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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Genetic Genealogy at 20 Years: Where Have We Been, Where Are We Going and What’s Important?

Not only have we put 2020 in the rear-view mirror, thankfully, we’re at the 20-year, two-decade milestone. The point at which genetics was first added to the toolbox of genealogists.

It seems both like yesterday and forever ago. And yes, I’ve been here the whole time,  as a spectator, researcher, and active participant.

Let’s put this in perspective. On New Year’s Eve, right at midnight, in 2005, I was able to score kit number 50,000 at Family Tree DNA. I remember this because it seemed like such a bizarre thing to be doing at midnight on New Year’s Eve. But hey, we genealogists are what we are.

I knew that momentous kit number which seemed just HUGE at the time was on the threshold of being sold, because I had inadvertently purchased kit 49,997 a few minutes earlier.

Somehow kit 50,000 seemed like such a huge milestone, a landmark – so I quickly bought kits, 49,998, 49,999, and then…would I get it…YES…kit 50,000. Score!

That meant that in the 5 years FamilyTreeDNA had been in business, they had sold on an average of 10,000 kits per year, or 27 kits a day. Today, that’s a rounding error. Then it was momentous!

In reality, the sales were ramping up quickly, because very few kits were sold in 2000, and roughly 20,000 kits had been sold in 2005 alone. I know this because I purchased kit 28,429 during the holiday sale a year earlier.

Of course, I had no idea who I’d test with that momentous New Year’s Eve Y DNA kit, but I assuredly would find someone. A few months later, I embarked on a road trip to visit an elderly family member with that kit in tow. Thank goodness I did, and they agreed and swabbed on the spot, because they are gone today and with them, the story of the Y line and autosomal DNA of their branch.

In the past two decades, almost an entire generation has slipped away, and with them, an entire genealogical library held in their DNA.

Today, more than 40 million people have tested with the four major DNA testing companies, although we don’t know exactly how many.

Lots of people have had more time to focus on genealogy in 2020, so let’s take a look at what’s important? What’s going on and what matters beyond this month or year?

How has this industry changed in the last two decades, and where it is going?

Reflection

This seems like a good point to reflect a bit.

Professor Dan Bradley reflecting on early genetic research techniques in his lab at the Smurfit Institute of Genetics at Trinity College in Dublin. Photo by Roberta Estes

In the beginning – twenty years ago, there were two companies who stuck their toes in the consumer DNA testing water – Oxford Ancestors and Family Tree DNA. About the same time, Sorenson Genomics and GeneTree were also entering that space, although Sorenson was a nonprofit. Today, of those, only FamilyTreeDNA remains, having adapted with the changing times – adding more products, testing, and sophistication.

Bryan Sykes who founded Oxford Ancestors announced in 2018 that he was retiring to live abroad and subsequently passed away in 2020. The website still exists, but the company has announced that they have ceased sales and the database will remain open until Sept 30, 2021.

James Sorenson died in 2008 and the assets of Sorenson Molecular Genealogy Foundation, including the Sorenson database, were sold to Ancestry in 2012. Eventually, Ancestry removed the public database in 2015.

Ancestry dabbled in Y and mtDNA for a while, too, destroying that database in 2014.

Other companies, too many to remember or mention, have come and gone as well. Some of the various company names have been recycled or purchased, but aren’t the same companies today.

In the DNA space, it was keep up, change, die or be sold. Of course, there was the small matter of being able to sell enough DNA kits to make enough money to stay in business at all. DNA processing equipment and a lab are expensive. Not just the equipment, but also the expertise.

The Next Wave

As time moved forward, new players entered the landscape, comprising the “Big 4” testing companies that constitute the ponds where genealogists fish today.

23andMe was the first to introduce autosomal DNA testing and matching. Their goal and focus was always medical genetics, but they recognized the potential in genealogists before anyone else, and we flocked to purchase tests.

Ancestry settled on autosomal only and relies on the size of their database, a large body of genealogy subscribers, and a widespread “feel-good” marketing campaign to sell DNA kits as the gateway to “discover who you are.”

FamilyTreeDNA did and still does offer all 3 kinds of tests. Over the years, they have enhanced both the Y DNA and mitochondrial product offerings significantly and are still known as “the science company.” They are the only company to offer the full range of Y DNA tests, including their flagship Big Y-700, full sequence mitochondrial testing along with matching for both products. Their autosomal product is called Family Finder.

MyHeritage entered the DNA testing space a few years after the others as the dark horse that few expected to be successful – but they fooled everyone. They have acquired companies and partnered along the way which allowed them to add customers (Promethease) and tools (such as AutoCluster by Genetic Affairs), boosting their number of users. Of course, MyHeritage also offers users a records research subscription service that you can try for free.

In summary:

One of the wonderful things that happened was that some vendors began to accept compatible raw DNA autosomal data transfer files from other vendors. Today, FamilyTreeDNA, MyHeritage, and GEDmatch DO accept transfer files, while Ancestry and 23andMe do not.

The transfers and matching are free, but there are either minimal unlock or subscription plans for advanced features.

There are other testing companies, some with niche markets and others not so reputable. For this article, I’m focusing on the primary DNA testing companies that are useful for genealogy and mainstream companion third-party tools that complement and enhance those services.

The Single Biggest Change

As I look back, the single biggest change is that genetic genealogy evolved from the pariah of genealogy where DNA discussion was banned from the (now defunct) Rootsweb lists and summarily deleted for the first few years after introduction. I know, that’s hard to believe today.

Why, you ask?

Reasons varied from “just because” to “DNA is cheating” and then morphed into “because DNA might do terrible things like, maybe, suggest that a person really wasn’t related to an ancestor in a lineage society.”

Bottom line – fear and misunderstanding. Change is exceedingly difficult for humans, and DNA definitely moved the genealogy cheese.

From that awkward beginning, genetic genealogy organically became a “thing,” a specific application of genealogy. There was paper-trail traditional genealogy and then the genetic aspect. Today, for almost everyone, genealogy is “just another tool” in the genealogist’s toolbox, although it does require focused learning, just like any other tool.

DNA isn’t separate anymore, but is now an integral part of the genealogical whole. Having said that, DNA can’t solve all problems or answer all questions, but neither can traditional paper-trail genealogy. Together, each makes the other stronger and solves mysteries that neither can resolve alone.

Synergy.

I fully believe that we have still only scratched the surface of what’s possible.

Inheritance

As we talk about the various types of DNA testing and tools, here’s a quick graphic to remind you of how the different types of DNA are inherited.

  • Y DNA is inherited paternally for males only and informs us of the direct patrilineal (surname) line.
  • Mitochondrial DNA is inherited by everyone from their mothers and informs us of the mother’s matrilineal (mother’s mother’s mother’s) line.
  • Autosomal DNA can be inherited from potentially any ancestor in random but somewhat predictable amounts through both parents. The further back in time, the less identifiable DNA you’ll inherit from any specific ancestor. I wrote about that, here.

What’s Hot and What’s Not

Where should we be focused today and where is this industry going? What tools and articles popped up in 2020 to help further our genealogy addiction? I already published the most popular articles of 2020, here.

This industry started two decades ago with testing a few Y DNA and mitochondrial DNA markers, and we were utterly thrilled at the time. Both tests have advanced significantly and the prices have dropped like a stone. My first mitochondrial DNA test that tested only 400 locations cost more than $800 – back then.

Y DNA and mitochondrial DNA are still critically important to genetic genealogy. Both play unique roles and provide information that cannot be obtained through autosomal DNA testing. Today, relative to Y DNA and mitochondrial DNA, the biggest challenge, ironically, is educating newer genealogists about their potential who have never heard about anything other than autosomal, often ethnicity, testing.

We have to educate in order to overcome the cacophony of “don’t bother because you don’t get as many matches.”

That’s like saying “don’t use the right size wrench because the last one didn’t fit and it’s a bother to reach into the toolbox.” Not to mention that if everyone tested, there would be a lot more matches, but I digress.

If you don’t use the right tool, and all of the tools at your disposal, you’re not going to get the best result possible.

The genealogical proof standard, the gold standard for genealogy research, calls for “a reasonably exhaustive search,” and if you haven’t at least considered if or how Y
DNA
and mitochondrial DNA along with autosomal testing can or might help, then your search is not yet exhaustive.

I attempt to obtain the Y and mitochondrial DNA of every ancestral line. In the article, Search Techniques for Y and Mitochondrial DNA Test Candidates, I described several methodologies to find appropriate testing candidates.

Y DNA – 20 Years and Still Critically Important

Y DNA tracks the Y chromosome for males via the patrilineal (surname) line, providing matching and historical migration information.

We started 20 years ago testing 10 STR markers. Today, we begin at 37 markers, can upgrade to 67 or 111, but the preferred test is the Big Y which provides results for 700+ STR markers plus results from the entire gold standard region of the Y chromosome in order to provide the most refined results. This allows genealogists to use STR markers and SNP results together for various aspects of genealogy.

I created a Y DNA resource page, here, in order to provide a repository for Y DNA information and updates in one place. I would encourage anyone who can to order or upgrade to the Big Y-700 test which provides critical lineage information in addition to and beyond traditional STR testing. Additionally, the Big Y-700 test helps build the Y DNA haplotree which is growing by leaps and bounds.

More new SNPs are found and named EVERY SINGLE DAY today at FamilyTreeDNA than were named in the first several years combined. The 2006 SNP tree listed a grand total of 459 SNPs that defined the Y DNA tree at that time, according to the ISOGG Y DNA SNP tree. Goran Rundfeldt, head of R&D at FamilyTreeDNA posted this today:

2020 was an awful year in so many ways, but it was an unprecedented year for human paternal phylogenetic tree reconstruction. The FTDNA Haplotree or Great Tree of Mankind now includes:

37,534 branches with 12,696 added since 2019 – 51% growth!
defined by
349,097 SNPs with 131,820 added since 2019 – 61% growth!

In just one year, 207,536 SNPs were discovered and assigned FT SNP names. These SNPs will help define new branches and refine existing ones in the future.

The tree is constructed based on high coverage chromosome Y sequences from:
– More than 52,500 Big Y results
– Almost 4,000 NGS results from present-day anonymous men that participated in academic studies

Plus an additional 3,000 ancient DNA results from archaeological remains, of mixed quality and Y chromosome coverage at FamilyTreeDNA.

Wow, just wow.

These three new articles in 2020 will get you started on your Y DNA journey!

Mitochondrial DNA – Matrilineal Line of Humankind is Being Rewritten

The original Oxford Ancestor’s mitochondrial DNA test tested 400 locations. The original Family Tree DNA test tested around 1000 locations. Today, the full sequence mitochondrial DNA test is standard, testing the entire 16,569 locations of the mitochondria.

Mitochondrial DNA tracks your mother’s direct maternal, or matrilineal line. I’ve created a mitochondrial DNA resource page, here that includes easy step-by-step instructions for after you receive your results.

New articles in 2020 included the introduction of The Million Mito Project. 2021 should see the first results – including a paper currently in the works.

The Million Mito Project is rewriting the haplotree of womankind. The current haplotree has expanded substantially since the first handful of haplogroups thanks to thousands upon thousands of testers, but there is so much more information that can be extracted today.

Y and Mitochondrial Resources

If you don’t know of someone in your family to test for Y DNA or mitochondrial DNA for a specific ancestral line, you can always turn to the Y DNA projects at Family Tree DNA by searching here.

The search provides you with a list of projects available for a specific surname along with how many customers with that surname have tested. Looking at the individual Y DNA projects will show the earliest known ancestor of the surname line.

Another resource, WikiTree lists people who have tested for the Y DNA, mitochondrial DNA and autosomal DNA lines of specific ancestors.

Click on images to enlarge

On the left side, my maternal great-grandmother’s profile card, and on the right, my paternal great-great-grandfather. You can see that someone has tested for the mitochondrial DNA of Nora (OK, so it’s me) and the Y DNA of John Estes (definitely not me.)

MitoYDNA, a nonprofit volunteer organization created a comparison tool to replace Ysearch and Mitosearch when they bit the dust thanks to GDPR.

MitoYDNA accepts uploads from different sources and allows uploaders to not only match to each other, but to view the STR values for Y DNA and the mutation locations for the HVR1 and HVR2 regions of mitochondrial DNA. Mags Gaulden, one of the founders, explains in her article, What sets mitoYDNA apart from other DNA Databases?.

If you’ve tested at nonstandard companies, not realizing that they didn’t provide matching, or if you’ve tested at a company like Sorenson, Ancestry, and now Oxford Ancestors that is going out of business, uploading your results to mitoYDNA is a way to preserve your investment. PS – I still recommend testing at FamilyTreeDNA in order to receive detailed results and compare in their large database.

CentiMorgans – The Word of Two Decades

The world of autosomal DNA turns on the centimorgan (cM) measure. What is a centimorgan, exactly? I wrote about that unit of measure in the article Concepts – CentiMorgans, SNPs and Pickin’ Crab.

Fortunately, new tools and techniques make using cMs much easier. The Shared cM Project was updated this year, and the results incorporated into a wonderfully easy tool used to determine potential relationships at DNAPainter based on the number of shared centiMorgans.

Match quality and potential relationships are determined by the number of shared cMs, and the chromosome browser is the best tool to use for those comparisons.

Chromosome Browser – Genetics Tool to View Chromosome Matches

Chromosome browsers allow testers to view their matching cMs of DNA with other testers positioned on their own chromosomes.

My two cousins’ DNA where they match me on chromosomes 1-4, is shown above in blue and red at Family Tree DNA. It’s important to know where you match cousins, because if you match multiple cousins on the same segment, from the same side of your family (maternal or paternal), that’s suggestive of a common ancestor, with a few caveats.

Some people feel that a chromosome browser is an advanced tool, but I think it’s simply standard fare – kind of like driving a car. You need to learn how to drive initially, but after that, you don’t even think about it – you just get in and go. Here’s help learning how to drive that chromosome browser.

Triangulation – Science Plus Group DNA Matching Confirms Genealogy

The next logical step after learning to use a chromosome browser is triangulation. If fact, you’re seeing triangulation above, but don’t even realize it.

The purpose of genetic genealogy is to gather evidence to “prove” ancestral connections to either people or specific ancestors. In autosomal DNA, triangulation occurs when:

  • You match at least two other people (not close relatives)
  • On the same reasonably sized segment of DNA (generally 7 cM or greater)
  • And you can assign that segment to a common ancestor

The same two cousins are shown above, with triangulated segments bracketed at MyHeritage. I’ve identified the common ancestor with those cousins that those matching DNA segments descend from.

MyHeritage’s triangulation tool confirms by bracketing that these cousins also match each other on the same segment, which is the definition of triangulation.

I’ve written a lot about triangulation recently.

If you’d prefer a video, I recorded a “Top Tips” Facebook LIVE with MyHeritage.

Why is Ancestry missing from this list of triangulation articles? Ancestry does not offer a chromosome browser or segment information. Therefore, you can’t triangulate at Ancestry. You can, however, transfer your Ancestry DNA raw data file to either FamilyTreeDNA, MyHeritage, or GEDmatch, all three of which offer triangulation.

Step by step download/upload transfer instructions are found in this article:

Clustering Matches and Correlating Trees

Based on what we’ve seen over the past few years, we can no longer depend on the major vendors to provide all of the tools that genealogists want and need.

Of course, I would encourage you to stay with mainstream products being used by a significant number of community power users. As with anything, there is always someone out there that’s less than honorable.

2020 saw a lot of innovation and new tools introduced. Maybe that’s one good thing resulting from people being cooped up at home.

Third-party tools are making a huge difference in the world of genetic genealogy. My favorites are Genetic Affairs, their AutoCluster tool shown above, DNAPainter and DNAGedcom.

These articles should get you started with clustering.

If you like video resources, here’s a MyHeritage Facebook LIVE that I recorded about how to use AutoClusters:

I created a compiled resource article for your convenience, here:

I have not tried a newer tool, YourDNAFamily, that focuses only on 23andMe results although the creator has been a member of the genetic genealogy community for a long time.

Painting DNA Makes Chromosome Browsers and Triangulation Easy

DNAPainter takes the next step, providing a repository for all of your painted segments. In other words, DNAPainter is both a solution and a methodology for mass triangulation across all of your chromosomes.

Here’s a small group of people who match me on the same maternal segment of chromosome 1, including those two cousins in the chromosome browser and triangulation sections, above. We know that this segment descends from Philip Jacob Miller and his wife because we’ve been able to identify that couple as the most distant ancestor intersection in all of our trees.

It’s very helpful that DNAPainter has added the functionality of painting all of the maternal and paternal bucketed matches from Family Tree DNA.

All you need to do is to link your known matches to your tree in the proper place at FamilyTreeDNA, then they do the rest by using those DNA matches to indicate which of the rest of your matches are maternal and paternal. Instructions, here. You can then export the file and use it at DNAPainter to paint all of those matches on the correct maternal or paternal chromosomes.

Here’s an article providing all of the DNAPainter Instructions and Resources.

DNA Matches Plus Trees Enhance Genealogy

Of course, utilizing DNA matching plus finding common ancestors in trees is one of the primary purposes of genetic genealogy – right?

Vendors have linked the steps of matching DNA with matching ancestors in trees.

Genetic Affairs take this a step further. If you don’t have an ancestor in your tree, but your matches have common ancestors with each other, Genetic Affairs assembles those trees to provide you with those hints. Of course, that common ancestor might not be relevant to your genealogy, but it just might be too!

click to enlarge

This tree does not include me, but two of my matches descend from a common ancestor and that common ancestor between them might be a clue as to why I match both of them.

Ethnicity Continues to be Popular – But Is No Shortcut to Genealogy

Ethnicity is always popular. People want to “do their DNA” and find out where they come from. I understand. I really do. Who doesn’t just want an answer?

Of course, it’s not that simple, but that doesn’t mean it’s not disappointing to people who test for that purpose with high expectations. Hopefully, ethnicity will pique their curiosity and encourage engagement.

All four major vendors rolled out updated ethnicity results or related tools in 2020.

The future for ethnicity, I believe, will be held in integrated tools that allow us to use ethnicity results for genealogy, including being able to paint our ethnicity on our chromosomes as well as perform segment matching by ethnicity.

For example, if I carry an African segment on chromosome 1 from my father, and I match one person from my mother’s side and one from my father’s side on that same segment – one or the other of those people should also have that segment identified as African. That information would inform me as to which match is paternal and which is maternal

Not only that, this feature would help immensely tracking ancestors back in time and identifying their origins.

Will we ever get there? I don’t know. I’m not sure ethnicity is or can be accurate enough. We’ll see.

Transition to Digital and Online

Sometimes the future drags us kicking and screaming from the present.

With the imposed isolation of 2020, conferences quickly moved to an online presence. The genealogy community has all pulled together to make this work. The joke is that 2020’s most used phrase is “can you hear me?” I can vouch for that.

Of course while the year 2020 is over, the problem isn’t and is extending at least through the first half of 2021 and possibly longer. Conferences are planned months, up to a year, in advance and they can’t turn on a dime, so don’t even begin to expect in-person conferences until either late in 2021 or more likely, 2022 if all goes well this year.

I expect the future will eventually return to in-person conferences, but not entirely.

Finding ways to be more inclusive allows people who don’t want to or can’t travel or join in-person to participate.

I’ve recorded several sessions this year, mostly for 2021. Trust me, these could be a comedy, mostly of errors😊

I participated in four MyHeritage Facebook LIVE sessions in 2020 along with some other amazing speakers. This is what “live” events look like today!

Screenshot courtesy MyHeritage

A few days ago, I asked MyHeritage for a list of their LIVE sessions in 2020 and was shocked to learn that there were more than 90 in English, all free, and you can watch them anytime. Here’s the MyHeritage list.

By the way, every single one of the speakers is a volunteer, so say a big thank you to the speakers who make this possible, and to MyHeritage for the resources to make this free for everyone. If you’ve ever tried to coordinate anything like this, it’s anything but easy.

Additonally, I’ve created two Webinars this year for Legacy Family Tree Webinars.

Geoff Rasmussen put together the list of their top webinars for 2020, and I was pleased to see that I made the top 10! I’m sure there are MANY MORE you’d be interested in watching. Personally, I’m going to watch #6 yet today! Also, #9 and #22. You can always watch new webinars for free for a few days, and you can subscribe to watch all webinars, here.

The 2021 list of webinar speakers has been announced here, and while I’m not allowed to talk about something really fun that’s upcoming, let’s just say you definitely have something to look forward to in the springtime!

Also, don’t forget to register for RootsTech Connect which is entirely online and completely free, February 25-27, here.

Thank you to Penny Walters for creating this lovely graphic.

There are literally hundreds of speakers providing sessions in many languages for viewers around the world. I’ve heard the stats, but we can’t share them yet. Let me just say that you will be SHOCKED at the magnitude and reach of this conference. I’m talking dumbstruck!

During one of our zoom calls, one of the organizers says it feels like we’re constructing the plane as we’re flying, and I can confirm his observation – but we are getting it done – together! All hands on deck.

I’ll be presenting an advanced session about triangulation as well as a mini-session in the FamilySearch DNA Resource Center about finding your mother’s ancestors. I’ll share more information as it’s released and I can.

Companies and Owners Come & Go

You probably didn’t even notice some of these 2020 changes. Aside from the death of Bryan Sykes (RIP Bryan,) the big news and the even bigger unknown is the acquisition of Ancestry by Blackstone. Recently the CEO, Margo Georgiadis announced that she was stepping down. The Ancestry Board of Directors has announced an external search for a new CEO. All I can say is that very high on the priority list should be someone who IS a genealogist and who understands how DNA applies to genealogy.

Other changes included:

In the future, as genealogy and DNA testing becomes ever more popular and even more of a commodity, company sales and acquisitions will become more commonplace.

Some Companies Reduced Services and Cut Staff

I understand this too, but it’s painful. The layoffs occurred before Covid, so they didn’t result from Covid-related sales reductions. Let’s hope we see renewed investment after the Covid mess is over.

In a move that may or may not be related to an attempt to cut costs, Ancestry removed 6 and 7 cM matches from their users, freeing up processing resources, hardware, and storage requirements and thereby reducing costs.

I’m not going to beat this dead horse, because Ancestry is clearly not going to move on this issue, nor on that of the much-requested chromosome browser.

Later in the year, 23andMe also removed matches and other features, although, to their credit, they have restored at least part of this functionality and have provided ethnicity updates to V3 and V4 kits which wasn’t initially planned.

It’s also worth noting that early in 2020, 23andMe laid off 100 people as sales declined. Since that time, 23andMe has increasingly pushed consumers to pay to retest on their V5 chip.

About the same time, Ancestry also cut their workforce by about 6%, or about 100 people, also citing a slowdown in the consumer testing market. Ancestry also added a health product.

I’m not sure if we’ve reached market saturation or are simply seeing a leveling off. I wrote about that in DNA Testing Sales Decline: Reason and Reasons.

Of course, the pandemic economy where many people are either unemployed or insecure about their future isn’t helping.

The various companies need some product diversity to survive downturns. 23andMe is focused on medical research with partners who pay 23andMe for the DNA data of customers who opt-in, as does Ancestry.

Both Ancestry and MyHeritage provide subscription services for genealogy records.

FamilyTreeDNA is part of a larger company, GenebyGene whose genetics labs do processing for other companies and medical facilities.

A huge thank you to both MyHeritage and FamilyTreeDNA for NOT reducing services to customers in 2020.

Scientific Research Still Critical & Pushes Frontiers

Now that DNA testing has become a commodity, it’s easy to lose track of the fact that DNA testing is still a scientific endeavor that requires research to continue to move forward.

I’m still passionate about research after 20 years – maybe even more so now because there’s so much promise.

Research bleeds over into the consumer marketplace where products are improved and new features created allowing us to better track and understand our ancestors through their DNA that we and our family members inherit.

Here are a few of the research articles I published in 2020. You might notice a theme here – ancient DNA. What we can learn now due to new processing techniques is absolutely amazing. Labs can share files and information, providing the ability to “reprocess” the data, not the DNA itself, as more information and expertise becomes available.

Of course, in addition to this research, the Million Mito Project team is hard at work rewriting the tree of womankind.

If you’d like to participate, all you need to do is to either purchase a full sequence mitochondrial DNA kit at FamilyTreeDNA, or upgrade to the full sequence if you tested at a lower level previously.

Predictions

Predictions are risky business, but let me give it a shot.

Looking back a year, Covid wasn’t on the radar.

Looking back 5 years, neither Genetic Affairs nor DNAPainter were yet on the scene. DNAAdoption had just been formed in 2014 and DNAGedcom which was born out of DNAAdoption didn’t yet exist.

In other words, the most popular tools today didn’t exist yet.

GEDmatch, founded in 2010 by genealogists for genealogists was 5 years old, but was sold in December 2019 to Verogen.

We were begging Ancestry for a chromosome browser, and while we’ve pretty much given up beating them, because the horse is dead and they can sell DNA kits through ads focused elsewhere, that doesn’t mean genealogists still don’t need/want chromosome and segment based tools. Why, you’d think that Ancestry really doesn’t want us to break through those brick walls. That would be very bizarre, because every brick wall that falls reveals two more ancestors that need to be researched and spurs a frantic flurry of midnight searching. If you’re laughing right now, you know exactly what I mean!

Of course, if Ancestry provided a chromosome browser, it would cost development money for no additional revenue and their customer service reps would have to be able to support it. So from Ancestry’s perspective, there’s no good reason to provide us with that tool when they can sell kits without it. (Sigh.)

I’m not surprised by the management shift at Ancestry, and I wouldn’t be surprised to see several big players go public in the next decade, if not the next five years.

As companies increase in value, the number of private individuals who could afford to purchase the company decreases quickly, leaving private corporations as the only potential buyers, or becoming publicly held. Sometimes, that’s a good thing because investment dollars are infused into new product development.

What we desperately need, and I predict will happen one way or another is a marriage of individual tools and functions that exist separately today, with a dash of innovation. We need tools that will move beyond confirming existing ancestors – and will be able to identify ancestors through our DNA – out beyond each and every brick wall.

If a tester’s DNA matches to multiple people in a group descended from a particular previously unknown couple, and the timing and geography fits as well, that provides genealogical researchers with the hint they need to begin excavating the traditional records, looking for a connection.

In fact, this is exactly what happened with mitochondrial DNA – twice now. A match and a great deal of digging by one extremely persistent cousin resulting in identifying potential parents for a brick-wall ancestor. Autosomal DNA then confirmed that my DNA matched with 59 other individuals who descend from that couple through multiple children.

BUT, we couldn’t confirm those ancestors using autosomal DNA UNTIL WE HAD THE NAMES of the couple. DNA has the potential to reveal those names!

I wrote about that in Mitochondrial DNA Bulldozes Brick Wall and will be discussing it further in my RootsTech presentation.

The Challenge

We have most of the individual technology pieces today to get this done. Of course, the combined technological solution would require significant computing resources and processing power – just at the same time that vendors are desperately trying to pare costs to a minimum.

Some vendors simply aren’t interested, as I’ve already noted.

However, the winner, other than us genealogists, of course, will be the vendor who can either devise solutions or partner with others to create the right mix of tools that will combine matching, triangulation, and trees of your matches to each other, even if you don’t’ share a common ancestor.

We need to follow the DNA past the current end of the branch of our tree.

Each triangulated segment has an individual history that will lead not just to known ancestors, but to their unknown ancestors as well. We have reached critical mass in terms of how many people have tested – and more success would encourage more and more people to test.

There is a genetic path over every single brick wall in our genealogy.

Yes, I know that’s a bold statement. It’s not future Jetson’s flying-cars stuff. It’s doable – but it’s a matter of commitment, investment money, and finding a way to recoup that investment.

I don’t think it’s possible for the one-time purchase of a $39-$99 DNA test, especially when it’s not a loss-leader for something else like a records or data subscription (MyHeritage and Ancestry) or a medical research partnership (Ancestry and 23andMe.)

We’re performing these analysis processes manually and piecemeal today. It’s extremely inefficient and labor-intensive – which is why it often fails. People give up. And the process is painful, even when it does succeed.

This process has also been made increasingly difficult when some vendors block tools that help genealogists by downloading match and ancestral tree information. Before Ancestry closed access, I was creating theories based on common ancestors in my matches trees that weren’t in mine – then testing those theories both genetically (clusters, AutoTrees and ThruLines) and also by digging into traditional records to search for the genetic connection.

For example, I’m desperate to identify the parents of my James Lee Clarkson/Claxton, so I sorted my spreadsheet by surname and began evaluating everyone who had a Clarkson/Claxton in their tree in the 1700s in Virginia or North Carolina. But I can’t do that anymore now, either with a third-party tool or directly at Ancestry. Twenty million DNA kits sold for a minimum of $79 equals more than 1.5 billion dollars. Obviously, the issue here is not a lack of funds.

Including Y and mitochondrial DNA resources in our genetic toolbox not only confirms accuracy but also provides additional hints and clues.

Sometimes we start with Y DNA or mitochondrial DNA, and wind up using autosomal and sometimes the reverse. These are not competing products. It’s not either/or – it’s *and*.

Personally, I don’t expect the vendors to provide this game-changing complex functionality for free. I would be glad to pay for a subscription for top-of-the-line innovation and tools. In what other industry do consumers expect to pay for an item once and receive constant life-long innovations and upgrades? That doesn’t happen with software, phones nor with automobiles. I want vendors to be profitable so that they can invest in new tools that leverage the power of computing for genealogists to solve currently unsolvable problems.

Every single end-of-line ancestor in your tree represents a brick wall you need to overcome.

If you compare the cost of books, library visits, courthouse trips, and other research endeavors that often produce exactly nothing, these types of genetic tools would be both a godsend and an incredible value.

That’s it.

That’s the challenge, a gauntlet of sorts.

Who’s going to pick it up?

I can’t answer that question, but I can say that 23andMe can’t do this without supporting extensive trees, and Ancestry has shown absolutely no inclination to support segment data. You can’t achieve this goal without segment information or without trees.

Among the current players, that leaves two DNA testing companies and a few top-notch third parties as candidates – although – as the past has proven, the future is uncertain, fluid, and everchanging.

It will be interesting to see what I’m writing at the end of 2025, or maybe even at the end of 2021.

Stay tuned.

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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

Y DNA Resources and Repository

I’ve created a Y DNA resource page with the information in this article, here, as a permanent location where you can find Y DNA information in one place – including:

  • Step-by-step guides about how to utilize Y DNA for your genealogy
  • Educational articles and links to the latest webinars
  • Articles about the science behind Y DNA
  • Ancient DNA
  • Success stories

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

If you haven’t already taken a Y DNA test, and you’re a male (only males have a Y chromosome,) you can order one here. If you also purchase the Family Finder, autosomal test, those results can be used to search together.

What is Y DNA?

Y DNA is passed directly from fathers to their sons, as illustrated by the blue arrow, above. Daughters do not inherit the Y chromosome. The Y chromosome is what makes males, male.

Every son receives a Y chromosome from his father, who received it from his father, and so forth, on up the direct patrilineal line.

Comparatively, mitochondrial DNA, the pink arrow, is received by both sexes of children from the mother through the direct matrilineal line.

Autosomal DNA, the green arrow, is a combination of randomly inherited DNA from many ancestors that is inherited by both sexes of children from both parents. This article explains a bit more.

Y DNA has Unique Properties

The Y chromosome is never admixed with DNA from the mother, so the Y chromosome that the son receives is identical to the father’s Y chromosome except for occasional minor mutations that take place every few generations.

This lack of mixture with the mother’s DNA plus the occasional mutation is what makes the Y chromosome similar enough to match against other men from the same ancestors for hundreds or thousands of years back in time, and different enough to be useful for genealogy. The mutations can be tracked within extended families.

In western cultures, the Y chromosome path of inheritance is usually the same as the surname, which means that the Y chromosome is uniquely positioned to identify the direct biological patrilineal lineage of males.

Two different types of Y DNA tests can be ordered that work together to refine Y DNA results and connect testers to other men with common ancestors.

FamilyTreeDNA provides STR tests with their 37, 67 and 111 marker test panels, and comprehensive STR plus SNP testing with their Big Y-700 test.

click to enlarge

STR markers are used for genealogy matching, while SNP markers work with STR markers to refine genealogy further, plus provide a detailed haplogroup.

Think of a haplogroup as a genetic clan that tells you which genetic family group you belong to – both today and historically, before the advent of surnames.

This article, What is a Haplogroup? explains the basic concept of how haplogroups are determined.

In addition to the Y DNA test itself, Family Tree DNA provides matching to other testers in their database plus a group of comprehensive tools, shown on the dashboard above, to help testers utilize their results to their fullest potential.

You can order or upgrade a Y DNA test, here. If you also purchase the Family Finder, autosomal test, those results can be used to search together.

Step-by-Step – Using Your Y DNA Results

Let’s take a look at all of the features, functions, and tools that are available on your FamilyTreeDNA personal page.

What do those words mean? Here you go!

Come along while I step through evaluating Big Y test results.

Big Y Testing and Results

Why would you want to take a Big Y test and how can it help you?

While the Big Y-500 has been superseded by the Big Y-700 test today, you will still be interested in some of the underlying technology. STR matching still works the same way.

The Big Y-500 provided more than 500 STR markers and the Big Y-700 provides more than 700 – both significantly more than the 111 panel. The only way to receive these additional markers is by purchasing the Big Y test.

I have to tell you – I was skeptical when the Big Y-700 was introduced as the next step above the Big Y-500. I almost didn’t upgrade any kits – but I’m so very glad that I did. I’m not skeptical anymore.

This Y DNA tree rocks. A new visual format with your matches listed on their branches. Take a look!

Educational Articles

I’ve been writing about DNA for years and have selected several articles that you may find useful.

What kinds of information are available if you take a Y DNA test, and how can you use it for genealogy?

What if your father isn’t available to take a DNA test? How can you determine who else to test that will reveal your father’s Y DNA information?

Family Tree DNA shows the difference in the number of mutations between two men as “genetic distance.” Learn what that means and how it’s figured in this article.

Of course, there were changes right after I published the original Genetic Distance article. The only guarantees in life are death, taxes, and that something will change immediately after you publish.

Sometimes when we take DNA tests, or others do, we discover the unexpected. That’s always a possibility. Here’s the story of my brother who wasn’t my biological brother. If you’d like to read more about Dave’s story, type “Dear Dave” into the search box on my blog. Read the articles in publication order, and not without a box of Kleenex.

Often, what surprise matches mean is that you need to dig further.

The words paternal and patrilineal aren’t the same thing. Paternal refers to the paternal half of your family, where patrilineal is the direct father to father line.

Just because you don’t have any surname matches doesn’t necessarily mean it’s because of what you’re thinking.

Short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs) aren’t the same thing and are used differently in genealogy.

Piecing together your ancestor’s Y DNA from descendants.

Haplogroups are something like our pedigree charts.

What does it mean when you have a zero for a marker value?

There’s more than one way to break down that brick wall. Here’s how I figured out which of 4 sons was my ancestor.

Just because you match the right line autosomally doesn’t mean it’s because you descend from the male child you think is your ancestor. Females gave their surnames to children born outside of a legal marriage which can lead to massive confusion. This is absolutely why you need to test the Y DNA of every single ancestral line.

When the direct patrilineal line isn’t the line you’re expecting.

You can now tell by looking at the flags on the haplotree where other people’s ancestral lines on your branch are from. This is especially useful if you’ve taken the Big Y test and can tell you if you’re hunting in the right location.

If you’re just now testing or tested in 2018 or after, you don’t need to read this article unless you’re interested in the improvements to the Big Y test over the years.

2019 was a banner year for discovery. 2020 was even more so, keeping up an amazing pace. I need to write a 2020 update article.

What is a terminal SNP? Hint – it’s not fatal😊

How the TIP calculator works and how to best interpret the results. Note that this tool is due for an update that incorporates more markers and SNP results too.

You can view the location of the Y DNA and mitochondrial DNA ancestors of people whose ethnicity you match.

Tools and Techniques

This free public tree is amazing, showing locations of each haplogroup and totals by haplogroup and country, including downstream branches.

Need to search for and find Y DNA candidates when you don’t know anyone from that line? Here’s how.

Yes, it’s still possible to resolve this issue using autosomal DNA. Non-matching Y DNA isn’t the end of the road, just a fork.

Science Meets Genealogy – Including Ancient DNA

Haplogroup C was an unexpected find in the Americas and reaches into South America.

Haplogroup C is found in several North American tribes.

Haplogroup C is found as far east as Nova Scotia.

Test by test, we made progress.

New testers, new branches. The research continues.

The discovery of haplogroup A00 was truly amazing when it occurred – the base of the phylotree in Africa.

The press release about the discovery of haplogroup A00.

In 2018, a living branch of A00 was discovered in Africa, and in 2020, an ancient DNA branch.

Did you know that haplogroups weren’t always known by their SNP names?

This brought the total of SNPs discovered by Family Tree DNA in mid-2018 to 153,000. I should contact the Research Center to see how many they have named at the end of 2020.

An academic paper split ancient haplogroup D, but then the phylogenetic research team at FamilyTreeDNA split it twice more! This might not sound exciting until you realize this redefines what we know about early man, in Africa and as he emerged from Africa.

Ancient DNA splits haplogroup P after analyzing the remains of two Jehai people from West Malaysia.

For years I doubted Kennewick Man’s DNA would ever be sequenced, but it finally was. Kennewick Man’s mitochondrial DNA haplogroup is X2a and his Y DNA was confirmed to Q-M3 in 2015.

Compare your own DNA to Vikings!

Twenty-seven Icelandic Viking skeletons tell a very interesting story.

Irish ancestors? Check your DNA and see if you match.

Ancestors from Hungary or Italy? Take a look. These remains have matches to people in various places throughout Europe.

The Y DNA story is no place near finished. Dr. Miguel Vilar, former Lead Scientist for National Geographic’s Genographic Project provides additional analysis and adds a theory.

Webinars

Y DNA Webinar at Legacy Family Tree Webinars – a 90-minute webinar for those who prefer watching to learn! It’s not free, but you can subscribe here.

Success Stories and Genealogy Discoveries

Almost everyone has their own Y DNA story of discovery. Because the Y DNA follows the surname line, Y DNA testing often helps push those lines back a generation, or two, or four. When STR markers fail to be enough, we can turn to the Big Y-700 test which provides SNP markers down to the very tip of the leaves in the Y DNA tree. Often, but not always, family-defining SNP branches will occur which are much more stable and reliable than STR mutations – although SNPs and STRs should be used together.

Methodologies to find ancestral lines to test, or maybe descendants who have already tested.

DNA testing reveals an unexpected mystery several hundred years old.

When I write each of my “52 Ancestor” stories, I include genetic information, for the ancestor and their descendants, when I can. Jacob was special because, in addition to being able to identify his autosomal DNA, his Y DNA matches the ancient DNA of the Yamnaya people. You can read about his Y DNA story in Jakob Lenz (1748-1821), Vinedresser.

Please feel free to add your success stories in the comments.

What About You?

You never know what you’re going to discover when you test your Y DNA. If you’re a female, you’ll need to find a male that descends from the line you want to test via all males to take the Y DNA test on your behalf. Of course, if you want to test your father’s line, your father, or a brother through that father, or your uncle, your father’s brother, would be good candidates.

What will you be able to discover? Who will the earliest known ancestor with that same surname be among your matches? Will you be able to break down a long-standing brick wall? You’ll never know if you don’t test.

You can click here to upgrade an existing test or order a Y DNA test.

Share the Love

You can always forward these articles to friends or share by posting links on social media. Who do you know that might be interested?

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Genealogy Research

Books

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.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

Glossary – DNA – Deoxyribonucleic Acid

What is DNA and why do I care?

Good questions. Let’s take a look at the answer in general, then why we use DNA for genealogy.

The Recipe for You

DNA, deoxyribonucleic acid, is the book of life for all organisms. In essence, it’s the recipe for you – and what makes you unique.

DNA is formed of strands that twist to form the familiar double helix pattern.

The two strands are joined together by one of 4 different nucleotides, one extending from each side to connect in the middle. The nucleotides are:

  • Cytosine – C
  • Guanine – G
  • Thymine – T
  • Adenine – A

The nucleotide names don’t really matter for genetic genealogy, but what does matter is that the sequence of these nucleotides when chained together is what encodes information on long structures called chromosomes. Each person carries 22 chromosomes, plus the 23rd chromosome pair which is gender specific.

Using DNA for Genetic Genealogy

There are four different kinds of DNA that genealogists use in different ways for obtaining ancestors’ information relevant to genetic genealogy. Thankfully, we have 4 different kinds of DNA available to us because of unique inheritance patterns for each kind of DNA – meaning we inherited different kinds of DNA from different ancestral paths. If one kind of DNA doesn’t work in a particular situation, chances are good that another type will.

Genetic genealogy makes use of 4 different types of DNA.

  • Y DNA – passed from males to male children, only (your father’s paternal line)
  • Mitochondrial DNA – passed from females to both genders of children, but only females pass it on (your mother’s matrilineal line)

Y and mitochondrial DNA inheritance paths are shown on a pedigree chart in the graphic below, with the blue boxes representing Y DNA and the red circles representing mitochondrial DNA inheritance.

In addition to Y and mitochondrial DNA, genetic genealogists also use two kinds of DNA that reflect inheritance from additional ancestral lines, in addition to the red and blue lines shown above – meaning the ancestral lines with no color.

  • Autosomal DNA – the 22 chromosomes that recombine during reproduction.
  • X Chromosome – always contributed by the mother, but only contributed by the father to female children – this is the 23rd chromosome pair which recombines with a unique inheritance pattern.  You can read more about that in the article, X Marks the Spot.

Receiving What Kind of DNA from Whom

While the Y and mitochondrial DNA have unique and very prescribed inheritance patterns as shown by the red arrows pointing to the blue Y chromosome below at far left, and the red mitochondrial circles at far right, the 22 autosomal chromosomes are contributed equally by each parent. In other words, for each chromosome, a child inherits half of each parent’s DNA. How the selection of which DNA is contributed to each child is unknown.

A child’s gender is determined by the parent’s contributions to the 23rd chromosome, not shown above. The following chart explains gender determination by the X and Y combinations of the 23rd chromosome.

Received from Mother Received from Father
Male child X Y
Female child X X

The Y chromosome is what makes males male.

No Y chromosome?  You’re a female.

However, this X chromosome inheritance pattern provides us with the ability to look at X matches for males and know immediately that they had to have come from his mother’s lineage – because males don’t inherit an X chromosome from their father.

Autosomal DNA and Genetic Genealogy

The 22 non-gender chromosomes recombine in each generation, with half of each chromosome being contributed by each parent, as shown in the illustrations above.

You can see that in the first generation, the child received one blue and one yellow, or one pink and one green, chromosome. In giving each child exactly half of their DNA, each parent contributes some amount of ancestral DNA from generations upstream, as you can see in the mother/father and son/daughter generations.

For example, each child receives, on average, 25% of each of their grandparent’s DNA – although they can receive somewhat more or less than 25%, depending on the random nature of recombination.

Therefore, genetic genealogy testing companies compare tester’s autosomal DNA with other testers and look for common segments contributed by common ancestors, resulting in autosomal matching.

When relatively large segments match between three or more relatives who are not immediate family, we can attribute that DNA to a common ancestor. Of course, the challenge, and the thrill, is to determine which common ancestor contributed that common DNA to our triangulated match group. It’s a great way to verify our research and to break down brick walls.

Let’s face it, you received ALL of your DNA from SOME combination of ancestors, and if you carry large enough pieces from any specific ancestor, we can, hopefully, identify the source of that DNA segment by looking at the genealogy of those we match on that segment.

It’s a great puzzle to unravel, and best of all, it’s the puzzle of you.

More Info

The great news is that you can utilize your Y DNA, mitochondrial DNA and autosomal DNA differently, to provide you with different kinds of information about different ancestors and genealogy lines.

If you’d like to read more about how the 4 Kinds of DNA can be used, please read the short article, 4 Kinds of DNA for Genetic Genealogy.

You can also enter any word or phrase into the search box in the upper right hand corner of this blog to find additional useful information about any topic.

If You Want to Test

If you’d like to learn more about the various kinds of DNA tests available, and which one or ones would be the best for you, please read the article, Which DNA Test is Best?

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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