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!!!

_____________________________________________________________

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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

Genealogy Research

Books

Most Popular Articles of 2020

We all know that 2020 was a year like no other, right? So, what were we reading this year as we spent more time at home?

According to my blog stats, these are the ten most popular articles of 2020.

2020 Rank Blog Article Name Publication Date/Comment
1 Concepts – Calculating Ethnicity Percentages Jan 11, 2017
2 Proving Native American Ancestry Using DNA December 18, 2012
3 Ancestry to Remove DNA Matches Soon – Preservation Strategies with Detailed Instructions Now obsolete article – July 16, 2020
4 Ancestral DNA Percentages – How Much of Them is in You? June 27, 2017
5 Full or Half Siblings? April 3, 2019
6 442 Ancient Viking Skeletons Hold DNA Surprises – Does Your Y or Mitochondrial DNA Match? September 18, 2020
7 Migration Pedigree Chart March 25, 2016
8 DNA Inherited from Grandparents and Great-Grandparents January 14, 2020
9 Optimizing Your Tree at Ancestry for More Hints and DNA ThruLines February 22, 2020
10 Phylogenetic Tree of Novel Coronavirus (hCoV-19) Covid-19 March 12, 2020

Half of these articles were published this year, and half are older.

One article is now obsolete. The Ancestry purge has already happened, so there’s nothing to be done now.

Let’s take a look at the rest and what messages might be held in these popular selections.

Ethnicity

I’m not the least bit surprised by ethnicity being the most popular topic, nor that Concepts – Calculating Ethnicity Percentages is the most popular article. Not only is ethnicity a perennially favorite, but all four major vendors introduced something new this year.

By the way, my perennial caveat still applies – ethnicity is only an estimate😊

While Genetic Groups isn’t actually ethnicity, per se, it’s a layer on top of ethnicity that provides you with locations where your ancestors might have been from and migrated to, based on genetic clusters. Clusters are defined by the locations of ancestors of other people within that genetic cluster.

There’s actually good news at 23andMe. Since this article was published in October, 23andMe has indeed updated the V3 and V4 kits with new ethnicity updates. 23andMe had originally stated they weren’t going to do that, clearly in the hope that people would pay to retest by purchasing the V5 Health + Ancestry test. I’m so glad to see their reversal.

Viewing the older V2 kits, the “updated” date at the bottom of their Ancestry Composition page says they were updated on December 9th or 10th, but I don’t see a difference and they don’t have the “updated” icon like the V3 and V4 kits do.

23andMe made another reversal too and also restored the original matches. They had reduced the number of matches to 1500 for non-Health+Ancestry testers who don’t also subscribe. If you wanted between 1500 and 5000 matches, you had to retest and subscribe for $29 per year. (It’s worth noting that I have over 5000 matches at all of the other vendors.)

To date, 23andMe has restored previous matches and also restored some but not all of the search functionality that they had removed.

What isn’t clear is whether 23andMe will continue to add to this number of matches until the tester reaches the earlier limit of 2000, or whether they have simply restored the previous matches, but the match total will not increase unless you have a subscription.

Consumer feedback works – so thanks to everyone who provided feedback to 23andMe.

Native American Ancestry

The article, Proving Native American Ancestry Using DNA, written 8 years ago, only 5 months after launching this blog, has been in the top 10 every year since I’ve been counting.

I created a Native American reference and resource page too, which you can find here.

I’ll also be publishing some new articles after the first of the year which I promise you’ll find VERY INTERESTING. Something to look forward to.

Understanding Autosomal DNA

2020 has seen more people delving into genealogy + DNA testing which means they need to understand both the results and the concepts underlying their results.

Whooohooo – more people in the pool. Jump on in – the water’s fine!

The articles Ancestral DNA Percentages – How Much of Them is in You? and DNA Inherited from Grandparents and Great-Grandparents both explain how DNA is passed from your ancestors to you.

These are great basic articles if you’re looking to help someone new, and so is First Steps When Your DNA Results are Ready – Sticking Your Toe in the Genealogy Water.

I always look forward to the end of January because there will be lots of matches from holiday gifts being posted. Feel free to forward any of these articles to your new matches. It’s always fun helping new people because you just never know when they might be able to help you.

Surprises

With more and more people testing, more and more people are receiving “surprises” in their results. Need to figure out the difference between full and half-siblings? Then Full or Half Siblings? is the article for you.

Trying to discern other relationships? My favorite tool is the Shared cM Project tool at DNAPainter, here.

Vikings

Who doesn’t want to know if they are related to the ancient Vikings??? You can make that discovery in the article, 442 Ancient Viking Skeletons Hold DNA Surprises – Does Your Y or Mitochondrial DNA Match?. Not only is this just plain fun, but I snuck in a little education too.

Of course, you’ll need to have your Y DNA or mitochondrial DNA results, which you can easily order, here. If you’re unsure and would like to read a short article about the different kinds of DNA and how they can help you, 4 Kinds of DNA for Genetic Genealogy is perfect.

Do you think your DNA isn’t Viking because your ancestors aren’t from Scandinavia? Guess again!

Those Vikings didn’t stay home, and they didn’t restrict their escapades to the British Isles either.

This drawing depicts Viking ships besieging Paris in the year 845. Vikings voyaged into Russia and as far as the Mediterranean.

Have a child studying at home? This might be an interesting topic!

Migration Pedigree Chart

Another just plain fun idea is the Migration Pedigree Chart.

I created this migration pedigree chart in a spreadsheet, but you can also create a pedigree chart in genealogy software with whatever “names” you want. This will also help you figure out the estimated percentages of ethnicity you might reasonably expect.

Another idea for helping kids learn at home and they might accidentally learn about figuring percentages in the process.

ThruLines

ThruLines is the Ancestry tool that assists DNA testers with trees connect the dots to common ancestors with their matches. There are ways to optimize your tree to improve your connections, both in terms of accuracy and the number of Thrulines that form.

Optimizing Your Tree at Ancestry for More Hints and DNA ThruLines provides step by step instructions, which reminds me – I need to write a similar article for MyHeritage’s Theories of Family Relativity. I keep meaning to…

Covid

You know, it wouldn’t be 2020 if I didn’t HAVE to mention that word.

I’m glad to know that people were and hopefully still are educating themselves about Covid. Phylogenetic Tree of Novel Coronavirus (hCoV-19) Covid-19 reflected early information about the novel virus and our first efforts to sequence the DNA. Of course, as expected, just like any other organism, mutations have occurred since then.

Goodness knows, we are all tired of Covid and the resulting safety protocols. Keep on keeping on. We need you on the other side.

Stay home, mask up when you must leave, stay away from other people outside your family that you live with, wash your hands, and get vaccinated as soon as you can.

And until we can all see each other in person again, hopefully, sooner than later, keep on doing genealogy.

Locked in the Library

Be careful what you ask for.

Remember that dream where you’re locked in a library? Remember saying you don’t have enough time for genealogy?

Well, now you are and now you do.

The library is your desk with your computer or maybe your laptop on a picnic table in the yard.

DNA results, matches, and research tools are the books and you’re officially locked in for at least a few more weeks. Free articles like these are your guide.

Hmmm, pandemic isolation doesn’t sound so bad now, does it??

We’ll just rename it “genealogy library lock-in.”

Happy New Year!

What can you discover?

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Genealogy Research

Books

Ancestry Releases Updated Ethnicity Estimates – Hope You Still Have Your Kilt!

Ancestry has been rolling out their new DNA ethnicity results over the past couple of weeks. By now, pretty much all customers have updated results.

When you sign on and click on your DNA tab, you’ll see a message at the top that tells you whether you have new results or they are coming soon.

I wrote about how ethnicity results are calculated in the article, Ethnicity Testing – A Conundrum. You might want to take a minute and read the article because it applies to methods generally and is not specific to any one vendor.

Ethnicity analysis is quite accurate at the continental level, plus Jewish, but less so within continents like Europe. Your results will vary from vendor to vendor and from update to update with the same vendor over time.

To be very clear, your DNA doesn’t change – and neither does your genealogy, obviously – but the evaluation methods used by various vendors change as more people test, reference populations grow, and the vendors improve their algorithms.

Of course, “improve” is subjective. Changes that “improve” one person’s results have the exact opposite effect on other people.

The Eye of the Beholder

Every time vendors release new population or ethnicity results, everyone runs to check. Then – queue up either “they finally got it right” or teeth gnashing! 😊

Everyone hopes for “better” results – but expectations vary widely and how people determine what “better” means to them is quite subjective.

So yes, the accuracy of the results is truly in the eye of the beholder and often related to how much genealogy they’ve actually done. Surprises in your genealogy can equal surprises in your ethnicity too.

Quantitative Analysis

First, let’s be very clear – you do NOT inherit exactly half of the DNA of each of your distant ancestors in each generation. So you might have NO DNA of an ancestor several generations back in time and multiple segments contributed by another ancestor in the same generation. I wrote about how inheritance actually works in the article, Concepts: Inheritance.

Obviously, if you don’t carry a specific ancestor’s DNA, you also don’t carry any genetic markers for any portion of their ethnic heritage either.

Measuring

The best you can do in terms of ancestral ethnicity percentage expectations is to methodically analyze your tree for the geographic and ethnic heritage of your ancestors.

I explained how I calculated realistic ethnicity estimate percentages in the article, Concepts – Calculating Ethnicity Percentages.

In summary, I made a spreadsheet of my 64 great-great-great-great-great-grandparents, each of which, if the DNA was divided in exactly half and passed to the next generation, would contribute 1.56% of my DNA.

Vendors can typically measure geographically-associated DNA less than 1%. At some point, however, the segments are simply too small to reliably identify and associate with a geographic location or population.

Over time, how different vendors refer to and label different parts of the world both vary and change.

Region Names and Ancestral Assignment

I created a spreadsheet where I track both my “expected” DNA based on my genealogy and the amount of reported DNA from that region by each vendor. As I added vendor results, I sometimes had to add categories since their categories aren’t exactly the same as mine. You’ll observe this in the following sections.

You might notice the “inferred” category. I wrote about this in the Calculating Ethnicity Percentages article, but the inferred locations stem from situations like an unknown wife of a man who is living in England or Germany. We can probably infer that they are from that same country.

In the US, an earlier era spouse’s ethnicity might be inferred from marrying a Scot’s-Irish person, living in a Scots-Irish community or being a member of a Scots-Irish church, for example. Chances are very high that a Scots-Irish man’s wife is also from the “British Isles” someplace.

When creating my spreadsheet, I was intentionally conservative in my genealogical estimates.

Ancestry Update in General

Are there any trends or themes in this most recent Ancestry update? As a matter of fact, yes.

Everybody’s Scottish it seems. I hope you didn’t trade your kilt in for that liederhosen a few years ago, because it looks like you just might need that kilt again.

In fact, Ancestry wrote a blog article about why so many people now have Scotland as an ethnicity location, or have a higher percentage if they already showed Scotland before. I had to laugh, because let me summarize the net-net of the Ancestry article for you, the British Isles is “all mixed up,” meaning highly admixed of course. That’s pretty much the definition of my genealogy!

Another theme is that many testers have Scandinavian origins again.

Back in 2012, Ancestry had a “Scandinavian problem,” and pretty much everyone was Scandinavian in that release, even if they had nary a drop of Scandinavian ancestry. And no, not every person has an unknown paternity event and if they did, the Scandinavians cannot possibly be responsible for all of them. The Viking prowess was remarkable, but not THAT remarkable.

Eight years later, Scandinavian is back.

So, how did Ancestry do on my percentages?

Well, I’m Not Scottish…

In the greatest of ironies, I now show no Scottish at all. My calculations show 5.46%, and it’s probably higher because I descend from Scots-Irish that I can’t place in a location.

I guess I need to turn in my Campbell tartan along with a few others.

I do, however, have Norway back again, but no Scandinavian genealogy.

This chart shows all of the Ancestry updates over time, including this latest, plus a range column for this update.

In addition to the 2020 percentage numbers, I’ve included the ranges shown by Ancestry in the far right column for the 2020 update.

Ranges

When viewing your own results, be sure to click on the right arrow for a population to view the range.

You’ll be able to view the range and additional information.

In this case, Ancestry is confident that I have at least 35% DNA from England & Northwest Europe, and perhaps as much as 41%.

You’ll note that my range for the questionable Scandinavia is 0-5. The only two ethnicities that have ranges that do not include zero are England & Northwestern Europe and Germanic Europe.

My Opinion

I know that I have Native American heritage and that it’s reflected in my ethnicity – or should be.

23andMe results, below, shows me the chromosome locations of Native American segments, and when I track those segments back in time, they track to the ancestors in the Acadian population known to have married Native American partners as reflected in church records. Those ancestors were proven as Native through Y and mitochondrial DNA of their descendants which you can view in the Acadian AmerIndian DNA Project, here.

I wrote about using ethnicity segments identified at 23andMe with DNAPainter to triangulate ancestors in the article, Native American and Minority Ancestors Identified Using DNAPainter Plus Ethnicity Segments.

For me personally, including my Native heritage in my ethnicity results is important. I can’t “do” anything much with that at Ancestry, other than view my match’s shared ethnicity. Since my Native heritage doesn’t show at Ancestry, I can’t use it at all genetically.

Why is this important? Looking at a match on my Acadian line and seeing that we share at least some Native heritage MIGHT, just MIGHT be a hint about a common ancestor. Of course, that’s just a clue, because we might both be native from different sources. If my Native ethnicity is missing at Ancestry, I can’t do that. It’s worth noting that in 2017, Ancestry did report my Native heritage and other vendors do as well.

23andMe provides detailed, downloadable, segment information that translates into useful genealogical information. FamilyTreeDNA has announced that they will be providing ethnicity segment information as well after their new myOrigins release.

The Big 4

How do the Big 4 vendors stack up relative to my genealogy and ethnicity?

And for Native American heritage?

I took the liberty of highlighting which vendor is the closest to my estimated genealogy percentages, but want to remind you that these percentages will only be exactly accurate if the DNA is passed exactly in half in each generation, which doesn’t happen. Therefore, my genealogy is an educated estimate as well. Still, the results shouldn’t be WAY off.

An appropriate sanity check would be that my genealogy analysis and the DNA ethnicity results are relatively close. Many people think they are a lot more of something because those are the family stories they heard – but when they do the analysis, they realize that they might expect a different mixture. For example, my aunt told me that my paternal grandmother’s Appalachian family line was German and Jewish – and they are neither. However, German and Jewish lived in my head for a long time and that was what I initially expected to find.

What’s Next?

Both MyHeritage and Family Tree DNA are slated to release new versions of their population genetics tools – so you’ll be seeing new estimates from both vendors “soon.” Both announced at RootsTech they would deliver new results later in the year, and while I don’t have a release date for either vendor – keep in mind that both FamilyTreeDNA and MyHeritage have brought new labs online from scratch in record time in a humanitarian effort to fight Covid. This critically important work has assuredly interrupted their development schedules. You can read about that here and here.

Kudos to both vendors. Ethnicity can wait.

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Genealogy Research

Concepts: Inheritance

Inheritance.

What is it?

How does it work?

I’m not talking about possessions – but about the DNA that you receive from your parents, and their parents.

The reason that genetic genealogy works is because of inheritance. You inherit DNA from your parents in a known and predictable fashion.

Fortunately, we have more than one kind of DNA to use for genealogy.

Types of DNA

Females have 3 types of DNA and males have 4. These different types of DNA are inherited in various ways and serve different genealogical purposes.

Males Females
Y DNA Yes No
Mitochondrial DNA Yes Yes
Autosomal DNA Yes Yes
X Chromosome Yes, their mother’s only Yes, from both parents

Different Inheritance Paths

Different types of DNA are inherited from different ancestors, down different ancestral paths.

Inheritance Paths

The inheritance path for Y DNA is father to son and is inherited by the brother, in this example, from his direct male ancestors shown by the blue arrow. The sister does not have a Y chromosome.

The inheritance path for the red mitochondrial DNA for both the brother and sister is from the direct matrilineal ancestors, only, shown by the red arrow.

Autosomal DNA is inherited from all ancestral lines on both the father’s and mother’s side of your tree, as illustrated by the broken green arrow.

The X chromosome has a slightly different inheritance path, depending on whether you are a male or female.

Let’s take a look at each type of inheritance, how it works, along with when and where it’s useful for genealogy.

Autosomal DNA

Autosomal DNA testing is the most common. It’s the DNA that you inherit from both of your parents through all ancestral lines back in time several generations. Autosomal DNA results in matches at the major testing companies such as FamilyTreeDNA, MyHeritage, Ancestry, and 23andMe where testers view trees or other hints, hoping to determine a common ancestor.

How does autosomal DNA work?

22 autosomes

Every person has two each of 22 chromosomes, shown above, meaning one copy is contributed by your mother and one copy by your father. Paired together, they form the two-sided shape we are familiar with.

For each pair of chromosomes, you receive one from your father, shown with a blue arrow under chromosome 1, and one from your mother, shown in red. In you, these are randomly combined, so you can’t readily tell which piece comes from which parent. Therein lies the challenge for genealogy.

This inheritance pattern is the same for all chromosomes, except for the 23rd pair of chromosomes, at bottom right, which determined the sex of the child.

The 23rd chromosome pair is inherited differently for males and females. One copy is the Y chromosome, shown in blue, and one copy is the X, shown in red. If you receive a Y chromosome from your father, you’re a male. If you receive an X from your father, you’re a female.

Autosomal Inheritance

First, let’s talk about how chromosomes 1-22 are inherited, omitting chromosome 23, beginning with grandparents.

Inheritance son daughter

Every person inherits precisely half of each of their parents’ autosomal DNA. For example, you will receive one copy of your mother’s chromosome 1. Your mother’s chromosome 1 is a combination of her mother’s and father’s chromosome 1. Therefore, you’ll receive ABOUT 25% of each of your grandparents’ chromosome 1.

Inheritance son daughter difference

In reality, you will probably receive a different amount of your grandparent’s DNA, not exactly 25%, because your mother or father will probably contribute slightly more (or less) of the DNA of one of their parents than the other to their offspring.

Which pieces of DNA you inherit from your parents is random, and we don’t know how the human body selects which portions are and are not inherited, other than we know that large pieces are inherited together.

Therefore, the son and daughter won’t inherit the exact same segments of the grandparents’ DNA. They will likely share some of the same segments, but not all the same segments.

Inheritance maternal autosomalYou’ll notice that each parent carries more of each color DNA than they pass on to their own children, so different children receive different pieces of their parents’ DNA, and varying percentages of their grandparents’ DNA.

I wrote about a 4 Generation Inheritance Study, here.

Perspective

Keep in mind that you will only inherit half of the DNA that each of your parents carries.

Looking at a chromosome browser, you match your parents on all of YOUR chromosomes.

Inheritance parental autosomal

For example, this is me compared to my father. I match my father on either his mother’s side, or his father’s side, on every single location on MY chromosomes. But I don’t match ALL of my father’s DNA, because I only received half of what he has.

From your parents’ perspective, you only have half of their DNA.

Let’s look at an illustration.

Inheritance mom dad

Here is an example of one of your father’s pairs of chromosomes 1-22. It doesn’t matter which chromosome, the concepts are the same.

He inherited the blue chromosome from his father and the pink chromosome from his mother.

Your father contributed half of his DNA to you, but that half is comprised of part of his father’s chromosome, and part of his mother’s chromosome, randomly selected in chunks referred to as segments.

Inheritance mom dad segments

Your father’s chromosomes are shown in the upper portion of the graphic, and your chromosome that you inherited from you father is shown below.

On your copy of your father’s chromosome, I’ve darkened the dark blue and dark pink segments that you inherited from him. You did not receive the light blue and light pink segments. Those segments of DNA are lost to your line, but one of your siblings might have inherited some of those pieces.

Inheritance mom dad both segments

Now, I’ve added the DNA that you inherited from your Mom into the mixture. You can see that you inherited the dark green from your Mom’s father and the dark peach from your Mom’s mother.

Inheritance grandparents dna

These colored segments reflect the DNA that you inherited from your 4 grandparents on this chromosome.

I often see questions from people wondering how they match someone from their mother’s side and someone else from their father’s side – on the same segment.

Understanding that you have a copy of the same chromosome from your mother and one from your father clearly shows how this happens.

Inheritance match 1 2

You carry a chromosome from each parent, so you will match different people on the same segment. One match is to the chromosome copy from Mom, and one match is to Dad’s DNA.

Inheritance 4 gen

Here is the full 4 generation inheritance showing Match 1 matching a segment from your Dad’s father and Match 2 matching a segment from your Mom’s father.

Your Parents Will Have More Matches Than You Do

From your parents’ perspective, you will only match (roughly) half of the DNA with other people that they will match. On your Dad’s side, on segment 1, you won’t match anyone pink because you didn’t inherit your paternal grandmother’s copy of segment 1, nor did you inherit your maternal grandmother’s segment 1 either. However, your parents will each have matches on those segments of DNA that you didn’t inherit from them.

From your perspective, one or the other of your parents will match ALL of the people you match – just like we see in Match 1 and Match 2.

Matching you plus either of your parents, on the same segment, is exactly how we determine whether a match is valid, meaning identical by descent, or invalid, meaning identical by chance. I wrote about that in the article, Concepts: Identical by…Descent, State, Population and Chance.

Inheritance on chromosomes 1-22 works in this fashion. So does the X chromosome, fundamentally, but the X chromosome has a unique inheritance pattern.

X Chromosome

The X chromosome is inherited differently for males as compared to females. This is because the 23rd pair of chromosomes determines a child’s sex.

If the child is a female, the child inherits an X from both parents. Inheritance works the same way as chromosomes 1-22, conceptually, but the inheritance path on her father’s side is different.

If the child is a male, the father contributes a Y chromosome, but no X, so the only X chromosome a male has is his mother’s X chromosome.

Males inherit X chromosomes differently than females, so a valid X match can only descend from certain ancestors on your tree.

inheritance x fan

This is my fan chart showing the X chromosome inheritance path, generated by using Charting Companion. My father’s paternal side of his chart is entirely blank – because he only received his X chromosome from his mother.

You’ll notice that the X chromosome can only descend from any male though his mother – the effect being a sort of checkerboard inheritance pattern. Only the pink and blue people potentially contributed all or portions of X chromosomes to me.

This can actually be very useful for genealogy, because several potential ancestors are immediately eliminated. I cannot have any X chromosome segment from the white boxes with no color.

The X Chromsome in Action

Here’s an X example of how inheritance works.

Inheritance X

The son inherits his entire X chromosome from his mother. She may give him all of her father’s or mother’s X, or parts of both. It’s not uncommon to find an entire X chromosome inherited. The son inherits no X from his father, because he inherits the Y chromosome instead.

Inheritance X daughter

The daughter inherits her father’s X chromosome, which is the identical X chromosome that her father inherited from his mother. The father doesn’t have any other X to contribute to his daughter, so like her father, she inherits no portion of an X chromosome from her paternal grandfather.

The daughter also received segments of her mother’s X that her mother inherited maternally and paternally. As with the son, the daughter can receive an entire X chromosome from either her maternal grandmother or maternal grandfather.

This next illustration ONLY pertains to chromosome 23, the X and Y chromosomes.

Inheritance x y

You can see in this combined graphic that the Y is only inherited by sons from one direct line, and the father’s X is only inherited by his daughter.

X chromosome results are included with autosomal results at both Family Tree DNA and 23andMe, but are not provided at MyHeritage. Ancestry, unfortunately, does not provide segment information of any kind, for the X or chromosomes 1-22. You can, however, transfer the DNA files to Family Tree DNA where you can view your X matches.

Note that X matches need to be larger than regular autosomal matches to be equally as useful due to lower SNP density. I use 10-15 cM as a minimum threshold for consideration, equivalent to about 7 cM for autosomal matches. In other words, roughly double the rule of thumb for segment size matching validity.

Autosomal Education

My blog is full of autosomal educational articles and is fully keyword searchable, but here are two introductory articles that include information from the four major vendors:

When to Purchase Autosomal DNA Tests

Literally, anytime you want to work on genealogy to connect with cousins, prove ancestors or break through brick walls.

  • Purchase tests for yourself and your siblings if both parents aren’t living
  • Purchase tests for both parents
  • Purchase tests for all grandparents
  • Purchase tests for siblings of your parents or your grandparents – they have DNA your parents (and you) didn’t inherit
  • Test all older generation family members
  • If the family member is deceased, test their offspring
  • Purchase tests for estimates of your ethnicity or ancestral origins

Y DNA

Y DNA is only inherited by males from males. The Y chromosome is what makes a male, male. Men inherit the Y chromosome intact from their father, with no contribution from the mother or any female, which is why men’s Y DNA matches that of their father and is not diluted in each generation.

Inheritance y mtdna

If there are no adoptions in the line, known or otherwise, the Y DNA will match men from the same Y DNA line with only small differences for many generations. Eventually, small changes known as mutations accrue. After many accumulated mutations taking several hundred years, men no longer match on special markers called Short Tandem Repeats (STR). STR markers generally match within the past 500-800 years, but further back in time, they accrue too many mutations to be considered a genealogical-era match.

Family Tree DNA sells this test in 67 and 111 marker panels, along with a product called the Big Y-700.

The Big Y-700 is the best-of-class of Y DNA tests and includes at least 700 STR markers along with SNPs which are also useful genealogically plus reach further back in time to create a more complete picture.

The Big Y-700 test scans the entire useful portion of the Y chromosome, about 15 million base pairs, as compared to 67 or 111 STR locations.

67 and 111 Marker Panel Customers Receive:

  • STR marker matches
  • Haplogroup estimate
  • Ancestral Origins
  • Matches Map showing locations of the earliest known ancestors of matches
  • Haplogroup Origins
  • Migration Maps
  • STR marker results
  • Haplotree and SNPs
  • SNP map

Y, mitochondrial and autosomal DNA customers all receive options for Advanced Matching.

Big Y-700 customers receive, in addition to the above:

  • All of the SNP markers in the known phylotree shown publicly, here
  • A refined, definitive haplogroup
  • Their place on the Block Tree, along with their matches
  • New or unknown private SNPs that might lead to a new haplogroup, or genetic clan, assignment
  • 700+ STR markers
  • Matching on both the STR markers and SNP markers, separately

Y DNA Education

I wrote several articles about understanding and using Y DNA:

When to Purchase Y DNA Tests

The Y DNA test is for males who wish to learn more about their paternal line and match against other men to determine or verify their genealogical lineage.

Women cannot test directly, but they can purchase the Y DNA test for men such as fathers, brothers, and uncles.

If you are purchasing for someone else, I recommend purchasing the Big Y-700 initially.

Why purchase the Big Y-700, when you can purchase a lower level test for less money? Because if you ever want to upgrade, and you likely will, you have to contact the tester and obtain their permission to upgrade their test. They may be ill, disinterested, or deceased, and you may not be able to upgrade their test at that time, so strike while the iron is hot.

The Big Y-700 provides testers, by far, the most Y DNA data to work (and fish) with.

Mitochondrial DNA

Inheritance mito

Mitochondrial DNA is passed from mothers to both sexes of their children, but only females pass it on.

In your tree, you and your siblings all inherit your mother’s mitochondrial DNA. She inherited it from her mother, and your grandmother from her mother, and so forth.

Mitochondrial DNA testers at FamilyTreeDNA receive:

  • A definitive haplogroup, thought of as a genetic clan
  • Matching
  • Matches Map showing locations of the earliest know ancestors of matches
  • Personalized mtDNA Journey video
  • Mutations
  • Haplogroup origins
  • Ancestral origins
  • Migration maps
  • Advanced matching

Of course, Y, mitochondrial and autosomal DNA testers can join various projects.

Mitochondrial DNA Education

I created a Mitochondrial DNA page with a comprehensive list of educational articles and resources.

When to Purchase Mitochondrial DNA Tests

Mitochondrial DNA can be valuable in terms of matching as well as breaking down brick walls for women ancestors with no surnames. You can also use targeted testing to prove, or disprove, relationship theories.

Furthermore, your mitochondrial DNA haplogroup, like Y DNA haplogroups, provides information about where your ancestors came from by identifying the part of the world where they have the most matches.

You’ll want to purchase the mtFull sequence test provided by Family Tree DNA. Earlier tests, such as the mtPlus, can be upgraded. The full sequence test tests all 16,569 locations on the mitochondria and provides testers with the highest level matching as well as their most refined haplogroup.

The full sequence test is only sold by Family Tree DNA and provides matching along with various tools. You’ll also be contributing to science by building the mitochondrial haplotree of womankind through the Million Mito Project.

Combined Resources for Genealogists

You may need to reach out to family members to obtain Y and mitochondrial DNA for your various genealogical lines.

For example, the daughter in the tree below, a genealogist, can personally take an autosomal test along with a mitochondrial test for her matrilineal line, but she cannot test for Y DNA, nor can she obtain her paternal grandmother’s mitochondrial DNA directly by testing herself.

Hearts represent mitochondrial DNA, and stars, Y DNA.

Inheritance combined

However, our genealogist’s brother, father or grandfather can test for her father’s (blue star) Y DNA.

Her father or any of his siblings can test for her paternal grandmother’s (hot pink heart) mitochondrial DNA, which provides information not available from any other tester in this tree, except for the paternal grandmother herself.

Our genealogist’s paternal grandfather, and his siblings, can test for his mother’s (yellow heart) mitochondrial DNA.

Our genealogist’s maternal grandfather can test for his (green star) Y DNA and (red heart) mitochondrial DNA.

And of course, it goes without saying that every single generation upstream of the daughter, our genealogist, should all take autosomal DNA tests.

So, with several candidates, who can and should test for what?

Person Y DNA Mitochondrial Autosomal
Daughter No Y – can’t test Yes, her pink mother’s Yes – Test
Son Yes – blue Y Yes, his pink mother’s Yes – Test
Father Yes – blue Y Yes – his magenta mother’s Yes – Test
Paternal Grandfather Yes – blue Y – Best to Test Yes, his yellow mother’s – Test Yes – Test
Mother No Y – can’t test Yes, her pink mother’s Yes – Test
Maternal Grandmother No Y – can’t test Yes, her pink mother’s – Best to Test Yes – Test
Maternal Grandfather Yes – green Y – Test Yes, his red mother’s – Test Yes – Test

The best person/people to test for each of the various lines and types of DNA is shown bolded above…assuming that all people are living. Of course, if they aren’t, then test anyone else in the tree who carries that particular DNA – and don’t forget to consider aunts and uncles, or their children, as candidates.

If one person takes the Y and/or mitochondrial DNA test to represent a specific line, you don’t need another person to take the same test for that line. The only possible exception would be to confirm a specific Y DNA result matches a lineage as expected.

Looking at our three-generation example, you’ll be able to obtain a total of two Y DNA lines, three mitochondrial DNA lines, and 8 autosomal results, helping you to understand and piece together your family line.

You might ask, given that the parents and grandparents have all autosomally tested in this example, if our genealogist really needs to test her brother, and the answer is probably not – at least not today.

However, in cases like this, I do test the sibling, simply because I can learn and it may encourage their interest or preserve their DNA for their children who might someday be interested. We also don’t know what kind of advances the future holds.

If the parents aren’t both available, then you’ll want to test as many of your (and their) siblings as possible to attempt to recover as much of the parents’ DNA, (and matches) as possible.

Your family members’ DNA is just as valuable to your research as your own.

Increase Your Odds

Don’t let any of your inherited DNA go unused.

You can increase your odds of having autosomal matches by making sure you are in all 4 major vendor databases.

Both FamilyTreeDNA and MyHeritage accept transfers from 23andMe and Ancestry, who don’t accept transfers. Transferring and matching is free, and their unlock fees, $19 at FamilyTreeDNA, and $29 at MyHeritage, respectively, to unlock their advanced tools are both less expensive than retesting.

You’ll find easy-to-follow step-by-step transfer instructions to and from the vendors in the article DNA File Upload-Download and Transfer Instructions to and from DNA Testing Companies.

Order

You can order any of the tests mentioned above by clicking on these links:

Autosomal:

Transfers

_____________________________________________________________

Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Genealogy Research

Duplicate Copies of Parental Chromosomes – Uniparental Disomy

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

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

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

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

Uniparental Disomy in Brief

Here are a few summary bullet points about uniparental disomy:

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

Articles

This Atlantic article provides an overview:

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

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

What About You?

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

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

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

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

Are Your Parents Related to Each Other?

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

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

Using the “Are your parents related” Tool

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

Parents related.png

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

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

Parents are related.png

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

The legend for reading the graphic is shown below.

Parents related legend.png

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

Parents not related.png

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

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

A Duplicate Chromosome

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

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

Parents uniparental disomy.png

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

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

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

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

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

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

______________________________________________________________

Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

 

 

Native American & Minority Ancestors Identified Using DNAPainter Plus Ethnicity Segments

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

Reasons to be cautious about ethnicity estimates include:

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

Ethnicity states over Europe

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

Noise in this case is defined as:

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

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

On the Other Hand

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

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

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

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

beringia map

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

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

Family Inheritance

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

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

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

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

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

23andMe

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

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

Minority ethnicity ancestry composition.png

Scroll down until you see your painted chromosomes.

Minority ethnicity chromosome painting.png

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

Minority ethnicity Native.png

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

Versions May Differ

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

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

Minority ethnicity Native V4.png

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

Minority ethnicity sides.png

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

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

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

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

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

Downloading Ethnicity Segment Data

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

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

MInority ethnicity scientific details.png

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

Minority ethnicity download raw data.png

Save this spreadsheet to your computer in a known location.

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

Minority ethnicity download.png

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

DNAPainter

I wrote introductory articles about DNAPainter:

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

Go ahead – I’ll wait!

Getting Started

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

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

Minority ethnicity DNAPainter.png

Click on “Import 23andme ancestry composition.”

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

Minority ethnicity DNAPainter sides.png

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

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

MInority ethnicity DNAPainter Native painting

Click to enlarge

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

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

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

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

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

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

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

Minority ethnicity maternal side

Click to enlarge

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

Minority ethnicity chromosome 1.png

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

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

Minority ethnicity chromosome 2.png

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

Minority ethnicity common ancestor.png

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

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

Traditional Genealogy Research

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

Minority ethnicity Acadian map.png

The Acadians intermarried with the Mi’kmaq people.

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

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

Minority ethnicity Native mitochondrial tree

Click to enlarge

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

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

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

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

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

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

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

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

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

Segments, Traditional Research and DNAPainter

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

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

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

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

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

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

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

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

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

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

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

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

Projects

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

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

Minority ethnicity project search.png

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

23andMe Maternal and Paternal Sides

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

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

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

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

Minority ethnicity minority segment.png

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

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

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

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

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

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

Minority ethnicity relative connections.png

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

Minority ethnicity relative minority segments.png

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

Minority ethnicity Native side.png

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

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

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

Minority ethnicity match side.png

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

Download All of Your Matches

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

Minority ethnicity download aggregate data.png

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

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

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

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

Paint Those Matches

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

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

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

To Paint, You Must Test

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

Transfers

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

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

Here’s a quick cheat sheet.

DNA vendor transfer cheat sheet 2019

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

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

Summary Steps

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

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

Have fun!

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Disclosure

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

Thank you so much.

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MyHeritage LIVE Conference Day 2 – The Science Behind DNA Matching    

The MyHeritage LIVE Oslo conference is but a fond memory now, and I would count it as a resounding success.

Perhaps one of the reasons I enjoyed it so much is the scientific aspect and because the content is very focused on a topic I enjoy without being the size and complexity of Rootstech. The smaller, more intimate venue also provides access to the “right” people as well as the ability to meet other attendees and not be overwhelmed by the sheer size.

Here are some stats:

  • 401 registered guests
  • 28 countries represented including distant places like Australia and South America
  • More than 20 speakers plus the hands-on workshops where specialist teams worked with students
  • 38 sessions and workshops, plus the party
  • 60,000 livestream participants, in spite of the time differences around the world

I was blown away by the number of livestream attendees.

I don’t know what criteria Gilad Japhet will be using to determine “success” but I can’t imagine this conference being judged as anything but.

Let’s take a look at the second day. I spent part of the time talking to people and drifting in and out of the rear of several sessions for a few minutes. I meant to visit some of the workshops, but there was just too much good, distracting content elsewhere.

I began Sunday in Mike Mansfield’s presentation about SuperSearch. Yes, I really did attend a few sessions not about DNA, but my favorite was the session on Improved DNA Matching.

Improved DNA Matching

I’m sure it won’t surprise any of my readers that my favorite presentations were about the actual science of genetic genealogy.

Consumers don’t really need to understand the science behind autosomal results to reap the benefits, but the underlying science is part of what I love – and it’s important for me to understand the underpinnings to be able to unravel the fine points of what the resulting matches are and are not revealing. Misinterpretation of DNA results leading to faulty conclusions is a real issue in genetic genealogy today. Consequently, I feel that anyone working with other people’s results and providing advice really needs to understand how the science and technology together works.

Dr. Daphna Weissglas-Volkov, a population geneticist by training, although she clearly functions far beyond that scope today, gave a very interesting presentation about how MyHeritage handles (their greatly improved) DNA Matching. I’m hitting the high points here, but I would strongly encourage you to watch the video of this session when they are made available online.

In addition to Dr. Weissglas-Volkov’s slides, I’ve added some additional explanations and examples in various places. You can easily tell that the slides are hers and the graphics that aren’t MyHeritage slides are mine.

Dr. Weissglas-Volkov began the session by introducing the MyHeritage science team and then explaining terminology to set the stage.

A match is when two people match each other on a fairly long piece of DNA. Of course, “fairly long” is defined differently by each vendor.

Your genetic map (of your chromosomes) is comprised of the DNA you inherit from different ancestors by the process of recombination when DNA is transferred from the parents to the child. A centiMorgan is the relatively likelihood that a recombination will occur in a single generation. On average, 36 recombinations occur in each generation, meaning that the DNA is divided on any chromosome. However, women, for reasons unknown have about 1.5 times as many recombinations as men.

You can’t see that when looking at an example of a person compared to their parents, of course, because each individual is a full match to each parent, but you can see this visually when comparing a grandchild to their maternal grandmother and their paternal grandmother on a chromosome browser.

The above illustration is the same female grandchild compared to her maternal grandmother, at left, and her paternal grandmother at right. Therefore the number of crossovers at left is through a female child (her mother), and the number at right is through a male child (her father.)

# of Crossovers
Through female child – left 57
Through male child – right 22

There are more segments at left, through the mother, and the segments are generally shorter, because they have been divided into more pieces.

At right, fewer and larger segments through the father.

Keep in mind that because you have a strand of DNA from each parent, with exactly the same “street addresses,” that what is produced by DNA sequencing are two columns of data – but your Mom’s and Dad’s DNA is intermixed.

The information in the two columns can’t be identified as Mom’s or Dad’s DNA or strand at this point.

That interspersed raw data is called a genotype. A haplotype is when Mom’s and Dad’s DNA can be reassembled into “sides” so you can attribute the two letters at each address to either Mom or Dad.

Here’s a quick example.

The goal, of course, is to figure out how to reassemble your DNA into Mom’s side and Dad’s side so that we know that someone matching you is actually matching on all As (Mom) or all Gs (Dad,) in this example, and not a false match that zigzags back and forth between Mom and Dad.

The best way to accomplish that goal of course is trio phasing, when the child and both parents are available, so by comparing the child’s DNA with the parents you can assign the two strands of the child’s DNA.

Unfortunately, few people have both or even one parent available in order to actual divide their DNA into “sides,” so the next best avenue is statistical phasing. I’ve called this academic phasing in the past, as compared to parental phasing which MyHeritage refers to as trio phasing.

There’s a huge amount of confusion about phasing, with few people understanding there are two distinct types.

Statistical phasing is a type of machine learning where a large number of reference populations are studied. Since we know that DNA travels together in blocks when inherited, statistical phasing learns which DNA travels with which buddy DNA – and creates probabilities. Your DNA is then compared to these models and your DNA is reshuffled in order to assemble your DNA into two groups – one representing your Mom’s DNA and one representing your Dad’s DNA, according to statistical probability.

Looking at your genotype, if we know that As group together at those 6 addresses in my example 95% of the time, then we know that the most likely scenario to create a haplotype is that all of the As came from one parent and all of the Gs from the other parent – although without additional information, there is no way to yet assign the maternal and paternal identifier. At this point, we only know parent 1 and parent 2.

In order to train the computers (machine learning) to properly statistically phase testers’ results, MyHeritage uses known relationships of people to teach the machines. In other words, their reference panels of proven haplotypes grows all of the time as parent/child trios test.

Dr. Weissglas-Volkev then moved on to imputation.

When sequencing DNA, not every location reads accurately, so the missing values can be imputed, or “put back” using imputation.

Initially imputation was a hot mess. Not just for MyHeritage, but for all vendors, imputation having been forced upon them (and therefore us) by Illumina’s change to the GSA chip.

However, machine learning means that imputation models improve constantly, and matching using imputation is greatly improved at MyHeritage today.

Imputation can do more than just fill in blanks left by sequencing read errors.

The benefit of imputation to the genetic genealogy community is that vendors using disparate chips has forced vendors that want to allow uploads to utilize imputation to create a global template that incorporates all of the locations from each vendor, then impute the values they don’t actually test for themselves to complete the full template for each person.

In the example below, you can see that no vendor tests all available locations, but when imputation extends the sequences of all testers to the full 1-500 locations, the results can easily be compared to every other tester because every tester now has values in locations 1-500, regardless of which vendor/chip was utilized in their actual testing.

Therefore, using imputation, MyHeritage is able to match between quite disparate chips, such as the traditional Illumina chips (OmniExpress), the custom Ancestry chip and the new GSA chip utilized by 23andMe and LivingDNA.

So, how are matches determined?

Matching

First your DNA and that of another person are scanned for nearly identical seed sequences.

A minimum segment length of 6cM must be identified for further match processing to occur. Anything below 6cM is discarded at this point.

The match is then further evaluated to see if the seed match is of a high enough quality that it should be perfected and should count as a match. Other segments continue to be evaluated as well. If the total matching segment(s) is 8 total cM or greater, it’s considered a valid match. MyHeritage has taken the position that they would rather give you a few accidental false matches than to miss good matches. I appreciate that position.

Window cleaning is how they refer to the process of removing pileup regions known to occur in the human genome. This is NOT the same as Ancestry’s routine that removes areas they determine to be “too matchy” for you individually.

The difference is that in humans, for example, there is a segment of chromosome 6 where, for some reason, almost all humans match. Matching across that segment is not informative for genetic genealogy, so that region along with several others similar in nature are removed. At Ancestry, those genome-wide pileup segments are removed, along with other regions where Ancestry decides that you personally have too many matches. The problem is that for me, these “too matchy” segments are many of my Acadian matches. Acadians are endogamous, so lots of them match each other because as a small intermarried population, they share a great deal of the same DNA. However, to me, because I have one great-grandfather that’s Acadian, that “too matchy” information IS valuable although I understand that it wouldn’t be for someone that is 100% Acadian or Jewish.

In situations such as Ashkenazi Jewish matching, which is highly endogamous, MyHeritage uses a higher matching threshold. Otherwise every Ashkenazi person would match every other Ashkenazi person because they all descend from a small founder population, and for genealogy, that’s not useful.

The last step in processing matches is to establish the confidence level that the match is accurately predicted at the correct level – meaning the relationship range based on the amount of matching DNA and other criteria.

For example, does this match cluster with other proven matches of the same known relationship level?

From several confidence ascertainment steps, a confidence score is assigned to the predicted relationship.

Of course, you as a customer see none of this background processing, just the fact that you do match, the size of the match and the confidence score. That’s what genealogists need!

Matching Versus Triangulation Thresholds

Confusion exists about matching thresholds versus triangulation thresholds.

While any single segment must be over 6 cM in length for the matching process to begin, the actual match threshold at MyHeritage is a total of 8 cM.

I took a look at my lowest match at MyHeritage.

I have two segments, one 6.1 cM segment, and one 6 cM segment that match. It would appear that if I only had one 6 cM segment, it would not show as a match because I didn’t have the minimum 8 cM total.

Triangulation Threshold

However, after you pass that matching criteria and move on to triangulation with a matching individual, you have the option of selecting the triangulation threshold, which is not the same thing as the match threshold. The match threshold does not change, but you can change the triangulation threshold from 2 cM to 8 cM and selections in-between.

In the example below, I’m comparing myself against two known relatives.

You won’t be shown any matches below the 6 cM individual segment threshold, BUT you can view triangulated segments of different sizes. This is because matching segments often don’t line up exactly and the triangulated overlap between several individuals may be very small, but may still be useful information.

Flying your mouse over the location in the bubble, which is the triangulated segment, tells you the size of the triangulated portion. If you selected the 2 cM triangulation, you would see smaller triangulated portions of matches.

Closing Session

The conference was closed by Aaron Godfrey, a super-nice MyHeritage employee from the UK. The closing session is worth watching on the recorded livestream when it becomes available, in part because there are feel good moments.

However, the piece of information I was looking for was whether there will be a MyHeritage LIVE conference in 2019, and if so, where.

I asked Gilad afterwards and he said that they will be evaluating the feedback from attendees and others when making that decision.

So, if you attended or joined the livestream sessions and found value, please let MyHeritage know so that they can factor your feedback onto their decision. If there are topics you’d like to see as sessions, I’m sure they’d love to hear about that too. Me, I’m always voting for more DNA😊

I hope to hear about MyHeritage LIVE 2019, and I’m voting for any of the following locations:

  • Australia
  • New Zealand
  • Israel
  • Germany
  • Switzerland

What do you think?

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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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Genealogy Services

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Elizabeth Warren’s Native American DNA Results: What They Mean

Elizabeth Warren has released DNA testing results after being publicly challenged and derided as “Pochahontas” as a result of her claims of a family story indicating that her ancestors were Native America. If you’d like to read the specifics of the broo-haha, this Washington Post Article provides a good summary, along with additional links.

I personally find name-calling of any type unacceptable behavior, especially in a public forum, and while Elizabeth’s DNA test was taken, I presume, in an effort to settle the question and end the name-calling, what it has done is to put the science of genetic testing smack dab in the middle of the headlines.

This article is NOT about politics, it’s about science and DNA testing. I will tell you right up front that any comments that are political or hateful in nature will not be allowed to post, regardless of whether I agree with them or not. Unfortunately, these results are being interpreted in a variety of ways by different individuals, in some cases to support a particular political position. I’m presenting the science, without the politics.

This is the first of a series of two articles.

I’m dividing this first article into four sections, and I’d ask you to read all four, especially before commenting. A second article, Possibilities – Wringing the Most Out of Your DNA Ethnicity Test will follow shortly about how to get the most out of an ethnicity test when hunting for Native American (or other minority, for you) ethnicity.

Understanding how the science evolved and works is an important factor of comprehending the results and what they actually mean, especially since Elizabeth’s are presented in a different format than we are used to seeing. What a wonderful teaching opportunity.

  • Family History and DNA Science – How this works.
  • Elizabeth Warren’s Genealogy
  • Elizabeth Warren’s DNA Results
  • Questions and Answers – These are the questions I’m seeing, and my science-based answers.

My second article, Possibilities – Wringing the Most Out of Your DNA Ethnicity Test will include:

  • Potential – This isn’t all that can be done with ethnicity results. What more can you do to identify that Native ancestor?
  • Resources with Step by Step Instructions

Now, let’s look at Elizabeth’s results and how we got to this point.

Family Stories and DNA

Every person that grows up in their biological family hears family stories. We have no reason NOT to believe them until we learn something that potentially conflicts with the facts as represented in the story.

In terms of stories handed down for generations, all we have to go on, initially, are the stories themselves and our confidence in the person relating the story to us. The day that we begin to suspect that something might be amiss, we start digging, and for some people, that digging begins with a DNA test for ethnicity.

My family had that same Cherokee story. My great-grandmother on my father’s side who died in 1918 was reportedly “full blooded Cherokee” 60 years later when I discovered she had existed. Her brothers reportedly went to Oklahoma to claim headrights land. There were surely nuggets of truth in that narrative. Family members did indeed to go Oklahoma. One did own Cherokee land, BUT, he purchased that land from a tribal member who received an allotment. I discovered that tidbit later.

What wasn’t true? My great-grandmother was not 100% Cherokee. To the best of my knowledge now, a century after her death, she wasn’t Cherokee at all. She probably wasn’t Native at all. Why, then, did that story trickle down to my generation?

I surely don’t know. I can speculate that it might have been because various people were claiming Native ancestry in order to claim land when the government paid tribal members for land as reservations were dissolved between 1893 and 1914. You can read more about that in this article at the National Archives about the Dawes Rolls, compiled for the Cherokee, Creek, Choctaw, Chickasaw and Seminole for that purpose.

I can also speculate that someone in the family was confused about the brother’s land ownership, especially since it was Cherokee land.

I could also speculate that the confusion might have resulted because her husband’s father actually did move to Oklahoma and lived on Choctaw land.

But here is what I do know. I believed that story because there wasn’t any reason NOT to believe it, and the entire family shared the same story. We all believed it…until we discovered evidence through DNA testing that contradicted the story.

Before we discuss Elizabeth Warren’s actual results, let’s take a brief look at the underlying science.

Enter DNA Testing

DNA testing for ethnicity was first introduced in a very rudimentary form in 2002 (not a typo) and has progressed exponentially since. The major vendors who offer tests that provide their customers with ethnicity estimates (please note the word estimates) have all refined their customer’s results several times. The reference populations improve, the vendor’s internal software algorithms improve and population genetics as a science moves forward with new discoveries.

Note that major vendors in this context mean Family Tree DNA, 23andMe, the Genographic Project and Ancestry. Two newer vendors include MyHeritage and LivingDNA although LivingDNA is focused on England and MyHeritage, who utilizes imputation is not yet quite up to snuff on their ethnicity estimates. Another entity, GedMatch isn’t a testing vendor, but does provide multiple ethnicity tools if you upload your results from the other vendors. To get an idea of how widely the results vary, you can see the results of my tests at the different vendors here and here.

My initial DNA ethnicity test, in 2002, reported that I was 25% Native American, but I’m clearly not. It’s evident to me now, but it wasn’t then. That early ethnicity test was the dinosaur ages in genetic genealogy, but it did send me on a quest through genealogical records to prove that my family member was indeed Native. My father clearly believed this, as did the rest of the family. One of my early memories when I was about four years old was attending a (then illegal) powwow with my Dad.

In order to prove that Elizabeth Vannoy, that great-grandmother, was Native I asked a cousin who descends from her matrilineally to take a mitochondrial DNA test that would unquestionably provide the ethnicity of her matrilineal line – that of her mother’s mother’s mother’s direct line. If she was Native, her haplogroup would be a derivative either A, B, C, D or X. Her mitochondrial DNA was European, haplogroup J, clearly not Native, so Elizabeth Vannoy was not Native on that line of her family. Ok, maybe through her dad’s line then. I was able to find a Vanoy male descendant of her father, Joel Vannoy, to test his Y DNA and he was not Native either. Rats!

Tracking Elizabeth Vannoy’s genealogy back in time provided no paper-trail link to any Native ancestors, but there were and are still females whose surnames and heritage we don’t know. Were they Native or part Native? Possibly. Nothing precludes it, but nothing (yet) confirms it either.

Unexpected Results

DNA testing is notorious for unveiling unexpected results. Adoptions, unknown parents, unexpected ethnicities, previously unknown siblings and half-siblings and more.

Ethnicity is often surprising and sometimes disappointing. People who expect Native American heritage in their DNA sometimes don’t find it. Why?

  • There is no Native ancestor
  • The Native DNA has “washed out” over the generations, but they did have a Native ancestor
  • We haven’t yet learned to recognize all of the segments that are Native
  • The testing company did not test the area that is Native

Not all vendors test the same areas of our DNA. Each major company tests about 700,000 locations, roughly, but not the same 700,000. If you’re interested in specifics, you can read more about that here.

50-50 Chance

Everyone receives half of their autosomal DNA from each parent.

That means that each parent contributes only HALF OF THEIR DNA to a child. The other half of their DNA is never passed on, at least not to that child.

Therefore, ancestral DNA passed on is literally cut in half in each generation. If your parent has a Native American DNA segment, there is a 50-50 chance you’ll inherit it too. You could inherit the entire segment, a portion of the segment, or none of the segment at all.

That means that if you have a Native ancestor 6 generations back in your tree, you share 1.56% of their DNA, on average. I wrote the article, Ancestral DNA Percentages – How Much of Them is in You? to explain how this works.

These calculations are estimates and use averages. Why? Because they tell us what to expect, on average. Every person’s results will vary. It’s entirely possible to carry a Native (or other ethnic) segment from 7 or 8 or 9 generations ago, or to have none in 5 generations. Of course, these calculations also presume that the “Native” ancestor we find in our tree was fully Native. If the Native ancestor was already admixed, then the percentages of Native DNA that you could inherit drop further.

Why Call Ethnicity an Estimate?

You’ve probably figured out by now that due to the way that DNA is inherited, your ethnicity as reported by the major testing companies isn’t an exact science. I discussed the methodology behind ethnicity results in the article, Ethnicity Testing – A Conundrum.

It is, however, a specialized science known as Population Genetics. The quality of the results that are returned to you varies based on several factors:

  • World Region – Ethnicity estimates are quite accurate at the continental level, plus Jewish – meaning African, Indo-European, Asian, Native American and Jewish. These regions are more different than alike and better able to be separated.
  • Reference Population – The size of the population your results are being compared to is important. The larger the reference population, the more likely your results are to be accurate.
  • Vendor Algorithm – None of the vendors provide the exact nature of their internal algorithms that they use to determine your ethnicity percentages. Suffice it to say that each vendor’s staff includes population geneticists and they all have years of experience. These internal differences are why the estimates vary when compared to each other.
  • Size of the Segment – As with all genetic genealogy, bigger is better because larger segments stand a better chance of being accurate.
  • Academic Phasing – A methodology academics and vendors use in which segments of DNA that are known to travel together during inheritance are grouped together in your results. This methodology is not infallible, but in general, it helps to group your mother’s DNA together and your father’s DNA together, especially when parents are not available for testing.
  • Parental Phasing – If your parents test and they too have the same segment identified as Native, you know that the identification of that segment as Native is NOT a factor of chance, where the DNA of each of your parents just happens to fall together in a manner as to mimic a Native segment. Parental phasing is the ability to divide your DNA into two parts based on your parent’s DNA test(s).
  • Two Chromosomes – You have two chromosomes, one from your mother and one from your father. DNA testing can’t easily separate those chromosomes, so the exact same “address” on your mother’s and father’s chromosomes that you inherited may carry two different ethnicities. Unless your parents are both from the same ethnic population, of course.

All of these factors, together, create a confidence score. Consumers never see these scores as such, but the vendors return the highest confidence results to their customers. Some vendors include the capability, one way or another, to view or omit lower confidence results.

Parental Phasing – Identical by Descent

If you’re lucky enough to have your parents, or even one parent available to test, you can determine whether that segment thought to be Native came from one of your parents, or if the combination of both of your parent’s DNA just happened to combine to “look” Native.

Here’s an example where the “letters” (nucleotides) of Native DNA for an example segment are shown at left. If you received the As from one of your parents, your DNA is said to be phased to that parent’s DNA. That means that you in fact inherited that piece of your DNA from your mother, in the case shown below.

That’s known as Identical by Descent (IBD). The other possibility is what your DNA from both of your parents intermixed to mimic a Native segment, shown below.

This is known as Identical by Chance (IBC).

You don’t need to understand the underpinnings of this phenomenon, just remember that it can happen, and the smaller the segment, the more likely that a chance combination can randomly happen.

Elizabeth Warren’s Genealogy

Elizabeth Warren’s genealogy, is reported to the 5th generation by WikiTree.

Elizabeth’s mother, Pauline Herring’s line is shown, at WikiTree, as follows:

Notice that of Elizabeth Warren’s 16 great-great-great grandparents on her mother’s side, 9 are missing.

Paper trail being unfruitful, Elizabeth Warren, like so many, sought to validate her family story through DNA testing.

Elizabeth Warren’s DNA Results

Elizabeth Warren didn’t test with one of the major vendors. Instead, she went directly to a specialist. That’s the equivalent of skipping the family practice doctor and going to the Mayo Clinic.

Elizabeth Warren had test results interpreted by Dr. Carlos Bustamante at Stanford University. You can read the actual report here and I encourage you to do so.

From the report, here are Dr. Bustamante’s credentials:

Dr. Carlos D. Bustamante is an internationally recognized leader in the application of data science and genomics technology to problems in medicine, agriculture, and biology. He received his Ph.D. in Biology and MS in Statistics from Harvard University (2001), was on the faculty at Cornell University (2002-9), and was named a MacArthur Fellow in 2010. He is currently Professor of Biomedical Data Science, Genetics, and (by courtesy) Biology at Stanford University. Dr. Bustamante has a passion for building new academic units, non-profits, and companies to solve pressing scientific challenges. He is Founding Director of the Stanford Center for Computational, Evolutionary, and Human Genomics (CEHG) and Inaugural Chair of the Department of Biomedical Data Science. He is the Owner and President of CDB Consulting, LTD. and also a Director at Eden Roc Biotech, founder of Arc-Bio (formerly IdentifyGenomics and BigData Bio), and an SAB member of Imprimed, Etalon DX, and Digitalis Ventures among others.

He’s no lightweight in the study of Native American DNA. This 2012 paper, published in PLOS Genetics, Development of a Panel of Genome-Wide Ancestry Informative Markers to Study Admixture Throughout the Americas focused on teasing out Native American markers in admixed individuals.

From that paper:

Ancestry Informative Markers (AIMs) are commonly used to estimate overall admixture proportions efficiently and inexpensively. AIMs are polymorphisms that exhibit large allele frequency differences between populations and can be used to infer individuals’ geographic origins.

And:

Using a panel of AIMs distributed throughout the genome, it is possible to estimate the relative ancestral proportions in admixed individuals such as African Americans and Latin Americans, as well as to infer the time since the admixture process.

The methodology produced results of the type that we are used to seeing in terms of continental admixture, shown in the graphic below from the paper.

Matching test takers against the genetic locations that can be identified as either Native or African or European informs us that our own ancestors carried the DNA associated with that ethnicity.

Of course, the Native samples from this paper were focused south of the United States, but the process is the same regardless. The original Native American population of a few individuals arrived thousands of years ago in one or more groups from Asia and their descendants spread throughout both North and South America.

Elizabeth’s request, from the report:

To analyze genetic data from an individual of European descent and determine if there is reliable evidence of Native American and/or African ancestry. The identity of the sample donor, Elizabeth Warren, was not known to the analyst during the time the work was performed.

Elizabeth’s test included 764,958 genetic locations, of which 660,173 overlapped with locations used in ancestry analysis.

The Results section says after stating that Elizabeth’s DNA is primarily (95% or greater) European:

The analysis also identified 5 genetic segments as Native American in origin at high confidence, defined at the 99% posterior probability value. We performed several additional analyses to confirm the presence of Native American ancestry and to estimate the position of the ancestor in the individual’s pedigree.

The largest segment identified as having Native American ancestry is on chromosome 10. This segment is 13.4 centiMorgans in genetic length, and spans approximately 4,700,000 DNA bases. Based on a principal components analysis (Novembre et al., 2008), this segment is clearly distinct from segments of European ancestry (nominal p-value 7.4 x 10-7, corrected p-value of 2.6 x 10-4) and is strongly associated with Native American ancestry.

The total length of the 5 genetic segments identified as having Native American ancestry is 25.6 centiMorgans, and they span approximately 12,300,000 DNA bases. The average segment length is 5.8 centiMorgans. The total and average segment size suggest (via the method of moments) an unadmixed Native American ancestor in the pedigree at approximately 8 generations before the sample, although the actual number could be somewhat lower or higher (Gravel, 2012 and Huff et al., 2011).

Dr. Bustamante’s Conclusion:

While the vast majority of the individual’s ancestry is European, the results strongly support the existence of an unadmixed Native American ancestor in the individual’s pedigree, likely in the range of 6-10 generations ago.

I was very pleased to see that Dr. Bustamante had included the PCA (Principal Component Analysis) for Elizabeth’s sample as well.

PCA analysis is the scientific methodology utilized to group individuals to and within populations.

Figure one shows the section of chromosome 10 that showed the largest Native American haplotype, meaning DNA block, as compared to other populations.

Remember that since Elizabeth received a chromosome from BOTH parents, that she has two strands of DNA in that location.

Here’s our example again.

Given that Mom’s DNA is Native, and Dad’s is European in this example, the expected results when comparing this segment of DNA to other populations is that it would look half Native (Mom’s strand) and half European (Dad’s strand.)

The second graphic shows Elizabeth’s sample and where it falls in the comparison of First Nations (Canada) and Indigenous Mexican individuals. Given that Elizabeth’s Native ancestor would have been from the United States, her sample falls where expected, inbetween.

Let’s take a look at some of the questions being asked.

Questions and Answers

I’ve seen a lot of misconceptions and questions regarding these results. Let’s take them one by one:

Question – Can these results prove that Elizabeth is Cherokee?

Answer – No, there is no test, anyplace, from any lab or vendor, that can prove what tribe your ancestors were from. I wrote an article titled Finding Your American Indian Tribe Using DNA, but that process involves working with your matches, Y and mitochondrial DNA testing, and genealogy.

Q – Are these results absolutely positive?

A – The words “absolutely positive” are a difficult quantifier. Given the size of the largest segment, 13.4 cM, and that there are 5 Native segments totaling 25.6 cM, and that Dr. Bustamante’s lab performed the analysis – I’d say this is as close to “absolutely positive” as you can get without genealogical confirmation.

A 13.4 cM segment is a valid segment that phases to parents 98% of the time, according to Philip Gammon’s work, here, and 99% of the time in my own analysis here. That indicates that a 13.4 cM segment is very likely a legitimately ancestral segment, not a match by chance. The additional 4 segments simply increase the likelihood of a Native ancestor. In other words, for there NOT to be a Native ancestor, all 5 segments, including the large 13.4 cM segment would have to be misidentified by one of the premier scientists in the field.

Q – What did Dr. Bustamante mean by “evidence of an unadmixed Native American ancestor?”

A – Unadmixed means that the Native person was fully Native, meaning not admixed with European, Asian or African DNA. Admixture, in this context, means that the individual is a mixture of multiple ethnic groups. This is an important concept, because if you discover that your ancestor 4 generations ago was a Cherokee tribal member, but the reality was that they were only 25% Native, that means that the DNA was already in the process of being divided. If your 4th generation ancestor was fully Native, you would receive about 6.25% of their DNA which would be all Native. If they were only 25% Native, that means that while you will still receive about 6.25% of their DNA but only one fourth of that 6.25% is possibly Native – so 1.56%. You could also receive NONE of their Native DNA.

Q – Is this the same test that the major companies use?

A – Yes and no. The test itself was probably performed on the same Illumina chip platform, because the chips available cover the markers that Bustamante needed for analysis.

The major companies use the same reference data bases, plus their own internal or private data bases in addition. They do not create PCA models for each tester. They do use the same methodology described by Dr. Bustamante in terms of AIMs, along with proprietary algorithms to further define the results. Vendors may also use additional internal tools.

Q – Did Dr. Bustamante use more than one methodology in his analysis? What if one was wrong?

A – Yes, he utilized two different methodologies whose results agreed. The global ancestry method evaluates each location independently of any surrounding genetic locations, ignoring any correlation or relationship to neighboring DNA. The second methodology, known as the local ancestry method looks at each location in combination with its neighbors, given that DNA pieces are known to travel together. This second methodology allows comparisons to entire segments in reference populations and is what allows the identification of complete ancestral segments that are identified as Native or any other population.

Q – If Elizabeth’s DNA results hadn’t shown Native heritage, would that have proven that she didn’t have Native ancestry?

A – No, not definitively, although that is a possible reason for ethnicity results not showing Native admixture. It would have meant that either she didn’t have a Native ancestor, the DNA washed out, or we cannot yet detect those segments.

Q – Does this qualify Elizabeth to join a tribe?

A – No. Every tribe defines their own criteria for membership. Some tribes embrace DNA testing for paternity issues, but none, to the best of my knowledge, accept or rely entirely on DNA results for membership. DNA results alone cannot identify a specific tribe. Tribes are societal constructs and Native people genetically are more alike than different, especially in areas where tribes lived nearby, fought and captured other tribe’s members.

Q – Why does Dr. Bustamante use words like “strong probability” instead of absolutes, such as the percentages shown by commercial DNA testing companies?

A – Dr. Bustamante’s comments accurately reflect the state of our knowledge today. The vendors attempt to make the results understandable and attractive for the general population. Most vendors, if you read their statements closely and look at your various options indicate that ethnicity is only an estimate, and some provide the ability to view your ethnicity estimate results at high, medium and low confidence levels.

Q – Can we tell, precisely, when Elizabeth had a Native ancestor?

A – No, that’s why Dr. Bustamante states that Elizabeth’s ancestor was approximately 8 generations ago, and in the range of 6-10 generations ago. This analysis is a result of combined factors, including the total centiMorgans of Native DNA, the number of separate reasonably large segments, the size of the longest segment, and the confidence score for each segment. Those factors together predict most likely when a fully Native ancestor was present in the tree. Keep in mind that if Elizabeth had more than one Native ancestor, that too could affect the time prediction.

Q – Does Dr. Bustamante provide this type of analysis or tools for the general public?

A – Unfortunately, no. Dr. Bustamante’s lab is a research facility only.

Roberta’s Summary of the Analysis

I find no omissions or questionable methods and I agree with Dr. Bustamante’s analysis. In other words, yes, I believe, based on these results, that Elizabeth had a Native ancestor further back in her tree.

I would love for every tester to be able to receive PCA results like this.

However, an ethnicity confirmation isn’t all that can be done with Elizabeth’s results. Additional tools and opportunities are available outside of an academic setting, at the vendors where we test, using matching and other tools we have access to as the consuming public.

We will look at those possibilities in a second article, because Elizabeth’s results are really just a beginning and scratch the surface. There’s more available, much more. It won’t change Elizabeth’s ethnicity results, but it could lead to positively identifying the Native ancestor, or at least the ancestral Native line.

Join me in my next article for Possibilities, Wringing the Most Out of Your DNA Ethnicity Test.

In the mean time, you might want to read my article, Native American DNA Resources.

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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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Concepts – Percentage of Ancestors’ DNA

A very common question is, “How much DNA of an ancestor do I carry and how does that affect my ethnicity results?”

This question is particularly relevant for people who are seeking evidence of a particular ethnicity of an ancestor several generations back in time. I see this issue raise its head consistently when people take an ethnicity test and expect that their “full blood” Native American great-great-grandmother will show up in their results.

Let’s take a look at how DNA inheritance works – and why they might – or might not find the Native DNA they seek, assuming that great-great-grandma actually was Native.

Inheritance

Every child inherits exactly 50% of their autosomal DNA from each parent (except for the X chromosome in males.) However, and this is a really important however, the child does NOT inherit exactly half of the DNA of each ancestor who lived before the parents. How can this be, you ask?

Let’s step through this logically.

The number of ancestors you have doubles in each generation, going back in time.

This chart provides a summary of how many ancestors you have in each generation, an approximate year they were born using a 25 year generation and a 30 year generation, respectively, and how much of their DNA, on average, you could expect to carry, today. You’ll notice that by the time you’re in the 7th generation, you can be expected, on average, to carry 0.78% meaning less than 1% of that GGGGG-grandparent’s DNA.

Looking at the chart, you can see that you reach the 1% level at about the 6th generation with an ancestor probably born in the late 1700s or early 1800s.

It’s also worth noting here that generations can be counted differently. In some instances, you are counted as generation one, so your GGGGG-grandparent would be generation 8.

In general, DNA showing ethnicity below about 5% is viewed as somewhat questionable and below 2% is often considered to be “noise.” Clearly, that isn’t always the case, especially if you are dealing with continental level breakdowns, as opposed to within Europe, for example. Intra-continental (regional) ethnicity breakdowns are particularly difficult and unreliable, but continental level differences are easier to discern and are considered to be more reliable, comparatively.

If you want to learn more about how ethnicity calculations are derived and what they mean, please read the article Ethnicity Testing – A Conundrum.

On Average May Not Mean You

On average, each child receives half of the DNA of each ancestor from their parent.

The words “on average” are crucial to this discussion, because the average assumes that in fact each generation between your GGGGG-grandmother and you inherited exactly half of the DNA in each generation from their parent that was contributed by that GGGGG-grandmother.

Unfortunately, while averages are all that we have to work with, that’s not always how ancestral DNA is passed in each generation.

Let’s say that your GGGGG-grandmother was indeed full Native, meaning no admixture at all.

You can click to enlarge images.

Using the chart above, you can see that your GGGGG-grandmother was full native on all 20 “pieces” or segments of DNA used for this illustration. Those segments are colored red. The other 10 segments, with no color, were contributed by the father.

Let’s say she married a person who was not Native, and in every generation since, there were no additional Native ancestors.

Her child, generation 6, inherited exactly 50% of her DNA, shown in red – meaning 10 segments..

Generation 5, her grandchild, inherited exactly half of her DNA that was carried by the parent, shown in red – meaning 5 segments..

However, in the next generation, generation 4, that child inherited more than half of the Native DNA from their parent. They inherited half of their parent’s DNA, but the half that was randomly received included 3 Native segments out of a possible 5 Native segments that the parent carried.

In generation 3, that child inherited 2 of the possible 3 segments that their parent carried.

In generation 2, that person inherited all of the Native DNA that their parent carried.

In generation 1, your parent inherited half of the DNA that their parent carried, meaning one of 2 segments of Native DNA carried by your grandparent.

And you will either receive all of that one segment, part of that one segment, or none of that one segment.

In the case of our example, you did not inherit that segment, which is why you show no Native admixture, even though your GGGGG-grandmother was indeed fully Native..

Of course, even if you had inherited that Native segment, and that segment isn’t something the population reference models recognize as “Native,” you still won’t show as carrying any Native at all. It could also be that if you had inherited the red segment, it would have been too small and been interpreted as noise.

The “Received” column at the right shows how much of the ancestral DNA the current generation received from their parent.

The “% of Original” column shows how the percentage of GGGGG-grandmother’s DNA is reduced in each generation.

The “Expected” column shows how much DNA, “on average” we would expect to see in each generation, as compared to the “% of Original” which is how much they actually carry.

I intentionally made the chart, above, reflect a scenario close to what we could expect, on average. However, it’s certainly within the realm of possibility to see something like the following scenario, as well.

In the second example, above, neither you nor your parent or grandparent inherited any of the Native segments.

It’s also possible to see a third example, below, where 4 generations in a row, including you, inherited the full amount of Native DNA segments carried by the GG-grandparent.

Testing Other Relatives

Every child of every couple inherits different DNA from their parents. The 50% of their parents’ DNA that they inherit is not all the same. The three example charts above could easily represent three children of the GG-Grandparent and their descendants.

The pedigree chart below shows the three different examples, above.  The great-great-grandparent in the 4th generation who inherited 3 Native DNA segments is shown first, then the inheritance of the Native segments through all 3 children to the current generation.

Therefore, you may not have inherited the red segment of GGGGG-grandmother’s Native DNA, but your sibling might, or vice versa. As you can see in the chart above, one of your third cousins received 3 native segments from GGGGG-grandmother. but your other third cousin received none.

You can see why people are always encouraged to test their parents and grandparents as well as siblings. You never know where your ancestor’s DNA will turn up, and each person will carry a different amount, and different segments of DNA from your common ancestors.

In other words, your great-aunt and great-uncle’s DNA is every bit as important to you as your own grandparent’s DNA – so test everyone in older generations while you can, and their children if they are no longer available.

Back to Great-Great-Grandma

Going back to great-great-grandma and her Native heritage. You may not show Native ethnicity when you expected to see Native, but you may have other resources and recourses. Don’t give up!

Reason Resources and Comments
She really wasn’t Native. Genealogical research will help and mitochondrial DNA testing of an appropriate descendant will point the way to her true ethnic heritage, at least on her mother’s side.
She was Native, but the ethnicity test doesn’t show that I am. Test relatives and find someone descended from her through all females to take a mitochondrial test. The mitochondrial test will answer the question for her matrilineal line unquestionably.
She was partly, but not fully Native. This would mean that she had less Native DNA than you thought, which would mean the percentage coming to you is lower on average than anticipated. Mitochondrial DNA testing someone descended from her through all females to the current generation, which can be male, would reveal whether her mother was Native from her mother’s line.
She was Native, but several generations back in time. You or your siblings may show small percentages of Native or other locations considered to be a component of Native admixture in the absence of any other logical explanation for their presence, such as Siberian or Eastern Asian.

Using Y and Mitochondrial DNA Testing to Supplement Ethnicity Testing

When in doubt about ethnicity results, find an appropriately descended person to take a Y DNA test (males only, for direct paternal lineage) or a mitochondrial DNA test, for direct matrilineal results. These tests will yield haplogroup information and haplogroups are associated with specific world regions and ethnicities, providing a more definitive answer regarding the heritage of that specific line.

Y DNA reflects the direct male line, shown in blue above, and mitochondrial DNA reflects the direct matrilineal line, shown in red. Only males carry Y DNA, but both genders carry mitochondrial DNA.

For a short article about the different kinds of DNA and how they can help genealogists, please read 4 Kinds of DNA for Genetic Genealogy.

Ethnicity testing is available from any of the 3 major vendors, meaning Family Tree DNA, Ancestry or 23andMe. Base haplogroups are provided with 23andMe results, but detailed testing for Y and mitochondrial DNA is only available from Family Tree DNA.

To read about the difference between the two types of testing utilized for deriving haplogroups between 23andMe and Family Tree DNA, please read Haplogroup Comparisons between Family Tree DNA and 23andMe.

For more information on haplogroups, please read What is a Haplogroup?

For a discussion about testing family members, please read Concepts – Why DNA Testing the Oldest Family Members is Critically Important.

If you’d like to read a more detailed explanation of how inheritance works, please read Concepts – How Your Autosomal DNA Identifies Your Ancestors.

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research