Hit a Genetic Genealogy Home Run Using Your Double-Sided Two-Faced Chromosomes While Avoiding Imposters

Do you want to hit a home run with your DNA test, but find yourself a mite bewildered?

Yep, those matches can be somewhat confusing – especially if you don’t understand what’s going on. Do you have a nagging feeling that you might be missing something?

I’m going to explain chromosome matching, and its big sister, triangulation, step by step to remove any confusion, to help you sort through your matches and avoid imposters.

This article is one of the most challenging I’ve ever written – in part because it’s a concept that I’m so familiar with but can be, and is, misinterpreted so easily. I see mistakes and confusion daily, which means that resulting conclusions stand a good chance of being wrong.

I’ve tried to simplify these concepts by giving you easy-to-use memory tools.

There are three key phrases to remember, as memory-joggers when you work through your matches using a chromosome browser: double-sided, two faces and imposter. While these are “cute,” they are also quite useful.

When you’re having a confusing moment, think back to these memory-jogging key words and walk yourself through your matches using these steps.

These three concepts are the foundation of understanding your matches, accurately, as they pertain to your genealogy. Please feel free to share, link or forward this article to your friends and especially your family members (including distant cousins) who work with genetic genealogy. 

Now, it’s time to enjoy your double-sided, two-faced chromosomes and avoid those imposters:)

Are you ready? Grab a nice cup of coffee or tea and learn how to hit home runs!

Double-Sided – Yes, Really

Your chromosomes really are double sided, and two-faced too – and that’s a good thing!

However, it’s initially confusing because when we view our matches in a chromosome browser, it looks like we only have one “bar” or chromosome and our matches from both our maternal and paternal sides are both shown on our one single bar.

How can this be? We all have two copies of chromosome 1, one from each parent.

Chromosome 1 match.png

This is my chromosome 1, with my match showing in blue when compared to my chromosome, in gray, as the background.

However, I don’t know if this blue person matches me on my mother’s or father’s chromosome 1, both of which I inherited. It could be either. Or neither – meaning the dreaded imposter – especially that small blue piece at left.

What you’re seeing above is in essence both “sides” of my chromosome number 1, blended together, in one bar. That’s what I mean by double-sided.

There’s no way to tell which side or match is maternal and which is paternal without additional information – and misunderstanding leads to misinterpreting results.

Let’s straighten this out and talk about what matches do and don’t mean – and why they can be perplexing. Oh, and how to discover those imposters!

Your Three Matches

Let’s say you have three matches.

At Family Tree DNA, the example chromosome browser I’m using, or at any vendor with a chromosome browser, you select your matches which are viewed against your chromosomes. Your chromosomes are always the background, meaning in this case, the grey background.

Chromosome 1-4.png

  • This is NOT three copies each of your chromosomes 1, 2, 3 and 4.
  • This is NOT displaying your maternal and paternal copies of each chromosome pictured.
  • We CANNOT tell anything from this image alone relative to maternal and paternal side matches.
  • This IS showing three individual people matching you on your chromosome 1 and the same three people matching you in the same order on every chromosome in the picture.

Let’s look at what this means and why we want to utilize a chromosome browser.

I selected three matches that I know are not all related through the same parent so I can demonstrate how confusing matches can be sorted out. Throughout this article, I’ve tried to explain each concept in at least two ways.

Please note that I’m using only chromsomes 1-4 as examples, not because they are any more, or less, important than the other chromosomes, but because showing all 22 would not add any benefit to the discussion. The X chromosome has a separate inheritance path and I wrote about that here.

Let’s start with a basic question.

Why Would I Want to Use a Chromosome Browser?

Genealogists view matches on chromosome browsers because:

  • We want to see where our matches match us on our chromosomes
  • We’d like to identify our common ancestor with our match
  • We want to assign a matching segment to a specific ancestor or ancestral line, which confirmed those ancestors as ours
  • When multiple people match us on the same location on the chromosome browser, that’s a hint telling us that we need to scrutinize those matches more closely to determine if those people match us on our maternal or paternal side which is the first step in assigning that segment to an ancestor

Once we accurately assign a segment to an ancestor, when anyone else matches us (and those other people) on that same segment, we know which ancestral line they match through – which is a great head start in terms of identifying our common ancestor with our new match.

That’s a genetic genealogy home run!

Home Runs 

There are four bases in a genetic genealogy home run.

  1. Determine whether you actually match someone on the same segment
  2. Which is the first step in determining that you match a group of people on the same segment
  3. And that you descend from a common ancestor
  4. The fourth step, or the home run, is to determine which ancestor you have in common, assigning that segment to that ancestor

If you can’t see segment information, you can’t use a chromosome browser and you can’t confirm the match on that segment, nor can you assign that segment to a particular ancestor, or ancestral couple.

The entire purpose of genealogy is to identify and confirm ancestors. Genetic genealogy confirms the paper trail and breaks down even more brick walls.

But before you can do that, you have to understand what matches mean and how to use them.

The first step is to understand that our chromosomes are double-sided and you can’ t see both of your chromosomes at once!

Double Sided – You Can’t See Both of Your Chromosomes at Once

The confusing part of the chromosome browser is that it can only “see” your two chromosomes blended as one. They are both there, but you just can’t see them separately.

Here’s the important concept:

You have 2 copies of chromosomes 1 through 22 – one copy that you received from your mother and one from your father, but you can’t “see” them separately.

When your DNA is sequenced, your DNA from your parents’ chromosomes emerges as if it has been through a blender. Your mother’s chromosome 1 and your father’s chromosome 1 are blended together. That means that without additional information, the vendor can’t tell which matches are from your father’s side and which are from your mother’s side – and neither can you.

All the vendor can tell is that someone matches you on the blended version of your parents. This isn’t a negative reflection on the vendors, it’s just how the science works.

Chromosome 1.png

Applying this to chromosome 1, above, means that each segment from each person, the blue person, the red person and the teal person might match you on either one of your chromosomes – the paternal chromosome or the maternal chromosome – but because the DNA of your mother and father are blended – there’s no way without additional information to sort your chromosome 1 into a maternal and paternal “side.”

Hence, you’re viewing “one” copy of your combined chromosomes above, but it’s actually “two-sided” with both maternal and paternal matches displayed in the chromosome browser.

Parent-Child Matches

Let’s explain this another way.

Chromosome parent.png

The example above shows one of my parents matching me. Don’t be deceived by the color blue which is selected randomly. It could be either parent. We don’t know.

You can see that I match my parent on the entire length of chromosome 1, but there is no way for me to tell if I’m looking at my mother’s match or my father’s match, because both of my parents (and my children) will match me on exactly the same locations (all of them) on my chromosome 1.

Chromosome parent child.png

In fact, here is a combination of my children and my parents matching me on my chromosome 1.

To sort out who is matching on paternal and maternal chromosomes, or the double sides, I need more information. Let’s look at how inheritance works.

Stay with me!

Inheritance Example

Let’s take a look at how inheritance works visually, using an example segment on chromosome 1.

Chromosome inheritance.png

In the example above:

  • The first column shows addresses 1-10 on chromosome 1. In this illustration, we are only looking at positions, chromosome locations or addresses 1-10, but real chromosomes have tens of thousands of addresses. Think of your chromosome as a street with the same house numbers on both sides. One side is Mom’s and one side is Dad’s, but you can’t tell which is which by looking at the house numbers because the house numbers are identical on both sides of the street.
  • The DNA pieces, or nucleotides (T, A, C or G,) that you received from your Mom are shown in the column labeled Mom #1, meaning we’re looking at your mother’s pink chromosome #1 at addresses 1-10. In our example she has all As that live on her side of the street at addresses 1-10.
  • The DNA pieces that you received from your Dad are shown in the blue column and are all Cs living on his side of the street in locations 1-10.

In other words, the values that live in the Mom and Dad locations on your chromosome streets are different. Two different faces.

However, all that the laboratory equipment can see is that there are two values at address 1, A and C, in no particular order. The lab can’t tell which nucleotide came from which parent or which side of the street they live on.

The DNA sequencer knows that it found two values at each address, meaning that there are two DNA strands, but the output is jumbled, as shown in the First and Second read columns. The machine knows that you have an A and C at the first address, and a C and A at the second address, but it can’t put the sequence of all As together and the sequence of all Cs together. What the sequencer sees is entirely unordered.

This happens because your maternal and paternal DNA is mixed together during the extraction process.

Chromosome actual

Click to enlarge image.

Looking at the portion of chromosome 1 where the blue and teal people both match you – your actual blended values are shown overlayed on that segment, above. We don’t know why the blue and the teal people are matching you. They could be matching because they have all As (maternal), all Cs (paternal) or some combination of As and Cs (a false positive match that is identical by chance.)

There are only two ways to reassemble your nucleotides (T, A, C, and G) in order and then to identify the sides as maternal and paternal – phasing and matching.

As you read this next section, it does NOT mean that you must have a parent for a chromosome browser to be useful – but it does mean you need to understand these concepts.

There are two types of phasing.

Parental Phasing

  • Parental Phasing is when your DNA is compared against that of one or both parents and sorted based on that comparison.

Chromosome inheritance actual.png

Parental phasing requires that at least one parent’s DNA is available, has been sequenced and is available for matching.

In our example, Dad’s first 10 locations (that you inherited) on chromosome 1 are shown, at left, with your two values shown as the first and second reads. One of your read values came from your father and the other one came from your mother. In this case, the Cs came from your father. (I’m using A and C as examples, but the values could just as easily be T or G or any combination.)

When parental phasing occurs, the DNA of one of your parents is compared to yours. In this case, your Dad gave you a C in locations 1-10.

Now, the vendor can look at your DNA and assign your DNA to one parent or the other. There can be some complicating factors, like if both your parents have the same nucleotides, but let’s keep our example simple.

In our example above, you can see that I’ve colored portions of the first and second strands blue to represent that the C value at that address can be assigned through parental phasing to your father.

Conversely, because your mother’s DNA is NOT available in our example, we can’t compare your DNA to hers, but all is not lost. Because we know which nucleotides came from your father, the remaining nucleotides had to come from your mother. Hence, the As remain after the Cs are assigned to your father and belong to your mother. These remaining nucleotides can logically be recombined into your mother’s DNA – because we’ve subtracted Dad’s DNA.

I’ve reassembled Mom, in pink, at right.

Statistical/Academic Phasing

  • A second type of phasing uses something referred to as statistical or academic phasing.

Statistical phasing is less successful because it uses statistical calculations based on reference populations. In other words, it uses a “most likely” scenario.

By studying reference populations, we know scientifically that, generally, for our example addresses 1-10, we either see all As or all Cs grouped together.

Based on this knowledge, the Cs can then logically be grouped together on one “side” and As grouped together on the other “side,” but we still have no way to know which side is maternal or paternal for you. We only know that normally, in a specific population, we see all As or all Cs. After assigning strings or groups of nucleotides together, the algorithm then attempts to see which groups are found together, thereby assigning genetic “sides.” Assigning the wrong groups to the wrong side sometimes happens using statistical phasing and is called strand swap.

Once the DNA is assigned to physical “sides” without a parent or matching, we still can’t identify which side is paternal and which is maternal for you.

Statistical or academic phasing isn’t always accurate, in part because of the differences found in various reference populations and resulting admixture. Sometimes segments don’t match well with any population. As more people test and more reference populations become available, statistical/academic phasing improves. 23andMe uses academic phasing for ethnicity, resulting in a strand swap error for me. Ancestry uses academic phasing before matching.

By comparison to statistical or academic phasing, parental phasing with either or both parents is highly accurate which is why we test our parents and grandparents whenever possible. Even if the vendor doesn’t use our parents’ results, we certainly can!

If someone matches you and your parent too, you know that match is from that parent’s side of your tree.

Matching

The second methodology to sort your DNA into maternal and paternal sides is matching, either with or without your parents.

Matching to multiple known relatives on specific segments assigns those segments of your DNA to the common ancestor of those individuals.

In other words, when I match my first cousin, and our genealogy indicates that we share grandparents – assuming we match on the appropriate amount of DNA for the expected relationship – that match goes a long way to confirming our common ancestor(s).

The closer the relationship, the more comfortable we can be with the confirmation. For example, if you match someone at a parental level, they must be either your biological mother, father or child.

While parent, sibling and close relationships are relatively obvious, more distant relationships are not and can occur though unknown or multiple ancestors. In those cases, we need multiple matches through different children of that ancestor to reasonably confirm ancestral descent.

Ok, but how do we do that? Let’s start with some basics that can be confusing.

What are we really seeing when we look at a chromosome browser?

The Grey/Opaque Background is Your Chromosome

It’s important to realize that you will see as many images of your chromosome(s) as people you have selected to match against.

This means that if you’ve selected 3 people to match against your chromosomes, then you’ll see three images of your chromosome 1, three images of your chromosome 2, three images of your chromosome 3, three images of your chromosome 4, and so forth.

Remember, chromosomes are double-sided, so you don’t know whether these are maternal or paternal matches (or imposters.)

In the illustration below, I’ve selected three people to match against my chromosomes in the chromosome browser. One person is shown as a blue match, one as a red match, and one as a teal match. Where these three people match me on each chromosome is shown by the colored segments on the three separate images.

Chromosome 1.png

My chromosome 1 is shown above. These images are simply three people matching to my chromosome 1, stacked on top of each other, like cordwood.

The first image is for the blue person. The second image is for the red person. The third image is for the teal person.

If I selected another person, they would be assigned a different color (by the system) and a fourth stacked image would occur.

These stacked images of your chromosomes are NOT inherently maternal or paternal.

In other words, the blue person could match me maternally and the red person paternally, or any combination of maternal and paternal. Colors are not relevant – in other words colors are system assigned randomly.

Notice that portions of the blue and teal matches overlap at some of the same locations/addresses, which is immediately visible when using a chromosome browser. These areas of common matching are of particular interest.

Let’s look closer at how chromosome browser matching works.

What about those colorful bars?

Chromosome Browser Matching

When you look at your chromosome browser matches, you may see colored bars on several chromosomes. In the display for each chromosome, the same color will always be shown in the same order. Most people, unless very close relatives, won’t match you on every chromosome.

Below, we’re looking at three individuals matching on my chromosomes 1, 2, 3 and 4.

Chromosome browser.png

The blue person will be shown in location A on every chromosome at the top. You can see that the blue person does not match me on chromosome 2 but does match me on chromosomes 1, 3 and 4.

The red person will always be shown in the second position, B, on each chromosome. The red person does not match me on chromosomes 2 or 4.

The aqua person will always be shown in position C on each chromosome. The aqua person matches me on at least a small segment of chromosomes 1-4.

When you close the browser and select different people to match, the colors will change and the stacking order perhaps, but each person selected will always be consistently displayed in the same position on all of your chromosomes each time you view.

The Same Address – Stacked Matches

In the example above, we can see that several locations show stacked segments in the same location on the browser.

Chromosome browser locations.png

This means that on chromosome 1, the blue and green person both match me on at least part of the same addresses – the areas that overlap fully. Remember, we don’t know if that means the maternal side or the paternal side of the street. Each match could match on the same or different sides.

Said another way, blue could be maternal and teal could be paternal (or vice versa,) or both could be maternal or paternal. One or the other or both could be imposters, although with large segments that’s very unlikely.

On chromosome 4, blue and teal both match me on two common locations, but the teal person extends beyond the length of the matching blue segments.

Chromosome 3 is different because all three people match me at the same address. Even though the red and teal matching segments are longer, the shared portion of the segment between all three people, the length of the blue segment, is significant.

The fact that the stacked matches are in the same places on the chromosomes, directly above/below each other, DOES NOT mean the matches also match each other.

The only way to know whether these matches are both on one side of my tree is whether or not they match each other. Do they look the same or different? One face or two? We can’t tell from this view alone.

We need to evaluate!

Two Faces – Matching Can be Deceptive!

What do these matches mean? Let’s ask and answer a few questions.

  • Does a stacked match mean that one of these people match on my mother’s side and one on my father’s side?

They might, but stacked matches don’t MEAN that.

If one match is maternal, and one is paternal, they still appear at the same location on your chromosome browser because Mom and Dad each have a side of the street, meaning a chromosome that you inherited.

Remember in our example that even though they have the same street address, Dad has blue Cs and Mom has pink As living at that location. In other words, their faces look different. So unless Mom and Dad have the same DNA on that entire segment of addresses, 1-10, Mom and Dad won’t match each other.

Therefore, my maternal and paternal matches won’t match each other either on that segment either, unless:

  1. They are related to me through both of my parents and on that specific location.
  2. My mother and father are related to each other and their DNA is the same on that segment.
  3. There is significant endogamy that causes my parents to share DNA segments from their more distant ancestors, even though they are not related in the past few generations.
  4. The segments are small (segments less than 7cM are false matches roughly 50% of the time) and therefore the match is simply identical by chance. I wrote about that here. The chart showing valid cM match percentages is shown here, but to summarize, 7-8 cMs are valid roughly 46% of the time, 8-9 cM roughly 66%, 9-10 cM roughly 91%, 10-11 cM roughly 95, but 100 is not reached until about 20 cM and I have seen a few exceptions above that, especially when imputation is involved.

Chromosome inheritance match.png

In this inheritance example, we see that pink Match #1 is from Mom’s side and matches the DNA I inherited from pink Mom. Blue Match #2 is from Dad’s side and matches the DNA I inherited from blue Dad. But as you can see, Match #1 and Match #2 do not match each other.

Therefore, the address is only half the story (double-sided.)

What lives at the address is the other half. Mom and Dad have two separate faces!

Chromosome actual overlay

Click to enlarge image

Looking at our example of what our DNA in parental order really looks like on chromosome 1, we see that the blue person actually matches on my maternal side with all As, and the teal person on the paternal side with all Cs.

  • Does a stacked match on the chromosome browser mean that two people match each other?

Sometimes it happens, but not necessarily, as shown in our example above. The blue and teal person would not match each other. Remember, addresses (the street is double-sided) but the nucleotides that live at that address tell the real story. Think two different looking faces, Mom’s and Dad’s, peering out those windows.

If stacked matches match each other too – then they match me on the same parental side. If they don’t match each other, don’t be deceived just because they live at the same address. Remember – Mom’s and Dad’s two faces look different.

For example, if both the blue and teal person match me maternally, with all As, they would also match each other. The addresses match and the values that live at the address match too. They look exactly the same – so they both match me on either my maternal or paternal side – but it’s up to me to figure out which is which using genealogy.

Chromosome actual maternal.png

Click to enlarge image

When my matches do match each other on this segment, plus match me of course, it’s called triangulation.

Triangulation – Think of 3

If my two matches match each other on this segment, in addition to me, it’s called triangulation which is genealogically significant, assuming:

  1. That the triangulated people are not closely related. Triangulation with two siblings, for example, isn’t terribly significant because the common ancestor is only their parents. Same situation with a child and a parent.
  2. The triangulated segments are not small. Triangulation, like matching, on small segments can happen by chance.
  3. Enough people triangulate on the same segment that descends from a common ancestor to confirm the validity of the common ancestor’s identity, also confirming that the match is identical by descent, not identical by chance.

Chromosome inheritance triangulation.png

The key to determining whether my two matches both match me on my maternal side (above) or paternal side is whether they also match each other.

If so, assuming all three of the conditions above are true, we triangulate.

Next, let’s look at a three-person match on the same segment and how to determine if they triangulate.

Three Way Matching and Identifying Imposters

Chromosome 3 in our example is slightly different, because all three people match me on at least a portion of that segment, meaning at the same address. The red and teal segments line up directly under the blue segment – so the portion that I can potentially match identically to all 3 people is the length of the blue segment. It’s easy to get excited, but don’t get excited quite yet.

Chromosome 3 way match.png

Given that three people match me on the same street address/location, one of the following three situations must be true:

  • Situation 1- All three people match each other in addition to me, on that same segment, which means that all three of them match me on either the maternal or paternal side. This confirms that we are related on the same side, but not how or which side.

Chromosome paternal.png

In order to determine which side, maternal or paternal, I need to look at their and my genealogy. The blue arrows in these examples mean that I’ve determined these matches to all be on my father’s side utilizing a combination of genealogy plus DNA matching. If your parent is alive, this part is easy. If not, you’ll need to utilize common matching and/or triangulation with known relatives.

  • Situation 2 – Of these three people, Cheryl, the blue bar on top, matches me but does not match the other two. Charlene and David, the red and teal, match each other, plus me, but not Cheryl.

Chromosome maternal paternal.png

This means that at least either my maternal or paternal side is represented, given that Charlene and David also match each other. Until I can look at the identity of who matches, or their genealogy, I can’t tell which person or people descend from which side.

In this case, I’ve determined that Cheryl, my first cousin, with the pink arrow matches me on Mom’s side and Charlene and David, with the blue arrows, match me on Dad’s side. So both my maternal and paternal sides are represented – my maternal side with the pink arrow as well as my father’s side with the blue arrows.

If Cheryl was a more distant match, I would need additional triangulated matches to family members to confirm her match as legitimate and not a false positive or identical by chance.

  • Situation 3 – Of the three people, all three match me at the same addresses, but none of the three people match each other. How is this even possible?

Chromosome identical by chance.png

This situation seems very counter-intuitive since I have only 2 chromosomes, one from Mom and one from Dad – 2 sidesof the street. It is confusing until you realize that one match (Cheryl and me, pink arrow) would be maternal, one would be paternal (Charlene and me, blue arrow) and the third (David and me, red arrows) would have DNA that bounces back and forth between my maternal and paternal sides, meaning the match with David is identical by chance (IBC.)

This means the third person, David, would match me, but not the people that are actually maternal and paternal matches. Let’s take a look at how this works

Chromosome maternal paternal IBC.png

The addresses are the same, but the values that live at the addresses are not in this third scenario.

Maternal pink Match #1 is Cheryl, paternal blue Match #2 is Charlene.

In this example, Match #3, David, matches me because he has pink and blue at the same addresses that Mom and Dad have pink and blue, but he doesn’t have all pink (Mom) nor all blue (Dad), so he does NOT match either Cheryl or Charlene. This means that he is not a valid genealogical match – but is instead what is known as a false positive – identical by chance, not by descent. In essence, a wily genetic imposter waiting to fool unwary genealogists!

In his case, David is literally “two-faced” with parts of both values that live in the maternal house and the paternal house at those addresses. He is a “two-faced imposter” because he has elements of both but isn’t either maternal or paternal.

This is the perfect example of why matching and triangulating to known and confirmed family members is critical.

All three people, Cheryl, Charlene and David match me (double sided chromosomes), but none of them match each other (two legitimate faces – one from each parent’s side plus one imposter that doesn’t match either the legitimate maternal or paternal relatives on that segment.)

Remember Three Things

  1. Double-Sided – Mom and Dad both have the same addresses on both sides of each chromosome street.
  2. Two Legitimate Faces – The DNA values, nucleotides, will have a unique pattern for both your Mom and Dad (unless they are endogamous or related) and therefore, there are two legitimate matching patterns on each chromsome – one for Mom and one for Dad. Two legitimate and different faces peering out of the houses on Mom’s side and Dad’s side of the street.
  3. Two-Faced Imposters – those identical by chance matches which zig-zag back and forth between Mom and Dad’s DNA at any given address (segment), don’t match confirmed maternal and paternal relatives on the same segment, and are confusing imposters.

Are you ready to hit your home run?

What’s Next?

Now that we understand how matching and triangulation works and why, let’s put this to work at the vendors. Join me for my article in a few days, Triangulation in Action at Family Tree DNA, MyHeritage, 23andMe and GedMatch.

We will step through how triangulation works at each vendor. You’ll have matches at each vendor that you don’ t have elsewhere. If you haven’t transferred your DNA file yet, you still have time with the step by step instructions below:

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Durham DNA – 10 Things I Learned Despite No Y DNA Matches, 52 Ancestors #167

First and foremost, I want to thank my Durham cousin for stepping up and taking both the Y DNA and Family Finder tests to represent the Thomas Durham Sr. line of Richmond County, Virginia.

My cousin descends from Thomas Durham Jr., son of Thomas Durham Sr. and wife, Dorothy. Thomas Durham Sr.’s parents are unknown, which is part of why we needed a Durham male to take the Y DNA test.

What Might a Y DNA Test Tell Us?

A Y DNA test would tell us if our Durham line matches any other male Durham who had tested. In addition, if we were be lucky enough to find a match to a Durham who knew their ancestor’s location in the UK, where we presume our Durham family originated, we would have significant clues as to where to look for early records of our line.

What Did the Y DNA Test Tell Us?

The Y DNA test told us that our Durham cousin matches exactly no one, at any level, on his Y DNA test.

What, you might be asking? Is that even possible?

Yes, it is. I write the Personalized DNA Reports for customers, and I do still see people with absolutely no matches from time to time. When I drop their DNA results into a frequency chart and look at the percentage of people with their values in their haplogroup at each location, it’s usually immediately obvious why they have no matches. They have several mutations that are quite rare and those, cumulatively, keep them from matching others. In order to be considered at match, you must match other individuals at a minimum number of markers at each panel level, meaning 23, 15, 37, 67 and 111.

Now, this isn’t all bad news. It’s actually good news – because with rare markers, it’s very unlikely that you’re going to match a group of men by chance or just because your ancestor hundreds or thousands of years ago was very successfully prolific. I see some men in haplogroup R that have hundreds and thousands of matches, especially at 12 and 25 markers, so while no match is frustrating, it’s not a disaster because one day, our Durham line WILL have a match and it will be relevant.

The Durham Project

Being a curious skeptic, I visited the Durham DNA project and checked to be sure that my cousin’s DNA really didn’t match anyone, even distantly. I wanted to be sure that my cousins’ results weren’t “just one” marker difference in terms of allowable genetic distance to be considered a match.

Please note that you can click on any graphic to enlarge.

My Durham cousin’s haplogroup is I-M223.

There are no other people in the I-M223 Durham group. Checking my cousin’s markers, they are quite distant as well, so no Durham matches, even at a distance.

Now, here’s some good news.

Looking at the project’s Patriarch’s page, we can see which lines we don’t match.

We don’t match any of these lines, including the two that are from England. Two lines down, several to go.

Autosomal DNA

About this time, I began to have this nagging thought. What if my cousin’s Durham line isn’t really the right Durham line? What if the genealogy was wrong? What if the genealogy was right, but there was an adoption someplace in the 9 generations between Thomas Durham Sr. and my cousin? Those “what-ifs” will kill you, being a genetic genealogist.

So, I decided to see if my cousin’s autosomal results matched any of those known to be descended from the Durham-Dodson line. Thomas Durham Sr.’s daughter, Mary Durham, married Thomas Dodson. This line was prolific, having many children, so surely, if my Durham cousin descends from Thomas Durham’s son, Thomas Jr., some of the Dodson/Durham descendants from Thomas Durham Sr.’s other child, Mary, will match him, hopefully on a common segment.

Perusing my Durham cousin’s Family Finder DNA matches, and searching by Dodson, I found 27 matches.

I checked the Ancestry Surnames of those matches, and yes, 5 included both Dodson and Durham.

Checking pedigree charts, I verified that indeed, these people descended from the same Dodson/Durham lineage.

Thankfully, 4 of 5 matches had pedigree charts uploaded.

I selected those 5 people and viewed their results in a chromosome browser, compared to my Durham cousin.

As you can see, there are two sets of results where more than one person matches my Durham cousin on the same segment.

On chromosome 9, the green and orange person match the Durham cousin on segments of 12.36 cM

On chromosome 21, the pink and yellow person match my Durham cousin with a segment of 8.83 cM.

Now, as we know, just because two people match someone on the same segment does NOT automatically means that they match each other. They could be matching you on different sides of your DNA – one on your mother’s side and one on your father’s side

Next, I utilized the matrix tool to see if these individuals also match each other.

This matrix shows exactly what we would expect.

The bottom person, Gwen, matches the Durham cousin on chromosome 1 and doesn’t match any of the other cousins on that segment. The matrix tells us that Gwen doesn’t match either of these other two cousins either.

The matrix tells us that both kits managed by Ted match each other. This could be one person who uploaded two kits, but the photos are different. These two kits are the chromosome 9 match.

Then, the matrix tells us that Odis and Diana match each other, and sure enough, those are our chromosome 21 matches.

While this alone does not prove triangulation, because we can’t confirm that indeed, Gwen and Odis do match each other on this segment, at least not without asking them, my experience suggests that it would be a rare occasion indeed if this was not a triangulated match – indicating a common ancestor.

Triangulated matches minimally require:

  • Three people or more who are not close relatives
  • All matching each other on a common reasonably sized segment
  • Common ancestors

We Can Do More

We aren’t done yet. Next we can look to see which of these matches might ALSO match someone else in common with our Durham cousin.

Take each match, one at a time, and do an In Common With (ICW) search with them. You can read about the various options for in common with searching in the article, Increasing “In Common With” (ICW) Functionality at Family Tree DNA.

First, I just searched in common with the Durham surname, and none of these folks matched anyone else on the Durham surname match list.

To do this, search for Durham, select a match, then click on ICW, leaving Durham in the search box.

Second, I searched by selecting the match by checking the little checkbox by their name, but removed Durham from the search box so that I could see if my Durham cousin matched this person in common with anyone else on his match list, regardless of their ancestral surname.

As you would expect, many of the people returned on the ICW match list don’t have ancestral surnames listed.

When you have a few people to compare, the chromosome browser is wonderful, but for a lot of comparisons, there’s an easier way.

If I were my Durham cousin, I’d download my full list of matches with chromosome segments and see who matches me on those Durham/Dodson segments on chromosomes 9 and 21.  I would then look to see if they have pedigree charts uploaded, or contact them asking about genealogy.

You can download all of your match results at the top of your chromosome browser by clicking “download all matches.”

This enables you to sort the resulting spreadsheet by segment number and chromosome. You can read more about that in the article, Concepts – Sorting Spreadsheets for Autosomal DNA.

Of course, that’s how genetic genealogy addicts are born. You’re never really done.

What Did We Learn?

What did we learn, even though we had no Y matches, and are understandably disappointed.

  • We learned that the Durham Y DNA is quite rare.
  • We learned that the Y haplogroup is I-M223, found in the following locations, according to the SNP map tool at Family Tree DNA.

  • We can, if we wish, order additional SNP testing or the Big Y test to learn more about the ancestral origins of this line – even though we don’t have any STR matches today. We will very likely have Big Y matches because the Big Y test reaches further back in time, generally before the advent of surnames. Generally, the further down the SNP tree, the smaller the geographic range of where the SNP is found – because it’s closer in time.
  • We eliminated 18 different Durham groups, based on the Durham DNA project, that we now know aren’t our ancestors, including several in the US and some in Europe.
  • We confirmed that this Durham line is the Durham line that also married into the Dodson line- so the Durham Y DNA has not undergone an NPE or undocumented adoption between my cousin and our common ancestor. If there was an NPE or misattributed parentage in this line, then my Durham cousin would NOT match people from Thomas Durham’s daughter’s line – unless they all shared a different common line with my Durham cousin AND on the same segments.
  • We have confirmed some Durham DNA autosomal segments – passed all the way down from Thomas Durham to his descendants today.
  • We can tell our Durham/Dodson lineage cousins that certain segments of their Dodson DNA are actually Durham DNA. How cool is that?
  • Our Durham cousin now knows that those same segments are Durham DNA and not introduced in generations since by other lines.
  • Our Durham cousin can continue to identify the DNA of his various lineages by utilizing matching, trees, the matrix and the spreadsheet.
  • We’re not dead in the water in terms of Durham Y matches. We just have to be patient and wait.

Not All is Lost

I know it’s initially very discouraging to see that someone has no Y matches, but truly, all is not lost.

Not only is all not lost, we’ve learned a great deal. Y DNA testing in conjunction with autosomal is an extremely powerful tool.

Not to mention that our Durham cousin’s Y DNA results are now out their fishing, 24X7, 365 days per year, just waiting for that Durham man from some small village in the UK to test – and match. Yep, that’s my dream and I know, I just know, it will happen one day.

Thank you again, to my Durham cousin. When men Y DNA test, they not only serve their own interests, but those of others who descend from the same ancestral surname line.

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Using Spousal Surnames and DNA to Unravel Male Lines

When Y DNA matching at Family Tree DNA, it’s not uncommon for men to match other males of the same surname who share the same ancestor. In fact, that’s what we hope for, fervently!

However, if you’re stuck downstream, you may need to figure out which of several male children you descend from.

If you’re staring at a brick wall working yourselves back in time, you may need to try working forward, utilizing various types of information, including wives’ surnames.

For all intents and purposes, this is my Vannoy line, in Wilkes County, NC, so let’s use it as an example, because it embodies both the promise and the peril of this approach.

So, there you sit, disconnected from the Vannoy line. That little yellow box is just so depressing. So close, but yet so far. And yes, we’ve already exhausted the available paper trail records, years ago.

We know the lineage back through Elijah Vannoy, who was born between 1784-1786 in Wilkes County, or vicinity. We know my Vannoy cousin Y DNA matches with other men from the Vannoy line upstream of John Francis Vannoy, the known father of four sons in Wilkes County, NC and the first (and only) Vannoy to move from New Jersey to that part of North Carolina.

Therefore, we know who the candidates are to be Elijah’s father, but the connection in the yellow box is missing. Many Wilkes County records have gone missing over the years and births were not recorded in that timeframe.  The records from neighboring Ashe County where Daniel Vannoy lived burned during the Civil War, although some records did survive. In other words, the records are rather like Swiss cheese. Welcome to genealogy in the south.

Which of John Francis Vannoy’s four sons does Elijah descend from?

Let’s see what we can discover.

Contact Matches and Ask for Help

The first thing I would do is to ask for assistance from your surname matches.

Let’s say that you match a known descendant of each of these four men, meaning each of John Francis Vannoy’s sons. Ask each person if they know where the male Vannoy descendants of each son went along with any documentation they might have. If your ancestor, Elijah in this case, is not found in the same location as the sons, geography may be your friend.

In our case, we know that Francis Vannoy migrated to Knox County, Kentucky, but that was after he signed for his daughter’s marriage in Wilkes Co., NC in 1812. It was also about this time that Elijah Vannoy migrated to Claiborne County, TN, in the same direction, but not the same location. The two locations are an hour away by car today, separated by mountains and the Cumberland Gap, a nontrivial barrier.

We also know that Nathaniel Vannoy left a Bible that did not list Elijah as one of his children, but with a gap large enough to possibly encompass another child.  If you’re thinking to yourself, “Who would leave a child’s birth out of the Bible?,” I though the same thing until I encountered it myself personally in another line.  However, the Bible record does make Nathaniel a less likely father candidate, despite a persistent rumor that Nathaniel was Elijah’s father.

Our only other clues are some tax records recording the number of children in the household of various ages, but none are conclusive. None of these men had wills.

Y DNA Genetic Distance

Your Y DNA matches will show how many mutations you are from them at a particular marker level.

Please note that you can click to enlarge any graphic.

The number of mutations between two men is called the genetic distance.

The rule of thumb is that the more mutations, the further back in time the common ancestor. The problem is, the rule of thumb doesn’t always work. DNA mutates when it darned well pleases, not on any clock that we can measure with that degree of accuracy – at least not accurately enough to tell which of 4 sons a man descends from – unless that line has incurred a defining mutation between the ancestor and the current generation. We call those line marker mutations. To determine the mutation history, you need multiple men from each line to have tested.

You can read more about Y DNA matching in the article, Concepts – Y DNA Matching and Connecting with your Paternal Ancestor.

Check Autosomal DNA Tests

Next, check to see if your Y DNA matches from all Vannoy lines have also taken the autosomal Family Finder test, noted as FF, which shows matches from all ancestral lines, not just the paternal line.

You can see in the match list above that not many have taken the Family Finder test. Ask if they would be willing to upgrade. Be prepared to pay if need be – because you are, after all, the one with the “problem” to solve.

Generally, I simply offer to pay. It’s well worth it to me, and given that paper records don’t exist to answer the question – a DNA test under $100 is cheap. Right now, Family Finder tests are on sale for $69 until the end of the month.

Check for Intermarriage

While you’re waiting for autosomal DNA results, check the pedigrees for all for lines involved to see if you are otherwise related to these men or their wives.

For example, in Andrew Vannoy’s wife’s line and Elijah Vannoy’s wife’s line, we have a common ancestor. George Shepherd and Elizabeth Mary Angelique Daye are common to both lines, and John Shepherd’s wife is unknown, so we have one known problem and one unknown surname.

You can tell already that this could be messy, because we can’t really use Andrew Vannoy’s wife’s line to search for matches because Elijah’s line is likely to match through Andrew’s wife since Susannah Shepherd and Lois McNiel share a common lineage. Rats!

We’ll mark these in red to remind ourselves.

Check Advanced Matching

Family Tree DNA provides a wonderful tool that allows you to compare matches of different kinds of DNA. The Advanced Matching tab is found under “Tools and Apps” under the myFTDNA tab at the upper left.

In this case, I’m going to use the Advanced Match feature to see which of my Vannoy cousin’s Y matches at 37 markers, within the Vannoy DNA project, also match him autosomally.

This report is particularly nice, because it shows number of Y mutations, often indicating distance to a common ancestor, as well as the estimated autosomal relationship range.

You can see in this case that the first Vannoy male, “A,” is a close match both on Y DNA and autosomally, with 1 mutation difference and falling in the 2nd to 4th cousin range, as compared to the second Vannoy male, “D,” who is 3 mutations different and falls into the 4th to remote cousin range.

Not every Vannoy male may have joined the Vannoy project, so you’ll want to run this report a second time, replacing the Vannoy project search criteria with “The Entire Database.”

Unfortunately, not everyone that I need has taken the Family Finder test, so I’ll be contacting a few men, asking if I can sponsor their upgrades.

Let’s move on to our next tactic, using the wives’ surnames.

Search Utilizing the Wife’s Surname

We already know that we can’t rely on the Shepherd surname, so we’ll have to utilize the surnames of the other three wives:

  • Millicent Henderson – parents Thomas Henderson born circa 1730 Virginia, died 1806 Laurens, SC, wife Frances, surname unknown
  • Elizabeth Ray (Raye) – parents William Ray born circa 1725/1730 Herdford, England, died 1783 Wilkes Co., NC (the portion now Ashe Co.,) wife Elizabeth Gordon born circa 1783 Amherst Co., VA and died 1804 Surry Co., NC
  • Sarah Hickerson – parents Charles Hickerson born circa 1725 Stafford Co., VA, died before 1793 Wilkes Co., NC, wife Mary Lytle

Utilizing the Family Finder match search function, I’m going to search for matches that include the wives surnames, but are NOT descended from the Vannoy line.

Hickerson produced no non-Vannoy matches utilizing the matches of my first Vannoy cousin, but Henderson is another matter entirely.

Since the Henderson line would be on my cousin’s father’s side, the matches that are most relevant are the ones phased to his paternal line, those showing the blue person icon.

The surname that you have entered as the search criteria will show as blue in the Ancestral Surname list, at far right, and other matching surnames will show as black. Please note that this includes surnames from ANY person in the match’s tree if they have uploaded a Gedcom file, not just surnames of direct ancestral lines. Therefore, if the match has a tree, it’s important to click on the pedigree icon and search for the surname in question. Don’t assume.

Altogether, there are 76 Henderson matches, of which 17 are phased to his paternal line. You’ll need to review each one of at least the 17. Personally, I would painstakingly review each one of the 76. You never know where a shred of information will be found.

Please note, finding a match with a common surname DOES NOT MEAN THAT YOU MATCH THIS PERSON THROUGH THAT SURNAME. Even finding a person with a common ancestor doesn’t mean that you both descend from that ancestor. You may have a second common ancestor. It means that you have more work to do, as proof, but it’s the beginning you need.

Of course, the first thing we need to do is eliminate any matches who also descend from a Vannoy, because there is no way to know if the matching DNA is through the Vannoy or Henderson lines. However, first, take note of how that person descends from the Vannoy line.

You can see your matches entire surname list by clicking on their profile picture.

The surname, Ray, is more difficult, because the search for Ray also returns names like Bray and Wray, as well as Ray.

But Wait – There’s a Happy Ending!

If you’re thinking, “this is a lot of work,” yes, it is.

Yes, you are absolutely going to do the genealogy of the wives’ lines so you can recognize if and how your matches might connect.

I enter the wives’ lines into my genealogy software and then I search for the ancestors found in my matches trees to see if they descend from that line.

One tip to make this easier is to test multiple people in the same line – regardless of whether they are males or carry the desired surname. They simply need to be descendants – that’s the beauty of autosomal DNA and why I carry kits with me wherever I go.  And yes, I’m really serious about that!

When you have multiple testers from the same line, you can utilize each test independently, searching for each surname in the Family Finder results.  Then, from the surname match list, select a sibling or other close relative with that same surname in their list, then choose the ICW feature. This allows you to see who both of those people match who also carries the Henderson surname in their surname list.

Not successful with that initial cousin’s match results – like I wasn’t with Hickerson?

Rinse and repeat, with every single person who you can find who has descended from the line in question. I started the process over again with a second cousin and a Hickerson search.

About the time you’re getting really, really tired of looking at all of those trees, extending the branches of other people’s lines, and are about to give up and go to bed because it’s 3 AM and you’re discouraged, you see something like this:

Yep, it’s good old Charles Hickerson and Mary Lytle.  I could hardly believe my eyes!!! This Hickerson match to a cousin in my Vannoy line descends from Charles Hickerson’s son, Joshua.

All of a sudden…it’s all worthwhile! Your fatigue is gone, replaced by adrenalin and you couldn’t sleep now if your life depended on it!

Using the ICW (in common with feature) to find additional known cousins who match the person with Charles Hickerson and Mary Lytle in their tree, I found a total of three Vannoy cousins with significant matches.

Using the chromosome browser to compare, I’ve confirmed that one segment is a triangulated match of 12.69 cM (blue) on chromosome 2.

You can read more about triangulation in the article, Concepts – Why Genetic Genealogy and Triangulation? as well as the article, Concepts – Match Groups and Triangulation.

Do I wish I had more than three people in my triangulation group? Yes, of course, but with a match of this size triangulated between cousins and a Hickerson descendant who is a 30 year genealogist, sporting a relatively complete tree and no other common lines, it’s a great place to begin digging deeper! This isn’t the end, but a new beginning!

After obsessively digging through the matches of every Elijah Vannoy descended cousin I can find (sleep is overrated anyway) and whose account I have access to, I have now discovered matches with four additional people who have no other common lines with the Vannoy cousins and who descend from Charles Hickerson and Mary Lytle through sons David and Joseph Hickerson. I can’t tell if they triangulate without access to accounts that I don’t have access to, so I’ve sent e-mails requesting additional information.

WooHoo Happy Day!!! There’s a really big crack in the brick wall and I’ve just witnessed the sunrise of a beautiful, amazing day.

I think Elijah’s parents are…drum roll…Daniel Vannoy and Sarah Hickerson!

Which walls do you need to fall and how can you use this technique?

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Disclosure

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

Thank you so much.

DNA Purchases and Free Transfers

Genealogy Services

Genealogy Research