FamilyTreeDNA Relaunch – New Feature Overview

The brand-new FamilyTreeDNA website is live!

I’m very pleased with the investment that FamilyTreeDNA has made in their genealogy platform and tools. This isn’t just a redesign, it’s more of a relaunch.

I spoke with Dr. Lior Rauchberger, CEO of myDNA, the parent company of FamilyTreeDNA briefly yesterday. He’s excited too and said:

“The new features and enhancements we are releasing in July are the first round of updates in our exciting product roadmap. FamilyTreeDNA will continue to invest heavily in the advancement of genetic genealogy.”

In other words, this is just the beginning.

In case you were wondering, all those features everyone asked for – Lior listened.

Lior said earlier in 2021 that he was going to do exactly this and he’s proven true to his word, with this release coming just half a year after he took the helm. Obviously, he hit the ground running.

A few months ago, Lior said that his initial FamilyTreeDNA focus was going to be on infrastructure, stability, and focusing on the customer experience. In other words, creating a foundation to build on.

The new features, improvements, and changes are massive and certainly welcome.

I’ll be covering the new features in a series of articles, but in this introductory article, I’m providing an overview so you can use it as a guide to understand and navigate this new release.

Change is Challenging

I need to say something here.

Change is hard. In fact, change is the most difficult challenge for humans. We want improvements, yet we hate it when the furniture is rearranged in our “room.” However, we can’t have one without the other.

So, take a deep breath, and let’s view this as a great new adventure. These changes and tools will provide us with a new foundation and new clues. Think of this as finding long-lost documents in an archive about your ancestors. If someone told me that there is a potential for discovering the surname of one of my elusive female ancestors in an undiscovered chest in a remote library, trust me, I’d be all over it – regardless of where it was or how much effort I had to expend to get there. In this case, I can sit right here in front of my computer and dig for treasure.

We just need to learn to navigate the new landscape in a virtual room. What a gift!

Let’s start with the first thing you’ll see – the main page when you sign in.

Redesigned Main Page

The FamilyTreeDNA main page has changed. To begin with, the text is darker and the font is larger across the entire platform. OMG, thank you!!!

The main page has been flipped left to right, with results on the left now. Projects, surveys, and other information, along with haplogroup badges are on the right. Have you answered any surveys? I don’t think I even noticed them before. (My bad!)

Click any image to enlarge.

The top tabs have changed too. The words myTree and myProjects are now gone, and descriptive tabs have replaced those. The only “my” thing remaining is myOrigins. This change surprises me with myDNA being the owner.

The Results & Tools tab at the top shows the product dropdowns.

The most popular tabs are shown individually under each product, with additional features being grouped under “See More.”

Every product now has a “See More” link where less frequently used widgets will be found, including the raw data downloads. This is the Y DNA “See More” dropdown by way of example.

You can see the green Updated badge on the Family Finder Matches tab. I don’t know if that badge will always appear when customers have new matches, or if it’s signaling that all customers have updated Family Finder Matches now.

We’ll talk about matches in the Family Finder section.

The Family Finder “See More” tab includes the Matrix, ancientOrigins, and the raw data file download.

The mitochondrial DNA section, titled Maternal Line Ancestry, mtDNA Results and Tools includes several widgets grouped under the “See More” tab.

Additional Tests and Tools

The Additional Tests and Tools area includes a link to your Family Tree (please do upload or create one,) Public Haplotrees, and Advanced Matches.

Public haplotrees are free-to-the-public Y and mitochondrial DNA trees that include locations. They are also easily available to FamilyTreeDNA customers here.

Please note that you access both types of trees from one location after clicking the Public Haplotrees page. The tree defaults to Y-DNA, but just click on mtDNA to view mitochondrial haplogroups and locations. Both trees are great resources because they show the location flags of the earliest known ancestors of the testers within each haplogroup.

Advanced Matches used to be available from the menu within each test type, but since advanced matching includes all three types of tests, it’s now located under the Additional Tests and Tools banner. Don’t forget about Advanced Matches – it’s really quite useful to determine if someone matches you on multiple types of tests and/or within specific projects.

Hey, look – I found a tooltip. Just mouse over the text and tabs on various pages to see where tooltips have been added.

Help and Help Center

The new Help Center is debuting in this release. The former Learning Center is transitioning to the Help Center with new, updated content.

Here’s an example of the new easy-to-navigate format. There’s a search function too.

Each individual page, test type, and section on your personal home page has a “Helpful Information” button.

On the main page, at the top right, you’ll see a new Help button.

Did you see that Submit Feedback link?

If you click on the Help Center, you’ll be greeted with context-sensitive help.

I clicked through from the dashboard, so that’s what I’m seeing. However, other available topics are shown at left.

I clicked on both of the links shown and the content has been updated with the new layout and features. No wonder they launched a new Help Center!

Account Settings

Account settings are still found in the same place, and those pages don’t appear to have changed. However, please keep in mind that some settings make take up to 24 hours to take effect.

Family Finder Rematching

Before we look at what has changed on your Family Finder pages, let’s talk about what happened behind the scenes.

FamilyTreeDNA has been offering the Family Finder test for 11 years, one of two very early companies to enter that marketspace. We’ve learned so much since then, not only about DNA itself, but about genetic genealogy, matching, triangulation, population genetics, how to use these tools, and more.

In order to make improvements, FamilyTreeDNA changing the match criteria which necessitated rematching everyone to everyone else.

If you have a technology background of any type, you’ll immediately realize that this is a massive, expensive undertaking requiring vast computational resources. Not only that, but the rematching has to be done in tandem with new kits coming in, coordinated for all customers, and rolled out at once. Based on new matches and features, the user interface needed to be changed too, at the same time.

Sounds like a huge headache, right?

Why would a company ever decide to undertake that, especially when there is no revenue for doing so? The answer is to make functionality and accuracy better for their customers. Think of this as a new bedrock foundation for the future.

FamilyTreeDNA has made computational changes and implemented several features that require rematching:

  • Improved matching accuracy, in particular for people in highly endogamous populations. People in this category have thousands of matches that occur simply because they share multiple distant ancestors from within the same population. That combination of multiple common ancestors makes their current match relationships appear to be closer in time than they are. In order to change matching algorithms, FamilyTreeDNA had to rewrite their matching software and then run matching all over to enable everyone to receive new, updated match results.
  • FamilyTreeDNA has removed segments below 6 cM following sustained feedback from the genealogical community.
  • X matching has changed as well and no longer includes anyone as an X match below 6 cM.
  • Family Matching, meaning paternal, maternal and both “bucketing” uses triangulation behind the scenes. That code also had to be updated.
  • Older transfer kits used to receive only closer matches because imputation was not in place when the original transfer/upload took place. All older kits have been imputed now and matched with the entire database, which is part of why you may have more matches.
  • Relationship range calculations have changed, based on the removal of microsegments, new matching methodology and rematching results.
  • FamilyTreeDNA moved to hg37, known as Build 37 of the human genome. In layman’s terms, as scientists learn about our DNA, the human map of DNA changes and shifts slightly. The boundary lines change somewhat. Versions are standardized so all researchers can use the same base map or yardstick. In some cases, early genetic genealogy implementers are penalized because they will eventually have to rematch their entire database when they upgrade to a new build version, while vendors who came to the party later won’t have to bear that internal expense.

As you can see, almost every aspect of matching has changed, so everyone was rematched against the entire database. You’ll see new results. Some matches may be gone, especially distant matches or if you’re a member of an endogamous population.

You’ll likely have new matches due to older transfer kits being imputed to full compatibility. Your matches should be more accurate too, which makes everyone happy.

I understand a white paper is being written that will provide more information about the new matching algorithms.

Ok, now let’s check out the new Family Finder Matches page.

Family Finder Matches

FamilyTreeDNA didn’t just rearrange the furniture – there’s a LOT of new content.

First, a note. You’ll see “Family Finder” in some places, and “Autosomal DNA” in other places. That’s one and the same at FamilyTreeDNA. The Family Finder test is their autosomal test, named separately because they also have Y DNA and mitochondrial DNA tests.

When you click on Family Finder matches for the first time, you will assuredly notice one thing and will probably notice a second.

First, you’ll see a little tour that explains how to use the various new tools.

Secondly, you will probably see the “Generating Matches” notice for a few seconds to a few minutes while your match list is generated, especially if the site is busy because lots of people are signing on. I saw this message for maybe a minute or two before my match list filled.

This should be a slight delay, but with so many people signing in right now, my second kit took longer. If you receive a message that says you have no matches, just refresh your page. If you had matches before, you DO have matches now.

While working with the new interface this morning, I’ve found that refreshing the screen is the key to solving issues.

My kits that have a few thousand matches loaded Family Matching (bucketing) immediately, but this (Jewish) kit that has around 30,000 matches received this informational message instead. FamilyTreeDNA has removed the little spinning icon. If you mouse over the information, you’ll see the following message:

This isn’t a time estimate. Everyone receives the same message. The message didn’t even last long enough for me to get a screenshot on the first kit that received this message. The results completed within a minute or so. The Family Matching buckets will load as soon as the parental matching is ready.

These delays should only happen the first time, or if someone has a lot of matches that they haven’t yet viewed. Once you’ve signed in, your matches are cached, a technique that improves performance, so the loading should be speedy, or at least speedier, during the second and subsequent visits.

Of course, right now, all customers have an updated match list, so there’s something new for everyone.

Getting Help

Want to see that tutorial again?

Click on that little Help box in the upper right-hand corner. You can view the Tutorial, look at Quick References that explain what’s on this page, visit the Help Center or Submit Feedback.

Two Family Finder Matches Views – Detail and Table

The first thing you’ll notice is that there are two views – Detail View and Table View. The default is Detail View.

Take a minute to get used to the new page.

Detail View – Filter Matches by Match Type

I was pleased to see new filter buttons, located in several places on the page.

The Matches filter at left allows you to display only specific relationship levels, including X-Matches which can be important in narrowing matches to a specific subset of ancestors.

You can display only matches that fall within certain relationship ranges. Note the new “Remote Relative” that was previously called speculative.

Parental Matching and Filtering by Test Type or Trees

All of your matches are displayed by default, of course, but you can click on Paternal, Maternal or Both, like before to view only matches in those buckets. In order for the Family Matching bucketing feature to be enabled, you must attach known relatives’ DNA matches to their proper place in your tree.

Please note that I needed to refresh the page a couple of times to get my parental matches to load the first time. I refreshed a couple of times to be sure that all of my bucketed matches loaded. This should be a first-time loading blip.

There’s a new filter button to the right of the bucketing tabs.

You can now filter by who has trees and who has taken which kinds of tests.

You can apply multiple filters at the same time to further narrow your matches.

Important – Clearing Filters

It’s easy to forget you have a filter enabled. This section is important, in part because Clear Filter is difficult to find.

The clear filter button does NOT appear until you’ve selected a filter. However, after applying that filter, to clear it and RESET THE MATCHES to unfiltered, you need to click on the “Clear Filter” button which is located at the top of the filter selections, and then click “Apply” at the bottom of the menu. I looked for “clear filter” forever before finding it here.

You’re welcome😊

Enhanced Search

Thank goodness, the search functionality has been enhanced and simplified too. Full name search works, both here and on the Y DNA search page.

If you type in a surname without selecting any search filters, you’ll receive a list of anyone with that word in their name, or in their list of ancestral surnames. This does NOT include surnames in their tree if they have not added those surnames to their list of ancestral surnames.

Notice that your number of total matches and bucketed people will change based on the results of this search and any filters you have applied.

I entered Estes in the search box, with no filters. You can see that I have a total of 46 matches that contain Estes in one way or another, and how they are bucketed.

Estes is my birth surname. I noticed that three people with Estes in their information are bucketed maternally. This is the perfect example of why you can’t assume a genetic relationship based on only a surname. Those three people’s DNA matches me on my mother’s side. And yes, I confirmed that they matched my mother too on that same segment or segments.

Search Filters

You can also filter by haplogroup. This is very specific. If you select mitochondrial haplogroup J, you will only receive Family Finder matches that have haplogroup J, NOT J1 or J1c or J plus anything.

If you’re looking for your own haplogroup, you’ll need to type your full haplogroup in the search box and select mtDNA Haplogroup in the search filter dropdown.

Resetting Search Results

To dismiss search results, click on the little X. It’s easy to forget that you have initiated a search, so I need to remember to dismiss searches after I’m finished with each one.

Export Matches

The “Export CSV” button either downloads your entire match list, or the list of filtered matches currently selected. This is not your segment information, but a list of matches and related information such as which side they are bucketed on, if any, notes you’ve made, and more.

Your segment information is available for download on the chromosome browser.

Sort By

The Sort By button facilitates sorting your matches versus filtering your matches. Filters ONLY display the items requested, while sorts display all of the items requested, sorting them in a particular manner.

You can sort in any number of ways. The default is Relationship Range followed by Shared DNA.

Your Matches – Detail View

A lot has changed, but after you get used to the new interface, it makes more sense and there are a lot more options available which means increased flexibility. Remember, you can click to enlarge any of these images.

To begin with, you can see the haplogroups of your matches if they have taken a Y or mitochondrial DNA test. If you match someone, you’ll see a little check in the haplogroup box. I’m not clear whether this means you’re a haplogroup match or that person is on your match list.

To select people to compare in the chromosome browser, you simply check the little square box to the left of their photo and the chromosome browser box pops up at the bottom of the page. We’ll review the chromosome browser in a minute.

The new Relationship Range prediction is displayed, based on new calculations with segments below 6 cM removed. The linked relationship is displayed below the range.

A linked relationship occurs when you link that person to their proper place in your tree. If you have no linked relationship, you’ll see a link to “assign relationship” which takes you to your tree to link this person if you know how you are related.

The segments below 6 cM are gone from the Shared DNA total and X matches are only shown if they are 6 cM or above.

In Common With and Not In Common With

In Common With and Not In Common With is the little two-person icon at the right.

Just click on the little person icon, then select “In Common With” to view your shared matches between you, that match, and other people. The person you are viewing matches in common with is highlighted at the top of the page, with your common matches below.

You can stack filters now. In this example, I selected my cousin, Don, to see our common matches. I added the search filter of the surname Ferverda, my mother’s maiden name. She is deceased and I manage her kit. You can see that my cousin Don and I have 5 total common matches – four maternal and one both, meaning one person matches me on both my maternal and paternal lines.

It’s great news that now Cousin Don pops up in the chromosome browser box at the bottom, enabling easy confusion-free chromosome segment comparisons directly from the In Common With match page. I love this!!!.

All I have to do now is click on other people and then on Compare Relationship which pushes these matches through to the chromosome browser. This is SOOOO convenient.

You’ll see a new tree icon at right on each match. A dark tree means there’s content and a light tree means this person does not have a tree. Remember, you can filter by trees with content using the filter button beside “Both”.

Your notes are shown at far right. Any person with a note is dark grey and no note is white.

If you’re looking for the email contact information, click on your match’s name to view their placard which also includes more detailed ancestral surname information.

Family Finder – Table View

The table view is very similar to the Detail View. The layout is a bit different with more matches visible in the same space.

This view has lots of tooltips on the column heading bar! Tooltips are great for everyone, but especially for people just beginning to find their way in the genetic genealogy world.

I’ll have to experiment a bit to figure out which view I prefer. I’d like to be able to set my own default for whichever view I want as my default. In fact, I think I’ll submit that in the “Submit Feedback” link. For every suggestion, I’m going to find something really positive to say. This was an immense overhaul.

Chromosome Browser

Let’s look at the chromosome Browser.

You can arrive at the Chromosome Browser by selecting people on your match page, or by selecting the Chromosome Browser under the Results and Tools link.

Everything is pretty much the same on the chromosome browser, except the default view is now 6 cM and the smaller segments are gone. You can also choose to view only segments above 10 cM.

If you have people selected in the chromosome browser and click on Download Segments in the upper right-hand corner, it downloads the segments of only the people currently selected.

You can “Clear All” and then click on Download All Segments which downloads your entire segment file. To download all segments, you need to have no people selected for comparison.

The contents of this file are greatly reduced as it now contains only the segments 6 cM and above.

Family Tree

No, the family tree has not changed, and yes, it needs to, desperately. Trust me, the management team is aware and I suspect one of the improvements, hopefully sooner than later, will be an improved tree experience.

Y DNA

The Y DNA page has received an update too, adding both a Detail View and a Table View with the same basic functionality as the Family Finder matching above. If you are reading this article for Y DNA only, please read the Family Finder section to understand the new layout and features.

Like previously, the match comparison begins at the 111 marker level.

However, there’s a BIG difference. If there are no matches at this level, YOU NEED TO CLICK THE NEXT TAB. You can easily see that this person has matches at the 67 level and below, but the system no longer “counts down” through the various levels until it either finds a level with a match or reaches 12 markers.

If you’re used to the old interface, it’s easy to think you’re at the final destination of 12 markers with no matches when you’re still at 111.

Y DNA Detail View

The Y-DNA Detail and Table views features are the same as Family Finder and are described in that section.

The new format is quite different. One improvement is that the Paternal Country of Origin is now displayed, along with a flag. How cool is that!

The Paternal Earliest Known Ancestor and Match Date are at far right. Note that match dates have been reset to the rerun date. At this point, FamilyTreeDNA is evaluating the possibility of restoring the original match date. Regardless, you’ll be able to filter for match dates when new matches arrive.

Please check to be sure you have your Country of Origin, Earliest Known Ancestor, and mapped location completed and up to date.

Earliest Known Ancestor

If you haven’t completed your Earliest Known Ancestor (EKA) information, now’s the perfect time. It’s easy, so let’s do it before you forget.

Click on the Account Settings gear beneath your name in the right-hand upper corner. Click on Genealogy, then on Earliest Known Ancestors and complete the information in the red boxes.

  • Direct paternal line means your father’s father’s father’s line – as far up through all fathers as you can reach. This is your Y DNA lineage, but females should complete this information on general principles.
  • Direct maternal line means your mother’s mother’s mother’s line – as far up through all mothers that you can reach. This is your mitochondrial DNA lineage, so relevant for both males and females.

Completing all of the information, including the location, will help you and your matches as well when using the Matches Map.

Be sure to click Save when you’re finished.

Y DNA Filters

Y DNA has more filter options than autosomal.

The Y DNA filter, located to the right of the 12 Markers tab allows testers to filter by:

  • Genetic distance, meaning how many mutations difference between you and your matches
  • Groups meaning group projects that the tester has joined
  • Tree status
  • Match date
  • Level of test taken

If none of your matches have taken the 111 marker test or you don’t match anyone at that level, that test won’t show up on your list.

Y DNA Table View

As with Family Finder, the Table View is more condensed and additional features are available on the right side of each match. For details, please review the Family Finder section.

If you’re looking for the old Y DNA TiP report, it’s now at the far right of each match.

The actual calculator hasn’t changed yet. I know people were hoping for the new Y DNA aging in this release, but that’s yet to follow.

Other Pages

Other pages like the Big Y and Mitochondrial DNA did not receive new features or functionality in this release, but do sport new user-friendly tooltips.

I lost track, but I counted over 100 tooltips added across the platform, and this is just the beginning.

There are probably more new features and functionality that I haven’t stumbled across just yet.

And yes, we are going to find a few bugs. That’s inevitable with something this large. Please report anything you find to FamilyTreeDNA.

Oh wait – I almost forgot…

New Videos

I understand that there are in the ballpark of 50 new videos that are being added to the new Help Center, either today or very shortly.

When I find out more, I’ll write an article about what videos are available and where to find them. People learn in various ways. Videos are often requested and will be a popular addition. I considered making videos, but that’s almost impossible for anyone besides the vendor because the names on screens either need to be “fake” or the screen needs to be blurred.

So hurray – very glad to hear these are imminent!

Stay Tuned

Stay tuned for new developments. As Lior said, FamilyTreeDNA is investing heavily in genetic genealogy and there’s more to come.

My Mom used to say that the “proof is in the pudding.” I’d say the myDNA/FamilyTreeDNA leadership team has passed this initial test with flying colors.

Of course, there’s more to do, but I’m definitely grateful for this lovely pudding. Thank you – thank you!

I can’t wait to get started and see what new gems await.

Take a Look!

Sign in and take a look for yourself.

Do you have more matches?

Are your matches more accurate?

How about predicted relationships?

How has this new release affected you?

What do you like the best?

_____________________________________________________________

Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Books

Genealogy Research

Heads Up – Great Changes Coming at FamilyTreeDNA

This should be subtitled “Confessions of a Squeaky Wheel.”

Yes, I’ve been incessantly squeaky for a long time now, and it looks for all the world like this nagging, er, squeaking has worked.

Just a few minutes ago, this email arrived from FamilyTreeDNA, addressed to project administrators.

There’s at least one thing that’s time-sensitive, so be sure to read this today.

You may have been one of the FamilyTreeDNA customers who received one of two surveys a few weeks ago, after myDNA merged with FamilyTreeDNA. FamilyTreeDNA asked for feedback about what customers would like to see.

At that time, there was a raft of unfounded rumors that myDNA wasn’t committed to genealogy.

That was wrong, dead wrong. Couldn’t be further from the truth, and that’s not just extrapolated from this email. It’s a function of being that squeaky wheel. Based on this, FamilyTreeDNA obviously listened.

This is certainly welcome news!

That list of things we’ve been asking for…well, here you go.

Increased matches for many, along with improved matches. Did you see that?

There’s a lot here. It’s no wonder the matches page has been redesigned with all these new features.

It looks like the Y DNA page has been redesigned for the same reason. No mention of mitochondrial DNA though. Maybe that’s coming soon.

Thank goodness – a new Help Center.

And VIDEOs too!!!

Yes!!!

Ok, who loves that “Houston we have a problem” message? No one with their hand up? Me either.

However, I’ve already seen an improvement over the past few weeks, so maybe this has been an ongoing behind-the-scenes process.

And tooltips too!

For those who don’t know, a tooltip is a little information box with a couple of sentences that you can just mouse over. For example, a good place for a tooltip would be on the column headers explaining what that column means.

Ok, here’s the time-sensitive part.

I know FamilyTreeDNA said that they had closed the National Geographic Genographic transfer portal a year ago, but clearly they left it open as a courtesy.

However, with all these changes, it’s going away for good, now.

If you don’t transfer your Nat Geo Genographic kit before end of day on June 30th, you will not be able to do so. You can find instructions, here.

What’s Next?

We don’t know when these features will be released, exactly, but we do know it’s coming in July.

The fact that the Genographic transfer is gone as of June 30th suggests that at least some changes are imminent.

This cumulative list equates to a huge change, so I’d wager that it won’t be one big release, but a series of releases that build on each other.

I don’t know about you, but I can hardly wait. I’ll be writing about the new features as soon as they arrive.

I’m signing in now to record the number of matches I have so I can compare when the new features arrive. You can too, by clicking here.

If you have kits from other vendors that you’ve been meaning to upload to FamilyTreeDNA, now would be a great time to do that. You can find step-by-step instructions for downloading raw data files from each vendor and uploading them elsewhere, here.

Feel free to share this article with groups or anyone else who 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

Books

Genealogy Research

How Many Men Discover or Confirm Their Surname with Y DNA Testing?

About 15 years ago, Bennett Greenspan, founder of FamilyTreeDNA, at one of the early conferences said that about 30% of men who take a Y DNA test find a strong surname match. That number has increased now to nearly 100%, or “almost everyone.”

Exceptions

Of course, there are exceptions that fall into a number of categories:

  • Jewish families from regions where surnames weren’t adopted until in the 1800s.
  • Jewish families whose direct paternal line suffered dramatic losses during the Holocaust.
  • Dutch families who did not adopt surnames until Napoleon’s edict in 1811.
  • Cultures who have or recently had patronymic surnames that change every generation.
  • Men whose DNA is either extremely rare (and no relatives have tested) or are from under-sampled regions of the world.
  • Males whose paternal line may be recent immigrants and people in the homeland don’t participate in genealogy or don’t DNA test.
  • Males whose ancestors were enslaved. In the US, families adopted surnames after the Civil War ended slavery in the 1860s, so Y DNA testing plus autosomal is critically important to reunite these families. Please note that the Y DNA haplogroup, even an estimate provided with STR testing, will indicate whether the direct paternal lineage is European, African, Native American/Asian – all of which are found in the descendants of men who were enslaved. The Big Y-700 provides significantly more information along with placement on the haplotree.

I started writing Y DNA reports for clients in 2004 (although I no longer accept private clients) and at that time, often saw men with no matches. Today, a man with no matches is extremely unusual, and most have strong surname matches. As more men test, everyone will have more matches, of course, and the more we can learn about our ancestors.

What do matches reveal?

Matches Reveal

In essence, matches to other men with common surnames do one of two things:

  1. Confirm the surname lineage, at least to the common ancestor.
  2. Identify the surname where the tester is likely to find his ancestral roots.
  3. Provide perspective further back in time answering the question, “Where did I come from?”

Of course, this second point is crucial for males searching for the identity of their paternal lines.

While time has moved on, the number of testers in the database has dramatically increased, and almost everyone has relevant matches now – I still see the 30% metric oft-repeated. Let’s put this to the test and see what we find.

Setting Up the Experiment

I selected 20 men who have taken the Big Y test whose kits I manage or who were randomly selected from projects that I manage and who have given permission for their results to be published on public project pages.

I recorded results for the tester’s own or very similar surnames. Slightly different but recognizable spellings are counted as the same name.

I included matches at 12 markers, 111 markers, and the Big Y results. Men who purchase or upgrade to the Big Y-700 test will have all 111 STR panel markers included. Obviously, individual testers should check their results at every level.

Big Y testers actually receive 700+ STR markers, but can only easily filter for matches at 111 (or below), so that’s the number I used. Plus, males can purchase  37 and 111 panels without taking the Big Y test, so this comparative information will be valid for all Y DNA testers.

Click to enlarge image.

Additionally, I used the Advanced Matches feature to check for people who match someone on BOTH the Y DNA and their Family Finder autosomal test. Of course, this doesn’t guarantee that the reason they match on both tests is because of their common surname line – but it’s a hint and may be very useful, especially with closer Family Finder matches.

I intentionally included some men with recent European heritage who are unlikely to have matches simply because their families have been in colonial America since the 1600s or 1700s and their ancestor had a dozen sons who each had a dozen sons.

Why Did I Include 12 Marker Results?

You may wonder why I included 12 marker matches since that test is no longer sold individually and is the least granular. Truthfully, it’s too often deemed useless and overlooked.

Hear me out on this one😊

Many of the men who originally took the 12 and 25 marker tests, before the higher panels (37, 67, 111, and Big Y) were available are deceased now. Twenty years is a generation, and FamilyTreeDNA began testing the Y chromosome in the year 2000.

While these low marker tests alone are not conclusive, with additional information, such as trees, common ancestors, and other testers who match, they form pieces of evidence that can be invaluable. Some have also taken an autosomal test which can be especially important, given that they are another generation or two (or three) further back in time than the people testing today.

You won’t see these men as matches at 37, 67 or 111 markers, because they are deceased and can’t upgrade, but they may provide the nugget of information you need by matching at 12 or 25 markers. You’ll need to evaluate that match in light of other information. I’ll review that in the next two sections.

20 Men

If you’re a man or can find a male to test for each of your genealogy lines, the Y DNA is the fastest, most reliable way to identify an ancestral surname – not just in your father’s generation, but moving back in time.

Of the 20 men selected, all men had matches to their surname. However, one Smith man, #18, had a unique situation that might be very genealogically relevant.

I’ll discuss each match briefly with some commentary below the chart.

Surname Match Name 12 Marker 111 Marker Big Y Advanced – 12 + FF Both
1 Howery Howery 9 of 20 2 of 2 0 (none tested) 1
2 Graves Graves 8 of 51 2 of 8 1 Graves + others 1 – different surname
3 Perkins Perkins/McDonald 16 of 1762 1 of 63, many McDonalds 0 Perkins (no testers) but several McD names 8 – 2 McDonald
4 Napier Napier 19 of 19,217 2 of 13 2 Napier + others 1 + many others
5 Rice Rice 45 of 58 14 of 19 7 of 10 1
6 Rader Rader  13 of 18,576 7 of 7 7 3
7 Estes Estes 69 of 502 21 of 24 9 of 10 2 + 4 different surname
8 Campbell Campbell 178 of 369 61 of 103 7 of 10 4 of 5
9 Lentz Lentz 1 of 1 0 of 1 1 different name, no other Lentz Big Y testers 0
10 Bonnevie Bonnevie 1 of 1 (tested to 37) 0 0 no test
11 Vannoy Vannoy 7 of 49 2 of 4 0 of 1 0
12 Lore/Lord Lore/Lord 3 of 7 1 of 3 1 of 1 0
13 Clarkson/Claxton Clarkson/Claxton 19 of 540 1 of 1 0 of 9 (No Big Y testers) 0 of 3
14 Muncey Muncy/Muncey 9 of 155 7 of 16 1 of 4 1
15 Miller Miller 5 of 6 2 at 67, no 111 testers 0 – no Miller match testers 1 of 2
16 Speak(s) Speak(s) 9 of 9 21 of 51 4 of 17 0
17 Smith Smith/Jennings 2 of 16, 9 Jennings 0 of 2 (Jennings) 1 Jennings of 3 1 Jennings
18 Bolton Bolton 8 of 1750 2 of 2 0 of 28 0 of 12
19 Crumley Crumley 10 of 79 7 of 93 3 of 127 0 of 2
20 Harrell Harrell 81 of 17,638 3 of 7 2 of 2 0 of 119

Messages Revealed in the Results

Let’s briefly review the information we’ve discovered and extrapolate from each of these 20 matches. Analysis is the key to success.

  1. The Howery surname is rather unusual. This man had only two 111 marker matches and both were to men of the same surname. Half of his 12 marker matches are the same surname. None of his matches had taken the Big Y test, so he has no same-surname or other surname matches there. He did match one of his Y DNA matches on the Family Finder test though. This is high-quality confirmation that Howery is indeed the biological ancestral surname and our tester can set about finding and confirming his common ancestors with his matches.
  2. The Graves male had several 12-marker matches, but many 12-marker matches have not tested at the 111 marker level. He matches one Graves male on the Big Y plus some men with other surnames. The Big Y reaches back further in time, so these matches may reflect common ancestors before the advent of surnames.
  3. Our Perkins male has very interesting matches. He does have both 12 and 111 Perkins matches, but he also had a LOT of McDonald matches. More McDonald matches than Perkins matches. This suggests that indeed, his ancestors were Perkins, at least back to the earliest known ancestor (EKA), but before that, he may well be a member of the McDonald Y DNA clan. There were no Perkins Big Y testers, but if I were him, I’d ask my Perkins matches to upgrade.
  4. I can tell by looking at the huge number of 12 marker matches for our Napier man that he is haplogroup R, the most common in Europe, with an EXTREMELY common 12 marker haplotype. Note how dramatically the number of 111 marker matches drops – from 19,000+ to 13 – a perfect example of why we suggest men upgrade to at least 111 markers to refine their matches. Both of his 111 marker Napier matches have upgraded to the Big Y, and he matches them there as well. He does match one Napier on both the 12 marker test and Family Finder Advanced Matching – but he also matches MANY other men. This is because of the extremely high number of 12 marker matches. In his case, I would only use Y DNA marker panels higher than 12 markers in the Advanced Matching.
  5. Lots of Rice testers from this line confirm a common ancestor. I wonder if there is a Rice male from someplace overseas who has tested. If so, this might be that “jump the pond” event that genealogists who have European ancestors who are found in colonial America seek.
  6. Our Rader tester also has many 12 marker matches, but his only matches at 111 and on the Big Y are his Rader kinsmen. No doubt about that surname whatsoever.
  7. My Estes line has several 12 marker matches, but that gets slimmed right down at 111 markers. Using the Big Y test, we further divided those branches of Estes men. I literally could not have sorted out who was descended from whom without the Big Y test results. Way too many Johns, Williams, and Elishas in burned counties in Virginia.
  8. Our Campbell tester is unquestionably confirmed to be descended from the Clan Campbell line from Inverary, Scotland. However, the challenge in this family is which Campbell male they descend from in Virginia. The Big Y-700 test has narrowed the possibilities significantly, and the tester is currently in the process of attempting to convince his three closest Y STR 111 matches to take the Big Y test. Yes, he has offered to pay as well. Hey, in genealogy, you do what you need to do. Y DNA is likely the only way this puzzle from the 1700s will ever be unraveled.
  9. The Lentz line is German with rare DNA, but they do have a confirming match to another Lentz male.
  10. Bonnievie spelled various ways is French and has one 12 marker match who only tested to 37 markers. He has no matches above that. Not only is his Y DNA quite rare, DNA testing is illegal in France which makes additional testers few and far between. Unfortunately, his one match has not taken a Family Finder test either.
  11. Several men from the Vannoy line have tested and a Big Y test match to another man confirmed that the ancestral line is Dutch – not French as was speculated for decades. The STR tests have revealed Vannoy lines, by similar spellings, from lines we didn’t know existed.
  12. Lore or Lord is a rare Acadian family surname. Our tester does have matches to other Lore/Lord men, which confirms the line to the ancestor who arrived in Acadia in the early 1600s, but future testers will be needed before we can confirm his origins to either France or as one of the English soldiers who served at the fort.
  13. The Clarkson/Claxton testers confirm two lines, one spelled each way, from Tennessee and North Carolina line to a common ancestor in either Virginia or North Carolina in the 1770s. However, the family is still working to further assemble that puzzle. Finding a Clarkson/Claxton match on STR markers or the Big Y who descends from a male not from the two known lines would help immensely. Our hope is that a Clarkson/Claxton from an earlier line or from the British Isles will test and provide that push over the brick wall. Any Clarkson/Clarkson men out there who haven’t taken the Y DNA test yet?
  14. The Muncy/Munsey line is confirmed to a common ancestor born in England in and died on Long Island in 1674. Based on both STR and SNP results from the Big Y, we can narrow the lineages of Muncy men who test and aren’t familiar with their Muncy genealogy. Of course, the Muncy line eventually migrated through Virginia and seemingly named every man in every generation either John, Samuel or Francis – but DNA testing helps immensely to sort this out.
  15. While Miller is a very common occupation surname, DNA testing has put to rest many incorrect myths about this particular Swiss Miller line. Men with the same surname in the same location, even in the same church, does not equate to the same genetic family line. Any male with a common surname absolutely needs to do Y DNA testing and at the highest level. There’s nothing worse than spending countless hours barking up the wrong tree – especially when Y DNA testing will save you.
  16. Our Speaks man matched another Speak male who knew where his ancestors were from in Lancashire. Testing additional men living in Lancashire at the 111 marker and Big Y levels allowed the Speak line to be divided into specific lineages beginning in the 1500s, piecing together the earlier ancestors into a descendant tree. Recently, an “orphan” line in the US has been connected to his ancestors, thanks to both STR values AND Big Y testing.
  17. Smith is quite interesting because we discover that something doesn’t add up. Our Smith man matches two Smith men who have the same ancestor born in 1810 but that son, John, does not match the descendants of his brothers. There seems to be an undocumented adoption of some sort at that point in time. John Smith’s Y DNA is not the same as his brothers whose descendants match each other. Given that our Smith tester, and his two matches, do not match the other descendants of the ancestor they are supposed to descend from, we can pinpoint the generation in which the adoption event occurred. However, we have a further clue, because these Smith men match the Jennings line closely- including one advanced match where the Smith man also matches autosomally in addition to the Y DNA. This is clearly a case of “you don’t know what you don’t know” and would never have known without Y DNA testing.
  18. Our Bolton tester matches several other Bolton men who descend from a common immigrant ancestor. If the Bolton matches upgrade to the Big Y-700 test, they might be able to determine separate genetic lines branching through the various sons of the immigrant ancestor. Evaluating the surnames that the tester matches at the Big Y level may assist with evaluating deeper ancestry in England and determining where the Bolton ancestors originated before the 1600s in London.
  19. Crumley is a difficult family to research, in part because several people with the same surname are found in close proximity, but Y DNA testing has shown that these men are not related. Big Y testing has disproved that the Crumley progenitor originated in Germany, although a different Crumley family did. The Big Y matches include many Mc… surnames along with Ferguson and Gillespie. The Big Y Block Tree shows the closest matches with ancestors born in Scotland, Ireland, and Northern Ireland – which is very likely where the Crumley progenitor originated too.
  20. Harrell is another difficult surname, spelled numerous ways with several Harrell/Herrell/Harrold/Herrald families moving westward in the 1600s and 1700s from the thirteen original colonies. This Harrell line has not been able to connect to a single progenitor in the colonies, yet, but Y DNA testing and the block tree confirm that this Harrell line originated in the British Isles, very likely England.

What Did These 20 Men Learn?

Every single one of these men benefitted from Y DNA testing, although exactly how depends to some extent on their testing goal. Other men also benefitted by matching.

One man, our Smith, #17, needs to look at the Jennings family prior to 1810. Is there a Jennings man living in close proximity, or do court records exist that might be illuminating?

If one of these 20 men had been an adoptee or otherwise searching for an unknown paternal line, they would have been able to identify a surname connection and perhaps a progenitor ancestor. I encourage everyone to either order a Family Finder autosomal test or transfer a DNA file (for free) from another vendor if they have taken an autosomal test elsewhere. Step-by-step transfer instructions are found here. Be sure that the Y DNA and autosomal tests are on the same kit/account at FamilyTreeDNA so that you can use the advanced matching tool.

With the Big Y-700 test, these men can discern or confirm lines descending from their direct paternal ancestors – sometimes within a generation or two of the tester. This test is so sensitive and granular and has such deep coverage (millions of bases) now that often we find small mutations between fathers and sons or brothers.

While STR markers, 12-111 are genealogically important, they do tend to mutate rapidly and sometimes back-mutate. SNPs, tested in the Big Y-700 test, don’t do that, and the power of STRs and SNPs together have the potential to break down brick walls and correct trees. In fact, it happens every single day.

Resources

If you’d like to watch a video about Y DNA, Y DNA-related genetic terms, and the benefits of Big Y-700 testing, you can watch a great educational video by Janine Cloud here. Be sure to note the part where she talks about why people who have previously taken the Big Y-500 might want to upgrade to the Big Y-700.

Also, check out my Y DNA Resource page, here.

What Don’t You Know?

Y DNA tests, including the Big Y-700 which includes all STR panels, and the autosomal Family Finder test are on sale at FamilyTreeDNA right now for Father’s Day.

There’s no better time to find missing pieces and discover information that you can’t find any other way.

Click here to order Y DNA tests, the Family Finder, or upgrade an existing test.

_____________________________________________________________

Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Books

Genealogy Research

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

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

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

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

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

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

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

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

Let’s go!

The Step-by-Step Educational Answer😊

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

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

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

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

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

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

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

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

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

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

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

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

Let’s start by dispelling a myth.

DNA Doesn’t Skip Generations!

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

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

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

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

Full stop.

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

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

DNA skipping generations is a fallacy.

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

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

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

We’ll talk about that more in a minute.

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

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

Legitimate Matches

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

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

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

Thankfully, there are ways to tell the difference.

Inheritance and Triangulation

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

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

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

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

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

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

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

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

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

This is exactly why triangulation works and is crucial.

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

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

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

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

This is the first step in identifying false matches.

Parental Cross-Matching

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Parental Phasing

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

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

See how easy that was!

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

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

There are four possible match conditions:

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

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

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

Automatic Phasing at FamilyTreeDNA

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

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

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

Parental Phasing Caveats

There are very rare instances where parental phasing may be technically accurate, but not genealogically relevant. By this, I mean that a parent may actually match one of your matches due to endogamy or a population level match, even if it’s considered a false positive because it’s not relevant in a genealogical timeframe.

Conversely, a parent may not match when the segment is actually legitimate, but it’s quite rare and only when pedigree collapse has occurred in a very specific set of circumstances where both parents share a common ancestor.

Let’s take a look at that.

Pedigree Collapse

It’s not terribly uncommon in the not-too-distant past to find first cousins marrying each other, especially in rather closely-knit religious communities. I encounter this in Brethren, Mennonite and Amish families often where the community was small and out-marrying was frowned upon and highly discouraged. These families and sometimes entire church congregations migrated cross-country together for generations.

When pedigree collapse is present, meaning the mother and father share a common ancestor not far in the past, it is possible to inherit half of one segment from Mom and the other half from Dad where those halves originated with the same ancestral couple.

For example, let’s say the matching segment between you and your match is 12 cM in length, shown below. You inherited the blue segment from your Dad and the neighboring peach segment from Mom – shown just below the segment numbers. You received 6 cM from both parents.

Another person’s DNA does match you, shown in the bottom row, but they are not shown on the DNA match list of either of your parents. That’s because the DNA segments of the parents just happened to recombine in 6 cM pieces, respectively, which is below the 7 cM matching threshold of the vendor in this example.

If the person matched you at 12 cM where you inherited 8 cM from one parent and 4 from the other, that person would show on one parent’s match list, but not the other. They would not be on the parent’s match list who contributed only 4 cM simply because the DNA divided and recombined in that manner. They would match you on a longer segment than they match your parent at 8 cM which you might notice as “odd.”

Let’s look at another example.

click to enlarge image

If the matching segment is 20 cM, the person will match you and both of your parents on different pieces of the same segment, given that both segments are above 7 cM. In this case, your match who matches you at 20 cM will match each of your parents at 10 cM.

You would be able to tell that the end location of Dad’s segment is the same as the start location of Mom’s segment.

This is NOT common and is NOT the “go to” answer when you think someone “should” match your parent and does not. It may be worth considering in known pedigree collapse situations.

You can see why someone observing this phenomenon could “presume” that DNA skipped a generation because the person matches you on segments where they don’t match your parent. But DNA didn’t skip anything at all. This circumstance was caused by a combination of pedigree collapse, random division of DNA, then random recombination in the same location where that same DNA segment was divided earlier. Clearly, this sequence of events is not something that happens often.

If you’ve uploaded your DNA to GEDmatch, you can select the “Are your parents related?” function which scans your DNA file for runs of homozygosity (ROH) where your DNA is exactly the same in both parental locations for a significant distance. This suggests that because you inherited the exact same sequence from both parents, that your parents share an ancestor.

If your parents didn’t inherit the same segment of DNA from both parents, or the segment is too short, then they won’t show as “being related,” even if they do share a common ancestor.

Now, let’s look at the opposite situation. Parental phasing and ROH sometimes do occur when common ancestors are far back in time and the match is not genealogically relevant.

Endogamy

I often see non-genealogical matching occur when dealing with endogamy. Endogamy occurs when an entire population has been isolated genetically for a long time. In this circumstance, a substantial part of the population shares common DNA segments because there were few original population founders. Much of the present-day population carries that same DNA. Many people within that population would match on that segment. Think about the Jewish community and indigenous Americans.

Consider our original example, but this time where much of the endogamous population carries all As in these positions because one of the original founders carried that nucleotide sequence. Many people would match lots of other people regardless of whether they are a close relative or share a distant ancestor.

People with endogamous lines do share relatives, but that matching DNA segment originated in ancestors much further back in time. When dealing with endogamy, I use parental phasing as a first step, if possible, then focus on larger matches, generally 20 cM or greater. Smaller matches either aren’t relevant or you often can’t tell if/how they are.

At FamilyTreeDNA, people with endogamy will find many people bucketed on the “Both” tab meaning they triangulate with people linked on both sides of the tester’s tree.

An example of a Jewish person’s bucketed matches based on triangulation with relatives linked in their tree is shown above.

Your siblings, their children, and your children will be related on both your mother’s and father’s sides, but other people typically won’t be unless you have experienced either pedigree collapse where you are related both maternally and paternally through the same ancestors or you descend from an endogamous population.

How Many Identical-by-Chance Matches Will I Have?

If you have both parents available to test, and you’re not dealing with either pedigree collapse or endogamy, you’ll likely find that about 15-20% of your matches don’t match your parents on the same segment and are identical by chance.

With endogamy, you’ll have MANY more matches on your endogamous lines and you’ll have some irrelevant matches, often referred to as “false positive” matches even though they technically aren’t, even using parental phasing.

Your Parents Have DNA That You Don’t

Sometimes people are confused when reviewing their matches and their parent’s match to the same person, especially when they match someone and their parent matches them on a different or an additional segment.

If you match someone on a specific segment and your parents do not, that’s a false positive FOR THAT SEGMENT. Every segment has its own individual history and should be evaluated individually. You can match someone on two segments, one from each parent. Or three segments, one from each parent and one that’s identical by chance. Don’t assume.

Often, your match will match both you and your parent on the same segment – which is a legitimate parentally phased match.

But what if your match matches your parent on a different segment where they don’t match you? That’s a false positive match for you.

Keep in mind that it is possible for one of your matches to match your parent on a separate or an additional segment that IS legitimate. You simply didn’t inherit that particular segment from your parent.

That’s NOT the same situation as someone matching you that does NOT match one of your parents on the same segment – which is an identical by chance or false match.

Your parent having a match that does not match you is the reverse situation.

I have several situations where I match someone on one segment, and they match my parent on the same segment. Additionally, that person matches my parent on another segment that I did NOT inherit from that parent. That’s perfectly normal.

Remember, you only inherit half of your parent’s DNA, so you literally did NOT inherit the other half of their DNA. Your mother, for example, should have twice as many matches as you on her side because roughly half of her matches won’t match you.

That’s exactly why testing your parents and close family members is so critical. Their matches are as valid and relevant to your genealogy as your own. The same is true for other relatives, such as aunts and uncles with whom you share ALL of the same ancestors.

You need to work with your family member’s matches that you don’t share.

No DNA Match Doesn’t Mean You’re Not Related

Some people think that not matching someone on a DNA test is equivalent to saying they aren’t related. Not sharing DNA doesn’t mean you’re not related.

People are often disappointed when they don’t match someone they think they should and interpret that to mean that the testing company is telling them they “aren’t related.” They are upset and take issue with this characterization. But that’s not what it means.

Let’s analyze this a bit further.

First, not sharing DNA with a second cousin once removed (2C1R) or more distant does NOT mean you’re NOT related to that person. It simply means you don’t share any measurable DNA ABOVE THE VENDOR THRESHOLD.

All known second cousins match, but about 10% of third cousins don’t match, and so forth on up the line with each generation further back in time having fewer cousins that match each other.

If you have tested close relatives, check to see if that cousin matches your relatives.

Second, it’s possible to match through the “other” or unexpected parent. I certainly didn’t think this would be the case in my family, because my father is from Appalachia and my mother’s family is primarily from the Netherlands, Germany, Canada, and New England. But I was wrong.

All it took was one German son that settled in Appalachia, and voila, a match through my mother that I surely thought should have been through my father’s side. I have my mother’s DNA and sure enough, my match that I thought should be on my father’s side matches Mom on the same segment where they match me, along with several triangulated matches. Further research confirmed why.

I’ve also encountered situations where I legitimately match someone on both my mother’s and father’s side, on different segments.

Third, imputation can be important for people who don’t match and think they should. Imputation can also cause matching segment length to be overreported.

Ok, so what’s imputation and why do I care?

Imputation

Every DNA vendor today has to use some type of imputation.

Let me explain, in general, what imputation is and why vendors use it.

Over the years, DNA processing vendors who sell DNA chips to testing companies have changed their DNA chips pretty substantially. While genealogical autosomal tests test about 700,000 DNA locations, plus or minus, those locations have changed over time. Today, some of these chips only have 100,000 or so chip locations in common with chips either currently or previously utilized by other vendors.

The vendors who do NOT accept uploads, such as 23andMe or Ancestry, have to develop methods to make their newest customers on their DNA processing vendor’s latest chip compatible with their first customer who was tested on their oldest chip – and all iterations in-between.

Vendors who do accept transfers/uploads from other vendors have to equalize any number of vendors’ chips when their customers upload those files.

Imputation is the scientific way to achieve this cross-platform functionality and has been widely used in the industry since 2017.

Imputation, in essence, fills in the blanks between tested locations with the “most likely” DNA found in the human population based on what’s surrounding the blank location.

Think of the word C_T. There are a limited number of letters and words that are candidates for C_T. If you use the word in a sentence, your odds of accuracy increase dramatically. Think of a genetic string of nucleotides as a sentence.

Imputation can be incorrect and can cause both false positive and false negative matches.

For the most part, imputation does not affect close family matches as much as more distant matches. In other words, imputation is NOT going to cause close family members not to match.

Imputation may cause more distant family members not to match, or to have a false positive match when imputation is incorrect.

Imputation is actually MUCH less problematic than I initially expected.

The most likely effect of imputation is to cause a match to be just above or below the vendor threshold.

How can we minimize the effects of imputation?

  • Generally, the best result will be achieved if both people test at the same vendor where their DNA is processed on the same chip and less imputation is required.
  • Upload the results of both people to both MyHeritage and FamilyTreeDNA. If your match results are generally consistent at those vendors, imputation is not a factor.
  • GEDmatch does not use imputation but attempts to overcome files with low overlapping regions by allowing larger mismatch areas. I find their matches to be less accurate than at the various vendors.

Additionally, Ancestry has a few complicating factors.

Ancestry Issues

AncestryDNA is different in three ways.

  • Ancestry doesn’t provide segment information so it’s impossible to triangulate or identify the segment or chromosome where people match. There is no chromosome browser or triangulation tool.
  • Ancestry down-weights and removes some segments in areas where they feel that people are “too matchy.” You can read Ancestry’s white papers here and here.

These “personal pileup regions,” as they are known, can be important genealogically. In my case, these are my mother’s Acadian ancestors. Yes, this is an endogamous population and also suffers from pedigree collapse, but since this is only one of my mother’s great-grandparents, this match information is useful and should not be removed.

  • Ancestry doesn’t show matches in common if the shared segments are less than 20cM. Therefore, you may not see someone on a shared match list with a relative when they actually are a shared match.

If two people both match a third person on less than a 20 cM segment at Ancestry, the third person won’t appear on the other person’s shared match list. So, if I match John Doe on 19 cM of DNA, and I looked at the shared matches with my Dad, John Doe does NOT appear on the shared match list of me and my Dad – even though he is a match to both of us at 19 cM.

The only way to determine if John Doe is a shared match is to check my Dad’s and my match list individually, which means Dad and I will need to individually search for John Doe.

Caveat here – Ancestry’s search sometimes does not work correctly.

Might someone who doesn’t understand that the shared match list doesn’t show everyone who shares DNA with both people presume that the ancestral DNA of that ancestor “skipped a generation” because John Doe matches me with a known ancestor, and not Dad on our shared match list? I mean, wouldn’t you think that a shared match would be shown on a tab labeled “Shared Matches,” especially since there is no disclaimer?

Yes, people can be forgiven for believing that somehow DNA “skipped” a generation in this circumstance, especially if they are relatively inexperienced and they don’t understand Ancestry’s anomalies or know that they need to or how to search for matches individually.

Even if John Doe does match me and Dad both, we still need to confirm that it’s on the same segment AND it’s a legitimate match, not IBC. You can’t perform either of these functions at Ancestry, but you can elsewhere.

Ancestry WorkArounds

To obtain this functionality, people can upload their DNA files for free to both FamilyTreeDNA and MyHeritage, companies that do provide full shared DNA reporting (in common with) lists of ALL matches and do provide segment information with chromosome browsers. Furthermore, both provide triangulation in different ways.

Matching is free, but an inexpensive unlock is required at both vendors to access advanced tools such as Family Matching (bucketing) and triangulation at Family Tree DNA and phasing/triangulation at MyHeritage.

I wrote about Triangulation in Action at FamilyTreeDNA, here.

MyHeritage actually brackets triangulated segments for customers on their chromosome browser, including parents, so you get triangulation and parental phasing at the same time if you and your parent have both tested or uploaded your DNA file to MyHeritage. You can upload, for free, here.

In this example, my mother is matching to me in red on the entire length of chromosome 18, of course, and three other maternal cousins triangulate with me and mother inside the bracketed portion of chromosome 18. Please note that if any one of the people included in the chromosome browser comparison do not triangulate, no bracket is drawn around any others who do triangulate. It’s all or nothing. I remove people one by one to see if people triangulate – or build one by one with my mother included.

I wrote about Triangulation in Action at MyHeritage, here.

People can also upload to GEDmatch, a third-party site. While GEDmatch is less reliable for matching, you can adjust your search thresholds which you cannot do at other vendors. I don’t recommend routinely working below 7 cM. I occasionally use GEDmatch to see if a pedigree collapse segment has recombined below another vendor’s segment matching threshold.

Do NOT check the box to prevent hard breaks when selecting the One-to-One comparison. Checking that box allows GEDmatch to combine smaller matching segments into mega-segments for matching.

I wrote about Triangulation in Action at GEDmatch, here.

Transferring/Uploading Your DNA 

If you want to transfer your DNA to one of these vendors, you must download the DNA file from one vendor and upload it to another. That process does NOT remove your DNA file from the vendor where you tested, unless you select that option entirely separately.

I wrote full step-by-step transfer/upload instructions for each vendor, here.

Testing Close Relatives Is VERY Useful – Just Not for Triangulation

Of course, your best bet if you don’t have your parents available to test is to test as many of your grandparents, great-aunts/uncles, aunts, and uncles as possible. Test your siblings as well, because they will have inherited some of the same and some different segments of DNA from your parents – which means they carry different pieces of your ancestors’ DNA.

Just because close relatives don’t make good triangulation candidates doesn’t mean they aren’t valuable. Close relatives are golden because when they DO share a match with you, you know where to start looking for a common ancestor, even if your relative matches that person on a different segment than you do.

Close relatives are also important because they will share pieces of your common ancestor’s DNA that you don’t. Their matches can unlock the answers to your genealogy questions.

Ok, back to triangulation.

Triangulated Matches

A triangulated match is, of course, when three people all descended from a common ancestor and match each other on the same segment of DNA.

That means all three people’s DNA matches each other on that same segment, confirming that the match is not by chance, and that segment did descend from a common ancestor or ancestral couple.

But, is this always true? You’re going to hate this answer…

“It depends.”

You knew that was coming, didn’t you! 😊

It depends on the circumstances and relationships of the three people involved.

  • One of those three people can match the other two by chance, not by descent, especially if two of those people are close relatives to each other.
  • Identical by chance means that one of you didn’t inherit that DNA from one single parent. That zigzag phenomenon.
  • Furthermore, triangulated DNA is only valid as far back as the closest common ancestor of any two of the three people.

Let’s explore some examples.

Building Triangulation Evidence – Ingredients and a Recipe

The strongest case of triangulation is when:

  • You and at least two additional cousins match on the same segment AND
  • Descend through different children of the common ancestral couple

Let’s look at a valid triangulated match.

In this first example, the magenta segment of DNA is at least partially shared by four of the six cousins and triangulates to their common great-grandfather. Let’s say that these cousins then match with two other people descended from different children of their great-great-great-grandparents on this same segment. Then the entire triangulation group will have confirmed that segment’s origin and push the descent of that segment back another two generations.

These people all coalesce into one line with their common great-grandparents.

I’m only showing 3 generations in this triangulated match, but the concept is the same no matter how many generations you reach back in time. Although, over time, segments inherited from any specific ancestor become smaller and smaller until they are no longer passed to the next generation.

In this pedigree chart, we’re only tracking the magenta DNA which is passed generation to generation in descendants.

Eventually, of course, those segments become smaller and indistinguishable as they either aren’t passed on at all or drop below vendor matching thresholds.

This chart shows the average amount of DNA you would carry from each generational ancestor. You inherit half of each parent’s DNA, but back further than that, you don’t receive exactly half of any ancestor’s DNA in any generation. Larger segments are generally cut in two and passed on partially, but smaller segments are often either passed on whole or not at all.

On average, you’ll carry 7 cM of your eight-times-great-grandparents. In reality, you may carry more or you may not carry any – and you are unlikely to carry the same segment as any random other descendants but we know it happens and you’ll find them if enough (or the right) descendants test.

Putting this another way, if you divide all of your approximate 7000 cM of DNA into 7 cM segments of equal length – you’ll have 1000 7 cM segments. So will every other descendant of your eight-times-great-grandparent. You can see how small the chances are of you both inheriting that same exact 7 cM segment through ten inheritance/transmission events, each. Yet it does happen.

I have several triangulated matches with descendants of Charles Dodson and his wife, Anne through multiple of their 9 (or so) children, ten generations back in my tree. Those triangulated matches range from 7-38 cM. It’s possible that those three largest matches at 38 cM could be related through multiple ancestors because we all have holes in our trees – including Anne’s surname.

Click to enlarge image

It helps immensely that Charles Dodson had several children who were quite prolific as well.

Of course, the further back in time, the more “proof” is necessary to eliminate other unknown common ancestors. This is exactly why matching through different children is important for triangulation and ancestor confirmation.

The method we use to confirm the common ancestor is that all of the descendants who match the tester on the same segment all also match each other. This greatly reduces the chances that these people are matching by chance. The more people in the triangulation group, the stronger the evidence. Of course, parental phasing or cross-matching, where available is an added confirmation bonus.

In our magenta inheritance example, we saw that three of the males and one of the females from three different descendants of the great-grandparents all carry at least a portion of that magenta segment of great-grandpa’s DNA.

Now, let’s take a look at a different scenario.

Why can’t siblings or close relatives be used as two of the three people needed for triangulation?

Aunts and Uncles

We know that the best way to determine if a match is valid is by parental phasing – your match also matching to one of your parents.

If both parents aren’t available, looking for close family matches in common with your match is the next hint that genealogists seek.

Let’s say that you and your match both match your aunt or uncle in common or their children.

You and your aunts or uncles matching DNA only pushes your common ancestor back to your grandparents.

At that point, your match is in essence matching to a segment that belongs to your grandparents. Your matches’ DNA, or your grandparents’ DNA could have randomly recombined and you and your aunt/cousins could be matching that third person by chance.

Ok, then, what about siblings?

Siblings

The most recent common ancestor (MRCA) of you and someone who also matches your sibling is your parents. Therefore, you and your sibling actually only count as one “person” in this scenario. In essence, it’s the DNA of your parent(s) that is matching that third person, so it’s not true triangulation. It’s the same situation as above with aunts/uncles, except the common ancestor is closer than your grandparents.

The DNA of your parents could have recombined in both siblings to look like a match to your match’s family. Or vice versa. Remember Parental Cross-Matching.

If you and a sibling inherited EXACTLY the same segment of your Mom’s and Dad’s DNA, and you match someone by chance – that person will match your sibling by chance as well.

In this example, you can see that both siblings 1 and 2 inherited the exact same segments of DNA at the same locations from both of their parents.

Of course, they also inherited segments at different locations that we’re not looking at that won’t match exactly between siblings, unless they are identical twins. But in this case, the inherited segments of both siblings will match someone whose DNA randomly combined with green or magenta dots in these positions to match a cross-section of both parents.

How False Positives Work and How to Avoid Them

We saw in our first example, displayed again above, what a valid triangulated match looks like. Now let’s expand this view and take a look more specifically at how false positive matches occur.

On the left-hand (blue) side of this graphic, we see four siblings that descend through their father from Great-grandpa who contributed that large magenta segment of DNA. That segment becomes reduced in descendants in subsequent generations.

In downstream generations, we can see gold, white and green segments being added to the DNA inherited by the four children from their ancestor’s spouses. Dad’s DNA is shown on the left side of each child, and Mom’s on the right.

  • Blue Children 1 and 2 inherited the same segments of DNA from Mom and Dad. Magenta from Dad and green from Mom.
  • Blue Child 3 inherited two magenta segments from Dad in positions 1 and 2 and one gold segment from Dad in position 3. They inherited all white segments from Mom.
  • Blue Child 4 inherited all gold segments from Dad and all white segments from Mom.

The family on the blue left-hand side is NOT related to the pink family shown at right. That’s important to remember.

I’ve intentionally constructed this graphic so that you can see several identical by chance (IBC) matches.

Child 5, the first pink sibling carries a white segment in position 1 from Dad and gold segments in positions 2 and 3 from Dad. From Mom, they inherited a green segment in position 1, magenta in position 2 and green in position 3.

IBC Match 1 – Looking at the blue siblings, we see that based on the DNA inherited from Pink Child 5’s parents, Pink Child 5 matches Blue Child 4 with white, gold and gold in positions 1-3, even though they weren’t inherited from the same parent in Blue Child 4. I circled this match in blue.

IBC Match 2 – Pink Child 5 also matches Blue Children 1 and 2 (red circles) because Pink Child 5 has green, magenta, and green in positions 1-3 and so do Blue Children 1 and 2. However, Blue Children 1 and 2 inherited the green and magenta segments from Mom and Dad respectively, not just from one parent.

Pink Child 5 matches Blue Children 1, 2 and 4, but not because they match by descent, but because their DNA zigzags back and forth between the blue children’s DNA contributed by both parents.

Therefore, while Pink Child 5 matches three of the Blue Children, they do not match either parent of the Blue Children.

IBC Match 3 – Pink Child 6 matches Blue Child 3 with white, magenta and gold in positions 1-3 based on the same colors of dots in those same positions found in Blue Child 3 – but inherited both paternally and maternally.

You can see that if we had the four parents available to test, that none of the Pink Children would match either the Blue Children’s mother or father and none of the Blue Children would match either of the Pink Children’s mother or father.

This is why we can’t use either siblings or close family relatives for triangulation.

Distant Cousins Are Best for Triangulation & Here’s Why

When triangulating with 3 people, the most recent common ancestor (MRCA) intersection of the closest two people is the place at which triangulation turns into only two lines being compared and ceases being triangulation. Triangle means 3.

If siblings are 2 of the 3 matching people, then their parents are essentially being compared to the third person.

If you, your aunt/uncle, and a third person match, your grandparents are the place in your tree where three lines converge into two.

The same holds true if you’re matching against a sibling pair on your match’s side, or a match and their aunt/uncle, etc.

The further back in your tree you can push that MRCA intersection, the more your triangulated match provides confirming evidence of a common ancestor and that the match is valid and not caused by random recombination.

That’s exactly what the descendants of Charles Dodson have been able to do through triangulation with multiple descendants from several of his children.

It’s also worth mentioning at this point that the reason autosomal DNA testing uses hundreds/thousands of base pairs in a comparison window and not 3 or 6 dots like in my example is that the probability of longer segments of DNA simply randomly matching by chance is reduced with length and SNP density which is the number of SNP locations tested within that cM range.

Hence a 7 cM/500 SNP minimum is the combined rule of thumb. At that level, roughly half of your matches will be valid and half will be identical by chance unless you’re dealing with endogamy. Then, raise your threshold accordingly.

Ok, So Where are We? A Triangulation Checklist for You!

I know this has been a relatively long educational article, but it’s important to really understand that testing close relatives is VERY important, but also why we can’t effectively use them for triangulation.

Here’s a handy-dandy summary matching/triangulation checklist for you to use as you work through your matches.

  • You inherit half of each of your parents’ DNA. There is no other place for you to obtain or inherit your DNA. There is no DNA fairy sprinkling you with DNA from another source:)
  • DNA does NOT skip generations, although in occasional rare circumstances, it may appear that this happened. In this situation, it’s incumbent upon you, the genealogist, to PROVE that an exception has occurred if you really believe it has. Those circumstances might be pedigree collapse or perhaps imputation. You’ll need to compare matches at vendors who provide a chromosome browser, triangulation, and full shared match list information. Never assume that you are the exception without hard and fast proof. We all know about assume, right?
  • Your siblings inherit half of your parents’ DNA too, but not the same exact half of your parent’s DNA that you other siblings did (unless they are identical twins.) You may inherit the exact same DNA from either or both of your parents on certain segments.
  • Your matches may match your parents on different or an additional segment that you did not inherit.
  • Every segment has an individual history. Evaluate every matching segment separately. One matching segment with someone could be maternal, one paternal, and one identical by chance.
  • You can confirm matches as valid if your match matches one of your parents, and you match one of your match’s parents. Parental Phasing is when your match matches your parent. Parental Cross-Matching is when you both match one of each other’s parents. To be complete, both people who match each other need to match one of the parents of the other person. This rule still holds even if you have a known common ancestor. I can’t even begin to tell you how many times I’ve been fooled.
  • 15-20% (or more with endogamy) of your matches will be identical by chance because either your DNA or your match’s DNA aligns in such a way that while they match you, they don’t match either of your parents.
  • Your siblings, aunts, and uncles will often inherit the same DNA as you – which means that identical by chance matches will also match them. That’s why we don’t use close family members for triangulation. We do utilize close family members to generate common match hints. (Remember the 20 cM shared match caveat at Ancestry)
  • While your siblings, aunts, and uncles are too close to use for triangulation, they are wonderful to identify ancestral matches. Some of their matches will match you as well, and some will not because your close family members inherited segments of your ancestor’s DNA that you did not. Everyone should test their oldest family members.
  • Triangulate your close family member’s matches separately from your own to shed more light on your ancestors.
  • Endogamy may interfere with parental phasing, meaning you may match because you and/or your match may have inherited some of the same DNA segment(s) from both sides of your tree and/or more DNA than might otherwise be expected.
  • Pedigree collapse needs to be considered when using parental phasing, especially when the same ancestor appears on both sides of your family tree. You may share more DNA with a match than expected.
  • Conversely, with pedigree collapse, your match may not match your parents, or vice versa, if a segment happens to have recombined in you in a way that drops the matching segments of your parents beneath the vendor’s match threshold.
  • While you will match all of your second cousins, you will only match approximately 90% of your third cousins and proportionally fewer as your relationship reaches further back in time.
  • Not being a DNA match with someone does NOT mean you’re NOT related to them, unless of course, you’re a second cousin (2C) or closer. It simply means you don’t carry any common ancestral segments above vendor thresholds.
  • At 2C or closer, if you’re not a DNA match, other alternative situations need to be considered – including the transfer/upload of the wrong person’s DNA file.
  • Imputation, a scientific process required of vendors may interfere with matching, especially in more distant relatives who have tested on different platforms.
  • Imputation artifacts will be less obvious when people are more closely related, meaning closer relatives can be expected to match on more and larger segments and imputation errors make less difference.
  • Imputation will not cause close relatives, meaning 2C or closer, to not match each other.
  • In addition to not supporting segment matching information, Ancestry down-weights some segments, removes some matching DNA, and does not show shared matches below 20cM, causing some people to misinterpret their lack of common matches in various ways.
  • To resolve questions about matching issues at Ancestry, testers can transfer/upload their DNA files to MyHeritage, FamilyTreeDNA, and GEDmatch and look for consistent matches on the same segment. Start and end locations may vary to some extent between vendors, but the segment size should be basically in the same location and roughly the same size.
  • GEDmatch does not use imputation but allows larger non-matching segments to combine as a single segment which sometimes causes extremely “generous” matches. GEDmatch matching is less reliable than FamilyTreeDNA or MyHeritage, but you can adjust the matching thresholds.
  • The best situation for matching is for both people to test at the same vendor who supports and provides segment data and a chromosome browser such as 23andMe, FamilyTreeDNA, or MyHeritage.
  • Siblings cannot be used for triangulation because the most recent common ancestor (MRCA) between you and your siblings is your parents. Therefore, the “three” people in the triangulation group is reduced to two lines immediately.
  • Uncles and aunts should not be used for triangulation because the most recent common ancestors between you and your aunts and uncles are your grandparents.
  • Conversely, you should not consider triangulating with siblings and close family members of your matches as proof of an ancestral relationship.
  • A triangulation group of 3 people is only confirmation as far back as when two of those people’s lines converge and reach a common ancestor.
  • Identical by chance (IBC) matching occurs when DNA from the maternal and paternal sides are mixed positionally in the child to resemble a maternal/paternal side match with someone else.
  • Identical by chance DNA admixture (when compared to a match) could have occurred in your parents or grandparent’s generation, or earlier, so the further back in time that people in a triangulation group reach, the more reliable the triangulation group is likely to be.
  • The larger the segments and/or the triangulation group, the stronger the evidence for a specific confirmed common ancestor.
  • Early families with a very large number of descendants may have many matching and triangulated members, even 9 or 10 generations later.
  • While exactly 50% of each ancestor’s DNA is not passed in each generation, on average, you will carry 7 cM of your ancestors 10 generations back in your tree. However, you may carry more, or none.
  • The percentage of matching descendants decreases with each generation beyond great-grandparents.
  • The ideal situation for triangulation is a significant number of people, greater than three, who match on the same reasonably sized segment (7 cM/500 SNP or larger) and descend from the same ancestor (or ancestral couple) through different children whose spouses in descendant generations are not also related.
  • This means that tree completion is an important factor in match/triangulation reliability.
  • Triangulating through different children of the ancestral couple makes it significantly less likely that a different unknown common ancestor is contributing that segment of DNA – like an unknown wife in a descendant generation.

Whew!!!

The Bottom Line

Here’s the bottom line.

  1. Don’t use close relatives to triangulate.
  2. Use parents for Parental Phasing.
  3. Use Parental Cross-Matching when possible.
  4. Use close relatives to look for shared common matches that may lead to triangulation possibilities.
  5. Triangulate your close relatives’ DNA in addition to your own for bonus genealogical information. They will match people that you don’t.
  6. For the most reliable triangulation results, use the most distant relatives possible, descended through different children of the common ancestral couple.
  7. Keep this checklist of best practices, cautions, and caveats handy and check the list as necessary when evaluating the strength of any match or triangulation group. It serves as a good reminder for what to check if something seems “off” or unusual.

Feel free to share and pass this article (and checklist) on to your genealogy buddies and matches as you explain triangulation and collaborate on your genealogy.

Have fun!!!

_____________________________________________________________

Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Products and Services

Books

Genealogy Research