Triangulation in Action at DNAPainter

Recently, I published the article, Hitting a Genealogy Home Run Using Your Double-Sided Two-Faced Chromosomes While Avoiding Imposters. The “Home Run” article explains why you want to use a chromosome browser, what you’re seeing and what it means to you.

This article, and the rest in the “Triangulation in Action” series introduces triangulation at FamilyTreeDNA, MyHeritage, 23andMe, GedMatch and DNAPainter, explaining how to use triangulation to confirm descent from a common ancestor. You may want to read the introductory article first.

This first section, “What is Triangulation” is a generic tutorial. If you don’t need the tutorial, skip to the “Transfers” or “Triangulation at DNAPainter” section.

What is Triangulation?

Think of triangulation as a three-legged stool – a triangle. Triangulation requires three things:

  1. At least three (not closely related) people must match
  2. On the same reasonably sized segment of DNA and
  3. Descend from a common ancestor

Triangulation is the foundation of confirming descent from a common ancestor, and thereby assigning a specific segment to that ancestor. Without triangulation, you might just have a match to someone else by chance. You can confirm mathematical triangulation, numbers 1 and 2, above, without knowing the identity of the common ancestor.

Reasonably sized segments are generally considered to be 7cM or above on chromosomes 1-22 and 15cM or above for the X chromosome.

Boundaries

Triangulation means that all three, or more, people much match on a common segment. However, what you’re likely to see is that some people don’t match on the entire segment, meaning more or less than others as demonstrated in the following examples.

FTDNA Triangulation boundaries

You can see that I match 5 different cousins who I know descend from my father’s side on chromosome 15 above. “I” am the grey background against which everyone else is being compared.

I triangulate with these matches in different ways, forming multiple triangulation groups that I’ve discussed individually, below.

Triangulation Group 1

FTDNA triangulation 1

Group 1 – On the left group of matches, above, I triangulate with the blue, red and orange person on the amount of DNA that is common between all of them, shown in the black box. This is triangulation group 1.

Triangulation Group 2

FTDNA triangulation 2

Group 2 – However, if you look just at the blue and orange triangulated matches bracketed in green, I triangulate on slightly more. This group excludes the red person because their beginning point is not the same, or even close. This is triangulation group 2.

Triangulation Group 3 and 4

FTDNA triang 3

Group 3 – In the right group of matches, there are two large triangulation groups. Triangulation group 3 includes the common portions of blue, red, teal and orange matches.

Group 4 – Triangulation group 4 is the skinny group at right and includes the common portion of the blue, teal and dark blue matches.

Triangulation Groups 5 and 6

FTDNA triang 5

Group 5 – There are also two more triangulation groups. The larger green bracketed group includes only the blue and teal people because their end locations are to the right of the end locations of the red and orange matches. This is triangulation group 5.

Group 6 – The smaller green bracketed group includes only the blue and teal person because their start locations are before the dark blue person. This is triangulation group 6.

There’s actually one more triangulation group. Can you see it?

Triangulation Group 7

FTDNA triang 7

Group 7 – The tan group includes the red, teal and orange matches but only the areas where they all overlap. This excludes the top blue match because their start location is different. Triangulation group 7 only extends to the end of the red and orange matches, because those are the same locations, while the teal match extends further to the right. That extension is excluded, of course.

Slight Variations

Matches with only slight start and end differences are probably descended from the same ancestor, but we can’t say that for sure (at this point) so we only include actual mathematically matching segments in a triangulation group.

You can see that triangulation groups often overlap because group members share more or less DNA with each other. Normally we don’t bother to number the groups – we just look at the alignment. I numbered them for illustration purposes.

Shared or In-Common-With Matching

Triangulation is not the same thing as a 3-way shared “in-common-with” match. You may share DNA with those two people, but on entirely different segments from entirely different ancestors. If those other two people match each other, it can be on a segment where you don’t match either of them, and thanks to an ancestor that they share who isn’t in your line at all. Shared matches are a great hint, especially in addition to other information, but shared matches don’t necessarily mean triangulation although it’s a great place to start looking.

I have shared matches where I match one person on my maternal side, one on my paternal side, and they match each other through a completely different ancestor on an entirely different segment. However, we don’t triangulate because we don’t all match each other on the SAME segment of DNA. Yes, it can be confusing.

Just remember, each of your segments, and matches, has its own individual history.

Imputation Can Affect Matching

Over the years the chips on which our DNA is processed at the vendors have changed. Each new generation of chips tests a different number of markers, and sometimes different markers – with the overlaps between the entire suite of chips being less than optimal.

I can verify that most vendors use imputation to level the playing field, and even though two vendors have never verified that fact, I’m relatively certain that they all do. That’s the only way they could match to their own prior “only somewhat compatible” chip versions.

The net-net of this is that you may see some differences in matching segments at different vendors, even when you’re comparing the same people. Imputation generally “fills in the blanks,” but doesn’t create large swatches of non-existent DNA. I wrote about the concept of imputation here.

What I’d like for you to take away from this discussion is to be focused on the big picture – if and how people triangulate which is the function important to genealogy. Not if the start and end segments are exactly the same.

Triangulation Solutions

All vendors except Ancestry offer some type of triangulation.

If you and your Ancestry matches have uploaded to GedMatch, Family Tree DNA or MyHeritage, you can triangulate with them there. Otherwise, you can’t triangulate Ancestry results, so encourage your Ancestry matches to transfer.

I wrote more specifically about triangulation here and here.

Transfer your results in order to obtain the maximum number of matches possible. Every vendor has people in their data base that haven’t tested elsewhere.

Transfers

Have you tested family members, especially everyone in the older generations? You can transfer their kits from Ancestry or 23andMe if they’ve tested there to FamilyTreeDNA, MyHeritage and GedMatch.

Here’s how to transfer:

Now that we’ve reviewed triangulation at each vendor; FamilyTreeDNA, MyHeritage, 23andMe and GedMatch, let’s looking at utilizing triangulation at DNAPainter.

Triangulation at DNAPainter

Once you identify your ancestral segments with matches, or using triangulation, you can paint them on your maternal or paternal chromosomes utilizing DNAPainter.

The great aspect of DNAPainter is that you don’t have to triangulate in order to use DNAPainter. Just identifying matches as maternal or paternal allows you to visually see where on your maternal or paternal chromosomes your matches fall, in essence triangulating groups for you.

DNAPainter assigns colors to each ancestor and shows your match names, which I’ve disabled in this example for privacy. I’ve also optionally painted my ethnicity segments from 23andMe, which I discussed in this article.

Triangulation DNAPainter chr 22.png

Above, on chromosome 22, I’ve painted matches that I know descend from either my mother’s (pink) or father’s (blue) side. At DNAPainter, I DO have both a maternal and paternal chromosome, but they are only useful AFTER I figure out which side of my family a match comes from, or if I paint my Family Matching bucketed maternal and paternal matches in an upload file from Family Tree DNA. I wrote instructions for how to do that, here. The combination of Family Matching and DNAPainter is awesome!

Looking at the graphic above, I know that three separate people who match me descend from the bright pink ancestor on my maternal chromosome; Curtis Lore and his wife. I’ve assigned Curtis the bright pink color, and now every match that I paint assigned to Curtis and his wife is colored pink.

One person descends from Curtis’s parents, Anthony Lore and his wife Rachel Hill who I’ve assigned as green.

Until someone else matches me and descends either from Anthony Lore’s parents or Rachel Hill’s parents on this green segment, I won’t know which of those two ancestors, or both, provided (pieces of) that segment to me.

Anthony Lore and Rachel Hill are my great-great-grandparents and Curtis Lore is their son. Even if I only have 2 matches on this segment, one pink and one green, I would know that the green portion of my maternal chromosome 22 is attributed to Anthony and Rachel which means I inherited that green segment from my pink ancestor, Curtis Lore.

In order to determine the source of the two pink triangulated matches at far right, I’ll need to wait until someone from either Curtis’s line or his wife Nora Kirsch’s line match me on that same segment.

We build these groups of triangulated segments slowly, creating in essence a timeline on our chromosomes. It seems like it’s taking forever, but four generations distance with 2 separate triangulated segments really isn’t bad at all!

At DNAPainter, triangulation is as simple as painting your identified matches, either individually, one by one, or using the group import features. I would only recommend utilizing that feature at Family Tree DNA where their Family Matching software divides your matches into maternal and paternal, allowing DNAPainter to paint them on the correct chromosome. Otherwise, the segments are painted, but you can’t tell which side, maternal or paternal, they come from, so I don’t find painting all matches useful without some way to differentiate between maternal and paternal. After all, the point and power of a chromosome browser is to determine how each person is related, from which side, and from which ancestor.

In the article, DNAPainter Instructions and Resources, I compiled my various articles about the many ways to use DNAPainter, including an introduction.

Transfer

Be sure to test at or transfer to each vendor who provides segment information. Unfortunately, Ancestry does not, but you can transfer your ancestry results to Family Tree DNA, MyHeritage and GedMatch, each of which has unique features that the others don’t have. Transferring and matching is free at each vendor.

I wrote transfer instructions for each vendor, here.

Then, paint and triangulate all in one step at DNAPainter.

Have fun!

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

Free Webinar: 3 Case Studies and How I Solved Them

I recorded my latest webinar live yesterday for Legacy Family Tree Webinars, but Murphy interfered a bit in the last 5 minutes or so. The great news is that we re-recorded that portion and it’s fixed seamlessly for your (free until March 10th) viewing pleasure.

This webinar utilizes historical and genealogical records, autosomal, Y or mitochondrial DNA, sometimes in combination with each other, to solve various cases. I use the features available at the major vendors plus third-party tools as well – whatever is needed to address the situation at hand.

Which resources I use, when, depends on what I have to work with and where I seek to go – kind of like following clues on a treasure map – except this treasure trove I’m unearthing is my ancestors!

You’re not going to believe how much information, and how many generations were revealed in the mitochondrial DNA case. This was a GOLD MINE!

3 Case Studies and How I Solved Them is free until March 10th by clicking here. This is a wonderful opportunity if you didn’t get to watch live or had viewing issues. Just scroll down to the very first webinar in the library.

Legacy Tree 3 case studies.png

After March 10th, you’ll need a subscription which you can purchase, here by clicking on the subscribe link in the upper right hand corner of the Legacy Family Tree Webinar  page.

Legacy Tree subscribe.png

If you want to order any of the tests mentioned in the webinar, they are available at the following links:

Instructions for transferring from vendors to either FamilyTreeDNA or My Heritage are found here. I recommend transferring to or between both. In other words, make sure you are in all 4 of the major testing databases. You never know where that critically important match is going to be found.

Need an autosomal testing and transfer strategy to minimize costs and mazimize results? Click here.

Enjoy and Share the Love

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

_____________________________________________________________

Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Genealogy Research

Fun DNA Stuff

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

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

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

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

DNA Painter New Import Tool

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

DNAPainter FF import.png

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

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

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

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

How reliable is bucketing?

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

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

Getting Started

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

DNAPainter mytree.png

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

DNAPainter FF matches.png

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

DNAPainter FF matches link.png

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

DNAPainter Ff sister.png

Here I am as my sister, Example Adoptee.

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

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

What Does DNAPainter Do with Bucketed Matches?

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

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

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

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

Painting Bucketed Matches at DNAPainter

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

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

DNAPainter duplicate profile.png

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

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

DNAPainter ff download segments.png

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

DNAPainter csv.png

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

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

DNAPainter import instructions

click to enlarge

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

DNAPainter both.png

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

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

DNAPainter chr 1 both.png

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

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

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

DNAPainter import bucket

click to enlarge

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

I love this tool!

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

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

It’s Soup!!!

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

DNAPainter import complete.png

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

DNAPainter legend.png

Your Painted Chromosomes

Let’s take a look at what we have.

DNAPainter both, mat, pat.png

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

Let’s look at chromosome 1.

DNAPainter chr 1 all.png

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

For a genealogist, this is beautiful!!!

How many matches were painted?

DNAPainter paternal total.png

DNAPainter maternal total.png

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

Here’s the exciting part!

DNAPainter ch1 1 mat expanded.png

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

DNAPainter maternal pedigree.png

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

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

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

DNAPainter chr 1 pat expanded.png

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

DNAPainter paternal pedigree.png

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

Woohoooo!

Manual Spreadsheet Compare

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

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

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

DNAPainter manual spreadsheet example.png

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

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

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

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

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

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

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

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

Creating a Mass Upload Template and File

DNAPainter custom mass upload.png

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

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

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

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

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

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

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

Before and After

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

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

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

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

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

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

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

X matches are not created equal.

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

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

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

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

DNAPainter X spreadsheet example.png

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

On the X chromosome, here’s what happened.

DNAPainter maternal X.png

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

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

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

Every Segment Has Its Own Story

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

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

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

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

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

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

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

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

What About You?

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

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

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

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Genealogy Research

Fun DNA Stuff

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

DNA Inherited from Grandparents and Great-Grandparents

Philip Gammon, our statistician friend has been working with crossover simulations again in order to tell us what we might expect relative to how much DNA we actually inherit from grandparents and great-grandparents.

We know that on average, we’re going to inherit 25% of our DNA from each grandparent – but we also know in reality that’s not what happens. We get more or less than exactly 25% from each person in a grandparent pair. It’s the total of the DNA of both grandparents that adds up to 50% for the couple.

How does this work, and does it make a difference whether we inherit our grandparent’s DNA through males or females?

Philip has answers for us as a result of his simulations.

DNA Inheritance from Grandparents

Philip Gammon:

When we consider the DNA that we inherit from our ancestors the only quantity that we can be certain of is that we receive half of our autosomal DNA from each parent. This is delivered to us in the form of the 22 segments (i.e. chromosomes) provided by our mothers in the ova and the 22 segments/chromosomes provided by our fathers in the sperm cell. Beyond parent-child relationships we tend to talk about averages. For instance, we receive an average of one quarter of our DNA from each of our four grandparents and an average of one-eighth of our DNA from each of our eight great-grandparents etc.

These figures vary because our parents didn’t necessarily pass on to us equal portions of the DNA that they received from their parents. The level of variation is driven by the number (and location) of crossover events that occur when the ova and the sperm cells are created.

The statistics relevant to the recombination process were discussed in detail in a previous article (Crossovers: Frequency and Inheritance Statistics – Male Versus Female Matters). With the availability these days of abundant real data from direct-to-consumer genetic testing companies (such as the 23andMe data utilised by Campbell et. al. in their paper titled “Escape from crossover interference increases with maternal age”) we can use this information as a basis for simulations that accurately mimic the crossover process. From these simulations we can measure the amount of variation that is expected to be observed in the proportions of DNA inherited from our ancestors. This is precisely what I have done in simulations run on my GAT-C model.

Before looking at the simulation results let’s anticipate what we expect to see. The previous article on crossover statistics revealed that there are an average of about 42 crossovers in female meiosis and about 27 in male meiosis. So, on the set of 22 chromosomes received from our mothers there will have been an average of 42 crossover locations where there was a switch between DNA she inherited from one parent to the other. That means that the DNA we inherit from our maternal grandparents typically comes in about 64 segments, but it won’t necessarily be 32 segments from each maternal grandparent. Chromosomes that experienced an odd number of crossovers contain an even number of segments (half originating from the grandmother, the other half from the grandfather) but chromosomes with an even number of crossovers (or zero!) have an odd number of segments so on these chromosomes you must receive one more segment from one grandparent than the other. And of course not all segments are the same size either. A single crossover occurring close to one end of the chromosome results in a small segment from one grandparent and a large segment from the other. All up there are quite a few sources of variation that can affect the amount of DNA inherited from grandparents. The only certainty here is that the amount inherited from the two maternal grandparents must add to 50%. If you inherit more than the average of 25% from one maternal grandparent that must be offset by inheriting less than 25% from the other maternal grandparent.

Gammon grandparents maternal percent.png

The above chart shows the results of 100,000 simulation runs. Excluding the bottom and top 1% of results, 98% of people will receive between 18.7% and 31.3% of their DNA from a maternal grandparent. The more darkly shaded region in the centre shows the people who receive a fairly even split of between 24% and 26% from the maternal grandparents. Only 28.8% of people are in this region and the remainder receive a less even contribution.

On the set of 22 chromosomes received from fathers there will have been an average of around 27 crossovers so the DNA received from the paternal grandparents has only been split into around 49 segments. It’s the same amount of DNA as received from mothers but just in larger chunks of the grandparent’s DNA. This creates greater opportunity for the father to pass on unequal amounts of DNA from the two grandparents so it would be expected that results from paternal inheritance will show more variation than from maternal inheritance.

Gammon grandparents paternal percent.png

The above chart shows the results of 100,000 simulated paternal inheritance events. They are more spread out than the maternal events with the middle 98% of people receiving between 16.7% and 33.3% of their DNA from a paternal grandparent. Only 21.9% of people receive a fairly even split of between 24% and 26% from each paternal grandparent as shown by the more darkly shaded region in the centre.

Gammon grandparents percent cM.png

To help with the comparison between maternal and paternal inheritance from grandparents the two distributions have been overlayed on the same scale in the chart above. And what are the chances of receiving a fairly even split of grandparents DNA from both your mother and your father? Only 6.3% of people can be expected to inherit an amount of between 24% and 26% of their DNA from all four grandparents.

Now I’ll extend the simulations out to the next generation and examine the variation in proportions of DNA inherited from the eight great-grandparents. There are effectively four groups of great-grandparents:

  • Mother’s maternal grandparents
  • Mother’s paternal grandparents
  • Father’s maternal grandparents
  • Father’s paternal grandparents

The DNA from group 1 has passed to you via two maternal recombination events, from your mother’s mother to your mother, then from your mother to you. On average there would have been 42 crossovers in each of these recombination events. Group 4 comprised two paternal recombination events averaging only 27 crossovers in each. The average amount of DNA received along each path is the same but along the group 1 path it would comprise of more numerous smaller segments than the group 4 path. Groups 2 and 3 would be somewhere between, both consisting of one maternal and one paternal recombination event.

Gammon greatgrandparents percent cM.png

The above chart shows the variation in the amount of DNA received from members of the four groups of great-grandparents. 25,000 simulations were performed. The average amount from any great-grandparent is 12.5% but there can be considerably more variation in the amount received from the father’s paternal grandparents than from the mother’s maternal grandparents. Groups 2 and 3 are between these two extremes and are equivalent. It doesn’t matter whether a paternal recombination follows a maternal one or vice versa – the end result is that both paths consist of the same average number of crossovers.

The table below shows the range in the amount of DNA that people receive from their great-grandparents. The bottom and top 1% of outcomes have been excluded. Note that these are based on a total of 3,418 cM for the 22 autosomes which is the length observed in the Campbell et. al. study. The average of 12.5% of total DNA is 854.5 cM:

Group 1st percentile 99th percentile
Mother’s maternal grandparents 522 cM 1219 cM
Mother’s paternal grandparents 475 cM 1282 cM
Father’s maternal grandparents 475 cM 1281 cM
Father’s paternal grandparents 426 cM 1349 cM

As a matter of interest, in each of the 25,000 simulations the amount of DNA received from the eight great-grandparents were sorted into order from the highest cM to the lowest cM. The averages of each of these eight amounts were then calculated and the results are below:

Gammon greatgrandparents average cM.png

On average, a person receives 1,129 cM from the great-grandparent that they inherited the most of their DNA from and only 600 cM from the great-grandparent that they received the least of their DNA from. But none of us are the result of 25,000 trials – we are each the product of recombination events that occurred once only. The above chart shows the average or typical variation in the amount of DNA received from the eight great-grandparents. Half of people will have experienced more variation than shown above and half of people will have experienced less variation.

Could you have received the same amount of DNA from all eight grandparents? Of course, it is possible, but it turns out that it is extremely unlikely. The average is 12.5% (854.5 cM) so anything between 12% (820.4 cM) and 13% (888.7 cM) could be considered as being close to this figure. The results reveal that this did not occur in any of the 25,000 simulations. Not one person received amounts between 12% and 13% from all eight great-grandparents.

Widening the criteria, I observe that there were 13 instances in the 25,000 simulations where people received between 11.5% and 13.5% of their DNA from all eight great-grandparents. That is still an extremely rare occurrence. Expanding the range further to between 11% and 14% saw a total of 126 instances, but this still only represents about half a percent of all observations. I think that we just have to face the fact that unless we are an extremely rare individual then we will not have inherited close to equal amounts of DNA from our eight great-grandparents.

Now, back to Roberta.

Thanks Philip.

Now we see why we might not inherit the same amount of DNA from our grandparents and great-grandparents.

We Don’t Have Equal Numbers of Matches on Tree Branches

This also might explain, at least in part, why people don’t have the same number of DNA matches on each branch of their tree.

Of course, other reasons include:

  • Uneven family sizes
  • Fewer or more cousins testing on different branches
  • Recent immigration meaning there are few people available to test
  • Family from a region where DNA testing and/or genealogy is not popular
  • Endogamy which dramatically increases the number of people you will match

Real Life Example

In our real-life example, two grandchildren are fortunate to have three grandparents and one great-grandparent available for matching.

For comparison purposes, let’s take a look at how many matches each grandchild has in common with their grandparents and great-grandparent.

The line of descent is as follows:

Gammon line of descent.png

Both end of line testers are female children.

The transmission path from their great-grandmother is:

  • Female to their paternal grandmother
  • Female to their father
  • Male to female tester

The transmission path from their maternal grandfather is:

  • Male to their mother
  • Female to female tester

The transmission path from their maternal grandmother is:

  • Female to their mother
  • Female to female tester

This first chart shows the number of common matches.

Matches Grand 1 Grand 2 GGF GGM Grand 3 Grand 4
Female 1 absent 1061 absent 238 529 1306
Female 2 absent 1225 absent 431 700 1064

It’s interesting that the matches in just 3 generations to the great-grandmother vary by 55%. The second tester has almost twice as many matches in common with her great-great-grandmother as she does the first tester. There a difference in the earlier generation, meaning matches to Grand 2, but only about 23%. That difference increased significantly in one generation.

The second chart shows the total number of matching cM with the matching family member.

Total cM Grand 1 Grand 2 GGF GGM Grand 3 Grand 4
Female 1 absent 1688 absent 713 1601 1818
Female 2 absent 1750 absent 852 1901 1511

We can see that the amount of DNA inherited from a grandparent does correlate with the number of matches to that grandparents. The more DNA shared, of course the better the chances of sharing that DNA with another person. However, multiple factors may be involved with why some people have more or fewer matches.

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Genealogy Research

Fun DNA Stuff

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

Triangulation in Action at 23andMe

Recently, I published the article, Hitting a Genealogy Home Run Using Your Double-Sided Two-Faced Chromosomes While Avoiding Imposters. The “Home Run” article explains why you want to use a chromosome browser, what you’re seeing and what it means to you.

This article, and the rest in the “Triangulation in Action” series introduces triangulation at FamilyTreeDNA, MyHeritage, 23andMe, GedMatch and DNAPainter, explaining how to use triangulation to confirm descent from a common ancestor. You may want to read the introductory article first.

This first section, “What is Triangulation” is a generic tutorial. If you don’t need the tutorial, skip to the “Triangulation at 23andMe” section.

What is Triangulation?

Think of triangulation as a three-legged stool – a triangle. Triangulation requires three things:

  1. At least three (not closely related) people must match
  2. On the same reasonably sized segment of DNA and
  3. Descend from a common ancestor

Triangulation is the foundation of confirming descent from a common ancestor, and thereby assigning a specific segment to that ancestor. Without triangulation, you might just have a match to someone else by chance. You can confirm mathematical triangulation, numbers 1 and 2, above, without knowing the identity of the common ancestor.

Reasonably sized segments are generally considered to be 7cM or above on chromosomes 1-22 and 15cM or above for the X chromosome.

Boundaries

Triangulation means that all three, or more, people much match on a common segment. However, what you’re likely to see is that some people don’t match on the entire segment, meaning more or less than others as demonstrated in the following examples.

FTDNA Triangulation boundaries

You can see that I match 5 different cousins who I know descend from my father’s side on chromosome 15 above. “I” am the grey background against which everyone else is being compared.

I triangulate with these matches in different ways, forming multiple triangulation groups that I’ve discussed individually, below.

Triangulation Group 1

FTDNA triangulation 1

Group 1 – On the left group of matches, above, I triangulate with the blue, red and orange person on the amount of DNA that is common between all of them, shown in the black box. This is triangulation group 1.

Triangulation Group 2

FTDNA triangulation 2

Group 2 – However, if you look just at the blue and orange triangulated matches bracketed in green, I triangulate on slightly more. This group excludes the red person because their beginning point is not the same, or even close. This is triangulation group 2.

Triangulation Group 3 and 4

FTDNA triang 3

Group 3 – In the right group of matches, there are two large triangulation groups. Triangulation group 3 includes the common portions of blue, red, teal and orange matches.

Group 4 – Triangulation group 4 is the skinny group at right and includes the common portion of the blue, teal and dark blue matches.

Triangulation Groups 5 and 6

FTDNA triang 5

Group 5 – There are also two more triangulation groups. The larger green bracketed group includes only the blue and teal people because their end locations are to the right of the end locations of the red and orange matches. This is triangulation group 5.

Group 6 – The smaller green bracketed group includes only the blue and teal person because their start locations are before the dark blue person. This is triangulation group 6.

There’s actually one more triangulation group. Can you see it?

Triangulation Group 7

FTDNA triang 7

Group 7 – The tan group includes the red, teal and orange matches but only the areas where they all overlap. This excludes the top blue match because their start location is different. Triangulation group 7 only extends to the end of the red and orange matches, because those are the same locations, while the teal match extends further to the right. That extension is excluded, of course.

Slight Variations

Matches with only slight start and end differences are probably descended from the same ancestor, but we can’t say that for sure (at this point) so we only include actual mathematically matching segments in a triangulation group.

You can see that triangulation groups often overlap because group members share more or less DNA with each other. Normally we don’t bother to number the groups – we just look at the alignment. I numbered them for illustration purposes.

Shared or In-Common-With Matching

Triangulation is not the same thing as a 3-way shared “in-common-with” match. You may share DNA with those two people, but on entirely different segments from entirely different ancestors. If those other two people match each other, it can be on a segment where you don’t match either of them, and thanks to an ancestor that they share who isn’t in your line at all. Shared matches are a great hint, especially in addition to other information, but shared matches don’t necessarily mean triangulation although it’s a great place to start looking.

I have shared matches where I match one person on my maternal side, one on my paternal side, and they match each other through a completely different ancestor on an entirely different segment. However, we don’t triangulate because we don’t all match each other on the SAME segment of DNA. Yes, it can be confusing.

Just remember, each of your segments, and matches, has its own individual history.

Imputation Can Affect Matching

Over the years the chips on which our DNA is processed at the vendors have changed. Each new generation of chips tests a different number of markers, and sometimes different markers – with the overlaps between the entire suite of chips being less than optimal.

I can verify that most vendors use imputation to level the playing field, and even though two vendors have never verified that fact, I’m relatively certain that they all do. That’s the only way they could match to their own prior “only somewhat compatible” chip versions.

The net-net of this is that you may see some differences in matching segments at different vendors, even when you’re comparing the same people. Imputation generally “fills in the blanks,” but doesn’t create large swatches of non-existent DNA. I wrote about the concept of imputation here.

What I’d like for you to take away from this discussion is to be focused on the big picture – if and how people triangulate which is the function important to genealogy. Not if the start and end segments are exactly the same.

Triangulation Solutions

Each of the major vendors, except Ancestry who does not have a chromosome browser, offers some type of triangulation solution, so let’s look at what each vendor offers. If you and your Ancestry matches have uploaded to GedMatch, Family Tree DNA or MyHeritage, you can triangulate with them there. Otherwise, you can’t triangulate Ancestry results, so encourage your Ancestry matches to transfer.

I wrote more specifically about triangulation here and here.

Let’s look at triangulation at 23andMe.

Triangulation at 23andMe

At 23andMe, click on “DNA Relatives” in the Ancestry dropdown at the top of your page.

Triangulation 23andMe DNA Relatives.png

You will then see your list of matches.

23andMe does offer a Mom’s side and Dad’s side option, but only if at least one of your parents has tested AND you and that parent BOTH elect to share with each other. It’s not automatic.

To view your relationship with someone on your match list, click on that person’s name. I selected a known relative on my father’s side, Stacy.

Scroll down to the “Relatives in Common” section where you will see your matches in common with the person you selected. Stacy and I have 284 matches in common.

Triangulation 23andMe shared DNA.png

You can view the relationships of the match to you, and also to the person you’ve selected.

“Yes,” in the shared DNA column indicates that you, the person you selected (Stacy) and this match share DNA on a common segment. In other words, you triangulate.

In this example, Stacy and I share a triangulated segment with my own V4 kit (of course), and with both James and Diana, but not with George or Everett. We both match James and Everett, just not on the same segment, so we don’t triangulate.

Let’s look at James. By clicking on “Yes,” I can view the chromosome browser.

Scrolling down, I see that Stacy (purple), me (background grey) and James (orange) share DNA on only one segment, on chromosome 17.

Triangulation 23andMe chromosome 17.png

That segment triangulates between the three of us. I know how I am related to Stacy, but not how I am related to James. I can tell via my matches and triangulation with James that our common segment descends to me through my Vannoy line.

Unfortunately, 23andMe does not support trees in the traditional way, but some people enter surnames and locations, and you can download some Family Search ancestors to 23andMe or place a link to a tree elsewhere. I wrote about that here.

Check your 23andMe matches for surnames, common locations and links to trees.

You can also download your 23andMe segment matches and their information by clicking on Download Aggregate Data at the bottom of your matches page. Segment matches tell you exactly where on each chromosome you match other people.

Triangulation 23andMe download.png

Segment matches is NOT the same thing as downloading your raw DNA data file to upload to another vendor. See the Transfer section for those instructions.

Other 23andMe Resources to Identify Common Ancestors

23andMe provides additional tools, noted below, with the links to instructional articles I’ve written.

Transfers

Have you tested family members, especially everyone in the older generations? You can transfer their kits from Ancestry or 23andMe if they have already tested there to MyHeritage, FamilyTreeDNA or GedMatch.

Here’s how to transfer:

I wrote recently about how to work with triangulation at FamilyTreeDNA. and MyHeritage. Join me soon for similar articles about how to work with triangulation at GedMatch and DNAPainter.

Most of all – have fun!

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Genealogy Research

Fun DNA Stuff

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

2019: The Year and Decade of Change

2019 ends both a year and a decade. In the genealogy and genetic genealogy world, the overwhelmingly appropriate word to define both is “change.”

Everything has changed.

Millions more records are online now than ever before, both through the Big 3, being FamilySearch, MyHeritage and Ancestry, but also through multitudes of other sites preserving our history. Everyplace from National Archives to individual blogs celebrating history and ancestors.

All you need to do is google to find more than ever before.

I don’t know about you, but I’ve made more progress in the past decade that in all of the previous ones combined.

Just Beginning?

If you’re just beginning with genetic genealogy, welcome! I wrote this article just for you to see what to expect when your DNA results are returned.

If you’ve been working with genetic genealogy results for some time, or would like a great review of the landscape, let’s take this opportunity to take a look at how far we’ve come in the past year and decade.

It’s been quite a ride!

What Has Changed?

EVERYTHING

Literally.

A decade ago, we had Y and mitochondrial DNA, but just the beginning of the autosomal revolution in the genetic genealogy space.

In 2010, Family Tree DNA had been in business for a decade and offered both Y and mitochondrial DNA testing.

Ancestry offered a similar Y and mtDNA product, but not entirely the same markers, nor full sequence mitochondrial. Ancestry subsequently discontinued that testing and destroyed the matching database. Ancestry bought the Sorenson database that included Y, mitochondrial and autosomal, then destroyed that data base too.

23andMe was founded in 2006 and began autosomal testing in 2007 for health and genealogy. Genealogists piled on that bandwagon.

Family Tree DNA added autosomal to their menu in 2010, but Ancestry didn’t offer an autosomal product until 2012 and MyHeritage not until 2016. Both Ancestry and MyHeritage have launched massive marketing and ad campaigns to help people figure out “who they are,” and who their ancestors were too.

Family Tree DNA

2019 FTDNA

Family Tree DNA had a banner year with the Big Y-700 product, adding over 211,000 Y DNA SNPs in 2019 alone to total more than 438,000 by year end, many of which became newly defined haplogroups. You can read more here. Additionally, Family Tree DNA introduced the Block Tree and public Y and public mitochondrial DNA trees.

Anyone who ignores Y DNA testing does so at their own peril. Information produced by Y DNA testing (and for that matter, mitochondrial too) cannot be obtained any other way. I wrote about utilizing mitochondrial DNA here and a series about how to utilize Y DNA begins in a few days.

Family Tree DNA remains the premier commercial testing company to offer high resolution and full sequence testing and matching, which of course is the key to finding genealogy solutions.

In the autosomal space, Family Tree DNA is the only testing company to provide Phased Family Matching which uses your matches on both sides of your tree, assuming you link 3rd cousins or closer, to assign other testers to specific parental sides of your tree.

Family Tree DNA accepts free uploads from other testing companies with the unlock for advanced features only $19. You can read about that here and here.

MyHeritage

MyHeritage, the DNA testing dark horse, has come from behind from their late entry into the field in 2016 with focused Europeans ads and the purchase of Promethease in 2019. Their database stands at 3.7 million, not as many as either Ancestry or 23andMe, but for many people, including me – MyHeritage is much more useful, especially for my European lines. Not only is MyHeritage a genealogy company, piloted by Gilad Japhet, a passionate genealogist, but they have introduced easy-to-use advanced tools for consumers during 2019 to take the functionality lead in autosomal DNA.

2019 MyHeritage.png

You can read more about MyHeritage and their 2019 accomplishments, here.

As far as I’m concerned, the MyHeritage bases-loaded 4-product “Home Run” makes MyHeritage the best solution for genetic genealogy via either testing or transfer:

  • Triangulation – shows testers where 3 or more people match each other. You can read more, here.
  • Tree Matching – SmartMatching for both DNA testers and those who have not DNA tested
  • Theories of Family Relativity – a wonderful new tool introduced in February. You can read more here.
  • AutoClusters – Integrated cluster technology helps you to visualize which groups of people match each other.

One of their best features, Theories of Family Relativity connects the dots between people you DNA match with disparate trees and other documents, such as census. This helps you and others break down long-standing brick walls. You can read more, here.

MyHeritage encourages uploads from other testing companies with basic functions such as matching for free. Advanced features cost either a one-time unlock fee of $29 or are included with a full subscription which you can try for free, here. You can read about what is free and what isn’t, here.

You can develop a testing and upload strategy along with finding instructions for how to upload here and here.

23andMe

Today, 23andMe is best known for health, having recovered after having had their wings clipped a few years back by the FDA. They were the first to offer Health results, leveraging the genealogy marketspace to attract testers, but have recently been eclipsed by both Family Tree DNA with their high end full Exome Tovana test and MyHeritage with their Health upgrade which provides more information than 23andMe along with free genetic counseling if appropriate. Both the Family Tree DNA and MyHeritage tests are medically supervised, so can deliver more results.

23andMe has never fully embraced genetic genealogy by adding the ability to upload and compare trees. In 2019, they introduced a beta function to attempt to create a genetic tree on your behalf based on how your matches match you and each other.

2019 23andMe.png

These trees aren’t accurate today, nor are they deep, but they are a beginning – especially considering that they are not based on existing trees. You can read more here.

The best 23andMe feature for genealogy, as far as I’m concerned, is their ethnicity along with the fact that they actually provide testers with the locations of their ethnicity segments which can help testers immensely, especially with minority ancestry matching. You can read about how to do this for yourself, here.

23andMe generally does not allow uploads, probably because they need people to test on their custom-designed medical chip. Very rarely, once that I know of in 2018, they do allow uploads – but in the past, uploaders do not receive all of the genealogy features and benefits of testing.

You can however, download your DNA file from 23andMe and upload elsewhere, with instructions here.

Ancestry

Ancestry is widely known for their ethnicity ads which are extremely effective in recruiting new testers. That’s the great news. The results are frustrating to seasoned genealogists who get to deal with the fallout of confused people trying to figure out why their results don’t match their expectations and family stories. That’s the not-so-great news.

However, with more than 15 million testers, many of whom DO have genealogy trees, a serious genealogist can’t *NOT* test at Ancestry. Testers do need to be aware that not all features are available to DNA testers who don’t also subscribe to Ancestry’s genealogy subscriptions. For example, you can’t see your matches’ trees beyond a 5 generation preview without a subscription. You can read more about what you do and don’t receive, here.

Ancestry is the only one of the major companies that doesn’t provide a chromosome browser, despite pleas for years to do so, but they do provide ThruLines that show you other testers who match your DNA and show a common ancestor with you in their trees.

2019 Ancestry.png

ThruLines will also link partial trees – showing you ancestral descendants from the perspective of the ancestor in question, shown above. You can read about ThruLines, here.

Of course, without a chromosome browser, this match is only as good as the associated trees, and there is no way to prove the genealogical connection. It’s possible to all be wrong together, or to be related to some people through a completely different ancestor. Third party tools like Genetic Affairs and cluster technology help resolve these types of issues. You can read more, here.

You can’t upload DNA files from other testing companies to Ancestry, probably due to their custom medical chip. You can download your file from Ancestry and upload to other locations, with instructions here.

Selling Customers’ DNA

Neither Family Tree DNA, MyHeritage nor Gedmatch sell, lease or otherwise share their customers’ DNA, and all three state (minimally) they will not in the future without prior authorization.

All companies utilize their customers’ DNA internally to enhance and improve their products. That’s perfectly normal.

Both Ancestry and 23andMe sell consumers DNA to both known and unknown partners if customers opt-in to additional research. That’s the purpose of all those questions.

If you do agree or opt-in, and for those who tested prior to when the opt-in began, consumers don’t know who their DNA has been sold to, where it is or for what purposes it’s being utilized. Although anonymized (pseudonymized) before sale, autosomal results can easily be identified to the originating tester (if someone were inclined to do so) as demonstrated by adoptees identifying parents and law enforcement identifying both long deceased remains and criminal perpetrators of violent crimes. You can read more about re-identification here, although keep in mind that the re-identification frequency (%) would be much higher now than it was in 2018.

People are widely split on this issue. Whatever you decide, to opt-in or not, just be sure to do your homework first.

Always read the terms and conditions fully and carefully of anything having to do with genetics.

Genealogy

The bottom line to genetic genealogy is the genealogy aspect. Genealogists want to confirm ancestors and discover more about those ancestors. Some information can only be discovered via DNA testing today, distant Native heritage, for example, breaking through brick walls.

This technology, as it has advanced and more people have tested, has been a godsend for genealogists. The same techniques have allowed other people to locate unknown parents, grandparents and close relatives.

Adoptees

Not only are genealogists identifying people long in the past that are their ancestors, but adoptees and those seeking unknown parents are making discoveries much closer to home. MyHeritage has twice provided thousands of free DNA tests via their DNAQuest program to adoptees seeking their biological family with some amazing results.

The difference between genealogy, which looks back in time several generations, and parent or grand-parent searches is that unknown-parent searches use matches to come forward in time to identify parents, not backwards in time to identify distant ancestors in common.

Adoptee matching is about identifying descendants in common. According to Erlich et al in an October 2018 paper, here, about 60% of people with European ancestry could be identified. With the database growth since that time, that percentage has risen, I’m sure.

You can read more about the adoption search technique and how it is used, here.

Adoptee searches have spawned their own subculture of sorts, with researchers and search angels that specialize in making these connections. Do be aware that while many reunions are joyful, not all discoveries are positively received and the revelations can be traumatic for all parties involved.

There’s ying and yang involved, of course, and the exact same techniques used for identifying biological parents are also used to identify cold-case deceased victims of crime as well as violent criminals, meaning rapists and murderers.

Crimes Solved

The use of genetic genealogy and adoptee search techniques for identifying skeletal remains of crime victims, as well as identifying criminals in order that they can be arrested and removed from the population has resulted in a huge chasm and division in the genetic genealogy community.

These same issues have become popular topics in the press, often authored by people who have no experience in this field, don’t understand how these techniques are applied or function and/or are more interested in a sensational story than in the truth. The word click-bait springs to mind although certainly doesn’t apply equally to all.

Some testers are adamantly pro-usage of their DNA in order to identify victims and apprehend violent criminals. Other testers, not so much and some, on the other end of the spectrum are vehemently opposed. This is a highly personal topic with extremely strong emotions on both sides.

The first such case was the Golden State Killer, which has been followed in the past 18 months or so by another 100+ solved cases.

Regardless of whether or not people want their own DNA to be utilized to identify these criminals and victims, providing closure for families, I suspect the one thing we can all agree on is that we are grateful that these violent criminals no longer live among us and are no longer preying on innocent victims.

I wrote about the Golden State Killer, here, as well as other articles here, here, here and here.

In the genealogy community, various vendors have adopted quite different strategies relating to these kinds of searches, as follows:

  • Ancestry, 23andMe and MyHeritage – have committed to fight all access attempts by law enforcement, including court ordered subpoenas.
  • MyHeritage, Family Tree DNA and GedMatch allow uploads, so forensic kits, meaning kits from deceased remains or rape kits could be uploaded to search for matches, the same as any other kit. Law Enforcement uploads violate the MyHeritage terms of service. Both Family Tree DNA and GEDmatch have special law enforcement procedures in place. All three companies have measures in place to attempt to detect unauthorized forensic uploads.
  • Family Tree DNA has provided a specific Law Enforcement protocol and guidelines for forensic uploads, here. All EU customers were opted out earlier in 2019, but all new or existing non-EU customers need to opt out if they do not want their DNA results available for matching to law enforcement kits.
  • GEDmatch was recently sold to Verogen, a DNA forensics company, with information, here. Currently GEDMatch customers are opted-out of matching for law enforcement kits, but can opt-in. Verogen, upon purchase of GEDmatch, required all users to read the terms and conditions and either accept the terms or delete their kits. Users can also delete their kits or turn off/on law enforcement matching at any time.

New Concerns

Concerns in late 2019 have focused on the potential misuse of genetic matching to potentially target subsets of individuals by despotic regimes such as has been done by China to the Uighurs.

You can read about potential risks here, here and here, along with a recent DoD memo here.

Some issues spelled out in the papers can be resolved by vendors agreeing to cryptographically sign their files when customers download. Of course, this would require that everyone, meaning all vendors, play nice in the sandbox. So far, that hasn’t happened although I would expect that the vendors accepting uploads would welcome cryptographic signatures. That pretty much leaves Ancestry and 23andMe. I hope they will step up to the plate for the good of the industry as a whole.

Relative to the concerns voiced in the papers and by the DoD, I do not wish to understate any risks. There ARE certainly risks of family members being identified via DNA testing, which is, after all, the initial purpose even though the current (and future) uses were not foreseen initially.

In most cases, the cow has already left that barn. Even if someone new chooses not to test, the critical threshold is now past to prevent identification of individuals, at least within the US and/or European diaspora communities.

I do have concerns:

  • Websites where the owners are not known in the genealogical community could be collecting uploads for clandestine purposes. “Free” sites are extremely attractive to novices who tend to forget that if you’re not paying for the product, you ARE the product. Please be very cognizant and leery. Actually, just say no unless you’re positive.
  • Fearmongering and click-bait articles in general will prevent and are already causing knee-jerk reactions, causing potential testers to reject DNA testing outright, without doing any research or reading terms and conditions.
  • That Ancestry and 23andMe, the two major vendors who don’t accept uploads will refuse to add crypto-signatures to protect their customers who download files.

Every person needs to carefully make their own decisions about DNA testing and participating in sharing through third party sites.

Health

Not surprisingly, the DNA testing market space has cooled a bit this past year. This slowdown is likely due to a number of factors such as negative press and the fact that perhaps the genealogical market is becoming somewhat saturated. Although, I suspect that when vendors announce major new tools, their DNA kit sales spike accordingly.

Look at it this way, do you know any serious genealogists who haven’t DNA tested? Most are in all of the major databases, meaning Ancestry, 23andMe, FamilyTreeDNA, MyHeritage and GedMatch.

All of the testing companies mentioned above (except GEDmatch who is not a testing company) now have a Health offering, designed to offer existing and new customers additional value for their DNA testing dollar.

23andMe separated their genealogy and health offering years ago. Ancestry and MyHeritage now offer a Health upgrade. For existing customers, FamilyTreeDNA offers the Cadillac of health tests through Tovana.

I would guess it goes without saying here that if you really don’t want to know about potential health issues, don’t purchase these tests. The flip side is, of course, that most of the time, a genetic predisposition is nothing more and not a death sentence.

From my own perspective, I found the health tests to be informative, actionable and in some cases, they have been lifesaving for friends.

Whoever knew genealogy might save your life.

Innovative Third-Party Tools

Tools, and fads, come and go.

In the genetic genealogy space, over the years, tools have burst on the scene to disappear a few months later. However, the last few years have been won by third party tools developed by well-known and respected community members who have created tools to assist other genealogists.

As we close this decade, these are my picks of the tools that I use almost daily, have proven to be the most useful genealogically and that I feel I just “couldn’t live without.”

And yes, before you ask, some of these have a bit of a learning curve, but if you are serious about genealogy, these are all well worthwhile:

  • GedMatch – offers a wife variety of tools including triangulation, half versus fully identical segments and the ability to see who your matches also match. One of the tools I utilize regularly is segment search to see who else matches me on a specific segment, attached to an ancestor I’m researching. GedMatch, started by genealogists, has lasted more than a decade prior to the sale in December 2019.
  • Genetic Affairs – a barn-burning newcomer developed by Evert-Jan Blom in 2018 wins this years’ “Best” award from me, titled appropriately, the “SNiPPY.”.

Genetic Affairs 2019 SNiPPY Award.png

Genetic Affairs offers clustering, tree building between your matches even when YOU don’t have a tree. You can read more here.

2019 genetic affairs.png

Just today, Genetic Affairs released a new cluster interface with DNAPainter, example shown above.

  • DNAPainter – THE chromosome painter created by Jonny Perl just gets better and better, having added pedigree tree construction this year and other abilities. I wrote a composite instructional article, here.
  • DNAGedcom.com and Genetic.Families, affiliated with DNAAdoption.org – Rob Warthen in collaboration with others provides tools like clustering combined with triangulation. My favorite feature is the gathering of all direct ancestors of my matches’ trees at the various vendors where I’ve DNA tested which allows me to search for common surnames and locations, providing invaluable hints not otherwise available.

Promising Newcomer

  • MitoYDNA – a non-profit newcomer by folks affiliated with DNAAdoption and DNAGedcom is designed to replace YSearch and MitoSearch, both felled by the GDPR ax in 2018. This website allows people to upload their Y and mitochondrial DNA results and compare the values to each other, not just for matching, which you can do at Family Tree DNA, but also to see the values that do and don’t match and how they differ. I’ll be taking MitoYDNA for a test drive after the first of the year and will share the results with you.

The Future

What does the future hold? I almost hesitate to guess.

  • Artificial Intelligence Pedigree Chart – I think that in the not-too-distant future we’ll see the ability to provide testers with a “one and done” pedigree chart. In other words, you will test and receive at least some portion of your genealogy all tidily presented, red ribbon untied and scroll rolled out in front of you like you’re the guest on one of those genealogy TV shows.

Except it’s not a show and is a result of DNA testing, segment triangulation, trees and other tools which narrow your ancestors to only a few select possibilities.

Notice I said, “the ability to.” Just because we have the ability doesn’t mean a vendor will implement this functionality. In fact, just think about the massive businesses built upon the fact that we, as genealogists, have to SEARCH incessantly for these elusive answers. Would it be in the best interest of these companies to just GIVE you those answers when you test?

If not, then these types of answers will rest with third parties. However, there’s a hitch. Vendors generally don’t welcome third parties offering advanced tools and therefore block those tools, even though they are being used BY the customer or with their explicit authorization to massage their own data.

On the other hand, as a genealogist, I would welcome this feature with open arms – because as far as I’m concerned, the identification of that ancestor is just the first step. I get to know them by fleshing out their bones by utilizing those research records.

In fact, I’m willing to pony up to the table and I promise, oh-so-faithfully, to maintain my subscription lifelong if one of those vendors will just test me. Please, please, oh pretty-please put me to the test!

I guess you know what my New Year’s Wish is for this and upcoming years now too😊

What About You?

What do you think the high points of 2019 have been?

How about the decade?

What do you think the future holds?

Do you care to make any predictions?

Are you planning to focus on any particular goal or genealogy problem in 2020?

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Disclosure

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

Thank you so much.

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Triangulation in Action at MyHeritage

Recently, I published the article, Hitting a Genealogy Home Run Using Your Double-Sided Two-Faced Chromosomes While Avoiding Imposters. The “Home Run” article explains why you want to use a chromosome browser, what you’re seeing and what it means to you.

This article, and the rest in the “Triangulation in Action” series introduces triangulation at FamilyTreeDNA, MyHeritage, 23andMe, GedMatch and DNAPainter, explaining how to use triangulation to confirm descent from a common ancestor. You may want to read the introductory article first.

This first section, “What is Triangulation” is a generic tutorial. If you don’t need the tutorial, skip to the “Triangulation at MyHeritage” section.

What is Triangulation?

Think of triangulation as a three-legged stool – a triangle. Triangulation requires three things:

  1. At least three (not closely related) people must match
  2. On the same reasonably sized segment of DNA and
  3. Descend from a common ancestor

Triangulation is the foundation of confirming descent from a common ancestor, and thereby assigning a specific segment to that ancestor. Without triangulation, you might just have a match to someone else by chance. You can confirm mathematical triangulation, numbers 1 and 2, above, without knowing the identity of the common ancestor.

Reasonably sized segments are generally considered to be 7cM or above on chromosomes 1-22 and 15cM or above for the X chromosome.

Boundaries

Triangulation means that all three, or more, people much match on a common segment. However, what you’re likely to see is that some people don’t match on the entire segment, meaning more or less than others as demonstrated in the following examples.

FTDNA Triangulation boundaries

You can see that I match 5 different cousins who I know descend from my father’s side on chromosome 15 above. “I” am the grey background against which everyone else is being compared.

I triangulate with these matches in different ways, forming multiple triangulation groups that I’ve discussed individually, below.

Triangulation Group 1

FTDNA triangulation 1

Group 1 – On the left group of matches, above, I triangulate with the blue, red and orange person on the amount of DNA that is common between all of them, shown in the black box. This is triangulation group 1.

Triangulation Group 2

FTDNA triangulation 2

Group 2 – However, if you look just at the blue and orange triangulated matches bracketed in green, I triangulate on slightly more. This group excludes the red person because their beginning point is not the same, or even close. This is triangulation group 2.

Triangulation Group 3 and 4

FTDNA triang 3

Group 3 – In the right group of matches, there are two large triangulation groups. Triangulation group 3 includes the common portions of blue, red, teal and orange matches.

Group 4 – Triangulation group 4 is the skinny group at right and includes the common portion of the blue, teal and dark blue matches.

Triangulation Groups 5 and 6

FTDNA triang 5

Group 5 – There are also two more triangulation groups. The larger green bracketed group includes only the blue and teal people because their end locations are to the right of the end locations of the red and orange matches. This is triangulation group 5.

Group 6 – The smaller green bracketed group includes only the blue and teal person because their start locations are before the dark blue person. This is triangulation group 6.

There’s actually one more triangulation group. Can you see it?

Triangulation Group 7

FTDNA triang 7

Group 7 – The tan group includes the red, teal and orange matches but only the areas where they all overlap. This excludes the top blue match because their start location is different. Triangulation group 7 only extends to the end of the red and orange matches, because those are the same locations, while the teal match extends further to the right. That extension is excluded, of course.

Slight Variations

Matches with only slight start and end differences are probably descended from the same ancestor, but we can’t say that for sure (at this point) so we only include actual mathematically matching segments in a triangulation group.

You can see that triangulation groups often overlap because group members share more or less DNA with each other. Normally we don’t bother to number the groups – we just look at the alignment. I numbered them for illustration purposes.

Shared or In-Common-With Matching

Triangulation is not the same thing as a 3-way shared “in-common-with” match. You may share DNA with those two people, but on entirely different segments from entirely different ancestors. If those other two people match each other, it can be on a segment where you don’t match either of them, and thanks to an ancestor that they share who isn’t in your line at all. Shared matches are a great hint, especially in addition to other information, but shared matches don’t necessarily mean triangulation although it’s a great place to start looking.

I have shared matches where I match one person on my maternal side, one on my paternal side, and they match each other through a completely different ancestor on an entirely different segment. However, we don’t triangulate because we don’t all match each other on the SAME segment of DNA. Yes, it can be confusing.

Just remember, each of your segments, and matches, has its own individual history.

Imputation Can Affect Matching

Over the years the chips on which our DNA is processed at the vendors have changed. Each new generation of chips tests a different number of markers, and sometimes different markers – with the overlaps between the entire suite of chips being less than optimal.

I can verify that most vendors use imputation to level the playing field, and even though two vendors have never verified that fact, I’m relatively certain that they all do. That’s the only way they could match to their own prior “only somewhat compatible” chip versions.

The net-net of this is that you may see some differences in matching segments at different vendors, even when you’re comparing the same people. Imputation generally “fills in the blanks,” but doesn’t create large swatches of non-existent DNA. I wrote about the concept of imputation here.

What I’d like for you to take away from this discussion is to be focused on the big picture – if and how people triangulate which is the function important to genealogy. Not if the start and end segments are exactly the same.

Triangulation Solutions

Each of the major vendors, except Ancestry who does not have a chromosome browser, offers some type of triangulation solution, so let’s look at what each vendor offers. If your Ancestry matches have uploaded to GedMatch, Family Tree DNA or MyHeritage, you can triangulate with them there. Otherwise, you can’t triangulate Ancestry results, so encourage your Ancestry matches to transfer.

I wrote more specifically about triangulation here and here.

Let’s start by looking at triangulation at MyHeritage.

Triangulation at MyHeritage

MyHeritage offers triangulation integrated into their chromosome browser.

Triangulation MyHeritage matches.png

At MyHeritage, select DNA Matches from the DNA dropdown menu, then click on the purple “Review DNA Match” of the person you want to compare. We re looking at my cousin, Cheryl F.

Triangulation MyHeritage review.png

When reviewing my DNA match with Cheryl, I can see the list of people that Cheryl and I both match, including my mother, first on the list. In addition to my mother’s relationship to me, I can also see an estimate of how closely my mother matches the other person – in this case, Cheryl. Cheryl is my mother’s first cousin (1C) and my first cousin, once removed (1C1R.)

Triangulation MyHeritage icon

Click to enlarge

For triangulation, the important image is the little purple icon at right, above.

Clicking on the purple triangulation icon shows the segments where Cheryl, my mother and I all three match and triangulate.

Finding my mother among Cheryl’s close matches tells me immediately which parent I share with Cheryl.

The areas on the chromosome browser below in the rounded squares are triangulated, meaning that I match Cheryl and the other person (who just happens to be my mother) on that same segment.

Triangulation MyHeritage browser.png

Showing triangulation with Cheryl and my mother provides a great example, because of course I triangulate with Cheryl and my mother on every segment where I match Cheryl – because I inherited all of those segments through my mother.

However, as far as triangulation goes, the fact that two of those people are closely related, me and my mother, makes it the same as only two people matching – Mom and Cheryl. Still, since Mom and Cheryl are first cousins, that match confirms my great-grandparents.

Cheryl carries pieces of my great-grandparent’s DNA that my mother doesn’t though, so matches in common with Cheryl may prove very genealogically useful.

At the top right of this chromosome browser page, I can “add or remove DNA matches” from my match list. I can look through my match list to find another close relative to see if they triangulate or I can download my match list to see who else matches me on that same segment. Instructions for the file download are at the end of this section.

Same Segment Matches

To illustrate that people will match you on the same segment, but don’t match each other because they descend from different sides of your family, I’ll add some cousins from my father’s side of the family.

I’m going to select cousins Charlene and David, and remove my mother.

Below, we show chromosome 3 again, but the triangulation bracket is gone. This tells us that this segment does NOT triangulate between me and ALL three people.

Please note that I may triangulate with some of the people. The absence of the bracket only means that I don’t triangulate with ALL of them.

I already know that while I match Cheryl, Charlene and David on this segment, only David and Charlene match each other because they are both from my father’s side, and Cheryl doesn’t match either of them because she is on my mother’s side.

Triangulation MyHeritage segments

Click to enlarge

To prove this, and to determine triangulation groups, I can compare the people two by two and continue adding people to see if they continue to triangulate.

Below, I’ve removed Cheryl, and I triangulate on chromosome 3 with both Charlene and David. The triangulation bracket appears.

Triangulation MyHeritage chromosome 3

Click to enlarge

Therefore, I know that Charlene and David descend through one of my parents, and Cheryl through the other – even if I didn’t know anything else at this point.

To reiterate, triangulation at MyHeritage means triangulation with everyone showing at the same time on the chromosome browser.

Other Resources to Identify Common Ancestors

For additional information, I can check the match information with each person to see if our trees, surnames or locations intersect.

SmartMatches and Theories of Family Relativity each provide clues and help to explain why we might triangulate.

SmartMatches tell you that you and another person share an ancestor in your and their tree, BUT, that common person may not be a direct ancestor of one or both of you. You also may or may not be DNA matches, and if so, your DNA match may or may not be through that ancestor.

Theories of Family Relativity (TOFR,) on the other hand, tell you that not only do you have a DNA match with this person, but that you have a common ancestor, and who that ancestor is. Sometimes the connection is made for you, even if one or both of you don’t show that ancestor in your tree simply because you have not extended your tree back far enough in time.

I wrote about how to use Theories of Family Relativity here.

Downloading Matches

You can request to download your matches list and also your shared DNA segments at MyHeritage by clicking on the three dots to the right at the top of your match list, then click on the option you wish. The resulting files will be e-mailed to you a few minutes later. If they don’t arrive, be sure to check your spam filter.

Triangulation MyHeritage export.png

Downloading your match list and/or shared DNA segments is NOT the same thing as downloading your raw data file to upload elsewhere. You’ll find those instructions in the Transfer section later in this article.

What About You?

Do you have a tree at MyHeritage?

Triangulation MyHeritage tree tab.png

If not, click on Family Tree to create or upload one including not only direct line ancestors, but their children and grandchildren which facilitates and encourages the formation of Theories of Family Relativity.

Connecting Your DNA to Your Tree

Assigning your kit and those of family members to the proper profile card in your tree is very important, especially for the formation of Theories of Family Relativity

To suggest a theory, MyHeritage searches through all the possible links in the MyHeritage database meaning SmartMatches between trees, Record matches, record to record matches, etc.

If a DNA kit is not associated with an individual that is connected to ancestors, this reduces the probability that MyHeritage will be able to find a theory.

For example, if I took a DNA test but only have myself in the tree, not connected to my father and mother, but my father appears in another user’s tree (and there are more ancestors in that tree) MyHeritage won’t be able to find the information to generate a theory.

If I add my father, then the system has a common ancestor to work with.

When the TOFR algorithm runs, it’s trying to find any possible route to connect the two individuals (you and your DNA Match). If you are associated with individuals in multiple sites or trees, MyHeritage will try all of them and generate multiple paths for you to evaluate.

Have you assigned the kits of family members you manage to the proper place in your tree?

Triangulation MyHeritage tree.png

You can do this easily under the Manage DNA Kits option, under the DNA tab. Click on the three little dots to the right of the kit.

Triangulation MyHeritage assign dots.png

Then click assign the kit.

Triangulation MyHeritage assign kit.png

You’ll be prompted

Triangulation MyHeritage kit name.png

If you start typing, you’ll be prompted with the names of people in your tree.

Other Resources to Identify Common Ancestors

MyHeritage includes other tools to help you identify common ancestors as well, including:

  • SmartMatches where MyHeritage matches individuals in trees
  • AutoClusters showing groups of people that match you and each other
  • Shared Matches indicating common DNA matches between you and another DNA match
  • Shared Ancestral Surnames show common surnames, even if a common ancestor does not show in a tree
  • Shared Ancestral Places indicating common locations in trees
  • Shared Ethnicities comparing ethnicity between matches, a feature typically only beneficial if looking for a minority (to you) ancestry match
  • Genealogical Records including matches from other databases such as Geni.com and FamilySearch
  • Trees

Transfers

Have you tested family members, especially everyone in the older generations? You can transfer their kits from Ancestry, 23andMe or FamilyTreeDNA if they’ve already tested there to MyHeritage.

The article, Are You DNA Testing the Right People? explains how to determine who to test. Make sure you aren’t missing anyone that you need.

Here’s how to transfer:

I wrote recently about how to work with triangulation at FamilyTreeDNA. Join me soon for similar articles about how to work with triangulation at 23andMe, GedMatch and DNAPainter.

Most of all – have fun!

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

Genetic Affairs Reconstructs Trees from Genetic Clusters – Even Without Your Tree or Common Ancestors

Since Genetic Affairs launched in 2018, they’ve added a LOT of new functionality. I initially wrote about their clustering functionality here.

Genetic Affairs AutoClustering, SuperClusters and brand-new AutoTree tree reconstruction are to-die-for features for traditional genealogists. For adoptees or people seeking unknown parentage, they are the best thing since sliced bread, automating tasks previously peformed manually over labor-filled hours, days and months.

Why Genetic Affairs?

Genetic Affairs works with matches from three vendors; Ancestry, FamilyTreeDNA’s Family Finder test and 23andMe.

MyHeritage has integrated a version of Genetic Affairs directly into their product offering on the MyHeritage website so every MyHeritage DNA customer receives clustering functionality, free, through MyHeritage, but not tree reconstruction.

GedMatch has also implemented an autocluster version for Tier 1 users, but GedMatch’s version only works at GedMatch, of course, and does not include the new tree reconstruction feature.

This article pertains to the functionality of the features available directly through Genetic Affairs, including:

  • Clustering your matches visually to identify ancestral lines of people that match you and each other
  • Reports by cluster including common surnames and locations
  • Analysis of trees within each cluster to identify common ancestors
  • Partially reconstructs trees with your known ancestors for each cluster
  • Partially reconstructs trees between your matches even if you don’t have a tree or don’t share the common ancestor

Genetic Affairs provides visualization for linked DNA matches along with critically important clues to help you figure out just how you are related to these people, and these clusters of interrelated people. The Genetic Affairs user manual can be found here.

Analysis

Each time you run Genetic Affairs is called an analysis. Each analysis scans your kit at the selected vendor(s) for all current matches. A few minutes later, you receive a zip file via e-mail with two or three files depending on your selections at Genetic Affairs and the tree availabilty of the vendor:

  • Autocluster file including the visual clusters plus additional information
  • Excel spreadsheet of cluster members and relevant information such as common ancestors and common locations
  • Tree file containing reconstructed trees (23andMe does not support trees, so no trees are available for 23andMe clusters)

Let’s look at each feature. Grab a cup of coffee and head for the computer.

Selecting Analysis Options

I encourage you to experiment. Selecting a wider range of cM (centimorgans) results in a larger file, but may also mean that the analysis times out.

For this report, I’m utilizing my matches at FamilyTreeDNA and selected a cM range of 50 minimum and 250 maximum. I wanted a minimum cluster size of 2 people, meaning 2 in addition to me. This resulted in 249 total matches that met that criteria and 20 people who met the cM criteria but did not have another person with whom to cluster.

I tried a second analysis using 20 cM – 300 cM resulting in a much larger file with 499 people in the cluster group. Currently, 499 is the maximum that will be processed.

Genetic Affairs profiles.png

On the Genetic Affairs Profiles page, I can view all of the profiles I manage. Users can schedule updates where Genetic Affairs automatically scans for matches and produces reports.

Genetic Affairs my profiles

Click to enlarge

By clicking on the Autoscan button, you can schedule automated recurring scans with e-mail notification.

Genetic Affairs autoscan

Click to enlarge

You can scan daily, weekly, monthly or never – whatever interval you select.

You can select both the minimum level of DNA match and the minimum cM. The lowest you can select is 9cM.

You can view any e-mails that have been sent to you by Genetic Affairs. The green envelope means that there’s something in your e-mail box. This answers the question about whether the report was completed and sent. If the report has been sent, but is not in your e-mail, check your spam filter.

Starting the Scan

Back on the Genetic Affairs profiles page, you can initiate an autocluster by clicking on the AutoCluster button where you’ll see the options based on which vendor you’ve selected.

Genetic Affairs autocluster.png

For example, at Ancestry, you can include only people in a particular group or only starred matches.

Genetic Affairs Ancestry autocluster

Click to enlarge

23andMe includes surname enrichment and triangulated groups options.

Genetic Affairs 23andme autocluster.png

FamilyTreeDNA and Ancestry both include the “AutoTree – identify common ancestors from trees” option. It’s very important that you click this box if you select the “Default AutoCluster” option – or you won’t get the reconstructed trees.

Genetic Affairs default autocluster.png

Of course, you can always run the analysis again.

Genetic Affairs autotree.png

If you click on the “AutoTree AutoCluster” function, the AutoTree box is already checked for you.

Genetic Affairs autotree autocluster.png

Rule Based AutoCluster

The “Rule based AutoCluster” is a dream-come-true for people seeking unknown parents or ancestors in a relatively recent timeframe.

Genetic Affairs Rule Based Autocluster.png

The “Rule based AutoCluster” provides you with options that allow you to do three things:

  • NOT – Exclude your matches with someone else. For example, your mother has tested. You can use the NOT rule to exclude anyone you might match through your mother’s side, providing you with clusters from your father’s side.
  • AND – Combine your results with someone else’s. If you have identified a half-sibling, you can view only clusters of only people who match you AND your half sibling.
  • OR – Combined rules. You can request a cluster of everyone in clusters with person A but not in a cluster with person B. In this case, if you match a number of half siblings, you can include all of their matches, except people who match them through their “other” parent, if that parent has tested.

Genetic Affairs has provided some graphics and examples here, but you may have to be a member of the site to access this page because the options are customized for you. So I’ll include the non-customized information, below. You can click these to open in a separate window and enlarge.

Genetic Affairs rule based 1.pngGenetic Affairs rule based 2.png

The “Rule based AutoCluster” explanations provided by Genetic Affairs.

Genetic Affairs rule based 3.png

Read the details of how these tools work. They are powerful, so don’t assume you understand without reading carefully.

Now let’s cluster!

Clustering Your Matches

Genetic Affairs autocluster order.png

At Genetic Affairs, if you initiate clustering by clicking on the AutoCluster button, you’ll need to put a checkmark in the AutoTree function box. If you began by clicking the AutoTree button, the box is automatically checked for you.

A few minutes later, you’ll receive an email with a zipped file. Save this file to someplace on your computer where you can find it, and open the zipped file by clicking.

Genetic Affairs zip file.png

You’ll see the files, above.

Click on the chrome AutoCluster HTML file which will display in your browser.

The first thing you will see is your visual autocluster. It’s so much fun to watch your matches “fly” into place!

Each of the people in this cluster are somehow related to the other people in the custer who have cells of the same color. The people with grey cells are included in two clusters – meaning the one to the right and the one above, both.

Genetic Affairs cluster.png

The names of the matches are listed to the left and above the display.

The legend is to the right.

Genetic Affairs cluster legend.png

I have a total of 41 clusters.

Scrolling down the page, each cluster has additional information, and each column is searchable or selectable, including comments I’ve entered at the vendor.

Genetic Affairs autocluster info

Click to enlarge

Just by looking at these first 3 matches, I know immediately which side of the family and which ancestors are involved with this cluster. I can look at my notes, to the right, which indicate whether I’ve identified our common ancestor. I paint identified matches at DNAPainter which I’ve entered into the notes field at the vendor.

If I’m signed in to my account at the vendor, I can click on my match’s tree link, above, and take a look. Keep in mind that these people can be related to you, and each other, through multiple ancestors.

Genetic Affairs autocluster members.png

You can hover over any person in the grid, above, to view additional information. For each person whose square is grey, indicating membership in (at least) two clusters, you can hover over the grey square and view the members of both clusters. In this case, I’m hovered over the grey square of Brooke and E.H and the black box shows me who is in both people’s clusters.

Note that while a match could be related to you through several ancestors, and hence be in more than 2 clusters, because of the grid nature of clustering, a match can only be displayed in a maximum of 2 different clusters.

Looking at the auto-generated table below, I see the common surnames in cluster 1. Keep in mind that many of these people maybe related to each other through a spouse that you aren’t. Your ancestor’s brother’s children, for example, are also related to each other through your ancestor’s brother’s wife.

Genetic Affairs surnames.png

I know that Vannoy is the common line, but Upton isn’t my ancestor – at least not that I know of. However, a surname with 20 people in a cluster needs to be investigated and evaluated. Do I have any missing wives in this line? Here’s a really great place to start digging.

In this case, it turns out that one of my ancestor’s children married an Upton, and several of his descendants have tested.

Let’s see what other tools we have.

The Ancestor Spreadsheet

Opening the spreadsheet file, I see several rows and columns.

Genetic Affairs common ancestor

Click to enlarge

The common ancestor between the people in the rows is listed at left. The green cells are from my tree.

Two example ancestors are shown above, Mary McDowell and William Harrell, who just happen to have been married to each other.

Scrolling on down, I see rows without green cells.

Genetic Affairs ancestors

Click to enlarge

These people share a common ancestor in their trees, an ancestor that isn’t in my tree. Presumably this is an ancestor I don’t share with them – or one I haven’t identified.

For example, “Bev” and “van” share William Grubb. “Vicki” and “Mark” share Martha Helen Smith. I don’t share either of these ancestors, but Martha Smith married Alvis Winster Bolton, the son of my ancestor – so I know why Martha Helen Smith appears as a common person in the trees of my matches, but not me.

Further down in the same cluster, I notice that one match shares multiple lines in our trees. Therefore, our DNA match could be on either line, or some segments from one line and some from the other.

Scrolling to the bottom of each cluster’s sheet, common locations are provided.

Genetic Affairs locations

Click to enlarge

While the designation of “Tennessee” isn’t terribly exciting, scrolling further down provides a list by county, and that IS exciting, especially if you’re chasing a brick wall. Sometimes a group of ancestors in a location where you’re seeking a female’s family is very suggestive especially when combined with ancestral names and surnames.

Let’s move on to the third group of files, Trees.

The Tree File

Click on the tree file and you’ll see the following.

Genetic Affairs tree file.png

Reconstructed Trees

For each cluster where trees can be reconstructed, you’ll see two files for cluster 1:

  • Ancestors 1
  • Tree 1

Opening the file labeled Ancestors 1, I see the following information for the first ancestor, meaning a common ancestor between the two people listed below that ancestor. You can click to enlarge these images.

Genetic Affairs ancestors by cluster.png

Opening the corresponding Tree 1 file, I see that Genetic Affairs has reconstructed the tree between me and the other testers as best it can based on the provided trees.

Genetic Affairs reconstructed trees.png

Looking at the tree for cluster 3, below, I see this line in cluster 1, above, has been extended because Sarah, the pink match and me all share a common ancestor, Elizabeth Shepherd.

Genetic Affairs reconstructed tree 2.png

Looking at another cluster, below, while I don’t share an ancestor in a tree, three people that I match at a relatively high level do.

Genetic Affairs reconstructed tree no common ancestor.png

As you can see, their common ancestor is Anne Adelaide Chiasson. This is my Acadian line, so our common ancestor or ancestors must be someplace on up that tree, or the result of an undocumented adoption, or a missing ancestor in our trees.

Constructing the trees of your matches to each other, even when you don’t have a common ancestor in your tree, is the best feature of all.

Clustering plus tree reconstruction, especially in combination with the other clues, is the key to breaking through those unyielding  brick walls.

Super AutoClusters

Just as I was getting ready to publish this article, Genetic Affairs released a new feature called Super AutoCluster.

I absolutely love this, because it combines your clusters from multiple vendors – today Ancestry, who does not provide segment information, along with Family Tree DNA, who  provides invaluable segment information.

This combination can be extremely powerful.

To begin a Super AutoCluster, click on that option under an AncestryDNA kit that also has a kit at Family Tree DNA. Both kits need to have a profile at Genetic Affairs.

Genetic Affairs supercluster.png

Next, you’ll see the screen confirming the kits to use. The combined autocluster tool is limited to a total of 500 matches, or 250 at each account. However, that’s more than enough to make some great progress.

Press “Perform Analysis.”

Drum roll please…

Voila, your combined cluster.

Genetic Affairs supercluster cluster

Click to enlarge

In this example, you can see the large peach and purple Ancestry clusters. The green red, brown and pink smaller clusters are Family Tree DNA clusters. The Family Tree DNA clusters have tiny little Fs in their cells. If you click the above graphic to enlarge, you can see the Fs.

However, the grey cells that intersect the two clusters, meaning an Ancestry and a Family Tree DNA cluster, are found in both of those clusters, connecting the clusters for you logically.

If you look closely at the cells labeled here with “common names,” you’ll see “N” in the cells indicating a common names for you to check out within that cluster.

The “Common Ancestors” box shows the people who connect to both clusters.

There are also a number of people that span the green and red Family Tree DNA clusters too.

Genetic Affairs then proceeds to combine the clustered DNA matches and trees for you from both vendors.

Genetic Affairs supercluster tree

Click to enlarge

In addition to the cluster graph and spreadsheet information that now includes combined information, you’ll see a much larger clustered tree.

And again, the best part is that even if you don’t know how you connect to people through trees, their tree and ancestors will be connected, even if you’re absent. You’ll be present in the genetic cluster itself, so you can work the combined tree cluster to see where you might fit in that branch of the family. Because trust me, you do fit – somehow, someplace.

Cost

Genetic Affairs uses a “credit” payment system. Your first 200 credits are free so you can learn. These may last you for weeks or months, depending on how often you run the clusters. If you manage multiple kits, you’ll use credits more quickly, but it’s worth every last dollar. Genetic Affairs is very inexpensive. I manage multiple accounts and I spend around $5 per month. You can read about Genetic Affairs’ payment plans and see sample calculations here.

My recommendation is simply to dive in and use your free credits. By the way, I’m gifting myself with a “credit purchase” for Christmas😊

Genetic Affairs is a wonderful genealogy gift idea for serious genealogists, adoptees or people seeking unknown parents or ancestors in recent generations.

Have You Tested or Transferred With All 4 Vendors?

If you haven’t yet tested at or transferred to each of the main 4 vendors, clustering, reconstructed trees and SuperClusters is yet another reason to do so. Additionally, every close relative’s DNA holds hints that yours doesn’t, so be sure to test them too.

You can purchase kits, below, or read about how to transfer your DNA to vendors who accept uploads – FamilyTreeDNA, MyHeritage and GedMatch, all for free, here.

Enjoy!

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

Triangulation in Action at Family Tree DNA

Recently, I published the article, Hitting a Genealogy Home Run Using Your Double-Sided Two-Faced Chromosomes While Avoiding Imposters. The “Home Run” article explains why you want to use a chromosome browser, what you’re seeing and what it means to you.

This article, and the rest in the “Triangulation in Action” series introduces triangulation at Family Tree DNA, MyHeritage, 23andMe, GedMatch and DNAPainter, explaining how to use triangulation to confirm descent from a common ancestor. You may want to read the introductory article first.

What is Triangulation?

Think of triangulation as a three-legged stool – a triangle. Triangulation requires three things:

  1. At least three (not closely related) people must match
  2. On the same reasonably sized segment of DNA and
  3. Descend from a common ancestor

Triangulation is the foundation of confirming descent from a common ancestor, and thereby assigning a specific segment to that ancestor. Without triangulation, you might just have a match to someone else by chance. You can confirm mathematical triangulation, numbers 1 and 2, above, without knowing the identity of the common ancestor.

Boundaries

Triangulation means that all three, or more, people much match on a common segment. However, what you’re likely to see is that some people don’t match on the entire segment, meaning more or less than others as demonstrated in the following examples.

FTDNA Triangulation boundaries.png

You can see that I match 5 different cousins who I know descend from my father’s side on chromosome 15 above. As always, I’m the background grey and these matches are all being compared against me.

I triangulate with them in different ways, forming multiple triangulation groups that I’ve discussed individually, below.

Triangulation Group 1

FTDNA triangulation 1.png

Group 1 – On the left group of matches, above, I triangulate with the blue, red and orange person on the amount of DNA that is common between all of them, shown in the black box. This is triangulation group 1.

I’ve overlayed additional triangulation groups below, so you can compare the groups.

Triangulation Group 2

FTDNA triangulation 2.png

Group 2 – However, if you look just at the blue and orange triangulated matches bracketed in green, I triangulate on slightly more, extending to the left. This group excludes the red person because their beginning point is not the same, or even close. This is triangulation group 2.

Triangulation Group 3 and 4

FTDNA triang 3.png

Group 3 – At right, we see two large triangulation groups. Triangulation group 3 includes the common portions of blue, red, teal and orange matches.

Group 4 – Triangulation group 4 is the skinny group at far right and includes the common portion of the blue, teal and dark blue matches.

Triangulation Groups 5 and 6

FTDNA triang 5.png

Group 5 – There are also two more triangulation groups. The larger green bracketed group includes only the blue and teal people because their end locations are to the right of the end locations of the red and orange matches. The start location varies as well. This is triangulation group 5.

Group 6 – The smaller green bracketed group includes only the blue and teal person because their start locations are before the dark blue person. This is triangulation group 6.

There’s actually one more triangulation group. Can you spot it?

Triangulation Group 7

FTDNA triang 7.png

Group 7 – The tan group includes the red, teal and orange matches but only the areas where they all overlap. This excludes the top blue match because their start location is different. Triangulation group 7 only extends to the end of the red and orange matches, because those are the same locations, while the teal match extends further to the right. That extension is excluded in this group, of course.

Slight Variations

Matches with only slight start and end differences are probably descended from the same ancestor, but we can’t say that for sure (at this point) so we only include actual mathematically matching segments in a triangulation group.

You can see that triangulation groups often overlap because group members share more or less DNA with each other. Normally we don’t bother to number the groups – we just look at the alignment. I numbered them for illustration purposes.

Shared or In-Common-With Matching

Triangulation is not the same thing as a 3-way shared “in-common-with” match. You may share DNA with those two people, but on entirely different segments from entirely different ancestors. If those other two people match each other, it can be on a segment where you don’t match either of them, and thanks to an ancestor that they share who isn’t in your line at all. Shared matches are a great hint, especially in addition to other information such as Phased Family Matching which we’ll talk about in a minute, but shared matches don’t necessarily mean triangulation has occurred, although it’s a great place to start looking.

I have shared matches where I match one person on my maternal side, one on my paternal side, and they match each other through a completely different ancestor on an entirely different segment. However, we don’t triangulate because we don’t all match each other on the SAME segment of DNA. Yes, it can be confusing.

Just remember, each of your segments, and matches, has its own individual history.

Imputation Can Affect Matching

Over the years the chips on which our DNA is processed at the vendors have changed. Each new generation of chips tests a different number of markers, and sometimes different markers – with the overlaps between the entire suite of chips being less than optimal.

I can verify that most vendors use imputation to level the playing field, and even though two vendors have never verified that fact, I’m relatively certain that they all do. That’s the only way they could match to their own prior “only somewhat compatible” chip versions.

The net-net of this is that you may see some differences in matching segments at different vendors, even when you’re comparing the same people. Imputation generally “fills in the blanks,” but doesn’t create large swatches of non-existent DNA. I wrote about the concept of imputation here.

What I’d like for you to take away from this discussion is to be focused on the big picture – if and how people triangulate which is the function important to genealogy. Not if the start and end segments are exactly the same.

Triangulation Solutions

Each of the major vendors, except Ancestry who does not have a chromosome browser, offers some type of triangulation solution, so let’s look at what each vendor offers. If your Ancestry matches have uploaded to GedMatch, Family Tree DNA or MyHeritage, you can triangulate with them there. Otherwise, you can’t triangulate Ancestry results, so encourage your Ancestry matches to transfer.

You can find step-by-step transfer instructions to and from each vendor, here.

I wrote more specifically about triangulation here and here.

Let’s start by looking at triangulation at Family Tree DNA.

Triangulation at Family Tree DNA

Family Tree DNA has two different tools that can be used separately in different circumstances to determine whether or not your segments triangulate.

Phased Family Matching can be used for triangulation.

The Matrix tool can be utilized for people who aren’t designated through Phased Family Matching as maternal or paternal matches to suggest or eliminate triangulation.

First, go to the Family Finder section of your personal page.

We’ll be working with Matches, the Chromosome Browser, and the Matrix.

FTDNA triangulation page.png

Phased Family Matching

At Family Tree DNA, I’ve tested my cousins:

  • Cheryl, my mother’s first cousin (1C)
  • Charlene, my first cousin once removed (1C1R) on my father’s side
  • David, my second cousin (2C) on my father’s side.

I’ve linked the test results of those cousins to my tree in their proper location, which allows Family Tree DNA to do something called Phased Family Matching.

If you don’t have a tree and don’t link your DNA results and those of your family members, Family Tree DNA can’t perform Phased Family Matching.

I explained phasing in the introductory article.

Testing your parents is wonderful if that’s possible, but parents aren’t always available to test. At Family Tree DNA, you don’t need to have tested your parents in order to have phased matches.

In essence, Family Tree DNA uses the DNA of known cousins, third cousins or closer, to assign matches to maternal or paternal tabs, or sides, also sometimes referred to as buckets. I wrote about Phased Family Matching here and here.

FTDNA triang buckets.png

You can see that of my 4806 matches, 1101 are assigned to my paternal side, 884 to my maternal side and 4 are assigned to both.

FTDNA triang header.pngFTDNA triang Charlene.png

My cousin Charlene is assigned to my paternal side, as shown by the blue icon, because I linked her to the correct position in my tree, as is my cousin, David, below.

FTDNA triang David.png

Conversely, my cousin Cheryl is assigned maternally because I linked her as well.

FTDNA triang Cheryl.png

These specific people are assigned maternally and paternally because I linked them to their proper place in my tree. These matches will allows Family Tree DNA to link other testers to the proper side of my tree too, because they match me and my cousin on the same segments – in essence phasing a large number of my matches for me which facilitates triangulation.

Linking Matches on Your Tree

In order to cause Phased Family Matching, aka, “bucketing” to occur, I linked my own test and that of my known 3rd cousins or closer to their proper places in my tree at Family Tree DNA.

If you don’t create a tree or upload a GEDCOM file and link yourself and your known matches, your matches can’t be assigned to maternal and paternal sides.

FTDNA triang tree.png

By utilizing the matching DNA between you and known close relatives on your maternal and paternal sides, Family Tree DNA assigns other people who match both of you on those same segments to the same side of your tree.

If you select matches from the same side of your tree and they match on the same segments, they triangulate.

Of course, that’s assuming the person doesn’t match you on both sides of your tree.

You can also download your matching segments in a file and sort to see who matches on the same locations, but the parental side designation (bucketing) is not reflected in the segment download file. Bucketing is reflected in the match download file which is a different file.

There are two separate download files, but they can be merged.

Two Download Files

The first file, your match download file, provides information about your matches such as their haplogroups, surnames and contact information, including bucketing assignment, but not the actual matching segment data.

The match file tells you a great deal and is both sortable and searchable. You can search for any surname, for example, or you can sort for everyone in the Paternal or Maternal matching bucket. You can creatively combine parts of this file with the matching segments file in order to quickly flag the people on your paternal side. Knowledge about how to work with spreadsheets is a plus.

FTDNA triang match file

Click to enlarge

This download is available at the bottom of the Family Finder match page.

FTDNA triang match.png

You can download all of your matches, or just those in a filtered view, such as in-common-with or as the result of a surname search.

FTDNA triang download.png

The second file, your matching segments file, is available on the chromosome browser page.

The matching segments file includes the match name along with the matching chromosome segments and number of matching SNPs.

FTDNA triang segment file.png

If you click through to the chromosome browser from your main page, as shown below, with NO MATCHES SELECTED, you will be able to download ALL matching segments.

FTDNA triang browser.png

You’ll see “Download All Segments” in the upper right-hand corner.

FTDNA triang download all seg.png

From that Chromosome Browser page, you will also have the ability to select matches to show on the browser.

FTDNA triang browser select

If you select people on the match page before clicking on the chromosome browser or select matches on the chromosome browser page, then clicking on “Download Segments,” will only download the matching segments of the people that you have currently selected to match against in the browser.

FTDNA triang download seg.png

Combinations of Tools and Filters

  • The chromosome browser tells you if people match you on the same segment.
  • The in-common-with filter on the match page tells you who you match in common with a specific person, but not if those two people match each other.

Of course, if both people are assigned to your same parental side bucket, and they both only match you on one large segment – and it’s the same segment, then you must triangulate.

If they aren’t both assigned to a parental bucket, then you can’t make that determination using parental side designations.

Is there a tool that allows you to compare people against each other at the same time to see if your matches also match each other?

Glad you asked.

Yes, there is.

The Matrix

Let’s say that you want to see if a group of people who you match also match each other.

FTDNA triang matrix.png

Family Tree DNA provides a Matrix tool that allows you to select 10 (or fewer) matches in order to determine if your matches also match each other.

FTDNA triang matrix match.png

I’ve entered Cheryl, Charlene and David. You can see that David and Charlene match each other, and Cheryl doesn’t match either Charlene or David.

Of course, we know that’s accurate because:

  • I already know these people and their relationship to me and each other
  • These three people are already assigned to maternal and paternal sides or buckets, so the matrix is verifying what we already know
  • I know where they match on the same segment on the chromosome browser

FTDNA triang 3 browser.png

Even though they match on the same segment on the chromosome browser, the fact that they are bucketed to different parental sides, and that the matrix shows that Cheryl doesn’t match either Charlene and David, confirms that David and Charlene triangulate with me, while Cheryl is not a member of that triangulation group.

This is exactly why triangulation is important. Looking at the image above, the only thing you know is that they all 3 match you – but with the additional information about bucketing and the matrix, we know that only the two bottom people, Charlene and David triangulate with me. Note that I’ve added the maternal and paternal icons for clarity.

FTDNA triang match group browser.png

However, if I didn’t have this knowledge, or not everyone was bucketed, the Matrix tool would be extremely useful. The matrix tool uses the matching threshold of approximately 7.69 cM.

The matrix doesn’t tell you if these people match each other on the same segment where they match you,

However, there’s a good probability that they do, especially if only one matching segment is involved.

You can check the chromosome browser to see if they both match you on the same segment. It’s possible if they don’t match you on the same segment that they match each other on different segments, and possibly through a different ancestor. You may need to reach out to them to ask if they match each other, and if they have known genealogy if they aren’t bucketed.

By utilizing the Matrix tool, you can isolate people to maternal and paternal sides of your tree.

Other Resources to Identify Common Ancestors

Be sure to check other clues at Family Tree DNA such as:

Shared surnames, shown on your matches page, with common surnames that you share bolded

FTDNA triang surnames.png

Trees, indicated by the blue pedigree icon on the match page.

FTDNA triang pedigree.png

Y and mitochondrial DNA haplogroups and matching. You can view your matches haplogroup and other information by clicking on their profile picture on your matches page.

FTDNA triang profile.png

Advanced Matching can be utilized to see if you match on combined tests, or in common projects.

FTDNA triang advanced match.png

This article discusses the 9 different autosomal tools available at Family Tree DNA.

What About You?

Do you have a tree at Family Tree DNA?

Have you connected your test and any family members to your tree?

Can you test a family member, third cousins or closer, or have them transfer a kit from another vendor?

Here’s how to transfer:

How many people do you have on your paternal and maternal tabs on your Family Finder matches page?

You can paint every single one of the people who are designated as maternal or paternal at DNAPainter to your grandparents on the respective maternal or paternal side. DNAPainter Instructions and Resources will explain how, and why.

Join me soon for similar articles about how to work with triangulation at MyHeritage, 23andMe, GedMatch and DNAPainter.

Most of all – have fun!

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research

Duplicate Copies of Parental Chromosomes – Uniparental Disomy

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

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

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

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

Uniparental Disomy in Brief

Here are a few summary bullet points about uniparental disomy:

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

Articles

This Atlantic article provides an overview:

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

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

What About You?

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

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

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

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

Are Your Parents Related to Each Other?

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

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

Using the “Are your parents related” Tool

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

Parents related.png

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

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

Parents are related.png

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

The legend for reading the graphic is shown below.

Parents related legend.png

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

Parents not related.png

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

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

A Duplicate Chromosome

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

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

Parents uniparental disomy.png

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

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

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

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

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

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

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