t affect your HVR1 matches, but it will affect your HVR2 and Coding Region matches. This means you will be shown as HVR1 match, not an HVR2 match, but will be a full sequence match.
  • If your heteroplasmic nonmatch is in the Coding Region, it won’t affect your HVR1 or HVR2 matches, but it will affect your Coding Region matches. However, it won’t preclude matches and you’ll be shown as a match in all three regions.

To be very clear, I have no issue with these match thresholds. It’s important to understand how this works, and therefore why heteroplasmic (and other) mismatches in specific regions affect our matches in the way they do.

Why Aren’t Mismatches of 1 Counted as Matches in the HVR1 or HVR2 Regions?

The match threshold at FamilyTreeDNA for the HVR1 and the HVR1+HVR2 regions, both small regions of about 1000 locations each, is that only an exact match is considered a match. Therefore, a heteroplasmic nonmatch in this region can really be confusing and sometimes misleading, especially if either or BOTH people have NOT tested at the full sequence level.

These are the match thresholds in effect today.

HVR1 GD or # of Mutations Allowed for a Match HVR2 GD or # of Mutations Allowed for a Match Coding Region GD or # of Mutations Allowed for a Match
0 – no mutations allowed 0 – no mutations allowed 3 mutations allowed

If both people match on either the heteroplasmy identified (Y in our case) or one person has the normal value – all is fine. But if one person has a heteroplasmy and the other has the mutated value – then a mismatch occurs. This is really only problematic when:

  • The heteroplasmy mismatch is in the HVR1 region and both people have only tested at that level, causing the two people to not match at all.
  • The heteroplasmy mismatch occurs in combination with other mutations that, cumulatively, push the two people over the GD 3 full sequence matching threshold.

The second scenario happens rarely, but I have seen situations where people don’t match their mothers, aunts, siblings, or other close relatives because of multiple heteroplasmic mutations occurring in different people.

And yes, this is hen’s teeth rare – but it does occasionally happen.

So, what’s the bottom line about heteroplasmies?

Heteroplasmy Bottom Line

  1. You can suspect a heteroplasmy if you have full sequence matches, but no exact matches.
  2. If you have a heteroplasmy in the HVR1 region, understand that you may not have many or any matches in the HVR1 and HVR2 regions. The remedy is to test at the full sequence level and check matches there.
  3. If you have a heteroplasmy and don’t match someone you expect to match – reach out to them and ask about their value at that specific location. If that location isn’t listed for them in their results, then they have no mutation there and your heteroplasmy is NOT the cause of you not matching with them.
  4. If you don’t match someone you expect to match, reach out to them and ask if THEY have any heteroplasmies. The easiest way to ask is, “Do you have any mutations listed that end with anything other than T, A, C, G or d?” Feel free to link to this article so that they’ll know where to look, and why you’re asking.

Do you have any heteroplasmies?

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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

Books

Genealogy Research

A Triangulation Checklist Born From the Question; “Why NOT Use Close Relatives for Triangulation?”

One of my readers asked why we don’t use close relatives for triangulation.

This is a great question because not using close relatives for triangulation seems counter-intuitive.

I used to ask my kids and eventually my students and customers if they wanted the quick short answer or the longer educational answer.

The short answer is “because close relatives are too close to reliably form the third leg of the triangle.” Since you share so much DNA with close relatives, someone matching you who is identical by chance can also match them for exactly the same reason.

If you trust me and you’re good with that answer, wonderful. But I hope you’ll keep reading because there’s so much to consider, not to mention a few gotchas. I’ll share my methodology, techniques, and workarounds.

We’ll also discuss absolutely wonderful ways to utilize close relatives in the genetic genealogical process – just not for triangulation.

At the end of this article, I’ve provided a working triangulation checklist for you to use when evaluating your matches.

Let’s go!

The Step-by-Step Educational Answer😊

Some people see “evidence” they believe conflicts with the concept that you should not use close relatives for triangulation. I understand that, because I’ve gone down that rathole too, so I’m providing the “educational answer” that explains exactly WHY you should not use close relatives for triangulation – and what you should do.

Of course, we need to answer the question, “Who actually are close relatives?”

I’ll explain the best ways to best utilize close relatives in genetic genealogy, and why some matches are deceptive.

You’ll need to understand the underpinnings of DNA inheritance and also of how the different vendors handle DNA matching behind the scenes.

The purpose of autosomal DNA triangulation is to confirm that a segment is passed down from a particular ancestor to you and a specific set of your matches.

Triangulation, of course, implies 3, so at least three people must all match each other on a reasonably sized portion of the same DNA segment for triangulation to occur.

Matching just one person only provides you with one path to that common ancestor. It’s possible that you match that person due to a different ancestor that you aren’t aware of, or due to chance recombination of DNA.

It’s possible that your or your match inherited part of that DNA from your maternal side and part from your paternal side, meaning that you are matching that other person’s DNA by chance.

I wrote about identical by descent (IBD), which is an accurate genealogically meaningful match, and identical by chance (IBC) which is a false match, in the article Concepts – Identical by…Descent, State, Population and Chance.

I really want you to understand why close relatives really shouldn’t be used for triangulation, and HOW close relative matches should be used, so we’re going to discuss all of the factors that affect and influence this topic – both the obvious and little-understood.

  • Legitimate Matches
  • Inheritance and Triangulation
  • Parental Cross-Matching
  • Parental Phasing
  • Automatic Phasing at FamilyTreeDNA
  • Parental Phasing Caveats
  • Pedigree Collapse
  • Endogamy
  • How Many Identical-by-Chance Matches Will I Have?
  • DNA Doesn’t Skip Generations (Seriously, It Doesn’t)
  • Your Parents Have DNA That You Don’t (And How to Use It)
  • No DNA Match Doesn’t Mean You’re Not Related
  • Imputation
  • Ancestry Issues and Workarounds
  • Testing Close Relatives is VERY Useful – Just Not for Triangulation
  • Triangulated Matches
  • Building Triangulation Evidence – Ingredients and a Recipe
  • Aunts/Uncles
  • Siblings
  • How False Positives Work and How to Avoid Them
  • Distant Cousins Are Best for Triangulation & Here’s Why
  • Where Are We? A Triangulation Checklist for You!
  • The Bottom Line

Don’t worry, these sections are logical and concise. I considered making this into multiple articles, but I really want it in one place for you. I’ve created lots of graphics with examples to help out.

Let’s start by dispelling a myth.

DNA Doesn’t Skip Generations!

Recently, someone emailed to let me know that they had “stopped listening to me” in a presentation when I said that if a match did not also match one of your parents, it was a false match. That person informed me that they had worked on their tree for three years at Ancestry and they have “proof” of DNA skipping generations.

Nope, sorry. That really doesn’t happen, but there are circumstances when a person who doesn’t understand either how DNA works, or how the vendor they are using presents DNA results could misunderstand or misinterpret the results.

You can watch my presentation, RootsTech session, DNA Triangulation: What, Why and How, for free here. I’m thrilled that this session is now being used in courses at two different universities.

DNA really doesn’t skip generations. You CANNOT inherit DNA that your parents didn’t have.

Full stop.

Your children cannot inherit DNA from you that you don’t carry. If you don’t have that DNA, your children and their descendants can’t have it either, at least not from you. They of course do inherit DNA from their other parent.

I think historically, the “skipping generations” commentary was connected to traits. For example, Susie has dimples (or whatever) and so did her maternal grandmother, but her mother did not, so Susie’s dimples were said to have “skipped a generation.” Of course, we don’t know anything about Susie’s other grandparents, if Susie’s parents share ancestors, recessive/dominant genes or even how many genetic locations are involved with the inheritance of “dimples,” but I digress.

DNA skipping generations is a fallacy.

You cannot legitimately match someone that your parent does not, at least not through that parent’s side of the tree.

But here’s the caveat. You can’t match someone one of your parents doesn’t with the rare exception of:

  • Relatively recent pedigree collapse that occurs when you have the same ancestors on both sides of your tree, meaning your parents are related, AND
  • The process of recombination just happened to split and recombine a segment of DNA in segments too small for your match to match your parents individually, but large enough when recombined to match you.

We’ll talk about that more in a minute.

However, the person working with Ancestry trees can’t make this determination because Ancestry doesn’t provide segment information. Ancestry also handles DNA differently than other vendors, which we’ll also discuss shortly.

We’ll review all of this, but let’s start at the beginning and explain how to determine if our matches are legitimate, or not.

Legitimate Matches

Legitimate matches occur when the DNA of your ancestor is passed from that ancestor to their descendants, and eventually to you and a match in an unbroken pathway.

Unbroken means that every ancestor between you and that ancestor carried and then passed on the segment of the ancestor’s DNA that you carry today. The same is true for your match who carries the same segment of DNA from your common ancestor.

False positive matches occur when the DNA of a male and female combine randomly to look like a legitimate match to someone else.

Thankfully, there are ways to tell the difference.

Inheritance and Triangulation

Remember, you inherit two copies of each of your chromosomes 1-22, one copy from your mother and one from your father. You inherit half of the DNA that each parent carries, but it’s mixed together in you so the labs can’t readily tell which nucleotide, A, C, T, or G you received from which parent. I’m showing your maternal and paternal DNA in the graphic below, stacked neatly together in a column – but in reality, it could be AC in one position and CA in the next.

For matching all that matters is the nucleotide that matches your match is present in one of those two locations. In this case, A for your mother’s side and C for your father’s side. If you’re interested, you can read more about that in the article, Hit a Genealogy Home Run Using Your Double-Sided Two-Faced Chromosomes While Avoiding Imposters.

You can see in this example that you inherited all As from your Mom and all Cs from your Dad.

  • A legitimate maternal match would match you on all As on this particular example segment.
  • A legitimate paternal match would match you on all Cs on this particular segment.
  • A false positive match will match you on some random combination of As and Cs that make it look like they match you legitimately, but they don’t.
  • A false positive match will NOT match either your mother or your father.

To be very clear, technically a false positive match DOES match your DNA – but they don’t match your DNA because you share a common ancestor with your match. They match you because random recombination on their side causes you to match each other by chance.

In other words, if part of your DNA came from your Mom’s side and part from your Dad’s but it randomly fell in the correct positional order, you’d still match someone whose DNA was from only their mother or father’s side. That’s exactly the situation shown above and below.

Looking at our example again, it’s evident that your identical by chance (IBC) match’s A locations (1, 3, 5, 7 & 9) will match your Mom. C locations (2, 4, 6 8, & 10) will match your Dad, but the nonmatching segments interleaved in-between that match alternating parents will prevent your match from matching either of your parents. In other words, out of 10 contiguous locations in our example, your IBC match has 5 As alternated with 5 Cs, so they won’t match either of your parents who have 10 As or 10 Cs in a row.

This recombination effect can work in either direction. Either or both matching people’s DNA could be randomly mixed causing them to match each other, but not their parents.

Regardless of whose DNA is zigzagging back and forth between maternal and paternal, the match is not genealogical and does not confirm a common ancestor.

This is exactly why triangulation works and is crucial.

If you legitimately match a third person, shown below, on your maternal side, they will match you, your first legitimate maternal match, and your Mom because they carry all As. But they WON’T match the person who is matching you because they are identical by chance, shown in grey below.

The only person your identical by chance match matches in this group is you because they match you because of the chance recombination of parental DNA.

That third person WILL also match all other legitimate maternal matches on this segment.

In the graphic above, we see that while the grey identical by chance person matches you because of the random combination of As from your mother and Cs from your father, your legitimate maternal matches won’t match your identical by chance match.

This is the first step in identifying false matches.

Parental Cross-Matching

Removing the identical by chance match, and adding in the parents of your legitimate maternal match, we see that your maternal match, above, matches you because you both have all As inherited from one parent, not from a combination of both parents.

We know that because we can see the DNA of both parents of both matches in this example.

The ideal situation occurs when two people match and they have both had their parents tested. We need to see if each person matches the other person’s parents.

We can see that you do NOT match your match’s father and your match does NOT match your father.

You do match your match’s mother and your match does match your mother. I refer to this as Parental Cross-matching.

Your legitimate maternal matches will also match each other and your mother if she is available for testing.

All the people in yellow match each other, while the two parents in gray do not match any of your matches. An entire group of legitimate maternal matches on this segment, no matter how many, will all match each other.

If another person matches you and the other yellow people, you’ll still need to see if you match their parents, because if not, that means they are matching you on all As because their two parents DNA combined just happened, by chance, to contribute an A in all of those positions.

In this last example, your new match, in green, matches you, your legitimate match and both of your mothers, BUT, none of the four yellow people match either of the new match’s parents. You can see that the new green match inherited their As from the DNA of their mother and father both, randomly zigzagging back and forth.

The four yellow matches phase parentally as we just proved with cross matching to parents. The new match at first glance appears to be a legitimate match because they match all of the yellow people – but they aren’t because the yellow people don’t match the green person’s parents.

To tell the difference between legitimate matches and identical by chance matches, you need two things, in order.

  • Parental matching known as parental phasing along with parental cross-matching, if possible, AND
  • Legitimate identical by descent (IBD) triangulated matches

If you have the ability to perform parental matching, called phasing, that’s the easiest first step in eliminating identical by chance matches. However, few match pairs will have parents for everyone. You can use triangulation without parental phasing if parents aren’t available.

Let’s talk about both, including when and how close relatives can and cannot be used.

Parental Phasing

The technique of confirming your match to be legitimate by your match also matching one of your parents is called parental phasing.

If we have the parents of both people in a match pair available for matching, we can easily tell if the match does NOT match either parent. That’s Parental Cross Matching. If either match does NOT match one of the other person’s parents, the match is identical by chance, also known as a false positive.

See how easy that was!

If you, for example, is the only person in your match pair to have parents available, then you can parentally phase the match on your side if your match matches your parents. However, because your match’s parents are unavailable, your match to them cannon tbe verified as legitimate on their side. So you are not phased to their parents.

If you only have one of your parents available for matching, and your match does not match that parent, you CANNOT presume that because your match does NOT match that parent, the match is a legitimate match for the other, missing, parent.

There are four possible match conditions:

  • Maternal match
  • Paternal match
  • Matches neither parent which means the match is identical by chance meaning a false positive
  • Matches both parents in the case of pedigree collapse or endogamy

If two matching people do match one parent of both matches (parental cross-matching), then the match is legitimate. In other words, if we match, I need to match one of your parents and you need to match one of mine.

It’s important to compare your matches’ DNA to generationally older direct family members such as parents or grandparents, if that’s possible. If your grandparents are available, it’s possible to phase your matches back another generation.

Automatic Phasing at FamilyTreeDNA

FamilyTreeDNA automatically phases your matches to your parents if you test that parent, create or upload a GEDCOM file, and link your test and theirs to your tree in the proper places.

FamilyTreeDNA‘s Family Matching assigns or “buckets” your matches maternally and paternally. Matches are assigned as maternal or paternal matches if one or both parents have tested.

Additionally, FamilyTreeDNA uses triangulated matches from other linked relatives within your tree even if your parents have not tested. If you don’t have your parents, the more people you identify and link to your tree in the proper place, the more people will be assigned to maternal and paternal buckets. FamilyTreeDNA is the only vendor that does this. I wrote about this process in the article, Triangulation in Action at Family Tree DNA.

Parental Phasing Caveats

There are very rare instances where parental phasing may be technically accurate, but not genealogically relevant. By this, I mean that a parent may actually match one of your matches due to endogamy or a population level match, even if it’s considered a false positive because it’s not relevant in a genealogical timeframe.

Conversely, a parent may not match when the segment is actually legitimate, but it’s quite rare and only when pedigree collapse has occurred in a very specific set of circumstances where both parents share a common ancestor.

Let’s take a look at that.

Pedigree Collapse

It’s not terribly uncommon in the not-too-distant past to find first cousins marrying each other, especially in rather closely-knit religious communities. I encounter this in Brethren, Mennonite and Amish families often where the community was small and out-marrying was frowned upon and highly discouraged. These families and sometimes entire church congregations migrated cross-country together for generations.

When pedigree collapse is present, meaning the mother and father share a common ancestor not far in the past, it is possible to inherit half of one segment from Mom and the other half from Dad where those halves originated with the same ancestral couple.

For example, let’s say the matching segment between you and your match is 12 cM in length, shown below. You inherited the blue segment from your Dad and the neighboring peach segment from Mom – shown just below the segment numbers. You received 6 cM from both parents.

Another person’s DNA does match you, shown in the bottom row, but they are not shown on the DNA match list of either of your parents. That’s because the DNA segments of the parents just happened to recombine in 6 cM pieces, respectively, which is below the 7 cM matching threshold of the vendor in this example.

If the person matched you at 12 cM where you inherited 8 cM from one parent and 4 from the other, that person would show on one parent’s match list, but not the other. They would not be on the parent’s match list who contributed only 4 cM simply because the DNA divided and recombined in that manner. They would match you on a longer segment than they match your parent at 8 cM which you might notice as “odd.”

Let’s look at another example.

click to enlarge image

If the matching segment is 20 cM, the person will match you and both of your parents on different pieces of the same segment, given that both segments are above 7 cM. In this case, your match who matches you at 20 cM will match each of your parents at 10 cM.

You would be able to tell that the end location of Dad’s segment is the same as the start location of Mom’s segment.

This is NOT common and is NOT the “go to” answer when you think someone “should” match your parent and does not. It may be worth considering in known pedigree collapse situations.

You can see why someone observing this phenomenon could “presume” that DNA skipped a generation because the person matches you on segments where they don’t match your parent. But DNA didn’t skip anything at all. This circumstance was caused by a combination of pedigree collapse, random division of DNA, then random recombination in the same location where that same DNA segment was divided earlier. Clearly, this sequence of events is not something that happens often.

If you’ve uploaded your DNA to GEDmatch, you can select the “Are your parents related?” function which scans your DNA file for runs of homozygosity (ROH) where your DNA is exactly the same in both parental locations for a significant distance. This suggests that because you inherited the exact same sequence from both parents, that your parents share an ancestor.

If your parents didn’t inherit the same segment of DNA from both parents, or the segment is too short, then they won’t show as “being related,” even if they do share a common ancestor.

Now, let’s look at the opposite situation. Parental phasing and ROH sometimes do occur when common ancestors are far back in time and the match is not genealogically relevant.

Endogamy

I often see non-genealogical matching occur when dealing with endogamy. Endogamy occurs when an entire population has been isolated genetically for a long time. In this circumstance, a substantial part of the population shares common DNA segments because there were few original population founders. Much of the present-day population carries that same DNA. Many people within that population would match on that segment. Think about the Jewish community and indigenous Americans.

Consider our original example, but this time where much of the endogamous population carries all As in these positions because one of the original founders carried that nucleotide sequence. Many people would match lots of other people regardless of whether they are a close relative or share a distant ancestor.

People with endogamous lines do share relatives, but that matching DNA segment originated in ancestors much further back in time. When dealing with endogamy, I use parental phasing as a first step, if possible, then focus on larger matches, generally 20 cM or greater. Smaller matches either aren’t relevant or you often can’t tell if/how they are.

At FamilyTreeDNA, people with endogamy will find many people bucketed on the “Both” tab meaning they triangulate with people linked on both sides of the tester’s tree.

An example of a Jewish person’s bucketed matches based on triangulation with relatives linked in their tree is shown above.

Your siblings, their children, and your children will be related on both your mother’s and father’s sides, but other people typically won’t be unless you have experienced either pedigree collapse where you are related both maternally and paternally through the same ancestors or you descend from an endogamous population.

How Many Identical-by-Chance Matches Will I Have?

If you have both parents available to test, and you’re not dealing with either pedigree collapse or endogamy, you’ll likely find that about 15-20% of your matches don’t match your parents on the same segment and are identical by chance.

With endogamy, you’ll have MANY more matches on your endogamous lines and you’ll have some irrelevant matches, often referred to as “false positive” matches even though they technically aren’t, even using parental phasing.

Your Parents Have DNA That You Don’t

Sometimes people are confused when reviewing their matches and their parent’s match to the same person, especially when they match someone and their parent matches them on a different or an additional segment.

If you match someone on a specific segment and your parents do not, that’s a false positive FOR THAT SEGMENT. Every segment has its own individual history and should be evaluated individually. You can match someone on two segments, one from each parent. Or three segments, one from each parent and one that’s identical by chance. Don’t assume.

Often, your match will match both you and your parent on the same segment – which is a legitimate parentally phased match.

But what if your match matches your parent on a different segment where they don’t match you? That’s a false positive match for you.

Keep in mind that it is possible for one of your matches to match your parent on a separate or an additional segment that IS legitimate. You simply didn’t inherit that particular segment from your parent.

That’s NOT the same situation as someone matching you that does NOT match one of your parents on the same segment – which is an identical by chance or false match.

Your parent having a match that does not match you is the reverse situation.

I have several situations where I match someone on one segment, and they match my parent on the same segment. Additionally, that person matches my parent on another segment that I did NOT inherit from that parent. That’s perfectly normal.

Remember, you only inherit half of your parent’s DNA, so you literally did NOT inherit the other half of their DNA. Your mother, for example, should have twice as many matches as you on her side because roughly half of her matches won’t match you.

That’s exactly why testing your parents and close family members is so critical. Their matches are as valid and relevant to your genealogy as your own. The same is true for other relatives, such as aunts and uncles with whom you share ALL of the same ancestors.

You need to work with your family member’s matches that you don’t share.

No DNA Match Doesn’t Mean You’re Not Related

Some people think that not matching someone on a DNA test is equivalent to saying they aren’t related. Not sharing DNA doesn’t mean you’re not related.

People are often disappointed when they don’t match someone they think they should and interpret that to mean that the testing company is telling them they “aren’t related.” They are upset and take issue with this characterization. But that’s not what it means.

Let’s analyze this a bit further.

First, not sharing DNA with a second cousin once removed (2C1R) or more distant does NOT mean you’re NOT related to that person. It simply means you don’t share any measurable DNA ABOVE THE VENDOR THRESHOLD.

All known second cousins match, but about 10% of third cousins don’t match, and so forth on up the line with each generation further back in time having fewer cousins that match each other.

If you have tested close relatives, check to see if that cousin matches your relatives.

Second, it’s possible to match through the “other” or unexpected parent. I certainly didn’t think this would be the case in my family, because my father is from Appalachia and my mother’s family is primarily from the Netherlands, Germany, Canada, and New England. But I was wrong.

All it took was one German son that settled in Appalachia, and voila, a match through my mother that I surely thought should have been through my father’s side. I have my mother’s DNA and sure enough, my match that I thought should be on my father’s side matches Mom on the same segment where they match me, along with several triangulated matches. Further research confirmed why.

I’ve also encountered situations where I legitimately match someone on both my mother’s and father’s side, on different segments.

Third, imputation can be important for people who don’t match and think they should. Imputation can also cause matching segment length to be overreported.

Ok, so what’s imputation and why do I care?

Imputation

Every DNA vendor today has to use some type of imputation.

Let me explain, in general, what imputation is and why vendors use it.

Over the years, DNA processing vendors who sell DNA chips to testing companies have changed their DNA chips pretty substantially. While genealogical autosomal tests test about 700,000 DNA locations, plus or minus, those locations have changed over time. Today, some of these chips only have 100,000 or so chip locations in common with chips either currently or previously utilized by other vendors.

The vendors who do NOT accept uploads, such as 23andMe or Ancestry, have to develop methods to make their newest customers on their DNA processing vendor’s latest chip compatible with their first customer who was tested on their oldest chip – and all iterations in-between.

Vendors who do accept transfers/uploads from other vendors have to equalize any number of vendors’ chips when their customers upload those files.

Imputation is the scientific way to achieve this cross-platform functionality and has been widely used in the industry since 2017.

Imputation, in essence, fills in the blanks between tested locations with the “most likely” DNA found in the human population based on what’s surrounding the blank location.

Think of the word C_T. There are a limited number of letters and words that are candidates for C_T. If you use the word in a sentence, your odds of accuracy increase dramatically. Think of a genetic string of nucleotides as a sentence.

Imputation can be incorrect and can cause both false positive and false negative matches.

For the most part, imputation does not affect close family matches as much as more distant matches. In other words, imputation is NOT going to cause close family members not to match.

Imputation may cause more distant family members not to match, or to have a false positive match when imputation is incorrect.

Imputation is actually MUCH less problematic than I initially expected.

The most likely effect of imputation is to cause a match to be just above or below the vendor threshold.

How can we minimize the effects of imputation?

  • Generally, the best result will be achieved if both people test at the same vendor where their DNA is processed on the same chip and less imputation is required.
  • Upload the results of both people to both MyHeritage and FamilyTreeDNA. If your match results are generally consistent at those vendors, imputation is not a factor.
  • GEDmatch does not use imputation but attempts to overcome files with low overlapping regions by allowing larger mismatch areas. I find their matches to be less accurate than at the various vendors.

Additionally, Ancestry has a few complicating factors.

Ancestry Issues

AncestryDNA is different in three ways.

  • Ancestry doesn’t provide segment information so it’s impossible to triangulate or identify the segment or chromosome where people match. There is no chromosome browser or triangulation tool.
  • Ancestry down-weights and removes some segments in areas where they feel that people are “too matchy.” You can read Ancestry’s white papers here and here.

These “personal pileup regions,” as they are known, can be important genealogically. In my case, these are my mother’s Acadian ancestors. Yes, this is an endogamous population and also suffers from pedigree collapse, but since this is only one of my mother’s great-grandparents, this match information is useful and should not be removed.

  • Ancestry doesn’t show matches in common if the shared segments are less than 20cM. Therefore, you may not see someone on a shared match list with a relative when they actually are a shared match.

If two people both match a third person on less than a 20 cM segment at Ancestry, the third person won’t appear on the other person’s shared match list. So, if I match John Doe on 19 cM of DNA, and I looked at the shared matches with my Dad, John Doe does NOT appear on the shared match list of me and my Dad – even though he is a match to both of us at 19 cM.

The only way to determine if John Doe is a shared match is to check my Dad’s and my match list individually, which means Dad and I will need to individually search for John Doe.

Caveat here – Ancestry’s search sometimes does not work correctly.

Might someone who doesn’t understand that the shared match list doesn’t show everyone who shares DNA with both people presume that the ancestral DNA of that ancestor “skipped a generation” because John Doe matches me with a known ancestor, and not Dad on our shared match list? I mean, wouldn’t you think that a shared match would be shown on a tab labeled “Shared Matches,” especially since there is no disclaimer?

Yes, people can be forgiven for believing that somehow DNA “skipped” a generation in this circumstance, especially if they are relatively inexperienced and they don’t understand Ancestry’s anomalies or know that they need to or how to search for matches individually.

Even if John Doe does match me and Dad both, we still need to confirm that it’s on the same segment AND it’s a legitimate match, not IBC. You can’t perform either of these functions at Ancestry, but you can elsewhere.

Ancestry WorkArounds

To obtain this functionality, people can upload their DNA files for free to both FamilyTreeDNA and MyHeritage, companies that do provide full shared DNA reporting (in common with) lists of ALL matches and do provide segment information with chromosome browsers. Furthermore, both provide triangulation in different ways.

Matching is free, but an inexpensive unlock is required at both vendors to access advanced tools such as Family Matching (bucketing) and triangulation at Family Tree DNA and phasing/triangulation at MyHeritage.

I wrote about Triangulation in Action at FamilyTreeDNA, here.

MyHeritage actually brackets triangulated segments for customers on their chromosome browser, including parents, so you get triangulation and parental phasing at the same time if you and your parent have both tested or uploaded your DNA file to MyHeritage. You can upload, for free, here.

In this example, my mother is matching to me in red on the entire length of chromosome 18, of course, and three other maternal cousins triangulate with me and mother inside the bracketed portion of chromosome 18. Please note that if any one of the people included in the chromosome browser comparison do not triangulate, no bracket is drawn around any others who do triangulate. It’s all or nothing. I remove people one by one to see if people triangulate – or build one by one with my mother included.

I wrote about Triangulation in Action at MyHeritage, here.

People can also upload to GEDmatch, a third-party site. While GEDmatch is less reliable for matching, you can adjust your search thresholds which you cannot do at other vendors. I don’t recommend routinely working below 7 cM. I occasionally use GEDmatch to see if a pedigree collapse segment has recombined below another vendor’s segment matching threshold.

Do NOT check the box to prevent hard breaks when selecting the One-to-One comparison. Checking that box allows GEDmatch to combine smaller matching segments into mega-segments for matching.

I wrote about Triangulation in Action at GEDmatch, here.

Transferring/Uploading Your DNA 

If you want to transfer your DNA to one of these vendors, you must download the DNA file from one vendor and upload it to another. That process does NOT remove your DNA file from the vendor where you tested, unless you select that option entirely separately.

I wrote full step-by-step transfer/upload instructions for each vendor, here.

Testing Close Relatives Is VERY Useful – Just Not for Triangulation

Of course, your best bet if you don’t have your parents available to test is to test as many of your grandparents, great-aunts/uncles, aunts, and uncles as possible. Test your siblings as well, because they will have inherited some of the same and some different segments of DNA from your parents – which means they carry different pieces of your ancestors’ DNA.

Just because close relatives don’t make good triangulation candidates doesn’t mean they aren’t valuable. Close relatives are golden because when they DO share a match with you, you know where to start looking for a common ancestor, even if your relative matches that person on a different segment than you do.

Close relatives are also important because they will share pieces of your common ancestor’s DNA that you don’t. Their matches can unlock the answers to your genealogy questions.

Ok, back to triangulation.

Triangulated Matches

A triangulated match is, of course, when three people all descended from a common ancestor and match each other on the same segment of DNA.

That means all three people’s DNA matches each other on that same segment, confirming that the match is not by chance, and that segment did descend from a common ancestor or ancestral couple.

But, is this always true? You’re going to hate this answer…

“It depends.”

You knew that was coming, didn’t you! 😊

It depends on the circumstances and relationships of the three people involved.

  • One of those three people can match the other two by chance, not by descent, especially if two of those people are close relatives to each other.
  • Identical by chance means that one of you didn’t inherit that DNA from one single parent. That zigzag phenomenon.
  • Furthermore, triangulated DNA is only valid as far back as the closest common ancestor of any two of the three people.

Let’s explore some examples.

Building Triangulation Evidence – Ingredients and a Recipe

The strongest case of triangulation is when:

  • You and at least two additional cousins match on the same segment AND
  • Descend through different children of the common ancestral couple

Let’s look at a valid triangulated match.

In this first example, the magenta segment of DNA is at least partially shared by four of the six cousins and triangulates to their common great-grandfather. Let’s say that these cousins then match with two other people descended from different children of their great-great-great-grandparents on this same segment. Then the entire triangulation group will have confirmed that segment’s origin and push the descent of that segment back another two generations.

These people all coalesce into one line with their common great-grandparents.

I’m only showing 3 generations in this triangulated match, but the concept is the same no matter how many generations you reach back in time. Although, over time, segments inherited from any specific ancestor become smaller and smaller until they are no longer passed to the next generation.

In this pedigree chart, we’re only tracking the magenta DNA which is passed generation to generation in descendants.

Eventually, of course, those segments become smaller and indistinguishable as they either aren’t passed on at all or drop below vendor matching thresholds.

This chart shows the average amount of DNA you would carry from each generational ancestor. You inherit half of each parent’s DNA, but back further than that, you don’t receive exactly half of any ancestor’s DNA in any generation. Larger segments are generally cut in two and passed on partially, but smaller segments are often either passed on whole or not at all.

On average, you’ll carry 7 cM of your eight-times-great-grandparents. In reality, you may carry more or you may not carry any – and you are unlikely to carry the same segment as any random other descendants but we know it happens and you’ll find them if enough (or the right) descendants test.

Putting this another way, if you divide all of your approximate 7000 cM of DNA into 7 cM segments of equal length – you’ll have 1000 7 cM segments. So will every other descendant of your eight-times-great-grandparent. You can see how small the chances are of you both inheriting that same exact 7 cM segment through ten inheritance/transmission events, each. Yet it does happen.

I have several triangulated matches with descendants of Charles Dodson and his wife, Anne through multiple of their 9 (or so) children, ten generations back in my tree. Those triangulated matches range from 7-38 cM. It’s possible that those three largest matches at 38 cM could be related through multiple ancestors because we all have holes in our trees – including Anne’s surname.

Click to enlarge image

It helps immensely that Charles Dodson had several children who were quite prolific as well.

Of course, the further back in time, the more “proof” is necessary to eliminate other unknown common ancestors. This is exactly why matching through different children is important for triangulation and ancestor confirmation.

The method we use to confirm the common ancestor is that all of the descendants who match the tester on the same segment all also match each other. This greatly reduces the chances that these people are matching by chance. The more people in the triangulation group, the stronger the evidence. Of course, parental phasing or cross-matching, where available is an added confirmation bonus.

In our magenta inheritance example, we saw that three of the males and one of the females from three different descendants of the great-grandparents all carry at least a portion of that magenta segment of great-grandpa’s DNA.

Now, let’s take a look at a different scenario.

Why can’t siblings or close relatives be used as two of the three people needed for triangulation?

Aunts and Uncles

We know that the best way to determine if a match is valid is by parental phasing – your match also matching to one of your parents.

If both parents aren’t available, looking for close family matches in common with your match is the next hint that genealogists seek.

Let’s say that you and your match both match your aunt or uncle in common or their children.

You and your aunts or uncles matching DNA only pushes your common ancestor back to your grandparents.

At that point, your match is in essence matching to a segment that belongs to your grandparents. Your matches’ DNA, or your grandparents’ DNA could have randomly recombined and you and your aunt/cousins could be matching that third person by chance.

Ok, then, what about siblings?

Siblings

The most recent common ancestor (MRCA) of you and someone who also matches your sibling is your parents. Therefore, you and your sibling actually only count as one “person” in this scenario. In essence, it’s the DNA of your parent(s) that is matching that third person, so it’s not true triangulation. It’s the same situation as above with aunts/uncles, except the common ancestor is closer than your grandparents.

The DNA of your parents could have recombined in both siblings to look like a match to your match’s family. Or vice versa. Remember Parental Cross-Matching.

If you and a sibling inherited EXACTLY the same segment of your Mom’s and Dad’s DNA, and you match someone by chance – that person will match your sibling by chance as well.

In this example, you can see that both siblings 1 and 2 inherited the exact same segments of DNA at the same locations from both of their parents.

Of course, they also inherited segments at different locations that we’re not looking at that won’t match exactly between siblings, unless they are identical twins. But in this case, the inherited segments of both siblings will match someone whose DNA randomly combined with green or magenta dots in these positions to match a cross-section of both parents.

How False Positives Work and How to Avoid Them

We saw in our first example, displayed again above, what a valid triangulated match looks like. Now let’s expand this view and take a look more specifically at how false positive matches occur.

On the left-hand (blue) side of this graphic, we see four siblings that descend through their father from Great-grandpa who contributed that large magenta segment of DNA. That segment becomes reduced in descendants in subsequent generations.

In downstream generations, we can see gold, white and green segments being added to the DNA inherited by the four children from their ancestor’s spouses. Dad’s DNA is shown on the left side of each child, and Mom’s on the right.

  • Blue Children 1 and 2 inherited the same segments of DNA from Mom and Dad. Magenta from Dad and green from Mom.
  • Blue Child 3 inherited two magenta segments from Dad in positions 1 and 2 and one gold segment from Dad in position 3. They inherited all white segments from Mom.
  • Blue Child 4 inherited all gold segments from Dad and all white segments from Mom.

The family on the blue left-hand side is NOT related to the pink family shown at right. That’s important to remember.

I’ve intentionally constructed this graphic so that you can see several identical by chance (IBC) matches.

Child 5, the first pink sibling carries a white segment in position 1 from Dad and gold segments in positions 2 and 3 from Dad. From Mom, they inherited a green segment in position 1, magenta in position 2 and green in position 3.

IBC Match 1 – Looking at the blue siblings, we see that based on the DNA inherited from Pink Child 5’s parents, Pink Child 5 matches Blue Child 4 with white, gold and gold in positions 1-3, even though they weren’t inherited from the same parent in Blue Child 4. I circled this match in blue.

IBC Match 2 – Pink Child 5 also matches Blue Children 1 and 2 (red circles) because Pink Child 5 has green, magenta, and green in positions 1-3 and so do Blue Children 1 and 2. However, Blue Children 1 and 2 inherited the green and magenta segments from Mom and Dad respectively, not just from one parent.

Pink Child 5 matches Blue Children 1, 2 and 4, but not because they match by descent, but because their DNA zigzags back and forth between the blue children’s DNA contributed by both parents.

Therefore, while Pink Child 5 matches three of the Blue Children, they do not match either parent of the Blue Children.

IBC Match 3 – Pink Child 6 matches Blue Child 3 with white, magenta and gold in positions 1-3 based on the same colors of dots in those same positions found in Blue Child 3 – but inherited both paternally and maternally.

You can see that if we had the four parents available to test, that none of the Pink Children would match either the Blue Children’s mother or father and none of the Blue Children would match either of the Pink Children’s mother or father.

This is why we can’t use either siblings or close family relatives for triangulation.

Distant Cousins Are Best for Triangulation & Here’s Why

When triangulating with 3 people, the most recent common ancestor (MRCA) intersection of the closest two people is the place at which triangulation turns into only two lines being compared and ceases being triangulation. Triangle means 3.

If siblings are 2 of the 3 matching people, then their parents are essentially being compared to the third person.

If you, your aunt/uncle, and a third person match, your grandparents are the place in your tree where three lines converge into two.

The same holds true if you’re matching against a sibling pair on your match’s side, or a match and their aunt/uncle, etc.

The further back in your tree you can push that MRCA intersection, the more your triangulated match provides confirming evidence of a common ancestor and that the match is valid and not caused by random recombination.

That’s exactly what the descendants of Charles Dodson have been able to do through triangulation with multiple descendants from several of his children.

It’s also worth mentioning at this point that the reason autosomal DNA testing uses hundreds/thousands of base pairs in a comparison window and not 3 or 6 dots like in my example is that the probability of longer segments of DNA simply randomly matching by chance is reduced with length and SNP density which is the number of SNP locations tested within that cM range.

Hence a 7 cM/500 SNP minimum is the combined rule of thumb. At that level, roughly half of your matches will be valid and half will be identical by chance unless you’re dealing with endogamy. Then, raise your threshold accordingly.

Ok, So Where are We? A Triangulation Checklist for You!

I know this has been a relatively long educational article, but it’s important to really understand that testing close relatives is VERY important, but also why we can’t effectively use them for triangulation.

Here’s a handy-dandy summary matching/triangulation checklist for you to use as you work through your matches.

  • You inherit half of each of your parents’ DNA. There is no other place for you to obtain or inherit your DNA. There is no DNA fairy sprinkling you with DNA from another source:)
  • DNA does NOT skip generations, although in occasional rare circumstances, it may appear that this happened. In this situation, it’s incumbent upon you, the genealogist, to PROVE that an exception has occurred if you really believe it has. Those circumstances might be pedigree collapse or perhaps imputation. You’ll need to compare matches at vendors who provide a chromosome browser, triangulation, and full shared match list information. Never assume that you are the exception without hard and fast proof. We all know about assume, right?
  • Your siblings inherit half of your parents’ DNA too, but not the same exact half of your parent’s DNA that you other siblings did (unless they are identical twins.) You may inherit the exact same DNA from either or both of your parents on certain segments.
  • Your matches may match your parents on different or an additional segment that you did not inherit.
  • Every segment has an individual history. Evaluate every matching segment separately. One matching segment with someone could be maternal, one paternal, and one identical by chance.
  • You can confirm matches as valid if your match matches one of your parents, and you match one of your match’s parents. Parental Phasing is when your match matches your parent. Parental Cross-Matching is when you both match one of each other’s parents. To be complete, both people who match each other need to match one of the parents of the other person. This rule still holds even if you have a known common ancestor. I can’t even begin to tell you how many times I’ve been fooled.
  • 15-20% (or more with endogamy) of your matches will be identical by chance because either your DNA or your match’s DNA aligns in such a way that while they match you, they don’t match either of your parents.
  • Your siblings, aunts, and uncles will often inherit the same DNA as you – which means that identical by chance matches will also match them. That’s why we don’t use close family members for triangulation. We do utilize close family members to generate common match hints. (Remember the 20 cM shared match caveat at Ancestry)
  • While your siblings, aunts, and uncles are too close to use for triangulation, they are wonderful to identify ancestral matches. Some of their matches will match you as well, and some will not because your close family members inherited segments of your ancestor’s DNA that you did not. Everyone should test their oldest family members.
  • Triangulate your close family member’s matches separately from your own to shed more light on your ancestors.
  • Endogamy may interfere with parental phasing, meaning you may match because you and/or your match may have inherited some of the same DNA segment(s) from both sides of your tree and/or more DNA than might otherwise be expected.
  • Pedigree collapse needs to be considered when using parental phasing, especially when the same ancestor appears on both sides of your family tree. You may share more DNA with a match than expected.
  • Conversely, with pedigree collapse, your match may not match your parents, or vice versa, if a segment happens to have recombined in you in a way that drops the matching segments of your parents beneath the vendor’s match threshold.
  • While you will match all of your second cousins, you will only match approximately 90% of your third cousins and proportionally fewer as your relationship reaches further back in time.
  • Not being a DNA match with someone does NOT mean you’re NOT related to them, unless of course, you’re a second cousin (2C) or closer. It simply means you don’t carry any common ancestral segments above vendor thresholds.
  • At 2C or closer, if you’re not a DNA match, other alternative situations need to be considered – including the transfer/upload of the wrong person’s DNA file.
  • Imputation, a scientific process required of vendors may interfere with matching, especially in more distant relatives who have tested on different platforms.
  • Imputation artifacts will be less obvious when people are more closely related, meaning closer relatives can be expected to match on more and larger segments and imputation errors make less difference.
  • Imputation will not cause close relatives, meaning 2C or closer, to not match each other.
  • In addition to not supporting segment matching information, Ancestry down-weights some segments, removes some matching DNA, and does not show shared matches below 20cM, causing some people to misinterpret their lack of common matches in various ways.
  • To resolve questions about matching issues at Ancestry, testers can transfer/upload their DNA files to MyHeritage, FamilyTreeDNA, and GEDmatch and look for consistent matches on the same segment. Start and end locations may vary to some extent between vendors, but the segment size should be basically in the same location and roughly the same size.
  • GEDmatch does not use imputation but allows larger non-matching segments to combine as a single segment which sometimes causes extremely “generous” matches. GEDmatch matching is less reliable than FamilyTreeDNA or MyHeritage, but you can adjust the matching thresholds.
  • The best situation for matching is for both people to test at the same vendor who supports and provides segment data and a chromosome browser such as 23andMe, FamilyTreeDNA, or MyHeritage.
  • Siblings cannot be used for triangulation because the most recent common ancestor (MRCA) between you and your siblings is your parents. Therefore, the “three” people in the triangulation group is reduced to two lines immediately.
  • Uncles and aunts should not be used for triangulation because the most recent common ancestors between you and your aunts and uncles are your grandparents.
  • Conversely, you should not consider triangulating with siblings and close family members of your matches as proof of an ancestral relationship.
  • A triangulation group of 3 people is only confirmation as far back as when two of those people’s lines converge and reach a common ancestor.
  • Identical by chance (IBC) matching occurs when DNA from the maternal and paternal sides are mixed positionally in the child to resemble a maternal/paternal side match with someone else.
  • Identical by chance DNA admixture (when compared to a match) could have occurred in your parents or grandparent’s generation, or earlier, so the further back in time that people in a triangulation group reach, the more reliable the triangulation group is likely to be.
  • The larger the segments and/or the triangulation group, the stronger the evidence for a specific confirmed common ancestor.
  • Early families with a very large number of descendants may have many matching and triangulated members, even 9 or 10 generations later.
  • While exactly 50% of each ancestor’s DNA is not passed in each generation, on average, you will carry 7 cM of your ancestors 10 generations back in your tree. However, you may carry more, or none.
  • The percentage of matching descendants decreases with each generation beyond great-grandparents.
  • The ideal situation for triangulation is a significant number of people, greater than three, who match on the same reasonably sized segment (7 cM/500 SNP or larger) and descend from the same ancestor (or ancestral couple) through different children whose spouses in descendant generations are not also related.
  • This means that tree completion is an important factor in match/triangulation reliability.
  • Triangulating through different children of the ancestral couple makes it significantly less likely that a different unknown common ancestor is contributing that segment of DNA – like an unknown wife in a descendant generation.

Whew!!!

The Bottom Line

Here’s the bottom line.

  1. Don’t use close relatives to triangulate.
  2. Use parents for Parental Phasing.
  3. Use Parental Cross-Matching when possible.
  4. Use close relatives to look for shared common matches that may lead to triangulation possibilities.
  5. Triangulate your close relatives’ DNA in addition to your own for bonus genealogical information. They will match people that you don’t.
  6. For the most reliable triangulation results, use the most distant relatives possible, descended through different children of the common ancestral couple.
  7. Keep this checklist of best practices, cautions, and caveats handy and check the list as necessary when evaluating the strength of any match or triangulation group. It serves as a good reminder for what to check if something seems “off” or unusual.

Feel free to share and pass this article (and checklist) on to your genealogy buddies and matches as you explain triangulation and collaborate on your genealogy.

Have fun!!!

_____________________________________________________________

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.

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RootsTech Connect 2021: Comprehensive DNA Session List

I wondered exactly how many DNA sessions were at RootsTech this year and which ones are the most popular.

Unfortunately, we couldn’t easily view a list of all the sessions, so I made my own. I wanted to be sure to include every session, including Tips and Tricks and vendor sessions that might only be available in their booths. I sifted through every menu and group and just kept finding more and more buried DNA treasures in different places.

I’m sharing this treasure chest with you below. And by the way, this took an entire day, because I’ve listed the YouTube direct link AND how many views each session had amassed today.

Two things first.

RootsTech Sessions

As you know, RootsTech was shooting for TED talk format this year. Roughly 20-minute sessions. When everything was said and done, there were five categories of sessions:

  • Curated sessions are approximately 20-minute style presentations curated by RootsTech meaning that speakers had to submit. People whose sessions were accepted were encouraged to break longer sessions into a series of two or three 20-minute sessions.
  • Vendor booth videos could be loaded to their virtual boots without being curated by RootsTech, but curated videos by their employees could also be loaded in the vendor booths.
  • DNA Learning Center sessions were by invitation and provided by volunteers. They last generally between 10-20 minutes.
  • Tips and Tricks are also produced by volunteers and last from 1 to 15 minutes. They can be sponsored by a company and in some cases, smaller vendors and service providers utilized these to draw attention to their products and services.
  • 1-hour sessions tend to be advanced and not topics could be easily broken apart into a series.

Look at this amazing list of 129 DNA or DNA-related sessions that you can watch for free for the next year. Be sure to bookmark this article so you can refer back easily.

Please note that I started compiling this list for myself and I’ve shortened some of the session names. Then I realized that if I needed this, so do you.

Top 10 Most-Viewed Sessions

I didn’t know whether I should list these sessions by speaker name, or by the most views, so I’m doing a bit of both.

Drum roll please…

The top 10 most viewed sessions as of today are:

Speaker/Vendor Session Title Type Link Views
Libby Copeland How Home DNA Testing Has Redefined Family History Curated Session https://youtu.be/LsOEuvEcI4A 13,554
Nicole Dyer Organize Your DNA Matches in a Diagram Tips and Tricks https://youtu.be/UugdM8ATTVo 6175
Roberta Estes DNA Triangulation: What, Why, and How 1 hour https://youtu.be/nIb1zpNQspY 6106
Tim Janzen Tracing Ancestral Lines in the 1700s Using DNA Part 1 Curated Session https://youtu.be/bB7VJeCR6Bs 5866
Amy Williams Ancestor Reconstruction: Why, How, Tools Curated Session https://youtu.be/0D6lAIyY_Nk 5637
Drew Smith Before You Test Basics Part 1 Curated Session https://youtu.be/wKhMRLpefDI 5079
Nicole Dyer How to Interpret a DNA Cluster Chart Tips and Tricks https://youtu.be/FI4DaWGX8bQ 4982
Nicole Dyer How to Evaluate a ThruLines Hypothesis Tips and Tricks https://youtu.be/ao2K6wBip7w 4823
Kimberly Brown Why Don’t I Match my Match’s Matches DNA Learning Center https://youtu.be/A8k31nRzKpc 4593
Rhett Dabling, Diahan Southard Understanding DNA Ethnicity Results Curated Session https://youtu.be/oEt7iQBPfyM 4287

Libby Copeland must be absolutely thrilled. I noticed that her session was featured over the weekend in a highly prominent location on the RootsTech website.

Sessions by Speaker

The list below includes the English language sessions by speaker. I apologize for not being able to discern which non-English sessions are about DNA.

Don’t let a smaller number of views discourage you. I’ve watched a few of these already and they are great. I suspect that sessions by more widely-known speakers or ones whose sessions were listed in the prime-real estate areas have more views, but what you need might be waiting just for you in another session. You don’t have to pick and choose and they are all here for you in one place.

Speaker/Vendor Session Title Type Link Views
Alison Wilde SCREEN Method: A DNA Match Note System that Really Helps DNA Learning Center https://youtu.be/WaNnh_v1rwE 791
Amber Brown Genealogist-on-Demand: The Help You Need on a Budget You Can Afford Curated Session https://youtu.be/9KjlD6GxiYs 256
Ammon Knaupp Pattern of Genetic Inheritance DNA Learning Center https://youtu.be/Opr7-uUad3o 824
Amy Williams Ancestor Reconstruction: Why, How, Tools Curated Session https://youtu.be/0D6lAIyY_Nk 5637
Amy Williams Reconstructing Parent DNA and Analyzing Relatives at HAPI-DNA, Part 1 Curated Session https://youtu.be/MZ9L6uPkKbo 1021
Amy Williams Reconstructing Parent DNA and Analyzing Relatives at HAPI-DNA, Part 2 Curated Session https://youtu.be/jZBVVvJmnaU 536
Ancestry DNA Matches Curated Session https://youtu.be/uk8EKXLQYzs 743
Ancestry ThruLines Curated Session https://youtu.be/RAwimOgNgUE 1240
Ancestry Ancestry DNA Communities: Bringing New Discoveries to Your Family History Research Curated Session https://youtu.be/depeGW7QUzU 422
Andre Kearns Helping African Americans Trace Slaveholding Ancestors Using DNA Curated Session https://youtu.be/mlnSU5UM-nQ 2211
Barb Groth I Found You: Methods for Finding Hidden Family Members Curated Session https://youtu.be/J93hxOe_KC8 1285
Beth Taylor DNA and Genealogy Basics DNA Learning Center https://youtu.be/-LKgkIqFhL4 967
Beth Taylor What Do I Do With Cousin Matches? DNA Learning Center https://youtu.be/LyGT9B6Mh00 1349
Beth Taylor Using DNA to Find Unknown Relatives DNA Learning Center https://youtu.be/WGJ8IfuTETY 2166
David Ouimette I Am Adopted – How Do I Use DNA to Find My Parents? Curated Session https://youtu.be/-jpKgKMLg_M 365
Debbie Kennett Secrets and Surprises: Uncovering Family History Mysteries through DNA Curated Session https://youtu.be/nDnrIWKmIuA 2899
Debbie Kennett Genetic Genealogy Meets CSI Curated Session https://youtu.be/sc-Y-RtpEAw 589
Diahan Southard What is a Centimorgan Tips and Tricks https://youtu.be/uQcfhPU5QhI 2923
Diahan Southard Using the Shared cM Project DNA Learning Center https://youtu.be/b66zfgnzL0U 3172
Diahan Southard Understanding Ethnicity Results DNA Learning Center https://youtu.be/8nCMrf-yJq0 1587
Diahan Southard Problems with Shared Centimorgans DNA Learning Center https://youtu.be/k7j-1yWwGcY 2494
Diahan Southard 4 Next Steps for Your DNA Curated Session https://youtu.be/poRyCaTXvNg 3378
Diahan Southard Your DNA Questions Answered Curated Session https://youtu.be/uUlZh_VYt7k 3454
Diahan Southard You Can Do the DNA – We Can Help Tips and Tricks https://youtu.be/V5VwNzcVGNM 763
Diahan Southard What is a DNA Match? Tips and Tricks https://youtu.be/Yt_GeffWhC0 314
Diahan Southard Diahan’s Tips for DNA Matches Tips and Tricks https://youtu.be/WokgGVRjwvk 3348
Diahan Southard Diahan’s Tips for Y DNA Tips and Tricks https://youtu.be/QyH69tk-Yiw 620
Diahan Southard Diahan’s Tips about mtDNA testing Tips and Tricks https://youtu.be/6d-FNY1gcmw 2142
Diahan Southard Diahan’s Tips about Ethnicity Results Tips and Tricks https://youtu.be/nZFj3zCucXA 1597
Diahan Southard Diahan’s Tips about Which DNA Test to Take Tips and Tricks https://youtu.be/t–4R8H8q0U 2043
Diahan Southard Diahan’s Tips about When Your Matches Don’s Respond Tips and Tricks https://youtu.be/LgHtM3nS60o 3009
Diahan Southard Three Next Steps: Using Known Matches Tips and Tricks https://youtu.be/z1SVq8ME42A 118
Diahan Southard Three Next Steps: MRCA/DNA and the Paper Trail Tips and Tricks https://youtu.be/JB0cVyk-Y4Q 80
Diahan Southard Three Next Steps: Start With Known Matches Tips and Tricks https://youtu.be/BSNhaQCNtAo 68
Diahan Southard Three Next Steps: Additional Tools Tips and Tricks https://youtu.be/PqNPBLQSBGY 140
Diahan Southard Three Next Steps: Ancestry ThruLines Tips and Tricks https://youtu.be/KWayyAO8p_c 335
Diahan Southard Three Next Steps: MyHeritage Theory of Relativity Tips and Tricks https://youtu.be/Et2TVholbAE 80
Diahan Southard Three Next Steps: Who to Test Tips and Tricks https://youtu.be/GyWOO1XDh6M 111
Diahan Southard Three Next Steps: Genetics vs Genealogy Tips and Tricks https://youtu.be/Vf0DC5eW_vA 294
Diahan Southard Three Next Steps: Centimorgan Definition Tips and Tricks https://youtu.be/nQF935V08AQ 201
Diahan Southard Three Next Steps: Shared Matches Tips and Tricks https://youtu.be/AYcR_pB6xgA 233
Diahan Southard Three Next Steps: Case Study – Finding an MRCA Tips and Tricks https://youtu.be/YnlA9goeF7w 256
Diahan Southard Three Next Steps: Why Use DNA Tips and Tricks https://youtu.be/v-o4nhPn8ww 266
Diahan Southard Three Next Steps: Finding Known Matches Tips and Tricks https://youtu.be/n3N9CnAPr18 688
Diana Elder Using DNA Ethnicity Estimates in Your Research Tips and Tricks https://youtu.be/aJgUK3TJqtA 1659
Diane Elder Using DNA in a Client Research Project to Solve a Family Mystery 1 hour https://youtu.be/ysGYV6SXxR8 1261
Donna Rutherford DNA and the Settlers of Taranaki, New Zealand Curated Session https://youtu.be/HQxFwie4774 214
Drew Smith Before You Test Basics Part 1 Curated Session https://youtu.be/wKhMRLpefDI 5079
Drew Smith Before You Test Basics Part 2 Curated Session https://youtu.be/Dopx04UHDpo 2769
Drew Smith Before You Test Basics Part 3 Curated Session https://youtu.be/XRd2IdtA-Ng 2360
Elena Fowler Whakawhanaungatanga Using DNA – It’s Complicated (Māori heritage) Curated Session https://youtu.be/6XTPMzVnUd8 470
Elena Fowler Whakawhanaungatanga Using DNA – FamilyTreeDNA (Māori heritage) Curated Session https://youtu.be/fM85tt5ad3A 269
Elena Fowler Whakawhanaungatanga Using DNA – Ancestry (Māori heritage) Curated Session https://youtu.be/-byO6FOfaH0 191
Esmee Mortimer-Taylor Living DNA: Anathea Ring – Her Story Tips and Tricks https://youtu.be/MTE4UFKyLRs 189
Esmee Mortimer-Taylor Living DNA: Coretta Scott King Academy – DNA Results Reveal Tips and Tricks https://youtu.be/CK1EYcuhqmc 82
Fonte Felipe Ethnic Filters and DNA Matches: The Way Forward to Finding Your Lineage Curated Session https://youtu.be/mt2Rv2lpj7o 553
FTDNA – Janine Cloud Big Y: What is it? Why Do I Need It? Curated Session https://youtu.be/jiDcjWk4cVI 2013
FTDNA – Sherman McRae Using DNA to Find Ancestors Lost in Slavery Curated Session https://youtu.be/i3VKwpmttBI 738
Jerome Spears Elusive Distant African Cousins: Using DNA, They Can Be Found Curated Session https://youtu.be/fAr-Z78f_SM 335
Karen Stanbary Ruling Out Instead of Ruling In: DNA and the GPS in Action 1 hour https://youtu.be/-WLhIHlSyLE 548
Katherine Borges DNA and Lineage Societies Tips and Tricks https://youtu.be/TBYGyLHHAOI 451
Kimberly Brown Why Don’t I Match my Match’s Matches DNA Learning Center https://youtu.be/A8k31nRzKpc 4593
Kitty Munson Cooper Basics of Unknown Parentage Research Using DNA Part 1 Curated Session https://youtu.be/2f3c7fJ74Ig 2931
Kitty Munson Cooper Basics of Unknown Parentage Research Using DNA Part 2 Curated Session https://youtu.be/G7h-LJPCywA 1222
Lauren Vasylyev Finding Cousins through DNA Curated Session https://youtu.be/UN7WocQzq78 1979
Lauren Vasylyev, Camille Andrus Finding Ancestors Through DNA Curated Session https://youtu.be/4rbYrRICzrQ 3919
Leah Larkin Untangling Endogamy Part 1 Curated Session https://youtu.be/0jtVghokdbg 2291
Leah Larkin Untangling Endogamy Part 2 Curated Session https://youtu.be/-rXLIZ0Ol-A 1441
Liba Casson-Budell Shining a Light on Jewish Genealogy Curated Session https://youtu.be/pHyVz94024Y 162
Libby Copeland How Home DNA Testing Has Redefined Family History Curated Session https://youtu.be/LsOEuvEcI4A 13,554
Linda Farrell Jumpstart your South African research Curated Session https://youtu.be/So7y9_PBRKc 339
Living DNA How to do a Living DNA Swab Tips and Tricks https://youtu.be/QkbxhqCw7Mo 50
Lynn Broderick Ethical Considerations Using DNA Results Curated Session https://youtu.be/WMcRiDxPy2k 249
Mags Gaulden Importance and Benefits of Y DNA Testing DNA Learning Center https://youtu.be/MVIiv0H7imI 1032
Maurice Gleeson Using Y -DNA to Research Your Surname Curated Session https://youtu.be/Ir4NeFH_aJs 1140
Melanie McComb Georgetown Memory Project: Preserving the Stories of the GU272 Curated Session https://youtu.be/Fv0gHzTHwPk 320
Michael Kennedy What Can You Do with Your DNA Test? DNA Learning Center https://youtu.be/rKOjvkqYBAM 616
Michelle Leonard Understanding X-Chromosome DNA Matching Curated Session https://youtu.be/n784kt-Xnqg 775
MyHeritage How to Analyze DNA Matches on MH Curated Session https://youtu.be/gHRvyQYrNds 1192
MyHeritage DNA – an Overview Curated Session https://youtu.be/AIRGjEOg_xo 389
MyHeritage Advanced DNA Tools Curated Session https://youtu.be/xfZUAjI5G_I 762
MyHeritage How to Get Started with Your DNA Matches Tips and Tricks https://youtu.be/rU_dq1vt6z4 1901
MyHeritage How to Filter and Sort Your DNA Matches Tips and Tricks https://youtu.be/aJ7dRwMTt90 1008
Nicole Dyer How to Interpret a DNA Cluster Chart Tips and Tricks https://youtu.be/FI4DaWGX8bQ 4982
Nicole Dyer How to Evaluate a ThruLines Hypothesis Tips and Tricks https://youtu.be/ao2K6wBip7w 4823
Nicole Dyer Organize Your DNA Matches in a Diagram Tips and Tricks https://youtu.be/UugdM8ATTVo 6175
Nicole Dyer Research in the Southern States Curated Session https://youtu.be/Pouw_yPrVSg 871
Olivia Fordiani Understanding Basic Genetic Genealogy DNA Learning Center https://youtu.be/-kbGOFiwH2s 810
Pamela Bailey Information Wanted: Reuniting an American Family Separated by Slavery Tips and Tricks https://youtu.be/DPCJ4K8_PZw 105
Patricia Coleman Getting Started with DNA Painter DNA Learning Center https://youtu.be/Yh_Bzj6Atck 1775
Patricia Coleman Adding MyHeritage Data to DNA Painter DNA Learning Center https://youtu.be/rP9yoCGjkLc 458
Patricia Coleman Adding 23andMe Data to DNA Painter DNA Learning Center https://youtu.be/pJBAwe6s0z0 365
Penny Walters Mixing DNA with Paper Trail DNA Learning Center https://youtu.be/PP4SjdKuiLQ 2693
Penny Walters Collaborating with DNA Matches When You’re Adopted DNA Learning Center https://youtu.be/9ioeCS22HlQ 1222
Penny Walters Differences in Ethnicity Between My 6 Children DNA Learning Center https://youtu.be/RsrXLcXRNfs 400
Penny Walters Differences in DNA Results Between My 6 Children DNA Learning Center https://youtu.be/drnzW3FXScI 815
Penny Walters Ethical Dilemmas in DNA Testing DNA Learning Center https://youtu.be/PRPoc0nB4Cs 437
Penny Walters Adoption – Background Context Curated Session https://youtu.be/qC1_Ln8WCNg 1054
Penny Walters Adoption – Utilizing DNA Testing to Construct a Bio Family Tree Curated Session https://youtu.be/zwJ5QofaGTE 941
Penny Walters Adoption – Ethical Dilemmas and Varied Consequences of Looking for Bio Family Curated Session https://youtu.be/ZLcHHTSfCIE 576
Penny Walters I Want My Mummy: Ancient and Modern Egypt Curated Session https://youtu.be/_HRO50RtzFk 311
Rebecca Whitman Koford BCG: Brief Step-by-Step Tour of the BCG Website Tips and Tricks https://youtu.be/YpV9bKG6sXk 317
Renate Yarborough Sanders DNA Understanding the Basics DNA Learning Center https://youtu.be/bX_flUQkBEA 2713
Renate Yarborough Sanders To Test or Not to Test DNA Learning Center https://youtu.be/58-qzvN4InU 1048
Rhett Dabling Finding Ancestral Homelands Through DNA Curated Session https://youtu.be/k9zixg4uL1I 505
Rhett Dabling, Diahan Southard Understanding DNA Ethnicity Results Curated Session https://youtu.be/oEt7iQBPfyM 4287
Richard Price Finding Biological Family Tips and Tricks https://youtu.be/L9C-SGVRZLM 101
Robert Kehrer Will They Share My DNA (Consent, policies, etc.) DNA Learning Center https://youtu.be/SUo-jpTaR1M 480
Robert Kehrer What is a Centimorgan? DNA Learning Center https://youtu.be/dopniLw8Fho 1194
Roberta Estes DNA Triangulation: What, Why and How 1 hour https://youtu.be/nIb1zpNQspY 6106
Roberta Estes Mother’s Ancestors DNA Learning Center https://youtu.be/uUh6WrVjUdQ 3074
Robin Olsen Wirthlin How Can DNA Help Me Find My Ancestors? Curated Session https://youtu.be/ZINiyKsw0io 1331
Robin Olsen Wirthlin DNA Tools Bell Curve Tips and Tricks https://youtu.be/SYorGgzY8VQ 1207
Robin Olsen Wirthlin DNA Process Trees Guide You in Using DNA in Family History Research Tips and Tricks https://youtu.be/vMOQA3dAm4k 1708
Shannon Combs-Bennett DNA Basics Made Easy DNA Learning Center https://youtu.be/4JcLJ66b0l4 1560
Shannon Combs-Bennett DNA Brick Walls DNA Learning Center https://youtu.be/vtFkT_PSHV0 450
Shannon Combs-Bennett Basics of Genetic Genealogy Part 1 Curated Session https://youtu.be/xEMbirtlBZo 2263
Shannon Combs-Bennett Basics of Genetic Genealogy Part 2 Curated Session https://youtu.be/zWMPja1haHg 1424
Steven Micheleti, Joanna Mountain Genetic Consequences of the Transatlantic Slave Trade Part 1 Curated Session https://youtu.be/xP90WuJpD9Q 2284
Steven Micheleti, Joanna Mountain Genetic Consequences of the Transatlantic Slave Trade Part 2 Curated Session https://youtu.be/McMNDs5sDaY 742
Thom Reed How Can Connecting with Ancestors Complete Us? Curated Session https://youtu.be/gCxr6W-tkoY 392
Tim Janzen Tracing Ancestral Lines in the 1700s Using DNA Part 1 Curated Session https://youtu.be/bB7VJeCR6Bs 5866
Tim Janzen Tracing Ancestral Lines in the 1700s Using DNA Part 2 Curated Session https://youtu.be/scOtMyFULGI 3008
Ugo Perego Strengths and Limitations of Genetic Testing for Family History DNA Learning Center https://youtu.be/XkBK1y-LVaE 480
Ugo Perego A Personal Genetic Journey DNA Learning Center https://youtu.be/Lv9CSU50xCc 844
Ugo Perego Discovering Native American Ancestry through DNA Curated Session https://youtu.be/L1cs748ctx0 884
Ugo Perego Mitochondrial DNA: Our Maternally-Inherited Family History Curated Session https://youtu.be/Z5bPTUzewKU 599
Vivs Laliberte Introduction to Y DNA DNA Learning Center https://youtu.be/rURyECV5j6U 752
Yetunde Moronke Abiola 6% Nigerian: Tracing my Missing Nigerian Ancestor Curated Session https://youtu.be/YNQt60xKgyg 494

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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

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Haplogroup Matching: What It Does (and Doesn’t) Mean

“Our haplogroups (sort of) match, so that means we’re related, right?”

Well, maybe.

It depends.

Great Question

This is an oft-asked great question. Of course, the answer varies depending on the context of the question and what is meant by “related.” A haplogroup match may or may not be a valid match for genealogy. A “match” or a “not match” can mean different things.

The questions people often ask include:

  • Does a haplogroup have to match exactly in order for another person to either be considered a match to you?
  • If they don’t match exactly, can they still be considered as a possible match?
  • Conversely, can we rule someone out as a match on a specific genealogical line based on haplogroup alone?

These questions often arise in relation to DNA testing at Family Tree DNA, sometimes when people are trying to compare results to people who have haplogroup estimates, either at FamilyTreeDNA or from testing elsewhere.

In other words, if one person is haplogroup J and someone else is J1, either at the same vendor or at another, what does that tell us? This question pertains to both Y DNA and mitochondrial DNA tests no matter where you’ve tested.

Family Tree DNA offers different levels of Y DNA testing. Interpreting those match results can sometimes be confusing. The same is true for mitochondrial DNA, especially if your matches have not taken the full mitochondrial sequence (mtFull) test.

You might be comparing apples and oranges, or you might be comparing a whole orange (detailed test) with a few slices (haplogroup estimate.) How can you know, and how can you make sense of the results?

If you’re comparing a haplogroup between sources, such as a partial haplogroup determined by testing through a company like 23andMe or LivingDNA to complete tests taken at FamilyTreeDNA, the answer can be less than straightforward.

I discussed the difference between autosomal-based haplogroup assignments and actual testing of both Y DNA and mitochondrial DNA which result in haplogroup assignments, here. In a nutshell, both LivingDNA and 23andMe provide a high-level (base) haplogroup estimates based on a few specific probes when you purchase an autosomal test, but that’s not the same as deeper testing of the Y chromosome or mitochondrial DNA.

The answer to whether your haplogroup has to match is both “yes”, and “no.” Don’t you hate it when this happens?

Let’s look at different situations. But to begin with, there is at least one common answer.

Yes, Your Base Haplogroup Must Match

To even begin to look further for a common ancestor on either your Y DNA line (direct patrilineal) or direct mitochondrial matrilineal line (your mother’s mother’s mother’s line on up the tree), your base haplogroup much match.

In other words, you and your matches must all be in the same base haplogroup. Haplogroups are defined by the presence of specific combinations of mutations which are called SNPs (single nucleotide polymorphisms) in the Y DNA.

Click to enlarge images

All of these men on the Y DNA matches page are a branch of haplogroup R as shown under the Y-DNA Haplogroup column. There are more matches on down the page (not shown here) with more and different haplogroups. However, you’ll notice that all matches are a subset of haplogroup R, the base haplogroup.

The same is true for mitochondrial DNA haplogroups. You can see in this example that people who have not tested at the FMS (full mitochondrial sequence) level have a less specific haplogroup. The entire mitochondria must be tested in order to obtain a full haplogroup, such as J1c2f, as opposed to haplogroup J.

The Y DNA Terminal SNP Might Not Match

For Y DNA testers, when looking at your matches, even to close relatives, you may not have the same exact haplogroup because:

  • Some people may have tested at different levels
  • Some people in recent generations may have developed a SNP specific to their line.

In other words, haplogroups, testing level, and known genealogy all need to be considered, especially when the haplogroups are “close to each other” on the tree.

For Y DNA, FamilyTreeDNA:

  • Provides all testers with base haplogroup estimates based on STR tests, meaning 12-111 marker panels. These are very accurate estimates, but are also very high level.
  • Offers or has offered in the past both individual SNP tests and SNP packs or bundles that test individual SNPs indicating their presence or absence. This confirms a SNP or haplogroup, but only to that particular level.
  • Offers the Big Y-700 test, along with upgrades to previous Big Y test levels. There have been 3 versions of the Big Y test over time. The Big Y reads the entire gold standard region of the Y chromosome, reporting the known (named) SNP mutations customers do and don’t have. Additionally, the test reports any unnamed SNPs which are considered private variants until multiple men on the same branch of the Y DNA tree test with the same mutation. At that point, the mutation is named and becomes a haplogroup.

That’s why the answer is “no,” your haplogroup does not have to match exactly for you to actually be a match to each other.

A father and son could test, with one having an estimated haplogroup of R-M269 and the other taking the Big Y-700 resulting in a very different Terminal SNP, quite distant on the tree. Conversely, both men could take the Big Y and the son could have a different terminal SNP than the father because a mutation occurred between them. An autosomal DNA test would confirm that they are in fact, father and son.

However, a father and son who test and are placed in different base haplogroups – one in haplogroup I, and the other in haplogroup R, for example, has a very different situation. Their autosomal test would likely confirm that they are not father and son.

Having said this about paternity, especially if haplogroups are estimated and specific Y DNA SNP testing has not been done, don’t have a premature freak-out moment. Look at autosomal DNA, assuming you DO want to know. Y DNA alone should never be used to infer paternity without autosomal testing.

Let’s look at some examples.

Matches and Haplogroups

In the example shown above, you can see that several people have taken the Big Y test, so their SNP will be shown on further down the haplotree than those testers who have not. These are a leaf, not a branch.

You can see by looking at the Terminal SNP column, at far right, that people who have either taken the Big Y, or had any positive SNP test will have a value in the Terminal SNP column.

Anyone who has NOT taken the Big Y or taken a SNP test will have their base haplogroup estimated based on their STR tests. In this case, that estimate is R-M269. People with estimated haplogroups will not show anything in the Terminal SNP column.

It’s possible that if all of these men took the Big Y test that at least some would share the same Terminal SNP, and others might be closely related, only a branch or so different on the tree.

These men in this example are all descendants of Robert Estes born in England in 1555. All have Estes surnames, except for one man who is seeking the identity of his paternal line.

Let’s Look at the Tree

Our tester in the screenshot is haplogroup R-ZS3700 and matches men in the following haplogroups:

  • R-M269
  • R-L21
  • R-BY490
  • R-BY154784

There are a few additional haplogroups not shown because they are further down on his match list, so let’s just work with these for now.

After determining that these men are on the same branch of the Y tree, haplogroup R, the real question is how closely they are related and how close or far distant their terminal SNPs are located. More distance means the common ancestor is further back in time.

However, looks can be deceiving, especially if not everyone has tested to the same level.

The haplogroup furthest up in the tree, meaning the oldest, is R-M269, followed by the man who took the single SNP test for R-L21. Notice that R-M269 has more than 15,000 branches, so while this haplogroup could be used to rule out a match, R-M269 alone isn’t useful to determine genealogical matching.

There are a lot of branches between R-L21 and the next haplogroup on the tree.

Finally, here we go. Our tester is haplogroup R-ZS3700 that has one descendant branch. R-ZS3700 is a branch of R-BY490 that has 2 branches.

R-BY154784 is the last SNP on this branch of the tree. Our tester matches this man too.

Another way of viewing these matches is on the Block Tree provided for Big Y testers.

In this view, you can see that the Estes men all match back to about 18 “SNP generations” ago according to the legend at left, but they don’t match men further back in time who have taken the Big Y test.

Notice the up-arrow where haplogroups R-L21 and R-M269 are shown across the top of the display.

If you click on R-L21, you’ll see that that it appears about 61 SNP generations back in time.

Haplogroup R-M269 appears even further back in time, about 174 SNP generations.

The only reason you will match someone at either the R-L21 or R-M269 level is because you both descend from a common long-ago ancestral branch, hundreds to thousands of years in the past. You and they would both need to take either the Big Y-700 test for Y DNA, or the full sequence mitochondrial DNA test in order to determine your full haplogroup and see your list of matches based on those full sequences.

Public Trees

You can view FamilyTreeDNA‘s extensive public Y DNA tree by haplogroup, here.

You can view their public mitochondrial DNA tree by haplogroup, here.

And the Answer Is…

As you can see, there is no single answer to the question of haplogroup relationships. The answer is also partly defined by the context in which the question is asked.

  1. For two men to be “related” on the Y DNA patrilineal line, yes, minimally, the base haplogroup does have to match. Base haplogroups are defined by the leading letter, like “R” in the examples above.
  2. “Related” based on base haplogroup only can be hundreds or thousands of years back in time, but additional testing can resolve that question.
  3. “Related” can mean before the advent of surnames. However, a match to a man with the same surname suggests a common ancestor with that surname in the past several hundred years. That match could, however, be much closer in time.
  4. For two men to be closely related, assuming they have taken the same version of Big Y test, their haplogroup branches need to be fairly closely adjacent on the haplotree. FamilyTreeDNA will be introducing haplogroup aging soon, meaning SNP/haplogroup branch dates on their haplotree. At that time, the “distance” between men will be easier to understand.
  5. You can exclude a genealogical relationship on the direct paternal line if the two men involved have a different base haplogroup. This question often occurs when people are trying to understand if they “might match” with someone whose haplogroup has been estimated.
  6. This holds true as well for mitochondrial DNA haplogroups and matching.

And there you have it, six answers about what haplogroup matching does and does not mean.

The bottom line is that haplogroups can be a great starting point and you can sometimes eliminate people as potential matches.

However, to confirm genealogical matches, you’ll always need more granular testing that includes actual Y DNA or mitochondrial DNA matching based on marker mutation results, not just haplogroups.

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