Category Archives: Triangulation

Wherefore Art Thou, Oh Ancestor? – New Generation Tree Chart Suggests Where to Look in Your Matches’ Trees

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When you see a DNA match, do you wonder how far back in your trees your common ancestors live? How do you know where to search?

I’ve been working through my DNA match list person by person, reviewing the information and trees for each match, searching for common ancestors.

Whether you’re looking at individual matches, shared matches, clusters or triangulation groups, trees are essential for finding common ancestors.

My favorite vendor-provided tree is my MyHeritage tree. They’ve done a great job, so I’m using their tree for my examples today.

Here’s the question I’m trying to answer – based on how much DNA I share with someone, how far up that person’s tree, roughly, do I need to look for our most recent common ancestor? And, is there something else I can tell?

Tree Size Matters aka How Far Up the Tree Do I Need to Look?

So, if you click on your matches’ trees, how far up their tree do you need to look for a common ancestor? How many times will you need to click to expand their tree beyond the 4 (Ancestry) or 5 (MyHeritage) generations initially displayed, assuming your match has a tree that size? How far out, meaning how many generations do you need to hope and pray they have extended their tree?

Conversely, how many generations do YOU need to include for your tree to be useful for:

  • Other testers to find common ancestors with you
  • Theories of Family Relativity provided by MyHeritage, suggesting common ancestors with other testers
  • ThruLines at Ancestry
  • Family Matching (bucketing) at FamilyTreeDNA which assigns your matches either maternally or paternally. (Note – FamilyTreeDNA is transitioning their trees to the MyHeritage platform.)

If you’re thinking that the size of YOUR tree doesn’t matter, think again.

Not only can the vendors not help you effectively without a tree – genealogy is a collaborative sport. Other people NEED the generations in your tree to locate your common ancestors, just like you NEED to see as many generations in their tree as possible. The vendors NEED as complete a tree as you can provide to help you further.

DNA+Trees Bulldoze Brick Walls

But maybe the most important aspect is that you NEED trees to break through brick walls – especially in conjunction with DNA and tools like clustering that show you visual images of genetic commonality.

We all need to be team players when we have that option – meaning we know who are ancestors are. Our brick walls can be solved, and you can be a puzzle piece of solving brick walls for others too.

Some of my closest friends and cousins are a direct result of DNA matches and genealogy collaboration over the years. (You know who you are!) I’ve even discovered that several friends are cousins too – which I would never have happened without DNA and trees.

Guidelines for What’s Reasonable

What is a reasonable number of generations to peruse for common ancestors?

The answer is – it depends! (I’m sorry…)

Let’s sort through this.

Given that, on AVERAGE, inherited autosomal DNA from a particular ancestor is halved in each successive generation during recombination between the parents, we can calculate the expected average. However, in reality – DNA isn’t always halved. Sometimes segments are passed intact, divided but not in half, or not inherited at all. That’s why you may not match some third cousins, but match some 7th cousins. Random recombination is, in fact, random.

Every segment has its own individual history.

That’s part of the reason we use triangulation, to confirm that a specific segment originated with a particular couple or ancestral line.

Here are a few rules of thumb, with links to articles that explain the various terms and concepts:

  • There are no known instances of second cousins or closer NOT matching.
  • Some (but not all) people find their common ancestor in the first 5 or 6 generations.
  • Many people have proven, triangulated matches to the 10th generation, but those are more difficult to prove, often due to incomplete trees (brick walls) at that distance on either your side, your match’s side, or both. I have no brick walls at 5 generations, counting my parents as generation 1, but I have 6 female brick walls in the 6th generation.
  • If you’re lucky, you can spot your common ancestral surname on the first page of your match’s tree – and follow that line back. Note that there may be additional common ancestors, so view each of their lines to the end. The MyHeritage tree makes this super easy!
  • Pedigree collapse, where you, and/or the other person share multiple lines, known or unknown, is a complicating factor. Pedigree collapse often means you share more DNA than would be expected for a specific relationship.
  • Endogamy, which is pedigree collapse on steroids, is real and will cause many smaller matches.
  • Based on the number of distant versus close cousins you have, you will have MANY more smaller matches than larger ones.
  • And last, but not least, some matches, especially smaller ones, are identical by chance (IBC), not identical by descent (IBD).

All of that said, we can estimate the number of generations back in our matches’ trees where we might need to look for that common ancestor.

As I’ve been reviewing all of my matches, I realized that I can look at the match cM size and mentally size up just about where in their tree I will find our common ancestor. In essence, I’ve “bottled that” for you, here.

Using Trees Effectively

One of the reasons I love the MyHeritage tree is that as you need to click further back in trees beyond the generations initially displayed, which occurs often – the next generations open to the right, the earlier generations just shift left and they all remain visible.

I know that might not sound important, but it is – incredibly – especially when you’re evaluating several matches. Otherwise, it’s easy to lose track of where you are in someone’s tree. I have 9 generations open, above, and I can just keep going – with the more recent generations just shifting left.

But there’s more!

When viewing matches’ trees, I can also click on anyone in their tree, and a profile box opens to the left with additional information about that person, leaving the tree open so I don’t lose my place and have to click around to find it again. I can’t even begin to tell you how wonderful this is, and it’s unique to MyHeritage. You can tell the MyHeritage tree was designed by actual genealogists.

This feature is incredibly useful because many, if not most, of the common ancestors with your matches will be beyond the first page displayed.

Thank you, thank you, MyHeritage!!!

Estimating the Number of Generations by the Amount of Shared DNA

How far up the tree you’ll need to look can be estimated by the amount of DNA that you share with a particular match.

Vendors estimate the relationship of DNA matches by either the percentage of shared DNA or the number of shared centimorgans (cMs), but there’s no quick reference to show you, generationally, where to focus in you and your matches’ trees for your common ancestor.

That’s the handy reference Generation Tree Chart that I’ve created here.

In the article, Shared cM Project 2020 Analysis, Comparison and Handy Reference Charts, I compiled information from multiple sources into one chart detailing HOW MUCH DNA can be expected to be shared at various relationship levels. Shared cM Project information is also visualized at DNAPainter

What I need to know now, though, isn’t an estimate of how closely we are related, but how many generations back to look for our common ancestor in my and their trees.

As I’m clicking through my matches, the majority, by far, are smaller than larger. That makes sense, of course, because we have many more distant relatives than close relatives.

At FamilyTreeDNA, I have 8758 matches who are not immediate or close family.

Number of Matches Relationship Range cM Range
10 Half-1C and 1C1R 318-637 cM
4 2C and equivalent 159-318 cM
7 Between 2C-3C, such as half-2C 80-159 cM
79 3C and equivalent 40-80 cM
814 3C-4C and equivalent 20-40 cM
7548 4C and equivalent 9-20 cM
293 Below 4C and equivalent 7-9 cM

I know the people in the first two categories and some of the people in the third category, but the genetic/ancestral scavenger hunt begins there.

All Cousins Are Not Equivalent

You’re probably wondering about the word “equivalent.” Genetically, people of different relationships carry the same amount of expected DNA. We not only have 5th cousins (5C), for example, we have:

  • Half-fifth-cousins
  • Fifth-cousins-once-removed (5C1R)
  • Fifth-cousins-twice-removed (5C2R)
  • And so forth

I wrote about determining cousin relationships, meaning halves and removed,here.

Genetically speaking, a 5C2R carries the same expected amount of shared DNA as a 6C, so they are functional equivalents. How do we resolve this and where do we look in our trees for our common ancestors?

I’m so glad you asked!

Where Do Various Cousin Levels Fall in My Tree?

We know that first cousins share grandparents, but as we get further back in our tree, it’s difficult to remember or calculate how many generations back a 6th cousin is in our tree.

I’ve used my MyHeritage tree to display 1st through 10th cousins, labeled in red, and the generation number they represent, in black. So, my common ancestors with my second cousins are found 3 generations out in my tree.

Making things more challenging, however, is that unless we know the match already, we’re trying to figure out how closely the match is actually related to us based on their DNA. Not all cousins of any level share the same amount of DNA, so the best vendors can do is provide an estimate or relationship range.

To determine our actual relationship, we need to find our most recent common ancestor.

Where, approximately, in my tree would I look for each category of match, especially that huge group of 7548 people?

Good question!

The Generation Tree Chart is Born

I needed a quick reference for approximately how many generations back in time our common ancestors existed by how much DNA we share, so I know how far back in someone’s tree I need to look.

I’ve reorganized the data from my earlier articles and created a new resource.

The Generation Tree Chart

The Generation Tree Chart:

  • Is not meant to identify parents or close relatives.
  • Does not include parents or grandparents.
  • Counts your parents as generation 1. Some people count themselves as generation 1. If you’re discussing this table, keep in mind that you may be one generation “off” in your discussions with someone who counts differently.
  • This chart clusters the relationships according to color, based on how much DNA people of that relationship are expected to share. For example, a first-cousin-twice-removed (1C2R) shares the same expected amount of DNA with you as a second-cousin (2C).
  • All cousin relationships that are expected to share the same amount of DNA are in the same color band.
  • If you’re using this chart with Ancestry’s numbers, use the unweighted (pre-Timber) amount of DNA.

The colored bands correlate to shared DNA, but the shared ancestor isn’t necessarily the same generation back in time.

This is my “show your work” chart. You’ll notice a few things.

  • The “Avg % Shared” column is the amount of shared DNA expected based on a 50% division (recombination) in each generation, which almost never happens exactly.
  • The “Expected cM” column is the expected cM amount based a 50% division in each generation.
  • I’ve incorporated the DNAPainter mean, low and high range for each relationship.
  • The expected number of shared cMs, in the “Expected cM” column is almost always smaller than the “cM Mean” from DNAPainter. The mean is the midpoint reported in the Shared cM Project for all respondents of that relationship who reported their shared DNA – minus the outliers.

This fact that reported is often significantly higher than expected is particularly interesting. In the closer generations, it doesn’t really matter, but beginning about the 6th blue band and the 7th red band in the chart, the mean is often twice the expected amount.

Remember that DNAPainter numbers are based on the Shared cM Project which relies on user-reported relationships and their associated cM match amounts. You can view Blaine Bettinger’s paper about the most recent Shared cM Project version (2020) and his methodologies here.

My theory is that the more distantly people match, the less likely they are to report the relationship accurately. They may be reporting the relationship they believe to be accurate, life a full versus a half cousin, but that’s not actually the case. It’s also possible that there are multiple unknown relationships or pedigree collapse, or both.

Furthermore, from the red band to the end of the chart, the reported amounts are significantly higher than expected, which is probably a function, in part, of “all or nothing” segment transmission. In other words, if someone’s parent carries a 10 cM segment, you’re probably going to inherit all of it or none of it. If it’s actually divided to 5 and 5 cM, you’re not going to see it on any match list.

In my case, I have several 8 cM triangulated matches who descend from common Dodson ancestors whose descendants intermarried a couple of generations later. Therefore, these matches are, respectively, both my 6C2R and 7C3R from the same line (20 cM total match), two matches at 6C1R (66 cM and 19 cM), and one 6C (51 cM). These people also triangulate on multiple segments. Given the high amount of shared DNA for this relationship level, I suspect additional pedigree collapse someplace. At least one person also matches on an unrelated line that I never realized before doing this match-by-match analysis, which opens up new possibilities.

Next, the meat of this chart.

  • The “Generations Back in Tree” column shows where your common ancestor with someone in that cousin generation would be expected. For example, in the first three bands, all of the first cousin variants are found two generations back, and your grandparents are your common ancestors.

All of the 2C variants descend through great-grandparents, which are 3 generations back in your tree.

Plase note that you can easily find the amount of DNA that you share with a match in the “Expected cM” and “Mean” Columns, and look to the right to see the Generations Back in Tree. 

For example, if I have a match where I share 20 cM of DNA, I’m going to be looking between the red band and the second white band. The generations back in tree range from 4-6, or the common ancestor could potentially be further back. In other words, if I’m lucky, I’ll spot common ancestors on the first tree page displayed, but I may well need to display additional generations.

  • The “Common Ancestors” column displays the common ancestor with anyone in that cousin generation. So, anyone in any variation of 3C shares great-great-grandparents with you.
  • “How Many” shows how many great-great-grandparents you have – 8.

Color Bands and Generations

Color bands represent the same amount of expected DNA, but the various relationships that are included in those bands represent at least two different “Generations Back in Tree.”

For example, looking at the green band, the half 1C3R will be found in the grandparents generation, or generation 2, the 2C2R and half 2C1R are in the great-grandparents, or generation 3, and the 3C is found in the great-great-grandparents, or generation 4.

Where I really needed this chart, though, was in the more distant generations. While we are clearly dealing with a range, if I see a match with 11 or 12 cM, our common ancestor is nearly always at least 6 generations out, and often more.

The Net-Net of This Exercise

The majority of my matches, 7548, fall into the red band of 9-20 cM, which should be the 4th or 5th generation, either great-great or GGG-grandparents, but in reality, common ancestors will often be found more distantly in matches’ trees.

Most of your matches will be 20 cM or below, meaning they are at least 4/5 generations distant, or further – which translates to NOT the first tree page displayed. This why using the MyHeritage tree is so convenient, because when you click to the next generations, they just open and it’s VERY easy to quickly click and expand every generation with no back-clicking needed. Tip – when viewing profile cards for their ancestors, be sure to note locations which are important hints too. You can also click to “research this person.”

If your match doesn’t have a tree developed to at least 5 generations, it’s unlikely that you will be able to find a common ancestor for someone with less than a 20 cM match. However, all is not lost because you may recognize a surname, and if you build out the tree for your match, you may find your common ancestor. I build out my matches’ trees often! (Yes, it’s painful and irritating, but just do it! After all, we’re genealogists. We got this.)

For people with smaller cM matches, you may be looking even further out. I have some solid triangulated matches with multiple people at 6 and 7 generations..

The further out in time, the more triangulated people you need to be confident that your common ancestor who contributed that segment is identified correctly. At that distance, most people will have dead end lines and brick walls, probably yourself included.

However, my research methodology has the potential to break through brick walls.

Brick Walls Breakers

When I’m working on match and triangulation clusters, not only am I looking for MY known ancestors, I’m also looking for common surnames, or more specifically, common ancestors between my matches trees.

In some cases, common ancestors only mean that I’m viewing first cousins to each other, but in other cases, those common ancestors between my matches, but not me, MAY POINT DIRECTLY TO A MISSING BRICK WALL ancestor of mine.

Another hint that this might be the case is when the shared cMs seem high relative to how far back your common identified ancestor is in your tree – which is the case with my Dodson cluster. There may be a second relationship obscured there, especially if they match each other more “normally” and it’s only my matches that are higher than expected with multiple people in this cluster.

Research Methodology

If you’re wondering how I approach this process, I use a spreadsheet organized by triangulation cluster because everyone in a triangulation cluster matches each other on a particular segment. This means that the triangulated segment comes from a common ancestor (or is idencal by chance.) Each match has it’s own row in the cluster on my spreadsheet.

This spreadsheet could also be organized by shared match or matrix cluster, but I prefer smaller triangulation clusters where everyone matches each other and me on the same segment – because it points to ONE shared souce of the DNA – meaning one ancestor or ancestral couple.

I downloaded my match list at FamilyTreeDNA where I can see which matches are assigned either maternally or paternally based on identified, linked relationships, and who matches on the same segments. I used that spreadsheet as the foundation of this spreadsheet, but I could also add people who match on that segment and triangulate from other vendors who provide matching segment information, such as MyHeritage.

Using my Dodson example group, this group of people above, on my father’s side, hence the blue color, also triangulates on other segments. Other clusters are significantly larger, with around 50 cluster members.

One person, JA, descends from Dodson cousins who intermarried, which is pedigree collapse, so they may carry more Dodson/Durham DNA than they would otherwise.

If someone has a small tree, I often use traditional genealogy resources to expand their tree if I recognize a surname.

I track my other ancestors’ surnames that I notice in their trees, which provides a clue for additional ancestors. Of course, common surnames sometimes aren’t useful. However, one match, JC, found in this group is a proven Crumley line cousin who has colonial Virginia ancestors, but no prior knowledge of a Dodson/Durham line – so this could be a HUGE hint for one of JC’s brick walls.

This example cluster from my mother’s side includes my mother, who I haven’t listed, and also RM, a known second cousin who I tested. Based on his known common ancestors with me, I know immediately that these segment matches all track to John David Miller and Margaret Elizabeth Lentz, or beyond. Sure enough DW has a tree where our common ancestor is David Miller, father of John David Miller, and TK is related to DW based on an obituary. So far, we know this segment originated with David Miller and his wife, Catherine Schaeffer, but we don’t know if the segment originated with the Miller or Schaeffer parent.

One additional cluster member shows a Cyrus Miller out of Pennsylvania and my initial attempt at extending their tree using WikiTree, MyHeritage and Ancestry to find a common ancestor was not fruitful, but a deep dive might well produce more, or the common ancestor could reach back into Europe.

As new people test and match, I can add them to the spreadsheet in the clusters where they fit.

Summary Generation Tree Chart

Here’s a summary version of the Generation Tree Chart for you to use, without the cM high and low ranges, and without the red boxes. This is the one I use the most.

Here’s the full chart, including the ranges, but with no red boxes.

The Bottom Line

To derive the most benefit, we all need to develop our trees as far as possible, and share with others. A rising tide lifts all ships!

It’s impossible to identify common ancestors without trees, which means it’s also impossible to use genetic genealogy to break through brick walls.

Please check your trees at the various vendors, if you have multiple trees, and at WikiTree, to be sure you’ve added your most distant known ancestor in each line.

Link your known relatives to their position in your tree at FamilyTreeDNA, which allows them to triangulate behind the scenes and assign (bucket) your matches either maternally or paternally on your match list.

What new information is waiting for you in your matches? Do you have brick walls that need to fall?

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FamilyTreeDNA’s New Matrix Shows How Your Matches Are Related to Each Other

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Click on any image to enlarge

FamilyTreeDNA’s new reworked Matrix includes relationships, in other words, how your matches are related to each other. But there’s more. It also includes the number of shared segments and the number of cMs shared between your matches.

You can then push those matches through to the chromosome browser to see exactly which segments overlap between you and your matches.

This is a game-changer!!

Why Are These Features Important?

For genealogists, knowing how your matches are related to each other, or not, is a HUGE clue about your common ancestor. Clusters of people who match each other are an important road sign directing you to a specific ancestor who contributed the same DNA segment or segments to all of you.

FamilyTreeDNA just released several VERY cool updates for their Matrix comparison tool. Plus, you get to select a group of 10 people to compare.

The purpose of the Matrix tool is to select Family Finder autosomal matches who are then displayed in a grid matrix for comparison, showing if and how those matches match each other.

Specifically:

  • Do your matches match each other?
  • What is their estimated relationship to each other?
  • How many segments of DNA do they share with each other?
  • How many cMs (centiMorgans) of DNA do they share with each other?

You can then push 7 matches through to the chromosome browser to see if they match on any of the same segments.

Automated Triangulation

If you are comparing bucketed (maternal or paternal) matches, or matches known to belong to the same side of your tree, the shared segments are automatically triangulated.

How cool is this?!!!

Keep in mind, though, that you may be related to someone through multiple ancestors, and they could be from both parent’s sides, so pay attention to the ancestral segment history.

Remember, every segment has its own unique history.

Let’s step through the new Matrix features and see how they work.

Select the Matrix

Navigate to the Matrix tool under “See More” under Autosomal DNA Results and Tools.

Under “Select Matches” you can select “All Matches” to choose from all of your matches, or you can select a grouping of matches to be displayed in the menu, below.

These groupings are shortcuts for you so you don’t have to pick everyone individually. You can also search for a name.

Click on the individuals you want to compare in the Matrix. The people you’ve selected from the group, at left, will appear in the box, at right. That’s who will be compared to each other.

Next, select which type of data will be compared.

I’m selecting “Close Relatives” for this example and “Relationship range.” First, I added my mother so I could see who matches with her.

Then I added the rest of the people I want to compare. In this case, I’ve added my closest matches, even though they are from both sides of my tree.

Relationship Range

I’ve selected “Relationship range,” which will show me how my matches estimated relationships to each other.

Based on the identity of these matches, and how they match each other, I can now determine their ancestral connection.

If I didn’t know who was related maternally and paternally, this grid would remove all doubt became I’m comparing to one of my parents.

If you don’t have a parent, adding close, known relatives on one or both sides will help immensely.

Be sure to make notes about what you’ve discovered on your matches page, and paint to DNAPainter if that’s how you’re tracking your segments to ancestors.

Number of Segments Shared

Now, I’ve selected “Number of segments shared” to compare the same group of people.

You can see the number of shared segments between Mom’s matches. Donald and Cheryl are full siblings.

The display shows how these people match Mom, and each other.

Melissa is Mom’s paternal second cousin. I was able to piece this together with the help of how she matches Mom and Mom’s known paternal first cousins, Cheryl and Donald.

Total cMs Shared

Next, I’m selecting “Total cMs shared” for comparison.

Looking at the number of shared cMs, even if I didn’t know that Donald and Cheryl were full siblings, I would now.

You can also push these through to the chromosome browser. I’ll illustrate in a minute.

Bucketed or Parental Side Matching

My favorite groupings for the new Matrix are the bucketed, meaning parental or maternal “side” matching.”

When your matches are already bucketed, thanks to having linked known matches to their profile card in your tree, the system does a lot of the “side” work for you behind the scenes.

When you select “Maternal, “Paternal” or “Paternal and Maternal” matches, the people who have been bucket to either side, or those related to you on both sides, are listed in the selection box.

I’m selecting 7 of my maternal bucketed matches because I’m going to push them through to the chromosome browser for additional evaluation. I’m not including my mother because I already know these people are related to both me and her, because they are bucketed maternally.

They’re compared in the various matrix configurations.

From the Shared cM comparison table, I can easily click to display matches in the chromosome browser.

If you’re comparing more than 7 people, you’ll need to reduce it to 7. I excluded my Mom because I already know she matches all of them.

Click on the Compare Chromosome Browser at the bottom for the 7 people selected.

I know that cousin Charles descends from Mom’s paternal Lentz line, and has no other connection, so I know that these other cousins who also match me on that same segment are also from Mom’s Lentz line.

I can also tell that the shared segments on chromosome 1 are from Mom’s maternal Lore line.

Shown here are the common ancestors in Mom’s pedigree chart. They are 4 and 5 generations back in time for me.

Look how easy that was!

I love this new Matrix tool.

Triangulation

Because three or more people, including me, match on the same segments, this means they also triangulate.

In the example above, we have two distinct triangulation groups. I’m only showing chromosomes 1-3 for illustration purposes, but there are also more triangulation groups on the other chromosomes. If I add other people, new triangulation groups will form!

Of course, these are my maternal bucketed matches, so I’m safe to reach that conclusion. If my father’s matches were also loaded here, I would have to check the matrix and see if these people also matched each other before I could determine that they triangulate.

Check Your Matches and Upload

Be sure to upload any tests to FamilyTreeDNA that you manage at other vendors, and encourage your cousins to upload too.

This combination of features is unique to FamilyTreeDNA. The more relatives you have available to match, especially when you already know the common ancestor, the better. Be sure to link your matches to their placard in your tree so that FamilyTreeDNA can do the bucketing for you.

Even if you don’t link people, you can still benefit greatly from the new matrix tool by just having your DNA available for matching. The matrix will help you sort out matches and identify who is related to whom, and how.

Take a look! What are you discovering?

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I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase your price but helps me 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.

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Six Ways to Figure Out How We’re Related

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In my latest Webinar, Six Ways to Figure Out How We’re Related, I discuss the various tools from Ancestry, FamilyTreeDNA, MyHeritage, and 23andMe – plus clusters from Genetic Affairs and the amazing DNAPainter.

This webinar lives in the Legacy Family Tree Webinar library, but as part of the “webtember” lineup, you can view it for free through the end of September.

It’s always exciting to discover a new match at one of the DNA testing companies, which, of course, begs the question of how you’re related.

So, what are the six ways to figure out how you’re related, and how do you use them?

Come along for a step-by-step guide!

Shared Matches

We begin with how each vendor handles shared matches, what that feature is called, where to find the information, and how to interpret what they are telling you.

23andMe goes a step further and creates a genetic tree, of sorts, although that functionality has changed since their breach last October.

Bucketing and Sides

Two vendors go a step further and provide unique tools to divide your matches maternally and paternally.

FamilyTreeDNA buckets your matches maternally and paternally (or both) based on matches you link to their profile cards in your tree. FamilyTreeDNA then uses your linked matches to triangulate with other matches and assign your matches accordingly, providing a maternal and paternal match list. Bucketing, also known as Family Matching, is one of my favorite tools.

Note that linking matches at FamilyTreeDNA requires that you have transferred your tree to MyHeritage. I wrote about that and provided instructions here and here, and produced a complimentary webinar, too.

Ancestry also divides your matches by parent, but they use a different technique based on their Sideview technology and either ethnicity or shared matches.

Surnames and Locations

Surnames and locations, either separately or together, provide HUGE hints!

MyHeritage provides a nice summary for each of your matches that includes ancestral surnames, a map of locations in common, and “Smart Matches” which shows you people in common in both of your trees. There are several ways to use these tools.

FamilyTreeDNA also provides a list of surnames. You can view either the surnames in common with a match, or all of their ancestral surnames, with locations if provided. The tester enters these surnames, and we review how to complete that step.

Ancestry also provides shared surnames, with clickable links to the number of people in your matches tree with that surname, plus common locations.

X-DNA

X-DNA is probably the most underutilized DNA matching tool. While each of the vendors actually test the X chromosome, only one, FamilyTreeDNA, provides X-matching. You can obtain X-matching results by uploading your DNA file to FamilyTreeDNA. I’ve provided upload/download instructions for all companies, here.

X-DNA has a very unique inheritance pattern because males only inherit an X chromosome from their mother which limits the number of potential common ancestors for any two testers. In other words, X-DNA matching does half your work for you!

Clustering Technology – AutoClusters, the Matrix and DNAPainter

In the past few years, match clustering has become a very useful tool. Clustering shows which of your matches match you and each other.

Genetic Affairs offers several flavors of these clusters, and both MyHeritage and GEDmatch have incorporated Genetic Affairs clusters into their product offerings.

If you haven’t used AutoClusters yet, by all means, try them out.

FamilyTreeDNA offers the Matrix, a slightly different version of clustering. You can select 10 people from your match list to see if they also match each other. Shared matches don’t automatically mean triangulation between you and those two people, or even that all three people descend from the same line. However, if the people are bucketed to your same side (parent) and they share common segments with you in the chromosome browser, they triangulate.

You’ll want to paint those matches to DNAPainter to determine which ancestor you share, especially if they haven’t provided a tree.

DNAPainter provides your chromosomes as the “canvas” upon which to paint your matches in order to correlate segments with ancestors and identify common ancestral lines with mystery matches.

Three vendors, FamilyTreeDNA, MyHeritage, and GEDmatch provide segment information with matches for you to paint. I illustrate how I walk segments back in time, identifying our most distant common ancestor possible.

Theories of Family Relativity and ThruLines

Both MyHeritage and Ancestry provide a combination of DNA matching and tree triangulation, where they search the trees of your DNA matches to find common ancestors with you – although their implementation is different.

MyHeritage’s Theories of Family Relativity provides varying theories about common ancestors for you and a specific match using both trees and historical documents. You can review the various pathways and confirm or reject theories. I love this tool.

Ancestry’s Thrulines functions a bit differently, showing you all of your matches that descend from a common ancestor in all your matches’ trees. Sometimes, the trees are incorrect, but Theories of Family Relativity and ThruLines should still be used as hints.

I showed how ThruLines helped me discover what happened to one of my ancestor’s grandchildren who was lost to the family at his mother’s death – and to all of us since. Not anymore.

Bonus – Y-DNA and Mitochondrial DNA at FamilyTreeDNA

Only FamilyTreeDNA offers both Y-DNA and Mitochondrial DNA testing and matching. All of the tools above pertain to autosomal DNA testing, which is named Family Finder at FamilyTreeDNA. Illustrated by the green arrow below, autosomal DNA testing measures and compares the DNA you inherited from each ancestral line, but that’s not the only game in town.

Y-DNA, in blue, for males, tracks the direct paternal line, which is the surname line in Western cultures. Mitochondrial DNA, in red, is passed from mothers to all of their children. Therefore, everyone can test, revealing matches and information about their mother’s direct matrilineal lineage.

Y-DNA testing includes the amazing Discover tool with a baker’s dozen different reports, including ancient DNA. Mitochondrial DNA will soon have its own MitoDiscover after the rollout of the new Mitotree.

Both tests include “Matches Maps” to help you determine how you are related to your matches, as well as where your ancestors came from before the advent of surnames.

The Advanced Matching feature allows you to select multiple tests to see if your matches match you on combined types of tests.

Tune In

Now that you know what we cover in the webinar, please tune in to see how to use these awesome tools. Be sure to fish in all four “ponds” plus GEDmatch, where you may find people who didn’t test at a company that provides a chromosome browser or matching segment information.

Tools provided by the DNA testing vendors facilitate multiple ways to determine how we match and which ancestor(s) we have in common.

You can watch the webinar, here.

Additionally, subscribers to Legacy Family Tree Webinars have access to the 25-page syllabus with even more information!

A Legacy Family Tree Webinar subscription normally costs $49.95 per year, but through the end of September, there’s a coupon code good for 20% off. Just click here, then enter webtember24 at the checkout.

Enjoy!

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Great News – Both e-Pub and Print Version of “The Complete Guide to FamilyTreeDNA” Now Available Worldwide  

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  • Anyone, anyplace, can order the full-color, searchable, e-pub version of The Complete Guide to FamilyTreeDNA – Y-DNA, Mitochondrial, Autosomal and X-DNA from the publisher, Genealogical.com, here.
  • Customers within the US can order the black and white print book from the publisher, here.
  • Customers outside the US can order the print book from their country’s Amazon website. The publisher does not ship print books outside the US due to customs, shipping costs, and associated delays. They arranged to have the book printed by an international printer so that it can be shipped directly to Amazon for order fulfillment without international customers incurring additional expenses and delays. If you ordered the book previously from Amazon and a long delivery time was projected, that should be resolved now and your book should be arriving soon.

Comprehensive

This book is truly comprehensive and includes:

  • 247 pages
  • More than 267 images
  • 288 footnotes
  • 12 charts
  • 68 tips
  • Plus, an 18-page glossary

To view the table of contents, click here. To order, click here.

Thank you, everyone, for your patience and your support.

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Complete Guide to FamilyTreeDNA Released in Hardcopy

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Just what many of you have been waiting for! The hardcopy print version of the Complete Guide to FamilyTreeDNA has just been released.

As shown in the table of contents below, The Complete Guide to FamilyTreeDNA contains lots of logically organized information! It includes basic education about genetic genealogy and how it works, instructions on using the FamilyTreeDNA tests and tools, plus an extensive glossary.

Enjoy!

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I receive a small contribution when you click on some of the links to vendors in my articles. This does NOT increase your price but helps me 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.

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MyHeritage DNA Uploads This Week – Free Access to ALL DNA Features, Forever

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MyHeritage has announced that DNA files uploaded this week, through October 8th, will receive all DNA tools and features, free, forever. This means no unlock fee, not today, not next month, not next year, not ever.

The DNA file upload, matching, and basic DNA features are always free. Normally, unlocking the advanced tools costs $29 – but not now. All DNA features, including advanced ones, are free if you upload this week.

It’s always a good thing to fish in multiple genetic ponds. You’re sure to match some of the 7.3 million testers at MyHeritage. In my case, I have more than 16,600 matches, many of whom are found nowhere else. That’s true for my European ancestral lineages and some US cousins who tested there and not elsewhere, including two close matches.

When you upload, you’ll receive these tools:

What a great value!

Click here to upload now.

Who will you match?________________________________________________________

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Ancestry’s ThruLines Are a Hot Mess Right Now – But Here Are Some Great Alternatives

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Right now, ThruLines at Ancestry is one hot mess.

Aside from the inherent frustration, especially over a holiday weekend when many people had planned to work on their genealogy, I’d like to say, “don’t panic.”

I don’t have any inside information about what’s going on at Ancestry, and I’ve attempted to make contact through their support page with no luck. They make talking to a person exceedingly difficult; plus, it’s a holiday weekend, and they are probably inundated.

Regardless, I have an idea of what is happening. Ancestry has been in the midst of recalculating “things,” perhaps in relation to their other changes, which I’ll write about separately in a few days.

In any event, Ancestry SURELY MUST KNOW there’s a significant problem because I imagine thousands of their customers are screaming right about now. Adding another voice won’t be helpful.

Symptoms

  • You may not have ThruLines at all.
  • If you do have ThruLines, don’t trust the information, or more to the point, don’t trust that it’s in any way complete.

I have two tests at Ancestry, both connected to different trees so that my matches and Thrulines are calculated separately for each test.

Test One

My first Ancestry test is connected to my primary tree. I’ve been amassing Thrulines cousins ever since the feature was released. I have hundreds of cousin matches descended from some of my more prolific ancestors.

Additionally, my sister’s grandchildren have tested, as have other close relatives who have connected their tests to their trees.

Today, those people are still showing on my match list, but are NOT showing as matches in ThruLines. None of them. Most of my ThruLines ancestors are showing zero matches, and the rest are only showing very few. Ancestors who had hundreds before now have 2, for example.

Here’s an example with my cousin, Erik.

My grandfather, William George Estes, shown in Erik’s tree, above, is his great-grandfather. Erik is my half first cousin, once removed, and we share 417 cM over 16 segments.

Yet, looking at my ThruLine for William George Estes, neither he nor my other cousins are shown as matches. Same for William George’s parents, and so forth.

ThruLines is VERY ill right now.

Test Two

My second DNA test at Ancestry is even worse. There are no ThruLines calculated, even though my DNA is tree-attached, and I had ThruLines previously.

I see this message now, and I can’t even begin to tell you how irritating this is – in part because it suggests the problem is my fault. It’s clearly not. My tree hasn’t changed one bit. I’m not alone, either. I’ve seen other people posting this same message.

And yes, if you’re thinking that there is absolutely no excuse for this – you’re right.

However, outrage isn’t good for us and won’t help – so let’s all do something else fun and productive instead.

Productive Genealogy Plans

Here are some productive suggestions.

At MyHeritage:

At FamilyTreeDNA:

  • Build your haplogroup pedigree chart by locating people through different companies descended from each ancestor in your tree through the appropriate line of descent, and see if they have or will take a Y-DNA or mtDNA test.
  • Tests are on sale right now, and there’s no subscription required at FamilyTreeDNA for anything.
  • Check Y-DNA and mtDNA tests to see if there are new matches and if you share a common ancestor.

At 23andMe:

  • Check for new matches and triangulation.
  • Check to see if 23andMe has added any of your new matches to your genetic tree.

Remember, the parental sides are typically accurate, but the exact placement may not be, and 23andMe deals poorly with half-relationships. It’s certainly still worth checking though, because 23andMe does a lot of heavy lifting for you.

DNAPainter

For me, the most productive thing to do this weekend would be to copy the segment information from new matches with whom I can identify common ancestors at FamilyTreeDNA, MyHeritage and 23andMe – the vendors who provide segment data – and paint those segments to DNAPainter.

Not only does DNAPainter allow me to consolidate my match data in one place, DNAPainter provides the ability for me to confirm ancestors through triangulation, and to assign unknown matches to ancestors as well.

As you can see, I’ve successfully assigned about 90% of my segments to an ancestor, meaning I’ve confirmed descent from that ancestor based on my autosomal matches’ descent from that same ancestor – preferably through another child. Will new matches propel me to 91%? I hope so.

What percentage can you or have you been able to assign?

If you need help getting started, or ideas, I’ve written about DNAPainter several times and provided a compiled resource library of those articles, here.

Have fun!!!

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

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Which DNA Test Should I Buy? And Why?

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Which DNA test should I buy, and why?

I receive questions like this often. As a reminder, I don’t take private clients anymore, which means I don’t provide this type of individual consulting or advice. However, I’m doing the next best thing! In this article, I’m sharing the step-by-step process that I utilize to evaluate these questions so you can use the process too.

It’s important to know what questions to ask and how to evaluate each situation to arrive at the best answer for each person.

Here’s the question I received from someone I’ll call John. I’ve modified the wording slightly and changed the names for privacy.

I’m a male, and my mother was born in Charleston, SC. My maternal grandmother’s maiden name was Jones and a paternal surname was Davis. The family was supposed to have been Black, Dutch, Pennsylvania Dutch, and Scots-Irish…only once was I told I was 3/16 Indian, with Davis being 3/4 and Jones being full Indian.

Do I have enough reasonable information to buy a test, and which one?

Please note that it’s common for questions to arrive without all the information you need to provide a sound answer – so it’s up to you to ask those questions and obtain clarification.

Multiple Questions

There are actually multiple questions here, so let me parse this a bit.

  1. John never mentioned what his testing goal was.
  2. He also never exactly said how the paternal line of Davis was connected, so I’ve made an assumption. For educational purposes, it doesn’t matter because we’re going to walk through the evaluation process, which is the same regardless.
  3. John did not include a tree or a link to a tree, so I created a rudimentary tree to sort through this. I need the visuals and normally just sketch it out on paper quickly.
  4. Does John have enough information to purchase a test?
  5. If so, which test?

There is no “one size fits all” answer, so let’s discuss these one by one.

Easy Answers First

The answer to #4 is easy.

Anyone with any amount of information can purchase a DNA test. Adoptees do it all the time, and they have no prior information.

So, yes, John can purchase a test.

The more difficult question is which test, because that answer depends on John’s goals and whether he’s just looking for some quick information or really wants to delve into genealogy and learn. Neither approach is wrong.

Many people think they want a quick answer –  and then quickly figure out that they really want to know much more about their ancestors.

I wrote an article titled DNA Results – First Glances at Ethnicity and Matching for new testers, here.

Goals

Based on what John said, I’m going to presume his goals are probably:

  • To prove or disprove the family oral history of Black, Dutch, Pennsylvania Dutch (which is actually German,) Scots-Irish, and potentially Native American.
  • John didn’t mention actual genealogy, which would include DNA matches and trees, so we will count that as something John is interested in secondarily. However, he may need genealogy records to reach his primary goal.

If you’re thinking, “The process of answering this seemingly easy question is more complex than I thought,” you’d be right.

Ethnicity in General

It sounds like John is interested in ethnicity testing. Lots of people think that “the answer” will be found there – and sometimes they are right. Often not so much. It depends.

The great news is that John really doesn’t need any information at all to take an autosomal DNA test, and it doesn’t matter if the test-taker is male or female.

To calculate each tester’s ethnicity, every testing company compiles their own reference populations, and John will receive different results at each of the major companies. Each company updates their ethnicity results from time to time as well, and they will change.

Additionally, each company provides different tools for their customers.

The ethnicity results at different companies generally won’t match each other exactly, and sometimes the populations look quite different.

Normally, DNA from a specific ancestor can be found for at least 5 or 6 generations. Of course, that means their DNA, along with the DNA from all of your other ancestors is essentially combined in a communal genetic “pot” of your chromosomes, and the DNA testing company needs to sort it out and analyze your DNA for ethnicity.

DNA descended from ancestors, and their populations, further back in people’s trees may not be discerned at all using autosomal DNA tests.

A much more specific “ethnicity” can be obtained for both the Y-DNA line, which is a direct patrilineal line for men (blue arrow,) and the mitochondrial DNA line (pink arrows,) which is a direct matrilineal line for everyone, using those specific tests.

We will discuss both of those tests after we talk about the autosomal tests available from the four major genealogy DNA testing companies. All of these tools can and should be used together.

Let’s Start with Native American

Let’s evaluate the information that John provided.

John was told that he “was 3/16 Indian, with Davis being 3/4 and Jones being full Indian.”

We need to evaluate this part of his question slightly differently.

I discussed this in the article, Ancestral DNA Percentages – How Much of Them is in You?

First, we need to convert generations to 16ths.

You have two ancestors in your parent’s generation, four in your grandparents, and so forth. You have 16 great-great-grandparents. So, if John was 3/16th Native, then three of his great-great-grandparents would have been fully Native, or an equivalent percentage. In other words, six ancestors in that generation could have been half-Native. Based on what John said, they would have come from his mother’s side of the tree. John is fortunate to have that much information to work with.

He told us enough about his tree that we can evaluate the statement that he might be 3/16ths Native.

Here’s the tree I quickly assembled in a spreadsheet based on John’s information.

His father, at left, is not part of the equation based on the information John provided.

On his mother’s side, John said that Grandfather Davis is supposed to be three-quarters Native, which translates to 12/16ths. Please note that it would be extremely beneficial to find a Y-DNA tester from his Davis line, like one of his mother’s brothers, for example.

John said that his Grandmother Jones is supposed to be 100% Native, so 16/16ths.

Added together, those sum to 28/32, which reduces down to 14/16th or 7/8th for John’s mother.

John would have received half of his autosomal DNA from his mother and half from his non-Native father. That means that if John’s father is 100% non-Native, John would be half of 14/16ths or 7/16ths, so just shy of half Native.

Of course, we know that we don’t always receive exactly 50% of each of our ancestors’ DNA (except for our parents,) but we would expect to see something in the ballpark of 40-45% Native for John if his grandmother was 100% Native and his grandfather was 75%.

Using simple logic here, for John’s grandmother to be 100% Native, she would almost assuredly have been a registered tribal member, and the same if his grandfather was 75% Native. I would think that information would be readily available and well-known to the family – so I doubt that this percentage is accurate. It would be easy to check, though, on various census records during their lifetimes where they would likely have been recorded as “Indian.” They might have been in the special “Indian Census” taken and might be living on a reservation.

It should also be relatively easy to find their parents since all family members were listed every ten years in the US beginning with the 1850 census.

The simple answer is that if John’s grandparents had as much Native as reported, he would be more than 3/16th – so both of these factoids cannot simultaneously be accurate. But that does NOT mean neither is accurate.

John could be 7/8th or 40ish%, 3/16th or 18ish%, or some other percentage. Sometimes, where there is smoke, there is fire. And that seems to be the quandary John is seeking to resolve.

Would  Ethnicity/Population Tests Show This Much Native?

Any of the four major testing companies would show Native for someone whose percentage would be in the 40% or 18% ballpark.

The easiest ethnicities to tell apart from one another are continental-level populations. John also stated that he thinks he may also have Black ancestry, plus Dutch, Pennsylvania Dutch (German), and Scots-Irish. It’s certainly possible to verify that using genealogy, but what can DNA testing alone tell us?

How far back can we expect to find ethnicities descending from particular ancestors?

In this table, you can see at each generation how many ancestors you have in that generation, plus the percentage of DNA, on average, you would inherit from each ancestor.

All of the major DNA testing companies can potentially pick up small trace percentages, but they don’t always. Sometimes one company does, and another doesn’t. So, if John has one sixth-generation Native American ancestor, he would carry about 1.56% Native DNA, if any.

  • Sometimes a specific ethnicity is not found because, thanks to random recombination, you didn’t inherit any of that DNA from those ancestors. This is why testing your parents, grandparents, aunts, uncles, and siblings can be very important. They share your same ancestors and may have inherited DNA that you didn’t that’s very relevant to your search.
  • Sometimes it’s not found because the reference populations and algorithms at that testing company aren’t able to detect that population or identify it accurately, especially at trace levels. Every DNA testing company establishes their own reference populations and writes internal, proprietary ethnicity analysis algorithms.
  • Sometimes it’s not found because your ancestor wasn’t Native or from that specific population.
  • Sometimes it’s there, but your population is called something you don’t expect.

For example, you may find Scandinavian when your ancestor was from England or Ireland. The Vikings raided the British Isles, so while some small amount of Scandinavian is not what you expect, that doesn’t mean it‘s wrong. However, if all of your family is from England, it’s not reasonable to have entirely Scandinavian ethnicity results.

It’s also less likely as each generation passes by that the information about their origins gets handed down accurately to following generations. Most non-genealogists don’t know the names of their great-grandparents, let alone where their ancestors were from.

Using a 25-year average generation length, by the 4th generation, shown in the chart above, you have 16 ancestors who lived approximately 100 years before your parents were born, so someplace in the mid-1800s. It’s unlikely for oral history from that time to survive intact. It’s even less likely from a century years earlier, where in the 7th generation, you have 128 total ancestors.

The best way to validate the accuracy of your ethnicity estimates is by researching your genealogy. Of course, you need to take an ethnicity test, or two, in order to have results to validate.

Ethnicity has a lot more to offer than just percentages.

Best Autosomal Tests for Native Ethnicity

Based on my experience with people who have confirmed Native ancestry, the two best tests to detect Native American ethnicity, especially in smaller percentages, are both FamilyTreeDNA and 23andMe.

Click images to enlarge

In addition to percentages, both 23andMe and FamilyTreeDNA provide chromosome painting for ethnicity, along with segment information in download files. In other words, they literally paint your ethnicity results on your chromosomes.

They then provide you with a file with the “addresses” of those ethnicities on your chromosomes, which means you can figure out which ancestors contributed those ethnicity segments.

The person in the example above, a tester at FamilyTreeDNA, is highly admixed with ancestors from European regions, African regions and Native people from South America.

Trace amounts of Native American with a majority of European heritage would appear more like this.

You can use this information to paint your chromosome segments at DNAPainter, along with your matching segments to other testers where you can identify your common ancestors. This is why providing trees is critically important – DNA plus ancestor identification with our matches is how we confirm our ancestry.

This combination allows you to identify which Native (or another ethnicity) segments descended from which ancestors. I was able to determine which ancestor provided that pink Native American segment on chromosome 1 on my mother’s side.

I’ve provided instructions for painting ethnicity segments to identify their origins in specific ancestors, here.

Autosomal and Genealogy

You may have noticed that we’ve now drifted into the genealogy realm of autosomal DNA testing. Ethnicity is nice, but if you want to know who those segments came from, you’ll need:

  • Autosomal test matching to other people
  • To identify your common ancestor with as many matches as you can
  • To match at a company who provides you with segment information for each match
  • To work with DNAPainter, which is very easy

The great news is that you can do all of that using the autosomal tests you took for ethnicity, except at Ancestry who does not provide segment information.

Best Autosomal Test for Matching Other Testers

The best autosomal test for matching may be different for everyone. Let’s look at some of the differentiators and considerations.

If you’re basing a testing recommendation solely on database size, which will probably correlate to more matches, then the DNA testing vendors fall into this order:

If you’re basing that recommendation on the BEST, generally meaning the closest matches for you, there’s no way of knowing ahead of time. At each of the four DNA testing companies, I have very good matches who have not tested elsewhere. If I weren’t in all four databases, I would have missed many valuable matches.

If you’re basing that recommendation on which vendor began testing earliest, meaning they have many tests from people who are now deceased, so you won’t find their autosomal tests in other databases that don’t accept uploads, the recommended testing company order would be:

If you’re basing that recommendation on matches to people who live in other countries, the order would be:

Ancestry and 23andMe are very distant third/fourth because they did not sell widely outside the US initially and still don’t sell in as many countries as the others, meaning their testers’ geography is more limited. However, Ancestry is also prevalent in the UK.

If you’re basing that recommendation on segment information and advanced tools that allow you to triangulate and confirm your genetic link to specific ancestors, the order would be:

Ancestry does NOT provide any segment information.

If you’re basing that recommendation on unique tools provided by each vendor, every vendor has something very beneficial that the others don’t.

In other words, there’s really no clear-cut answer for which single autosomal DNA test to order. The real answer is to be sure you’re fishing in all the ponds. The fish are not the same. Unique people test at each of those companies daily who will never be found in the other databases.

Test at or upload your DNA to all four DNA testing companies, plus GEDmatch. Step-by-step instructions for downloading your raw data file and uploading it to the DNA testing companies who accept uploads can be found, here.

Test or Upload

Not all testing companies accept uploads of raw autosomal DNA data files from other companies. The good news is that some do, and it’s free to upload and receive matches.

Two major DNA testing companies DO NOT accept uploads from other companies. In other words, you have to test at that company:

Two testing companies DO accept uploads from the other three companies. Uploads and matching are free, and advanced features can be unlocked very cost effectively.

  • FamilyTreeDNA – free matching and $19 unlock for advanced features
  • MyHeritage – free matching and $29 unlock.for advanced features

I recommend testing at both 23andMe and Ancestry and uploading one of those files to both FamilyTreeDNA and MyHeritage, then purchasing the respective unlocks.

GEDmatch

GEDmatch is a third-party matching site, not a DNA testing company. Consider uploading to GEDmatch because you may find matches from Ancestry who have uploaded to GEDmatch, giving you access to matching segment information.

Other Types of DNA

John provided additional information that may prove to be VERY useful. Both Y-DNA and mitochondrial DNA can be tested as well and may prove to be more useful than autosomal to positively identify the origins of those two specific lines.

Let’s assume that John takes an autosomal test and discovers that indeed, the 3/16th Native estimate was close. 3/16th equates to about 18% Native which would mean that three of his 16 great-great-grandparents were Native.

John told us that his Grandmother Jones was supposed to be 100% Native.

At the great-great-grandparent level, John has 16 ancestors, so eight on his mother’s side, four from maternal grandmother Jones and four from his maternal grandfather Davis.

John carries the mitochondrial DNA of his mother (red boxes and arrows,) and her mother, through a direct line of females back in time. John also carries the Y-DNA of his father (dark blue box, at left above, and blue arrows below.)

Unlike autosomal DNA which is admixed in every generation, mitochondrial DNA (red arrows) is inherited from that direct matrilineal line ONLY and never combines with the DNA of the father. Mothers give their mitochondrial DNA to both sexes of their children, but men never contribute their mitochondrial DNA to offspring. Everyone has their mother’s mitochondrial DNA.

Because it never recombines with DNA from the father, so is never “watered down,” we can “see” much further back in time, even though we can’t yet identify those ancestors.

However, more importantly, in this situation, John can test his own mitochondrial DNA that he inherited from his mother, who inherited it from her mother, to view her direct matrilineal line.

John’s mitochondrial DNA haplogroup that will be assigned during testing tells us unquestionably whether or not his direct matrilineal ancestor was Native on her mother’s line, or not. If not, it may well tell us where that specific line originated.

You can view the countries around the world where Y-DNA haplogroups are found, here, and mitochondrial haplogroups, here.

If John’s mitochondrial DNA haplogroup is Native, that confirms that one specific line is Native. If he can find other testers in his various lines to test either their Y-DNA or mitochondrial DNA, John can determine if other ancestors were Native too. If not, those tests will reveal the origins of that line, separate from the rest of his genealogical lines.

Although John didn’t mention his father’s line, if he takes a Y-DNA test, especially at the Big Y-700 level, that will also reveal the origins of his direct paternal line. Y-DNA doesn’t combine with the other parent’s DNA either, so it reaches far back in time too.

Y-DNA and mitochondrial DNA tests are laser-focused on one line each, and only one line. You don’t have to try to sort it out of the ethnicity “pot,” wondering which ancestor was or was not Native.

My Recommendation

When putting together a testing strategy, I recommend taking advantage of free uploads and inexpensive unlocks when possible.

  • To confirm Native American ancestry via ethnicity testing, I recommend testing at 23andMe and uploading to FamilyTreeDNA, then purchasing the $19 unlock. The free upload and $19 unlock are less expensive than testing there directly.
  • For matching, I recommend testing at Ancestry and uploading to MyHeritage, then unlocking the MyHeritage advanced features for $29, which is less expensive than retesting. Ancestry does not provide segment information, but MyHeritage (and the others) do.

At this point, John will have taken two DNA tests, but is now in all four databases, plus GEDmatch if he uploads there.

  • For genealogy research on John’s lines to determine whether or not his mother’s lines were Native, I recommend an Ancestry and a MyHeritage records subscription, plus using WikiTree, which is free.
  • To determine if John’s mother’s direct matrilineal female line was Native, I recommend that John order the mitochondrial DNA test at FamilyTreeDNA.
  • When ordering multiple tests, or uploading at FamilyTreeDNA, be sure to upload/order all of one person’s tests on the same DNA kit so that those results can be used in combination with each other.

Both males and females can take autosomal and mitochondrial DNA tests.

  • To discover what he doesn’t know about his direct paternal, meaning John’s surname line – I recommend the Big Y-700 test at FamilyTreeDNA.

Only males can take a Y-DNA test, so women would need to ask their father, brother, or paternal uncle, for example, to test their direct paternal line.

  • If John can find a male Davis from his mother’s line, I recommend that he purchase the Big Y-700 test at FamilyTreeDNA for that person, or check to see if someone from his Davis line may have already tested by viewing the Davis DNA Project. Like with mitochondrial DNA, the Y-DNA haplogroup will tell John the origins of his direct Davis male ancestor – plus matching of course. He will be able to determine if they were Native, and if not, discover the origins of the Davis line.
  • For assigning segments to ancestors and triangulating to confirm descent from a common ancestor, I recommend 23andMe, MyHeritage, FamilyTreeDNA and GEDmatch, paired with DNAPainter as a tool.

Shopping and Research List

Here are the tests and links recommended above:

More Than He Asked

I realize this answer is way more than John expected or even knew to ask. That’s because there is often no “one” or “one best” answer. There are many ways to approach the question after the goal is defined, and the first “answer” received may be a bit out of context.

For example, let’s say John has 2% Native ancestry and took a test at a vendor who didn’t detect it. John would believe he had none. But a different vendor might find that 2%. If it’s on his mother’s direct matrilineal line, mitochondrial DNA testing will confirm, or refute Native, beyond any doubt, regardless of autosomal ethnicity results – but only for that specific ancestral line.

Autosomal DNA can suggest Native across all your DNA, but Y-DNA and mitochondrial DNA confirm it for each individual ancestor.

Even when autosomal testing does NOT show Native American, or African, for example, it’s certainly possible that it’s just too far back in time or has not been passed down during random recombination, but either Y-DNA or mitochondrial DNA will unquestionably confirm (or refute) the ancestry in question if the right person is tested.

This is exactly why I attempt to find a cousin who descends appropriately from every ancestor and provide testing scholarships. It’s important to obtain Y-DNA and mitochondrial DNA information for each ancestor.

Which Test Should I Order?

What steps will help you decide which test or tests to take?

  1. Define your testing goal.
  2. Determine if your Y-DNA or mitochondrial DNA will help answer the question.
  3. Determine if you need to find ancestors another generation or two back in time to get the most benefit from DNA testing. In our example, if John discovered that both of his grandparents were enrolled tribal members, that’s huge, and the tribe might have additional information about his family.
  4. Subscribe to Ancestry and MyHeritage records collections as appropriate to perform genealogical research. Additional information not only provides context for your family, it also provides you with the ability to confirm or better understand your ethnicity results.
  5. Extend your tree so that you can obtain the best results from the three vendors who support trees; Ancestry, FamilyTreeDNA, and MyHeritage. All three use trees combined with DNA tests to provide you with additional information.
  6. Order 23andMe and Ancestry autosomal DNA tests.
  7. Either test at or upload one of those tests to MyHeritage, FamilyTreeDNA, and GEDmatch.
  8. If a male, order the Big Y-700 DNA test. Or, find a male from your ancestral line who has taken or will take that test. I always offer a testing scholarship and, of course, share the exciting results!
  9. Order a mitochondrial DNA test for yourself and for appropriately descended family members to represent other ancestors. Remember that your father (and his siblings) all carry your paternal grandmother’s mitochondrial DNA. That’s often a good place to start after testing your own DNA.
  10. If your parents or grandparents are alive, or aunts and uncles, test their autosomal DNA too. They are (at least) one generation closer to your ancestors than you are and will carry more of your ancestors’ DNA.
  11. Your siblings will carry some of your ancestors’ DNA that you do not, so test them too if both of your parents aren’t available for testing.

Enjoy!!!

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Comparing DNA Results – Different Tests at the Same Testing Company

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Several people have asked about different tests at the same DNA testing company. They wondered if matching is affected, meaning whether your matches are different if you have two different tests at the same company. Specifically, they asked if you are better off purchasing a test AT a DNA testing vendor that allows uploads, rather than uploading a test from a different vendor. Does it make a difference to the tester or their matches? Do they have the same matches?

These are great questions, and the answer isn’t conclusive. It varies based on several factors.

Having multiple tests at the same DNA testing company can occur in three ways:

  • The same person tests twice at the same DNA testing company.
  • The same person tests once at the DNA testing company and uploads a test from a different testing company. Only two of the primary four DNA testing companies accept uploads from other vendors – FamilyTreeDNA and MyHeritage.
  • The same person uploads two different files from other DNA testing companies to the DNA testing company in question. For example, the DNA company could be FamilyTreeDNA and the two uploaded DNA files could be from either MyHeritage, 23andMe or Ancestry.

All DNA testing companies allow users to download their raw DNA data files. This enables the tester to upload their DNA file to the vendors who accept uploaded files. Both FamilyTreeDNA and MyHeritage provide matching for free, but advanced tools require a small unlock fee of $19 and $29, respectively.

Testing Company Accepts Uploads from Other Companies Download Upload Instructions
23andMe No Instructions here
Ancestry No Instructions here
FamilyTreeDNA Yes, some Instructions here
MyHeritage Yes, some Instructions here

I wrote about developing a DNA testing and transfer/upload strategy, here, and about which companies accept which tests, here.

Not all DNA files are created equal. Therefore, not all files from vendors are compatible with other vendors for various reasons.

Multiple Tests at the Same DNA Testing Company

I have at least two tests at each of the four major vendors. I did this for research purposes, meaning to write articles to share with you.

If you actually test twice at a vendor, meaning purchase two separate tests and take them yourself, you will have two test results at that testing company. At some companies, specifically 23andMe, if you purchase a new test through their “upgrade” procedure, you won’t have two tests, just the newer one.

However, if you’re testing at the DNA testing company, and also uploading, I generally don’t recommend more than one test at each vendor. All it really does is clog up people’s match lists with no or little additional benefit. At 23andMe, with their restrictions on the size of your match list, if everyone had two tests, the effective match limit would be half of their stated limit of about 1500 matches for earlier testers and about 5000 for current testers with subscriptions.

So, in essence, I’m telling you to “do as I say, not as I do.” We all have better things to do with our money rather pay for the same test twice. If you haven’t tested your Y-DNA or mitochondrial DNA, that’s much more beneficial than two autosomal tests at one vendor.

Chips and Chip Evolution

Before we begin the side-by-side comparison, let’s briefly discuss DNA testing chips and how they work.

Each DNA testing company purchases DNA processing equipment. Illumina is the big dog in this arena. Illumina defines the capacity and structure of each chip. In part, how the testing companies use that capacity, or space on each chip, is up to each company. This means that the different testing companies test many of the same autosomal DNA SNP locations, but not all of the same locations.

Furthermore, the individual testing companies can specify a number of “other” locations to be included on their chip, up to the chip maximum size limit. The testing companies who offer Y-DNA or mitochondrial DNA haplogroups from autosomal tests use part of their chip array space for selected known haplogroup-defining SNP locations. This does NOT mean that Y-DNA or mitochondrial DNA is autosomal, just that the testing company used part of their chip array space to target these SNPs in your genome. Of course, for your most refined haplogroup and Y-DNA or mitochondrial DNA matching, you have to take those specific tests at FamilyTreeDNA .

This means that each testing company includes and reports many of the same, but also some different SNP locations when they scan your DNA.

In the lab, after your DNA is extracted from either your saliva or the cheek swab, it’s placed on this array chip which is then placed in the processing equipment.

There are several steps in processing your DNA. Each DNA location specified on the chip is scanned and read multiple times, and the results are recorded. The final output is the raw DNA results file that you see if/when you download your raw DNA file.

Here’s an example from my file. The RSID is the reference SNP cluster ID which is the naming convention used for specific SNPs. It’s not relevant to you, but it is to the lab, along with the chromosome number and position, which is in essence the address on the chromosome.

In the Result column, your file reports one nucleotide (T, A, C or G) that you inherited from each parent at each tested position. They are not listed in “parent order” because your DNA is not organized in that fashion. There’s no way for the lab to know which nucleotide came from which parent, unless they are the same, of course. You can read about nucleotides, here.

When you upload your raw DNA file to a different DNA testing company (vendor), they have to work with a file that isn’t entirely compatible with the files they generate, or the other files uploaded from other DNA testing companies.

In addition to dealing with different file formats and contents from multiple DNA vendors, companies change their own chips and file structure from time to time. In some cases, it’s a forced change by the chip manufacturer. Other times, the vendors want to include different locations or make improvements. For example, with 23andMe’s focus on health, they probably add new medically related SNP locations regularly. Regardless of why, some DNA files include locations not included in other files and are not 100% compatible.

Looking at the first few entries in my example file above, let’s say that the testing vendor included the first ten positions, but an uploaded file from another company did not. Or perhaps the chip changed, and a different version of the company’s own file contains different positions.

DNA testing companies have to “fill in the blanks” for compatibility, and they do this using a technique called imputation. Illumina forced their customers to adopt imputation in 2017 when they dropped the capacity of their chip. I was initially quite skeptical, but imputation has worked surprisingly well. Some of the matching differences you will see when comparing the results of two different DNA files is a result of imputation.

I wrote about imputation in an early article here. Please note the companies have fixed many issues with imputation and improved matching greatly, but the concepts and imputation processes still apply. The downloaded raw data files are your results BEFORE imputation, meaning that it’s up to any company where you upload to process your raw file in the same way they would process a file that they generated. A lot goes on behind the scenes when you upload a file to a DNA testing company.

At both 23andMe and Ancestry, you know that all of your matches tested there, meaning they did not upload a file from another testing company. You don’t know and can’t tell what chip was utilized when your matches tested. The only way to determine a chip testing version, aside from knowing the date or remembering the chip version from when you tested, is to look at the beginning of the raw data download file, although not all files contain that information.

Ok, now that you understand the landscape, let’s look at my results at each company.

23andMe

I tested twice at 23andMe on two different chip versions, V3 and V4, which tested some different locations of my DNA. Neither of these chips is the current version. I originally tested twice to evaluate the differences between the two test versions which you can read about, here.

23andMe named their ethnicity results Ancestry Composition.

They last updated my V3 test’s Ancestry Composition results on July 28, 2021.

The percentages are shown at left, and the country locations are highlighted at right for my 23andMe V3 test.

Click to enlarge any graphic

The 23andMe V4 test was also updated for the last time on July 28, 2021.

The ethnicity results differ substantially between the two chip versions, even though they were both updated on the same date.

In October of 2020, in an effort to “encourage” their customers to pay for a new test on their V5 chip, 23andMe announced that there would be no ethnicity updates on older tests. So, I really don’t know for sure when my tests were actually updated. Just note how different the results are. It’s also worth mentioning that 23andMe does not show trace amounts on their map, so even though my Indigenous American results were found, they aren’t displayed on the map.

Indigenous is, however, shown in yellow on their DNA Chromosome Painting.

No other testing company restricts updates, penalizing their customers who purchased earlier versions of tests.

Matches at 23andMe

23andMe limits your matches to about 1500 unless you have purchased the current test, including health AND pay for an annual $69 subscription which buys you about 5000 matches. I have not purchased this test.

Your number of actual matches displayed/retained is also affected by how many people you have communicated with, or at least initiated communications with. 23andMe does not roll those people off of your match list.

I have 1803 matches on both of my tests, meaning I’ve reached out to about 300 people who would have otherwise been removed from my match list. 23andMe retains your highest matches, deleting lower matches after you reach the maximum match threshold.

I’ve randomly evaluated several of the same matches at each vendor, at least five maternal and five paternal, separated by a blank row. I wanted to determine whether they match me on the same number of centimorgans, meaning the same amount of DNA, on both tests, and the same number of segments.

Match 23and Me V3 23and Me V4
Patricia 292 cM – 12 segments Same as V3
Joe 148 cM, 8 segments Same
Emily 73 cM, 4 segs 72 cM, 4 seg
Roland 27 cM, 1 seg Same
Ian 62 cM, 4 seg Same
Stacy 469 cM, 16 segments 482 cM, 16 segments
Harold 134 cM, 6 segments Same
Dean 69 cM, 3 seg Same
Carl 95 cM, 4 seg Same
Debbie 83 cM, 4 seg 84 cM, 4 seg

As you can see, the matches are either exact or xclose.

Please note that bolded matches are also found at another company. I will include a summary table at the end comparing the same match across multiple vendors.

23and Me Summary

The 23andMe V3 and V4 match results are very close. Since the match limit is the same, and the results are so close between tests, they are essentially identical in terms of matching.

The ethnicity results are similar, but the V4 test reflects a broader region. Italian baffles me in both versions.

Ethnicity should never be taken at face value at any DNA testing company, especially with smaller percentages which could be noise or a combination of other regions which just happens to resemble Italy, in my case.

I don’t know what type of comparison the current chip would yield since I suspect it has more medical and less genealogical SNPs on board.

Reprocessing Tests

This is probably a good place to note that it’s very expensive for any company to update their customer’s ethnicity results because every single customer’s DNA results file must be completely rerun. Note that this does not mean their DNA itself is retested. The output raw data file is reprocessed using a new algorithm.

Rerunning means reprocessing that specific portion of every test, meaning the vendors must rent “time in the cloud.” We are talking millions of dollars for each run. I don’t know how much it costs per test, but think about the expense if it takes $1 to rerun each test in the vendor’s database. Ancestry has more than 20 million tests.

While we, as consumers, are always chomping at the bit for new and better ethnicity results – the testing companies need to be sure it really is “better,” not just different before they invest the money to reprocess and update results.

This is probably why 23andMe decided to cease updating older kits. The newer tests require a subscription which is recurring revenue.

The same is true when DNA testing companies need to rematch their entire user base. This happens when the criteria for matching changes. For example, Ancestry purged a large number of matches for all of their customers back in 2020. While match algorithm changes necessitate rematching, with associated costs, this change also provided Ancestry with the huge benefit of eliminating approximately half of their customer’s matches. This freed up storage space, either physically in their data center or space rented in the cloud, representing substantial cost-savings.

How long can a DNA testing company reasonably be expected to continue investing in a product which never generates additional revenue but for which the maintenance and reinvestment costs never end?

Ancestry and MyHeritage both hope to offset the expenses of maintaining their customer’s DNA tests and providing free updates by selling subscriptions to their record services. 23andMe wants you to purchase a new test and a yearly subscription. FamilyTreeDNA wants you to purchase a Big Y-DNA and mitochondrial DNA test.

OK, now let’s look at my matches at Ancestry.

Ancestry

I’ve taken two Ancestry tests, V1 and V2. There were some differences, which I wrote about here and here. V2 is no longer the current chip.

Except for 23andMe who wants their customers to purchase their most current test, the other companies no longer routinely announce new chip versions. They just go about their business. The only way you know that a vendor actually changed something is when the other companies who accept uploads suddenly encounter an issue with file formats. It always takes a few weeks to sort that out.

My Ancestry V1 test’s ethnicity results don’t show my Native American ethnicity.

Ancestry results were updated in June 2022

However, my V2 results do include Native American ethnicity.

Matches at Ancestry

I have many more matches on my V1 test at Ancestry because I took steps to preserve my smaller matches when Ancestry initiated its massive purge in 2020. I wrote about that here and here.

Ancestry’s SideView breaks matches down into maternal, paternal, and unassigned based on your side selection. You tell Ancestry which side is which. You may be able to determine which “side” is maternal or paternal either by your ethnicity or shared matches. While SideView is not always accurate, it’s a good place to begin.

Match Category Ancestry V1 Test Ancestry V2 Test
Maternal 15,587 15,116
Paternal 42,247 41,870
Both 2 2
Unassigned 48,999 4,127
Total 106,835 61,115

Ancestry either displays all your matches or your matches by side, which I used to compile the table above. I suspect that Ancestry is not assigning any of the smaller preserved matches to “sides” based on the numbers above.

Ancestry implemented a process called Timber that removes DNA that they feel is “too matchy,” meaning you match enough people in this region that they think it’s a pileup region for you personally, and therefore not useful. In some cases, enough DNA is removed causing that person to no longer be considered a match because they fall beneath the match threshold. I am not a fan of Timber.

Your match amount shown is AFTER Timber has removed those segments. Unweighted shared DNA is your pre-Timber match amount.

You can view the Unweighted shared DNA by clicking on the amount of shared DNA on your match list.

You can read Ancestry’s Matching White Paper, here.

Let’s take a look at my matches. I’ve listed both weighted and unweighted where they are different.

Match Ancestry V1 Ancestry V2
Michael 755 cM, 35 seg 737 cM, 33 seg
Edward 66 cM, 4 seg (unweighted 86 cM) 65 cM, 4 seg (unweighted 86 cM)
Tom 59 cM, 3 seg (unweighted 63) Same
Jonathon 43 cM, 4 seg, (unweighted 52 cM) Same
Matthew 20 cM, 2 seg (unweighted 35 cM) Same
Harold 132 cM, 7 seg 135 cM, 6 seg
Dean 67 cM, 4 seg (unweighted 78 cM) 66 cM, 4 seg (unweighted 78 cM)
Debbie 93 cM, 5 seg Same
Valli 142 cM, 3 seg Same
Jared 20 cM, 1 seg (unweighted 22 cM) Same

Timber only removes DNA when the match is under 90 cM. Almost every match under 90 cM has some DNA removed.

Ancestry Summary

The results of the two Ancestry tests are very close.

In some circumstances, no DNA is removed by Timber, so the unweighted is the same as the weighted. However, in other cases, a significant amount is removed. 15 cM of Matthew’s 35 cM was removed by Timber, reducing his total to 20 cM.

Remember that Ancestry does not show shared matches unless they are greater than 20 cM, which is different than any other DNA testing company.

At one point, Ancestry was selling a health test that was also a genealogy test. That test utilized a different chip that is not accepted for uploads by other vendors. The results of that test might well be different that the “normal” Ancestry tests focused on genealogy. The Ancestry health test is no longer offered.

Companies that Accept Uploads

DNA testing companies that accept uploaded DNA files from other DNA testing companies need to process the uploaded file, just like a file that is generated in their own lab. Of course, they must deal with the differences between uploaded files and their own file format. The processing includes imputation and formulates the uploaded file so that it works with the tools that they provide for their customers, including ethnicity (by whatever name they use) matching, family matching (bucketing), advanced matching, the match matrix, triangulation, AutoClusters, Theories of Family Relativity, and other advanced tools.

Of course, the testing company accepting uploads can only work with the DNA locations provided by the original DNA testing company in the uploaded file.

Matching and some additional tools are free to uploaders, but advanced tools require an inexpensive unlock.

FamilyTreeDNA

I took a test at FamilyTreeDNA, plus uploaded a copy of both of my Ancestry DNA files.

FamilyTreeDNA named their population (ethnicity) test myOrigins and the current version is V3. I wrote about the rollout and comparison in September of 2020, here.

My DNA test taken at FamilyTreeDNA, above, reveals Native American segments that match reference populations found both in North and South America and the Caribbean Islands.

At FamilyTreeDNA, my Ancestry V1 uploaded file results show Native American population matches only in North America.

Interestingly, my Ancestry V1 file processed AT Ancestry did not reveal Native American ancestry, but the same file uploaded to and processed at FamilyTreeDNA did show Native American results, reflecting the difference between the vendors’ internal algorithms and reference populations utilized.

My myOrigins results from my Ancestry V2 uploaded file at FamilyTreeDNA also include my North American Native American segments. The V2 test also showed Native American ethnicity at Ancestry, so clearly something changed in Ancestry’s algorithm, locations tested, and/or reference populations between V1 and V2.

Fortunately, FamilyTreeDNA provides both chromosome painting and a population download file so I can match those Native segments with my autosomal matches to identify which of my ancestors contributed those specific segments.

One of my Native segments is shown in pink on Chromosome1. My mother has a Native segment in exactly the same location, so I know that this segment originated with my mother’s ancestors.

I downloaded the myOrigins population segment file and painted my results at DNAPainter, along with the matches where I can identify our common ancestor. This allowed me to pinpoint the ancestral line that contributed this Native segment in my maternal line. You can read about using DNAPainter, here.

FamilyTreeDNA Matches

I have significantly more matches at FamilyTreeDNA on their test than on either of my Ancestry tests that I uploaded. However, nearly the same number are maternally or paternally assigned through Family Matching, with the remainder unassigned. You can read about Family Matching here.

Match Category FamilyTreeDNA Test Ancestry V1 at FamilyTreeDNA Ancestry V2 at FamilyTreeDNA
Paternal 3,479 3,572 3,422
Maternal 1,549 1,536 1,477
Both 3 3 3
All 8,154 6,397 6,579

Family matching, aka bucketing, automatically assigns my matches as maternal and paternal by linking known relatives to their place in my tree.

I completed the following match chart using my original test taken at FamilyTreeDNA, plus the same match at FamilyTreeDNA for both of my Ancestry tests.

In other words, Cheryl matched me at 467 cM on 21 segments on the original test taken at FamilyTreeDNA. She matched me on 473 cM and 21 segments on my Ancestry V1 test uploaded to FamilyTreeDNA and on 483 cM and 22 segments on the Ancestry V2 test uploaded to FamilyTreeDNA.

Match FamilyTreeDNA Ancestry V1 at FTDNA Ancestry V2 at FTDNA
Cheryl 467 cM, 21 seg 473 cM, 21 seg 483 cM, 22 seg
Patricia 195 cM, 11 seg 189 cM, 11 seg 188 cM, 11 seg
Tom 77 cM, 4 seg 71 cM, 4 seg 76 cM, 4 seg
Thomas 72 cM, 3 seg 71 cM, 3 seg 74 cM, 3 seg
Roland 29 cM, 1 seg 35 cM, 2 seg 35 cM, 2 seg
Rex 62 cM, 4 seg 55 cM, 3 seg 57 cM, 3 seg
Don 395 cM, 18 seg 362 cM, 15 seg 398 cM, 18 seg
Ian 64 cM, 4 seg 56 cM, 4 seg 64 cM, 4 seg
Stacy 490 cM, 18 seg 494 cM, 15 seg 489 cM, 14 seg
Harold 127 cM, 5 cM 133 cM, 6 seg 143 cM, 6 seg
Dean 81 cM, 4 seg 75 cM, 3 seg 83 cM, 4 seg
Carl 103 cM, 4 seg 101 cM, 4 seg 102 cM, 4 seg
Debbie 99 cM, 5 seg 97 cM, 5 seg 99 cM, 5 seg
David 373 cM, 16 seg 435 cM, 19 seg 417 cM, 18 seg
Amos 176 cM, 7 seg 177 cM. 8 seg 177 cM, 7 seg
Buster 387 cM, 15 seg 396 cM, 16 seg 402 cM, 17 seg
Charlene 461 cM, 21 seg 450 cM, 21 seg 448 cM, 20 seg
Carol 65 cM, 6 seg 64 cM, 6 seg 65 cM, 6 seg

I have tested many of my cousins at FamilyTreeDNA and encouraged others to test or upload. I’ve attempted to include enough people so that I can have common matches at least at one other DNA testing company for comparison.

FamilyTreeDNA Summary

The matches are relatively close, with a few being exact.

Interestingly, some of the segment counts are different. In most cases, this results from one segment being broken into multiple segments by one or more of the tests, but not always. In the couple that I checked, the entire segment seems to descend from the same ancestral couple, so the break is likely a result of not all of the same DNA locations being tested, plus the limits of imputation.

MyHeritage

I have two tests at MyHeritage. One taken at MyHeritage, and an uploaded file from FamilyTreeDNA.

MyHeritage displays both ethnicity results and Genetic Groups which maps groups of people that you match. I left the Genetic Groups setting at the highest confidence level. Shifting it to lower displays additional Genetic Groups, some of which overlap with or are within ethnicity regions.

My test taken at MyHeritage, above, shows several ethnicities and Genetic Groups, but no Native American.

My FamilyTreeDNA kit processed at MyHeritage shows the same ethnicity regions, one additional Genetic Group, plus Native American heritage in the Amazon which is rather surprising given that I don’t show Native in North American regions where I’m positive my Native ancestors lived.

MyHeritage Matching

At MyHeritage, I compared the results of the test I took with MyHeritage, and a test I uploaded from FamilyTreeDNA. Fewer than half of my matches can be assigned to a parent via shared matching.

Matches MyHeritage Test FamilyTreeDNA at MyHeritage
Paternal 4,422 6,501
Maternal 2,660 3,655
Total 13,233 16,147

I have rounded my matches at MyHeritage to the closest cM.

Match MyHeritage Test FamilyTreeDNA at MyHeritage
Michael 801 cM, 32 seg 823 cM, 31 segments
Cheryl 467 cM, 23 seg 477 cM, 23 seg
Roland No match 28 cM, 1 seg
Patty 156 cM, 9 seg 151 cM, 9 seg
Rex 43 cM, 4 seg 53 cM, 3 seg
Don 369 cM, 16 seg 382 cM, 17 seg
 
David 449 cM, 17 seg 460 cM, 17 seg
Charlene 454 cM, 23 seg 477 cM, 24 seg
Buster 408 cM, 15 seg 410 cM, 16 seg
Amos 183 cM, 8 seg Same
Carol 78 cM, 6 seg 87 cM, 7 seg

MyHeritage Summary

I was surprised to discover that Roland had no match with the MyHeritage test, but did with the FamilyTreeDNA test. I wonder if this is a searching or matching glitch, especially since both companies use the same chip. 28 cM in one segment is a reasonably large match, and even if it was divided in two, it would still be over the matching threshold. I know this is a valid match because Roland triangulates with me and several cousins, I’m positive of our common ancestor, and he also matches me at both FamilyTreeDNA and 23andMe.

Other than that, the matches are reasonably close, with one being exact.

Your Matches Aren’t Everyplace

I unsuccessfully searched for someone who was a match to me in all four databases. Ancestry does not permit match downloads, so I had to search manually. People don’t always use the same names in different databases.

Surprisingly, I was unable to find one match who is in all of the databases. Many people only suggest testing at Ancestry because they have the largest database, but if you look at the following comparison chart that I’ve created, you’ll see that 16 of 26 people, or 62% were not at Ancestry. Conversely, many people were at Ancestry and not elsewhere. I could not find five maternal and five paternal matches at Ancestry that I could identify as matches in another database. 40% were not elsewhere.

If you think for one minute that it doesn’t matter for genealogy if you’re in all four major databases, please reconsider. It surely does matter.

Every single vendor has matches that the others don’t. Substantial, important matches. I have found first and second-cousin matches in every database that weren’t elsewhere.

Many of the original testers have passed away and can’t test again. My mother can never test at either 23andMe or Ancestry, but she is at both FamilyTreeDNA and MyHeritage because I could upgrade her kit at FamilyTreeDNA after she died. I uploaded her to MyHeritage. Of course, because she is a generation closer to our ancestors, she has many valuable matches that I don’t.

Each vendor provides either an email address or a messaging platform for you to contact your matches. Don’t be discouraged if they don’t answer. Just today, I received a reply that was years in the making.

Genealogists hope for immediate gratification, but we are actually in this for the long game. Play it with every tool at your disposal.

The Answer

Does it matter if you test at a DNA testing company, or upload a file?

I know this was a very long answer to what my readers hoped was a simple yes or no question.

There is no consistent answer at either FamilyTreeDNA or MyHeritage, the two DNA testing companies that accept uploads. Be sure you’re in both databases. My closest two matches that I did not test were found at MyHeritage. Here’s a direct link to upload at MyHeritage.

Of the vendors, those two should be the closest to each other because they are both processed in the GenebyGene lab, but again, the actual chip version, when the test was originally taken, and each vendor’s internal processing will result in differences. Neither the original test at the DNA testing company nor the uploaded files have consistently higher or lower matches. Neither type of test or upload appears to be universally more or less accurate. Differences in either direction seem to occur on a match-by-match basis. Many are so close as to be virtually equivalent, with a few seemingly random exceptions. Of course, we always have to consider Timber.

If you upload, unlock the advanced features at both FamilyTreeDNA and MyHeritage.

If you upload to a DNA testing company, you may discover in the future that some features and functions will only be available to original testers.

Personally, if I had the option, I would test at the company directly simply because it eliminates or at least reduces the possibility of future incompatibilities – with the exception of 23andMe which has chosen to not provide consistent updates to older tests. I’m incredibly grateful I didn’t test my mother or now deceased family members at 23andMe, and only there. I would be heartsick, heartbroken, and furious.

Our DNA is an extremely valuable resource for our genealogy. It’s the gift that truly keeps on giving, day after day, even when other records don’t exist. Be sure you and your family members are in each database one way or another, and test your Y-DNA (for males) and mitochondrial DNA (for everyone) to have a complete arsenal at your disposal.

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X Chromosome Master Class

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15

The X chromosome can be especially useful to genetic genealogists because it has a unique inheritance path. Thanks to that characteristic, some of the work of identifying your common ancestor is done just by simply HAVING an X match.

Unfortunately, X-DNA and X matching is both underutilized and somewhat misunderstood – in part because not all vendors utilize the X chromosome for matching.

The X chromosome has the capability of reaching further back in time and breaking down brick walls that might fall no other way.

Hopefully, you will read this article, follow along with your own DNA results and make important discoveries.

Let’s get started!

Who Uses the X Chromosome?

The X chromosome is autosomal in nature, meaning it recombines under some circumstances, but you only inherit your X chromosome from certain ancestors.

It’s important to understand why, and how to utilize the X chromosome for matching. In this article, I’ve presented this information in a variety of ways, including case studies, because people learn differently.

Of the four major testing vendors, only two provide X-DNA match results.

  • FamilyTreeDNA – provides X chromosome results and advanced matching capabilities including filtered X matching
  • 23andMe – provides X chromosome results, but not filtered X matching without downloading your results in spreadsheet format
  • Ancestry and MyHeritage do not provide X-DNA results but do include the X in your raw DNA file so you can upload to vendors who do provide X matching
  • GEDmatch – not a DNA testing vendor but a third-party matching database that provides X matching in addition to other tools

It’s worth noting at this point that X-DNA and mitochondrial DNA is not the same thing. I wrote about that, here. The source of this confusion is that the X chromosome and mitochondrial DNA are both associated in some way with descent from females – but they are very different and so is their inheritance path.

So, what is X-DNA and how does it work?

What is X-DNA?

Everyone inherits two copies of each of chromosomes 1-22, one copy of each chromosome from each of your parents.

That’s why DNA matching works and each match can be identified as “maternal” or “paternal,” depending on how your match is related to you. Each valid match (excluding identical by chance matches) will be related either maternally, or paternally, or sometimes, both.

Your 23rd chromosome is your sex determination chromosome and is inherited differently. Chromosome 23 is comprised of X and Y DNA.

Everyone inherits one copy of chromosome 23 from each parent.

  • Males inherit a Y chromosome from their father, which is what makes males male. They do not inherit an X chromosome from their father.
  • Males always inherit an X chromosome from their mother.
  • Females inherit an X chromosome from both parents, which is what makes them female. Females have two X chromosomes, and no Y chromosome.
Chromosome 23 Father Contributes Mother Contributes
Male Child Y chromosome X chromosome
Female Child X chromosome X chromosome

X-DNA and mitochondrial DNA are often confused, but they are not the same thing. In fact, they are completely different.

Mitochondrial DNA, in BOTH males and females is always inherited from only the mother and only descends from the direct matrilineal line, so only the mother’s mother’s mother’s direct line. X DNA can be inherited from a number of ancestors based on a specific inheritance path.

Everyone has both X-DNA AND mitochondrial DNA.

Because males don’t inherit an X chromosome from their father, X chromosome matching has a unique and specific pattern of descent which allows testers who match to immediately eliminate some potential common ancestors.

  • Males only inherit an X chromosome from their mother, which means they can only have legitimate X matches on their mother’s side of their tree.
  • Females, on the other hand, inherit an X chromosome from both their mother and father. Their father only has one X chromosome to contribute, so his daughter receives her paternal grandmother’s X chromosome intact.
  • Both males and females inherit their mother’s X chromosome just like any of the other 22 autosomes. I wrote about chromosomes, here.

However, the unique X chromosome inheritance path provides us with a fourth very useful type of DNA for genealogy, in addition to Y-DNA, mitochondrial and autosomal DNA.

For the vendors who provide X-matching, it’s included with your autosomal test and does not need to be purchased separately.

The Unique X Chromosome

The X chromosome, even though it is autosomal in nature, meaning it does recombine and divide in certain circumstances, is really its own distinct tool that is not equivalent to autosomal matching in the way we’re accustomed. We just need to learn about the message it’s delivering and how to interpret X matches.

FamilyTreeDNA is one of two vendors who utilizes X chromosome matching, along with 23andMe, which is another good reason to encourage your matches at other vendors to upload their DNA file to FamilyTreeDNA for free matching.

The four major vendors do include X-DNA results in their raw DNA download file, even if they don’t provide X-matching themselves. This means you can upload the results to either FamilyTreeDNA or GEDmatch where you can obtain X matches. I provided step-by-step download/upload instructions for each vendor here.

Let’s look how X matching is both different, and beneficial.

My X Chromosome Family Tree

We are going to build a simple case study. A case study truly is worth 1000 descriptions.

This fan chart of my family tree colorizes the X chromosome inheritance path. In this chart, males are colored blue and females pink, but the salient point is that I can inherit some portion of (or all of) a copy of my X chromosome from the colorized ancestors, and only those ancestors.

Because males don’t inherit an X chromosome from their father, they CANNOT inherit any portion of an X chromosome from their father’s ancestors.

Looking at my father’s half of the chart, at left, you see that I inherited an X chromosome from both of my parents, but my father only inherited an X chromosome from his mother, Ollie Bolton. His father’s portion of the tree is uncolored, so no X chromosome could have descended from his paternal ancestors to him. Therefore he could not pass any X chromosome segments to me from his paternal side – because he doesn’t have X DNA from his father.

Hence, I didn’t inherit an X chromosome from any of the people whose positions in the chart are uncolored, meaning I can only inherit an X chromosome from the pink or blue people.

Essentially any generational male to male, meaning father/son relationship is an X-DNA blocker.

I know positively that I inherited my paternal grandmother, Ollie Bolton’s entire X chromosome, because hers is the only X chromosome my father, in the fan chart above, had to give me. His entire paternal side of the fan chart is uncolored.

Men only ever inherit their X chromosome from their mother. The only exception to this is if a male has the rare genetic condition of Klinefelter Syndrome, also known as XXY. If you are an adult male, it’s likely that you’ll already know if you have Klinefelters, so that’s probably the last possibility you should consider if you appear to have paternal X matches, not the first.

Sometimes, men appear to have X matches on their father’s side, but (barring Klinefelter’s) this is impossible. Those matches must either be identical by chance, or somehow related in an unknown way on their mother’s side.

Everyone inherits an X chromosome from their mother that is some combination of the X from her father and mother. It’s possible to inherit all of your maternal grandmother or maternal grandfather’s X chromosome, meaning they did not recombine during meiosis.

Using DNA Painter as an X Tool

I use DNAPainter to track my matches and correlate segments with ancestors.

I paint my DNA segments for all my chromosomes at DNAPainter which provides me with a central tracking mechanism that is visual in nature and allows me to combine matches from multiple vendors who provide segment information. I provide step-by-step instructions for using DNAPainter, here.

This is my maternal X chromosome with my matches painted. I’ve omitted my matches’ names for privacy.

On the left side of the shaded grey column, those matches are from my maternal grandmother’s ancestors. On the right side, those matches are from my maternal grandfather’s ancestors.

The person in the grey column descends from unknown ancestors. In other words, I can tell that they descend from my maternal line, but I can’t (yet) determine through which of my two maternal grandparents.

There’s also an area to the right of the grey column where there are no matches painted, so I don’t know yet whether I inherited this portion of my X chromosome from my maternal grandmother or maternal grandfather.

The small darker pink columnar band is simply marking the centromere of the chromosome and does not concern us for this discussion.

Click on any image to enlarge

In this summary view of my paternal X chromosome, above, it appears that I may well have inherited my entire X chromosome from my paternal great-grandmother. We know, based on our inheritance rules that I clearly received my paternal grandmother’s X chromosome, because that’s all my father had to give me.

However, by painting my matches based on their ancestors, and selecting the summary view, you can see that most of my paternal X chromosome can be accounted for, with the exception of rather small regions with the red arrows.

It’s not terribly unusual for either a male or female to inherit their entire maternal X chromosome from one grandparent, or in this case, great-grandparent.

Of course, a male doesn’t inherit an X chromosome from their father, but a female can inherit her paternal X chromosome from either or both paternal grandparents.

Does Size Matter?

Generally speaking, an X match needs to be larger than a match on the other chromosomes to be considered genealogically equivalent in the same timeframe as other autosomal matches. This is due to:

  • The unique inheritance pattern, meaning fewer recombination events occurred.
  • The fact that X-DNA is NOT inherited from several lines.
  • The X chromosome has lower SNP density, meaning it contains fewer SNPs, so there are fewer possible locations to match when compared to the other chromosomes.

I know this equivalency requirement sounds negative, but it’s actually not. It means 7 cM (centimorgans) of DNA on the X chromosome will reach back further in time, so you may carry the DNA of an ancestor on the X chromosome that you no longer carry on other chromosomes. It may also mean that older segments remain larger. It’s actually a golden opportunity.

It sounds much more positive to say that a 16 cM X match for a female, or a 13 cM X match for a male is about the same as a 7 cM match for any other autosomal match in the same generation.

Of course, if the 7 cM match gets divided in the following generation, it has slipped below the matching threshold. If a 16 or 13 cM X match gets divided, it’s still a match. Plus, in some generations, if passed from father to daughter, it’s not divided or recombined. So a 7 cM X match may well be descended from ancestors further back in time.

X Chromosome Differences are Important!

Working with our great-great grandparent’s generation, we have 16 direct ancestors as illustrated in the earlier fan chart.

Given that females inherit from 8 X-chromosome ancestors in total, they are going to inherit an average of 45.25 cM of X-DNA from each of those ancestors. Females have two X chromosomes for a total length of 362 cM of X-DNA from both parents.

A male only has one X chromosome, 181 cM in length, so he will receive an average of 36.2 cM from each of 5 ancestors, and it’s all from his mother’s side.

In this chart, I’ve shown the total number of cMs for all of the autosomes, meaning chromosomes 1-22 and, separately, the X for males and females.

  • The average total cM for chromosomes 1-22 individually is 304 cM. (Yes, each chromosome is a different length, but that doesn’t matter for averages.)
  • That 304 cM can be inherited from any of 16 ancestors (in your great-grandparent’s generation)
  • The total number of cM on the X chromosomes for both parents for females totals 362
  • The total cM of X-DNA for males is 181 cM
  • The calculated average cM inherited for the X chromosome in the same generation is significantly different, shown in the bottom row.

The actual average for males and females for any ancestor on any random non-X chromosome (in the gg-grandparent generation) is still 19 cM. Due to the inheritance pattern of the X chromosome, the female X-chromosome average inheritance is 45.25 cM and the male average is 36.2 cM, significantly higher than the average of 19 cM that genetic genealogists have come to expect at this relationship distance on the other chromosomes, combined.

How Do I Interpret an X Match?

It’s important to remember when looking at X matching that you’re only looking at the amount of DNA from one chromosome. When you’re looking at any other matching amount, you’re looking at a total match across all chromosomes, as reported by that vendor. Vendors report total matching DNA differently.

  • The total amount of matching autosomal DNA does not include the X chromosome cMs at FamilyTreeDNA. X-DNA matching cMs are reported separately.
  • The total amount of matching autosomal DNA does include the X chromosome cMs in the total cM match at 23andMe
  • X-DNA is not used for matching or included in the match amount at either MyHeritage or Ancestry, but is included in the raw DNA data download files for all four vendors.
  • The total match amount shows the total for 22 (or 23) chromosomes, NOT just the X chromosome(s). That’s not apples to apples.

Therefore, an X match of 45 cM for a female or 36 for a male is NOT (necessarily) equivalent to a 19 cM non-X match. That 19 cM is the total for 22 chromosomes, while the X match amount is just for one chromosome.

You might consider a 20 cM match on the regular autosomes significant, but a 20 cM X-only match *could* be only roughly equivalent to a 10ish cM match on chromosomes 1-22 in the same generation. That’s the dog-leg inheritance pattern at work.

This is why FamilyTreeDNA does not report an X-only match if there is no other autosomal match. A 19 cM X match is not equivalent to a 19cM match on chromosomes 1-22. Not to mention, calculating relationships based on cM ranges becomes more difficult when the X is included.

However, the flip side is that because of the inheritance pattern of the X chromosome, that 19 cM match, if valid and not IBC, may well reach significantly further back in time than a regular autosomal matches. This can be particularly important for people seeking either Native or enslaved African ancestors for whom traditional records are elusive if they exist at all.

Critical Take-Away Messages

Here are the critical take-away messages:

  1. Because there are fewer ancestral lineages contributing to the tester’s X chromosome, the amount of X chromosomal DNA that a tester inherits from the ancestors who contribute to their X chromosome is increased substantially.
  2. The DNA of the contributing ancestors is more likely to be inherited, because there are fewer other possible contributing ancestors, meaning fewer recombination events or DNA divisions/recombinations.
  3. X-DNA is also more likely to be inherited because when passed from mother to son, it’s passed intact and not admixed with the DNA of the father.
  4. X matches cannot be compared equally to either percentages or cM amounts on any of the other chromosomes, or autosomal DNA in total, because X matching only reports the amount on one single chromosome, while your total cM match amount reports the amount of DNA that matches from all chromosomes (which includes the X at 23andMe).
  5. If you have X matches at 23andMe and/or FamilyTreeDNA, you can expect your total matching to be higher at 23andMe because they include the X matching cM in the total amount of shared DNA. FamilyTreeDNA provides the amount of X matching DNA separately, but not included in the total. MyHeritage and Ancestry do not include X matching DNA.

For clarity, at FamilyTreeDNA, you can see my shared DNA match with my mother. Of course, I match her on the total length of all my chromosomes, which is 3563 cM, the total Shared DNA for chromosomes 1-22. This includes all chromosomes except for the X chromosome which is reported separately at 181 cM. The longest contiguous block of shared DNA is 284 cM, the entire length of chromosome 1, the longest chromosome.

Because I’m a female, I match both parents on the full length of all 23 chromosomes, including 181 cM on both X chromosomes, respectively. Males will only match their mother on their X chromosome, meaning their total autosomal DNA match to their father, because the X is excluded, is 181 cM less than to their mother.

This difference in the amount of shared DNA with each parent, plus the differences in how DNA totals are reported by various vendors is also challenging for tools like DNAPainter’s Shared cM Tool which is based on the crowd sourced Shared cM Project that averages shared DNA numbers for known relationships at various vendors and translates those numbers into possible relationships for unknown matches.

Not all vendors report their total amount of shared DNA the same way. This is true for both X-DNA and half identical (HIR) versus fully identical (FIR) segments at 23andMe. This isn’t to say either approach is right or wrong, just to alert you to the differences.

Said Another Way

Let’s look at this another way.

If the average on any individual chromosome is 19 cMs for a relationship that’s 5 generations back in time. The average X-DNA for the same distance relationship is substantially more, which means that:

  • The X-DNA probably reaches further back in time than an equivalent relationship on any other autosome.
  • The X-DNA will have (probably) divided fewer times, and more DNA will descend from individual ancestors.
  • The inheritance path, meaning potential ancestors who contributed the X chromosomal DNA, is reduced significantly.

It’s challenging to draw equivalences when comparing X-DNA matching to the other chromosomes due to several variables that make interpretation difficult.

Based on the X-match size in comparison to the expected 19 cM single chromosome match at this genealogical distance, what is the comparable X-DNA segment size to the minimum 7 cM size generally accepted as valid on other chromosomes? What would be equal to a 7 cM segment on any other single random autosomal match, even though we know the inheritance probabilities are different and this isn’t apples to apples? Let’s pretend that it is.

This calculation presumes at the great-great-grandparent level that the 19 cM is in one single segment on a single chromosome. Now let’s divide 19 cM by 7 cM, which is 2.7, then divide the X amounts by the same number for the 7 cM equivalent of 16.75 cM for a female and 13.4 cM for a male.

When people say that you need a “larger X match to be equivalent to a regular autosomal match,” this is the phenomenon being referenced. Clearly a 7 cM X match is less relevant, meaning not equivalent, in the same generation as a 7 cM regular autosomal match.

Still, X matching compared to match amounts shown on the other chromosomes is never exact;u apples to apples because:

  • You’re comparing one X chromosome to the combined DNA amounts of many chromosomes.
  • The limited recombination path.
  • DNA from the other autosomes is less likely to be inherited from a specific ancestor.
  • The X chromosome has a lower SNP density than the other chromosomes, meaning fewer SNPs per cM.
  • The X-DNA may well reach further back in time because it has been divided less frequently.

Bottom Line

The X chromosome is different and holds clues that the other autosomes can’t provide.

Don’t dismiss X matches even if you can’t identify a common ancestor. Given the inheritance path, and the reduced number of divisions, your X-DNA may descend from an ancestor further back in time. I certainly would NOT dismiss X matches with smaller cMs than the 13 and 16 shown above, even though they are considered “equivalent” in the same generation.

X chromosome matching can’t really be equated to matching on the other chromosomes. They are two distinct tools, so they can’t be interpreted identically.

Different vendors treat the X chromosome differently, making comparison challenging.

  • 23andMe includes not only the X chromosome in their cM total, but doubles the Fully Identical Regions (FIR) when people, such as full siblings, share the same DNA from both parents. I wrote about that here.
  • Ancestry does not include the X in their cM match calculations.
  • Neither does MyHeritage.
  • FamilyTreeDNA shows an X match only when it’s accompanied by a match on another chromosome.

The Shared cM Project provides an average of all of the data input by crowdsourcing from all vendors, by relationship, which means that the cM values for some relationships are elevated when compared to the same relationship or even same match were it to be reported from a different vendor.

The Best Part!

The X chromosome inheritance pattern means that you’re much more likely to carry some amount of a contributing ancestor’s X-DNA than on any other chromosome.

  • X-DNA may well be “older” because it’s not nearly as likely to be divided, given that there are fewer opportunities for recombination.
  • When you’re tracking your X-DNA back in your tree, whenever you hit a male, you get an automatic “bump” back a generation to his mother. It’s like the free bingo X-DNA square!
  • You can immediately eliminate many ancestors as your most recent common ancestor (MRCA) with an X-DNA match.
  • Because X-DNA reaches further back in time, sometimes you match people who descend from common ancestors further back in time as well.

If you match someone on multiple segments, if one of those matching segments is X-DNA, that segment is more likely to descend from a different ancestor than the segments on chromosomes 1-22. I’ve found many instances where an X match descends from a different ancestor than matching DNA segments on the autosomes. Always evaluate X matches carefully.

Sometimes X-DNA is exactly what you need to solve a mystery.

Ok, now let’s step through how to use X-DNA in a real-life example.

Using X DNA to Solve a Mystery

Let’s say that I have a 30 cM X match with a male.

  • I know immediately that our most recent common ancestor (MRCA) is on HIS mother’s side.
  • I know, based on my fan chart, which ancestral lines are eliminated in my tree. I’ve immediately narrowed the ancestors from 16 to 5 on his side and 16 to 8 on my side.
  • Two matching males is even easier, because you know immediately that the common ancestor must be on both of their mother’s sides, with only 5 candidate lines each at the great-great-grandparent generation.

Female to female matches are slightly more complex, but there are still several immediately eliminated lines each. That means you’ve already eliminated roughly half of the possible relationships by matching another female on their X chromosome.

In this match with a female second cousin, I was able to identify who she was via our common ancestor based on the X chromosome path. In this chart, I’m showing the relevant halves of her chart at left (paternal), and mine (maternal), side by side.

I added blockers on her chart and mine too.

As it turns out, we both inherited most of our X chromosome from our great-grandparents, marked above with the black stars.

Several lines are blocked, and my grandfather’s X chromosome is not a possibility because the common ancestor is my maternal grandmother’s parents. My grandfather is not one of her ancestors.

Having identified this match as my closest relative (other than my mother) to descend on my mother’s maternal side, I was able to map that portion of my X chromosome to my great-grandparents Nora Kirsch and Curtis Benjamin Lore.

My X Chromosome at DNA Painter

Here’s my maternal X chromosome at DNAPainter and how I utilized chromosome painting to push the identification of the ancestors whose X chromosome I inherited back an additional two generations.

Using that initial X chromosome match with my second cousin, shown by the arrow at bottom of the graphic, I mapped a large segment of my maternal X chromosome to my maternal great-grandparents.

By viewing the trees of subsequent X maternal matches, I was then able to push those common segments, shown painted directly above that match with the same color, back another two generations, to Joseph Hill, born in 1790, and Nabby Hall. I was able to do that based on the fact that other matches descend from Joseph and Nabby through different children, meaning we all triangulate on that common segment. I wrote about triangulation at DNAPainter, here.

I received no known X-DNA from my great-grandmother, Nora Kirsch, although a small portion of my X chromosome is still unassigned in yellow as “Uncertain.”

I received a small portion of my maternal X chromosome, in magenta, at left, from my maternal great-great-grandparents, John David Miller and Margaret Lentz.

The X chromosome is a powerful tool and can reach far back in time.

In some cases, the X, and other chromosomes can be inherited intact from one grandparent. I could have inherited my mother’s entire copy of her mother’s, or her father’s X chromosome based on random recombination, or not. As it turns out, I didn’t, and I know that because I’ve mapped my chromosomes to identify my ancestors based on common ancestors with my matches.

X-DNA Advanced Matches at FamilyTreeDNA

At FamilyTreeDNA, the Advanced Matches tab includes the ability to search for X matches, either within the entire database, or within specific projects. I find the project selection to be particularly useful.

For example, within the Claxton project, my father’s maternal grandmother’s line, I recognize my match, Joy, which provides me an important clue as to the possible common ancestor(s) of our shared segments.

Joy’s tree shows that her 4-times great-grandparents are my 3-times great-grandparents, meaning we are 4th cousins once removed and share 17 cM of DNA on our X chromosome across two segments.

Don’t be deceived by the physical appearance of “size” on your chromosomes. The first segment that spans the centromere, or “waist” of the chromosome, above, is 10.29 cM, and the smaller segment at right is 7.02 cM. SNPs are not necessarily evenly distributed along chromosomes.

Remember, an X or other autosomal match doesn’t necessarily mean the entire match is contained in one segment so long as it’s large enough to be divided in two parts and survive the match threshold.

It’s worth noting that Joy and I actually share at least two different, unrelated ancestral lines, so I need to look at Joy’s blocked lines to see if one of those common ancestral lines is not a possibility for our X match. It’s important to evaluate all possible ancestors, plus the inheritance path to eliminate any lineage that involves a father to son inheritance on the X chromosome.

Last but not least, you may match on your X chromosome through a different ancestor than on other chromosomes. Every matching segment has its own individual history. It’s not safe to assume.

Now, take a look at your X chromosome matches at FamilyTreeDNA, 23andMe, and GedMatch. What will you discover?

_____________________________________________________________

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You’re always welcome to forward articles or links to friends and share on social media.

If you haven’t already subscribed (it’s free,) you can receive an email whenever I publish by clicking the “follow” button on the main blog page, here.

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

Thank you so much.

DNA Purchases and Free Uploads

Genealogy Products and Services

My Book

Genealogy Books

Genealogy Research