MyHeritage LIVE Conference Day 2 – The Science Behind DNA Matching    

The MyHeritage LIVE Oslo conference is but a fond memory now, and I would count it as a resounding success.

Perhaps one of the reasons I enjoyed it so much is the scientific aspect and because the content is very focused on a topic I enjoy without being the size and complexity of Rootstech. The smaller, more intimate venue also provides access to the “right” people as well as the ability to meet other attendees and not be overwhelmed by the sheer size.

Here are some stats:

  • 401 registered guests
  • 28 countries represented including distant places like Australia and South America
  • More than 20 speakers plus the hands-on workshops where specialist teams worked with students
  • 38 sessions and workshops, plus the party
  • 60,000 livestream participants, in spite of the time differences around the world

I was blown away by the number of livestream attendees.

I don’t know what criteria Gilad Japhet will be using to determine “success” but I can’t imagine this conference being judged as anything but.

Let’s take a look at the second day. I spent part of the time talking to people and drifting in and out of the rear of several sessions for a few minutes. I meant to visit some of the workshops, but there was just too much good, distracting content elsewhere.

I began Sunday in Mike Mansfield’s presentation about SuperSearch. Yes, I really did attend a few sessions not about DNA, but my favorite was the session on Improved DNA Matching.

Improved DNA Matching

I’m sure it won’t surprise any of my readers that my favorite presentations were about the actual science of genetic genealogy.

Consumers don’t really need to understand the science behind autosomal results to reap the benefits, but the underlying science is part of what I love – and it’s important for me to understand the underpinnings to be able to unravel the fine points of what the resulting matches are and are not revealing. Misinterpretation of DNA results leading to faulty conclusions is a real issue in genetic genealogy today. Consequently, I feel that anyone working with other people’s results and providing advice really needs to understand how the science and technology together works.

Dr. Daphna Weissglas-Volkov, a population geneticist by training, although she clearly functions far beyond that scope today, gave a very interesting presentation about how MyHeritage handles (their greatly improved) DNA Matching. I’m hitting the high points here, but I would strongly encourage you to watch the video of this session when they are made available online.

In addition to Dr. Weissglas-Volkov’s slides, I’ve added some additional explanations and examples in various places. You can easily tell that the slides are hers and the graphics that aren’t MyHeritage slides are mine.

Dr. Weissglas-Volkov began the session by introducing the MyHeritage science team and then explaining terminology to set the stage.

A match is when two people match each other on a fairly long piece of DNA. Of course, “fairly long” is defined differently by each vendor.

Your genetic map (of your chromosomes) is comprised of the DNA you inherit from different ancestors by the process of recombination when DNA is transferred from the parents to the child. A centiMorgan is the relatively likelihood that a recombination will occur in a single generation. On average, 36 recombinations occur in each generation, meaning that the DNA is divided on any chromosome. However, women, for reasons unknown have about 1.5 times as many recombinations as men.

You can’t see that when looking at an example of a person compared to their parents, of course, because each individual is a full match to each parent, but you can see this visually when comparing a grandchild to their maternal grandmother and their paternal grandmother on a chromosome browser.

The above illustration is the same female grandchild compared to her maternal grandmother, at left, and her paternal grandmother at right. Therefore the number of crossovers at left is through a female child (her mother), and the number at right is through a male child (her father.)

# of Crossovers
Through female child – left 57
Through male child – right 22

There are more segments at left, through the mother, and the segments are generally shorter, because they have been divided into more pieces.

At right, fewer and larger segments through the father.

Keep in mind that because you have a strand of DNA from each parent, with exactly the same “street addresses,” that what is produced by DNA sequencing are two columns of data – but your Mom’s and Dad’s DNA is intermixed.

The information in the two columns can’t be identified as Mom’s or Dad’s DNA or strand at this point.

That interspersed raw data is called a genotype. A haplotype is when Mom’s and Dad’s DNA can be reassembled into “sides” so you can attribute the two letters at each address to either Mom or Dad.

Here’s a quick example.

The goal, of course, is to figure out how to reassemble your DNA into Mom’s side and Dad’s side so that we know that someone matching you is actually matching on all As (Mom) or all Gs (Dad,) in this example, and not a false match that zigzags back and forth between Mom and Dad.

The best way to accomplish that goal of course is trio phasing, when the child and both parents are available, so by comparing the child’s DNA with the parents you can assign the two strands of the child’s DNA.

Unfortunately, few people have both or even one parent available in order to actual divide their DNA into “sides,” so the next best avenue is statistical phasing. I’ve called this academic phasing in the past, as compared to parental phasing which MyHeritage refers to as trio phasing.

There’s a huge amount of confusion about phasing, with few people understanding there are two distinct types.

Statistical phasing is a type of machine learning where a large number of reference populations are studied. Since we know that DNA travels together in blocks when inherited, statistical phasing learns which DNA travels with which buddy DNA – and creates probabilities. Your DNA is then compared to these models and your DNA is reshuffled in order to assemble your DNA into two groups – one representing your Mom’s DNA and one representing your Dad’s DNA, according to statistical probability.

Looking at your genotype, if we know that As group together at those 6 addresses in my example 95% of the time, then we know that the most likely scenario to create a haplotype is that all of the As came from one parent and all of the Gs from the other parent – although without additional information, there is no way to yet assign the maternal and paternal identifier. At this point, we only know parent 1 and parent 2.

In order to train the computers (machine learning) to properly statistically phase testers’ results, MyHeritage uses known relationships of people to teach the machines. In other words, their reference panels of proven haplotypes grows all of the time as parent/child trios test.

Dr. Weissglas-Volkev then moved on to imputation.

When sequencing DNA, not every location reads accurately, so the missing values can be imputed, or “put back” using imputation.

Initially imputation was a hot mess. Not just for MyHeritage, but for all vendors, imputation having been forced upon them (and therefore us) by Illumina’s change to the GSA chip.

However, machine learning means that imputation models improve constantly, and matching using imputation is greatly improved at MyHeritage today.

Imputation can do more than just fill in blanks left by sequencing read errors.

The benefit of imputation to the genetic genealogy community is that vendors using disparate chips has forced vendors that want to allow uploads to utilize imputation to create a global template that incorporates all of the locations from each vendor, then impute the values they don’t actually test for themselves to complete the full template for each person.

In the example below, you can see that no vendor tests all available locations, but when imputation extends the sequences of all testers to the full 1-500 locations, the results can easily be compared to every other tester because every tester now has values in locations 1-500, regardless of which vendor/chip was utilized in their actual testing.

Therefore, using imputation, MyHeritage is able to match between quite disparate chips, such as the traditional Illumina chips (OmniExpress), the custom Ancestry chip and the new GSA chip utilized by 23andMe and LivingDNA.

So, how are matches determined?

Matching

First your DNA and that of another person are scanned for nearly identical seed sequences.

A minimum segment length of 6cM must be identified for further match processing to occur. Anything below 6cM is discarded at this point.

The match is then further evaluated to see if the seed match is of a high enough quality that it should be perfected and should count as a match. Other segments continue to be evaluated as well. If the total matching segment(s) is 8 total cM or greater, it’s considered a valid match. MyHeritage has taken the position that they would rather give you a few accidental false matches than to miss good matches. I appreciate that position.

Window cleaning is how they refer to the process of removing pileup regions known to occur in the human genome. This is NOT the same as Ancestry’s routine that removes areas they determine to be “too matchy” for you individually.

The difference is that in humans, for example, there is a segment of chromosome 6 where, for some reason, almost all humans match. Matching across that segment is not informative for genetic genealogy, so that region along with several others similar in nature are removed. At Ancestry, those genome-wide pileup segments are removed, along with other regions where Ancestry decides that you personally have too many matches. The problem is that for me, these “too matchy” segments are many of my Acadian matches. Acadians are endogamous, so lots of them match each other because as a small intermarried population, they share a great deal of the same DNA. However, to me, because I have one great-grandfather that’s Acadian, that “too matchy” information IS valuable although I understand that it wouldn’t be for someone that is 100% Acadian or Jewish.

In situations such as Ashkenazi Jewish matching, which is highly endogamous, MyHeritage uses a higher matching threshold. Otherwise every Ashkenazi person would match every other Ashkenazi person because they all descend from a small founder population, and for genealogy, that’s not useful.

The last step in processing matches is to establish the confidence level that the match is accurately predicted at the correct level – meaning the relationship range based on the amount of matching DNA and other criteria.

For example, does this match cluster with other proven matches of the same known relationship level?

From several confidence ascertainment steps, a confidence score is assigned to the predicted relationship.

Of course, you as a customer see none of this background processing, just the fact that you do match, the size of the match and the confidence score. That’s what genealogists need!

Matching Versus Triangulation Thresholds

Confusion exists about matching thresholds versus triangulation thresholds.

While any single segment must be over 6 cM in length for the matching process to begin, the actual match threshold at MyHeritage is a total of 8 cM.

I took a look at my lowest match at MyHeritage.

I have two segments, one 6.1 cM segment, and one 6 cM segment that match. It would appear that if I only had one 6 cM segment, it would not show as a match because I didn’t have the minimum 8 cM total.

Triangulation Threshold

However, after you pass that matching criteria and move on to triangulation with a matching individual, you have the option of selecting the triangulation threshold, which is not the same thing as the match threshold. The match threshold does not change, but you can change the triangulation threshold from 2 cM to 8 cM and selections in-between.

In the example below, I’m comparing myself against two known relatives.

You won’t be shown any matches below the 6 cM individual segment threshold, BUT you can view triangulated segments of different sizes. This is because matching segments often don’t line up exactly and the triangulated overlap between several individuals may be very small, but may still be useful information.

Flying your mouse over the location in the bubble, which is the triangulated segment, tells you the size of the triangulated portion. If you selected the 2 cM triangulation, you would see smaller triangulated portions of matches.

Closing Session

The conference was closed by Aaron Godfrey, a super-nice MyHeritage employee from the UK. The closing session is worth watching on the recorded livestream when it becomes available, in part because there are feel good moments.

However, the piece of information I was looking for was whether there will be a MyHeritage LIVE conference in 2019, and if so, where.

I asked Gilad afterwards and he said that they will be evaluating the feedback from attendees and others when making that decision.

So, if you attended or joined the livestream sessions and found value, please let MyHeritage know so that they can factor your feedback onto their decision. If there are topics you’d like to see as sessions, I’m sure they’d love to hear about that too. Me, I’m always voting for more DNA😊

I hope to hear about MyHeritage LIVE 2019, and I’m voting for any of the following locations:

  • Australia
  • New Zealand
  • Israel
  • Germany
  • Switzerland

What do you think?

Ethnicity – Far More than Percentages!

Since ethnicity results have been in the news recently, I thought this might be a good time to talk about how to squeeze more out of your ethnicity results than just percentages.

You do know there’s more, right? You can tell a lot more about where your ethnicity came from by who you match, and how. Vendors provide that information too, but you need to know where to look. Plus, I have some tips about how to use this information effectively.

Genealogists are always trying to squeeze every last drop of information out of every DNA test, so I’d like to illustrate how I use ethnicity in combination with shared matches at Ancestry, Family Tree DNA, MyHeritage and 23andMe. Each vendor has a few unique features and tools as well, plus people in their databases that other vendors don’t have.

Come along and see what you might discover!

Ancestry

Ancestry recently introduced a new ethnicity comparison feature so let’s start there. Ancestry’s new tool:

  • Compares the ethnicity of you and a match side by side.
  • Shows Shared Migrations
  • Shows you common matches with that person.

At Ancestry, I have a V1 (older) and a V2 (newer) test, so I’m comparing my own V1 to my own V2 test for purposes of illustration.

To start, click on DNA Matches. You’ll see a new blue compare button, beneath the green View Match button, at right.

Clink on any image to enlarge

Click on the blue Compare button. You’ll see a side by side display, shown below.

My V1, at left, compared to my V2 test, at right. My V2 test results do not have a photo uploaded, so you just see my initials. It’s interesting to note that even though these are both me, just tested on different chips, that my ethnicity doesn’t match exactly, although it’s mighty close.

Next, you’ll see the shared migrations between the two people being compared. This helps determine where your common ancestor might be found.

Last, you’ll see the shared matches between you and the other person. This means that those people match both you and the person you’re comparing against, suggesting a potential common ancestor.

On your matches page, you can also sort your matches by your regions.

Where Did Your Ethnicity Come From?

Ethnicity comparisons can be helpful, especially if you’re a person who carries DNA from different continents. I do not suggest trying to compare intra-continental estimates in the same way. It’s simply too difficult for vendors to separate DNA from locations that all border each other where countries are the size of states in the US, such as the Netherlands, Germany, France and Switzerland for example.

As I’ve said before, ethnicity results are only estimates, but they are relatively accurate at the continental level, plus Jewish, as illustrated below.

To be specific, these regions are the easiest for vendors to tell apart from the other regions:

  • European
  • African
  • Native American (North American, South American, Central American and Siberian in conjunction with the Americas)
  • Asian
  • Jewish

For example, if you are 30% African, 35% Native American and 35% European, you could use this information to form a hypothesis about how you match a particular individual or group of individuals.

If the person you match is 50% Asian and 50% African, it’s most likely that the region you match them on is the common African side.

Of course, the next step would be to look at the shared matches to see if those matches include your known relatives with African heritage. This is one reason I always encourage testing of relatives. Who you and your known relative both match tells you a lot about where the common ancestor of a matching group of individuals is found in your tree. For example, if someone matches you and a first cousin, then the common ancestor of the three people is on the side of your tree that you share with the first cousin.

Not exactly sure, or dealing with smaller amounts of continental ethnicity? There’s another way to work with ethnicity.

Ethnicity Match Chart

Make an Ethnicity Match Chart that includes the ethnicity of each person in the match group, as follows.

In this example, the only category in which all people fall is African, so that’s where I’d look in my tree first for a family connection.

Keep in mind that you match person 1, and people 2-4 match both you and person 1.

That does NOT mean that:

  • Person 2, 3 or 4 match each other.
  • Any of those people share the same ancestor with each other. Yes, you can match due to different ancestors that might not have anything to do with each other.
  • These people match on any of the same segments. You can’t view segments at Ancestry. You’ll have to transfer your results to Family Tree DNA, MyHeritage or GedMatch to do that.

Next, look at the trees for each person in the common match group and see if you can discern any common genealogy or even common geography. The best hints of course, at Ancestry, are those green leaf Shared Ancestor Hints. If you find a common ancestor or line, you’re well on your way to identifying how those people are related to you and potentially your match as well.

You could also use this methodology as an adaptation of or in tandem with the Leeds Method that I wrote about here.

Comparing Segments – Yes, You’ll Need To

Ancestry doesn’t offer a chromosome browser, but Family Tree DNA, MyHeritage, 23andMe and GedMatch all do, allowing you to view segments and triangulate. I always suggest uploading Ancestry results to GedMatch, Family Tree DNA and MyHeritage. 23andMe does not accept uploads.

You’ll find instructions for downloading from Ancestry here, uploading to Family Tree DNA here, and to MyHeritage here.

Other Vendors

Each vendor offers their own version of ethnicity comparison. All vendors offer in common with (ICW) and shared match tools too, so you can create your Ethnicity Match Chart for a specific group of people from any vendor’s results – although I don’t mix vendor results on one chart. Plus, every vendor has people in their matching database that no other vendor has, so fish in every pond.

Family Tree DNA

Family Tree DNA offers shared ethnicity information on the myOrigins map. To view, click on MyOrigins, then on View MyOrigins Map.

Testers who opt in can view their ethnicity as compared to their matches’ ethnicity. You can also sort by ethnicity as well as use the pin function at bottom right to drop Y and mtDNA most distant ancestor pins on the map.

Please note that this is NOT where your match lives, but is the location of their most distant matrilineal (mtDNA) or patrilineal (surname) known individual.

If you’re looking for Native American matches, for example, you might look for someone with some percentage of Native American autosomal DNA and/or Native American Y or mitochondrial haplogroups. Click on any pin to view that person and their ethnicity that matches yours. You can also search for a specific individual to see how your ethnicity lines up.

On your match list, look for common surnames with those matches, see who you match in common and check your matches’ trees.

Linking your DNA matches to their location in your tree enables you to participate in Phased Family Matching, meaning you can then select people that are assigned to your maternal or paternal sides to view in the chromosome browser.

When viewing all maternal (red icon) or all paternal (blue icon) matches together on the chromosome browser, the segments are automatically mathematically triangulated. All you need to do is identify the common ancestor!

I love Phased Family Matches. Family Tree DNA is the only vendor to offer this feature and to incorporate Y and mitochondrial DNA.

MyHeritage

MyHeritage provides multiple avenues for comparison, allowing users to select matches by their ethnicity, country or to simply compare their ethnicity to each other. To view matches by ethnicity, click on the Filter button, but note that not all ethnicity locations are included. You can also combine options, such as looking for anyone from the Netherlands with Nigerian DNA.

To view your matches ethnicity as compared to yours, click on the match and scroll down.

Look for people you match in common as well as the triangulation icon, shown at right, below. Another feature, SmartMatches (a filter option) sort for people who have common ancestors with you in trees.

I love triangulation and DNA SmartMatches and MyHeritage is the only vendor to offer this combination of tools!

23andMe

At 23andMe, you can see your ethnicity beside that of your match by clicking on DNA Relatives, on the Ancestry tab, then click on the person you wish to compare to. In my case, I’ve also taken the V3 and V4 test at 23andMe, so I’m comparing to myself.

At 23andMe, you can view which portions of your segments are attributed to which ethnicity. Under the Ancestry tab, click Ancestry Composition and scroll down to view your Ancestry Composition Chromosome Painting.

You can see my Native American segments on chromosomes 1 and 2.

Click on Scientific Details, then scroll to the bottom to download your ethnicity raw data that includes the segment detail for the location of those specific segments.

Utilizing these chromosome and segment locations with any other vendor who supports a chromosome browser, and determining which side that ethnicity descends through allows you to identify matches who should also carry segments of that same ethnicity at that same location.

Here’s my Native segment on chromosome 2 from the download file. Remember, you have two copies of every chromosome – and in my case, only one of those copies on Chromosome 2 is Native. I know it’s from my mother, so anyone matching me on my maternal side at this location on chromosome 2 should also have a Native segment, and our common ancestor is the source of our common Native American heritage.

23andMe is the only vendor to identify ethnicity segments.

23andMe does show matches in common and common matching segments on the chromosome browser, but they don’t support trees.

Your Turn!

If you carry ethnicity from multiple continents (plus Jewish), what hints can you derive from using your ethnicity as a match tool?

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This standard disclosure appears at the bottom of every article in compliance with the FTC Guidelines.

I provide Personalized DNA Reports for Y and mitochondrial DNA results for people who have tested through Family Tree DNA. I provide Quick Consults for DNA questions for people who have tested with any vendor. I would welcome the opportunity to provide one of these services for you.

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DNA Painter – Touring the Chromosome Garden

This is the third article in a series about DNA Painter. To know DNA Painter is to love DNA Painter! Trust me!

The first two articles are:

The Chromosome Sudoku article introduces you to DNA Painter, it’s purpose and how to use the tool. The Mining Vendor Data article illustrates exactly how to find the segments you can paint from each of the main autosomal testing vendors and GedMatch.

This article is a leisurely tour through my colorful chromosome garden so that, together, we can see examples of how to utilize the information that chromosome painting unveils.

Chromosome painting can do amazing things: walk you back generations, show visual phasing…and reveal that there’s a mistake someplace, too.

If you’re not willing to be wrong and reconsider, this might not be the field for you😊

Automatic Triangulation

Chromosome painting automatically mathematically triangulates your DNA and in a much easier way than the old spreadsheet method. In fact, triangulation just happens, effortlessly IF you can determine which side is maternal and which side is paternal. Of course, you’ll always want to check to be sure that your matches also match each other. if not, then that’s an indication that maybe one or both are identical by chance.

The definition of triangulation in this context means:

  • To find a common segment
  • Of reasonable size (generally 7cM or over)
  • That is confirmed to a common ancestor with at least two other individuals
  • Who are not close family

Close family generally means parents, siblings, sometimes grandparents, although parents and grandparents can certainly be used to verify that the match is valid. The best triangulation situation is when you match those two other people through a second child, meaning siblings of your ancestor.

Different matches, depending on the circumstances, have a different level of value to you as a genealogist. In other words, some are more solid than others.

The X chromosome has special matching and triangulation rules, so we’ll talk about that when we get to that section.

Don’t think of chromosome painting as “doing” triangulation, because triangulation is a bonus of chromosome painting, and it just happens, automatically, so long as you can confirm that the segment is from either your maternal or paternal line.

What does triangulation look like in DNA Painter?

Here’s what my painted chromosome 15 looks like.

Here, I’ve drawn boxes around the areas that are triangulated. Actually, I made a small mistake and omitted one grey bar that’s also part of a second triangulation group. Can you spot it? Hint – look at the grey bars at far right in the overlapping triangulation group boxes where the red arrow is pointing. The box below should extend upwards to incorporate part of that top grey bar too.

Triangulation are those several segments piled up on top of each other. It means they match you at the same address on either the maternal or paternal chromosome. That’s good, but it’s not the same as an official “pileup area.”

Ok, so what’s a pileup area?

Pileup Areas

Certain locations in the human genome have been designated as pileup regions based on the fact that many people will match on these segments, not necessarily because they share a common relatively recent ancestor, but instead because a particular segment has a very high frequency in the general human population, or in the population of a specific region. Translated, this means that the segment might not be relevant to genealogy.

But before going too far with this discussion, it doesn’t mean that matches in pileup regions aren’t relevant to genealogy – just consider it a caution sign.

Aside from chromosome 6, which includes the HLA region, I’ve always been rather suspicious of pileup regions, because they don’t seem to hold true for me. You can view a chart that I assembled of the known pileup regions here.

DNA Painter generously includes pileup region warnings, in essence, along a chromosome bar at the top indicating “shared” or “both.”

Please note that you can click to enlarge any image.

Pileups regions are indicated by the grey hashed region at right. In my case, on chromosome 1, the pileup region isn’t piled up at all, on either the paternal (blue) chromosome or the maternal (pink) chromosome.

As you can see, I have exactly one match on the maternal side (green) and one (gold) on the paternal side (with a smidgen of a second grey match) as well, with both extending significantly beyond the pileup region. There is no reason to suspect that these gold and green matches aren’t valid.

If I saw many more matches in a pileup region than elsewhere, or many small matches, or DNA that was supposed to be from multiple ancestors not in the same line, then I’d have to question whether a pileup region was responsible.

Stacked Segments

DNA Painter provides you with the opportunity to see which of your ancestors’ segments stack. Stacking is a very important concept of DNA painting.

Before we talk about stacking, notice that the legend for which segments are color coded to specific ancestors is located at right. You can also click on the little grey box beside “Shared or Both,” at left, to show the match names beside the segments.  This is very useful when trying to analyze the accuracy of the match.

I wish DNA Painter offered an option to paint the ancestor’s names beside the segments. Maybe in V2. It’s really difficult to complain about anything because this tool is both free and awesome.

I’m using Powerpoint to label this group of stacked matches for this example.

This is a situation where I know my pedigree chart really well, so I know immediately upon looking at this stacked segment group who this piece of DNA descends from.

Here’s my pedigree chart that corresponds to the stacked segment.

We attribute each DNA segment to a couple initially based on who we match. In this case, that’s William George Estes and Ollie Bolton, my grandparents. The DNA remains attributed to them until we have evidence of which individual person in the couple received that DNA from their ancestors and passed it on to their descendant.

Therefore, the pink people are the half of the couple who we now know (thanks to DNA Painter) did NOT contribute that DNA segment, because we can track the DNA directly through the yellow line until we’re once again to another genetic brick wall couple.

My father is listed at left, and the DNA path runs back to William Crumley the second and his unknown wife who is haplogroup H2a1, the yellow couple at far right. How cool is this? One of those ancestors (or a combined segment from both) has been passed intact to me today. This is not a trivial segment either at 23.3 cM. I would not expect a segment passed to 5th cousins to be that large, but it is!

Also, note that the grey segment of DNA from Lazarus Estes (1848-1918) and Elizabeth Vannoy (1847-1918) is sitting slightly to the left of the dark blue segment from William Crumley III, so part or all of the grey or blue segment may originate with a different ancestor. Perhaps we’ll know more when additional people test and match on this same segment.

Double Related

I have one person who is related to me through two different lines. I need a way to determine which line (or both) our common DNA segment descends from.

I painted the segment for both of our common ancestor couples. The pink is George Dodson (1702-1770) & Margaret Dagord. The bright blue segment is William Crumley III (1788-1859) & Lydia Brown.

Those two lines don’t converge, at least not that we know of.

Now, as I map additional people, I’ll watch this segment for a tie breaker match between the two ancestors. The gold is not a tie breaker because that’s my grandparents who are downstream of both the pink and blue ancestors.

Painted Ethnicity

23andMe does us the favor of painting our ethnicity segments and allowing us to download a file with those segments. Conversely, DNA Painter does us the favor of allowing us to paint that entire file at once.

I already know my two Native segments on chromosome 1 and 2 descend through my mother, because her DNA is Native in exactly the same location. In other words, in this case, my ethnicity segment does in fact phase to my mother, although that’s not always the case with ethnicity.

Multiple Acadian ancestors are also proven to be Native by both genealogical records and maternal and/or paternal haplogroups.

Therefore, I’ve painted my Native segments on my mother’s side in order to determine exactly from which ancestor(s) those Native segment descend.

Confirming Questionable Ancestors

One very long-standing mystery that seemed almost unsolvable was the identity of the parents of Elijah Vannoy (1784->1850). We know he was the son of one of 4 Vannoy brothers living in Wilkes County, NC. Two were eliminated by existing Bibles and other records, but the other two remained candidates in spite of sifting through every available record and resource. We were out of luck unless DNA came to the rescue. Y DNA confirmed that Elijah was descended from one of the Vannoy males, but didn’t shed light on which one.

I decided that the wives would be the key, since we knew the identity of all four wives, thankfully. Of course, that means we’d be using autosomal DNA to attempt to gather more information.

I entered one candidate couple at Ancestry as Elijah’s parents – the one I felt most likely based on tax records and other criteria – Daniel Vannoy and Sarah Hickerson.  I also entered Sarah’s parents, Charles Hickerson (c 1725-<1793) and Mary Lytle.

I began getting matches to people who descend from Charles Hickerson and Mary Lytle through children other than Sarah.

The grey segment is from a descendant of Lazarus Estes & Elizabeth Vannoy. The salmon segments are from descendants of Charles Hickerson and Mary Lytle.

These segments aren’t small, 12.8 and 16.1 cM, so I’m fairly confident that these multiple segments in combination with the Elizabeth Vannoy segment do indeed descend from Charles Hickerson and Mary Lytle.

At Ancestry, I have 5 matches to Charles Hickerson and Mary Lytle through three of their children. However, only two of the individuals has transferred their results to either Family Tree DNA, MyHeritage or GedMatch where segment information is available to customers.

Finally, the thirty year old mystery is solved!

Shifting, Sliding, Offset or Staggered Segment Groups

Occasionally, you can prove an entire large segment by groups of shifting or sliding segments, sometimes referred as offset or staggered segments.

The entire bright pink region is inherited from Jacob Lentz (1783-1870) and Fredericka Reuhl (1788-1863.) However, it’s not proven by one individual but by a combination of 6 people whose segments don’t all overlap with each other.  The top two do match very closely with me and each other, then the third spans the two groups. The bottom 3 and part of the middle segment match very closely as well.

I can conclude that the entire dark pink region from left to right descends from Jacob and Fredericka.

Two Matches – 7 Generations

Two matches is all it took to identify this segment back to George Dodson and Margaret Dagord.

The mustard match is to my grandparents (22cM), and the pink match is to George Dodson (1702-1770) and his wife (22cM) – 7 generations. These people also match each other.

Additional matches would make this evidence stronger, although a 22cM triangulated match is very significant alone. Future might also suggest ancestors further back in time.

First Chromosome Fully Mapped

I actually have chromosome 5 entirely mapped to confirmed ancestors. I’m so excited.

Uh Oh – Something’s Wrong

I found a stack that clearly indicates something is wrong.  The question is, what?

The mustard represents my paternal grandparents, so these segments could have come through either of them, although on the pedigree chart below, we can see that this came through my grandfathers line..

There is only a small overlap with the magenta (Nicholas Speak 1782-1852 and Sarah Faires 1786-1865) and green (James Crumley 1711-1764 and Catherine c1712-c1790,) which could be by chance given that the Nicholas segment is 7.5 cM, so I’m leaving the magenta out of the analysis.

However, the rest of these segments overlap each other significantly, even though they are stepped or staggered.

As you can see from the colors on the pedigree chat, it’s impossible for the green segment to descend from the same ancestor as the purple segment. The purple and orange confirm that branch of the tree, but the red cannot be from the same ancestor or the same line as the green ancestor.

I suspect that the purple and orange line is correct, because there are 4 segments from different people with the same ancestral line.

This means that we have one of the following situations with the red and green segments:

  • The smaller segments are incorrect, false positives, meaning matching by chance. The green segment is 14 cM, so quite large to match by chance. The red segment is 10 cM. Possible, but not probable.
  • The segments are population-based matches, so appear in all 3 lines. Possible, technically, but also not probable due to the segment size.
  • The segments are genuine matches, and one of the lines is also found in one of the other lines, upstream. This is possible, but this would have to be the case with both the red and green lines. To continue to weigh this possibility, I’ll be watching for similar situations with these same ancestors.
  • Some combination of the above.

I need more matches on this segment for further clarity.

Visual Phasing – Crossovers

A crossover point is where the DNA on one side of a demarcation line is descended from one ancestor and the DNA on the other side is descended from another ancestor, represented by the pink and blue halves of the segment, below.

Crossovers occur when the DNA is combined from two different ancestors when it is passed to the child. In other words, a chunk of mom’s ancestors’ DNA is contributed by mom and a chunk of dad’s ancestors’ DNA is contributed as well. The seam between different ancestor’s DNA pieces is called a crossover.

In this example, the brown lines confirmed by several testers to be from Henry Bolton (c1759-1846) and Nancy Mann (c1780-1841) is shown with a very specific left starting point, all in a vertical line. It looks for all the world like this is a crossover point. The DNA to the left would have been contributed by another, as yet unidentified, ancestor.

The gold lines above are matches from more recent generations.

Naming Those Unnamed Acadians

My Acadian ancestry is hopelessly intertwined, but chromosome painting may in fact provide me with some prayer of unraveling this ball of twine. Eventually.

When I know that someone is Acadian, but I can’t tell which of many lines I connect through, I add them as “Acadian Undetermined.”

There’s a lot of Acadian DNA, because it’s an endogamous population and they just keep passing the same segments around and around in a very limited population.

On my maternal chromosome, all of the olive green is “Acadian Undetermined.”  However, that blue segment in the stack is Rene de Forest (1670-1751) and Francoise Dugas (1678->1751).

In essence, this one match identified all of the DNA of the other people who are now simply a row in the Acadian Undetermined stack. Now I need to go back and peruse the trees of these individuals to determine if they descend form this line, or a common ancestor of this line, or if (some of) these matches are a matter of endogamy.

Endogamous matches can be population based, meaning that you do match each other, but it’s because you share so much of the same DNA because you have small pieces of many common ancestors – not because a particular segment comes from one specific ancestor. You can also share part of your DNA from Mom’s side and part from Dad’s side, because both of your parents descend from a common population and not because the entire segment comes from any particular ancestor.

On some long cold winter weekend, I’ll go through and map all of the trees of my Acadian matches to see what I can unravel. I just love matches with trees. You just can’t do something like this otherwise.

Of course, those Acadians (and other endogamous populations) can be tricky, no matter what, one click up from a needle in a haystack.

Acadian Endogamy Haystack on Steroids

At first, our haystack looks like we’ve solved the mystery of the identity of the stack.  However, we soon discover that maybe things aren’t as neat and tidy as we think.

Of course, the olive green is Acadian Undetermined, but the three other colored segments are:

  • Pink – Guillaume Blanchard (1650-1715/17) & Huguette Goujon (c1647-1717)
  • Brown/Pink – Francois Broussard (c1653-1716) & Catherine Richard (c1663-1748)
  • Coffee – Daniel Garceau (1707-1772) & Anne Doucet (1713-1791)

Looking at the pedigree chart, we find two of these couples in the same lineage, so all is good, until we find the third, pink, couple, at the bottom.

Clearly, this segment can’t be in two different lines at once, so we have a problem.  Or do we?

Working the pink troublesome lines on back, we make a discovery.

We find a Blanchard line consisting of Guilluame Blanchard born circa 1590 and Huguette Poirier also born circa 1690.

Interesting. Let’s compare the Guillaume Blanchard and Huguette Goujon line. Is this the same couple, but with a different surname for her?

No, as it turns out, Guillaume Blanchard that married Huguette Goujon was the grandson of Guilluame Blanchard and Huguette Poirier. That haystack segment of DNA was passed down through two different lines, it appears, to converge in three descendants – me, the descendant of the pink segment couple and the descendant of the brown/burgundy segment couple. This segment reaches back in time to the birth of either Guilluame Blanchard or Huguette Poirier in 1590, someplace in France, rode over on the ship to Port Royal in the very early 1600s, probably before Jamestown was settled, and has been kicking around in my ancestors and their descendants ever since.

This 18 or so cM ancestral segment is buried someplace at Port Royal, Nova Scotia, but lives on in me and several other people through at least two divergent lines.

The X Chromsome

Several vendors don’t report the X chromosome segments. I do use X segments from those who do, but I utilize a different threshold because the SNP density is about half of that on the other chromosomes. In essence, you need a match twice as large to be equivalent to a match on another chromosome..

Generally, I don’t rely on segments below 10 for anyone, and I generally only use segments over 14cM and no less than 500 SNPs.

Having just said that, I have painted a few smaller segments, because I know that if they are inaccurate, they are very easy to delete. They can remain in speculative mode. The default for DNAPainter and that’s what I use.

The great thing about the X chromosome is that because of it’s special inheritance path, you can sometimes push these segments another 2 generations back in time.

Let’s use an X chromosome match in conjunction with my X fan chart printed through Charting Companion.

On the paternal X, I inherited the gold segment from the couple, William George Estes (1873-1971) & Ollie Bolton (1874-1955.) However, since my father didn’t inherit an X from William George Estes (because my father inherited the Y from his father,) that X segment has to be from Ollie Bolton, and therefore from her parents Joseph Bolton (1853-1920) and Margaret Claxton (1851-1920.)

The segment from Lazarus Estes (1848-1918) and Elizabeth Vannoy (1847-1918) that’s 14 cM is false. It can’t descend from that couple. Same for the 7.5 cM from Jotham Brown (c1740-c1799) & Phoebe unk (c1747-c1803.) That segment’s false too. The green 48 cM segment from Samuel Claxton (1827-1876) and Elizabeth Speak (1832-1907)?  That segment’s good to go!

On my mother’s side, there’s a 7.8 cM Acadian Undetermined, which must be false, because Curtis Benjamin Lore (1856-1909) did not inherit an X chromosome from his Acadian father, Antoine Lore (1805-1862/67.)  Therefore, my X chromosome has no Acadian at all. I never realized that before, and it makes my X chromosome MUCH easier.

How about that light green 33cM segment from Antoine Lore (1805-1862/67) & Rachel Hill (1814/15-1870/80)? That segment must come from Rachel Hill, so it’s pushed back another generation to Joseph Hill (1790-1871) and Nabby Hall (1792-1874.)

I love the X chromosome because when you find a male in the line, you automatically get bumped two more generations back to his mother’s parents. It’s like the X prize for genetic genealogy, pardon the pun!

Adoptees

Some adoptees are lucky and receive close matches immediately. Others, not so much and the search is a long process.

If you’re an adoptee trying to figure out how your matches connect together, use in-common-match groupings to cluster matches together, then paint them in groups.  Utilize the overlapping segments in order to view their trees, looking for common surnames. Always start with the groups with the longest segments and the most matches. The larger the match, the more likely you are to be able to find a connection in a more recent generation. The more matches, the more likely you are to be able to spot a common surname (or two.)

Painting can speed this process significantly.

Much More Than Painting

I hope this tour through my colorful chromosomes has illustrated how much fun analysis can be. You’ll have so much fun that you won’t even realize you’re triangulating, phasing and all of those other difficult words.

If you have something you absolutely have to do, set an alarm – or you’ll forget all about it. Voice of experience here!

So, go and find some segments to paint so all of these exciting things can happen to you too!

How far back will you be able to identity a segment to a specific ancestor?  How about a triangulated segment? An X segment?

Have fun!!! Don’t forget to eat!

PS – If you’d like to learn more about Phasing, Triangulation or hear my keynote speech, consider signing up for the Virtual DNA Conference June 21-24. I’ll be presenting on both of those topics. You can sign in anytime for the next year to listen to the sessions, not just during the conference days. The keynote will be recorded and available afterwards as well.

_____________________________________________________________________

Standard Disclosure

This standard disclosure appears at the bottom of every article in compliance with the FTC Guidelines.

Hot links are provided to Family Tree DNA, where appropriate.  If you wish to purchase one of their products, and you click through one of the links in an article to Family Tree DNA, or on the sidebar of this blog, I receive a small contribution if you make a purchase.  Clicking through the link does not affect the price you pay.  This affiliate relationship helps to keep this publication, with more than 900 articles about all aspects of genetic genealogy, free for everyone.

I do not accept sponsorship for this blog, nor do I write paid articles, nor do I accept contributions of any type from any vendor in order to review any product, etc.  In fact, I pay a premium price to prevent ads from appearing on this blog.

When reviewing products, in most cases, I pay the same price and order in the same way as any other consumer. If not, I state very clearly in the article any special consideration received.  In other words, you are reading my opinions as a long-time consumer and consultant in the genetic genealogy field.

I will never link to a product about which I have reservations or qualms, either about the product or about the company offering the product.  I only recommend products that I use myself and bring value to the genetic genealogy community.  If you wonder why there aren’t more links, that’s why and that’s my commitment to you.

Thank you for your readership, your ongoing support and for purchasing through the affiliate link if you are interested in making a purchase at Family Tree DNA, or one of the affiliate links below:

Affiliate links are limited to:

Introducing The Triangulator

Goran Runfeldt, a fellow genetic genealogist, has developed a killer app. You’ve heard of “The Terminator?” Well, meet “The Triangulator.”

Goran developed the Family Finder Segment Triangulator tool to run, using a user script or browser extension, on the Family Tree DNA site, after you sign in to your personal page. So there is no downloading, no spreadsheets, nothing messy.

The Triangulator tool is still in beta, so while the documentation is rather sparse, the tool is extremely intuitive if you understand triangulation.

What is Triangulation?

If you don’t understand triangulation, what it is, how it differs from match groups, and why you would want to utilize triangulation, may I please suggest that you read the following articles before utilizing the tool.

Concepts – Why Genetic Genealogy and Triangulation?

Concepts – Match Groups and Triangulation

Triangulation for Autosomal DNA

In a nutshell, triangulation provides you with a tool to show that not only do person A and B match you, on the same segment, but that they also match each other.

This means that they are not matching you on the same segment number from opposite sides of your family, meaning one person matching you from your mother’s side, and one from your father’s side. If they match other, as well as you, that means that they both descend from the same side of your tree (assuming they are not both matching you identically by chance.)

Family Tree DNA shows you, utilizing the chromosome browser, that two people match you, and on the same segment, but they don’t (yet) inform you about triangulation, although they are working on a triangulation tool.

Chromosome Browser

In the following example, we have 5 known relatives to Barbara, whose background chromosome is black. As you can see, there are three possible triangulation points where at least two of the people match Barbara.

Just to be sure, I downloaded these matches to a spreadsheet to illustrate that these matches are not trivial in size – meaning based on their size, they certainly should be legitimate matches.

All three matching areas on this chromosome (grey, gold and blue) are large enough to be considered substantial, and when compared to the charts created by Philip Gammon in the Match-Maker-Breaker article, we see that there is almost no likelihood that these are false matches, or matches by chance. In that article, when phasing matches to parents, we demonstrated that 97% of the matches of 12cM or more and/or SNP density of 2800 or more phase to one or the other parent, meaning they are legitimate matches. At 15cM, 100% of a child’s matches also match a parent, except for the X chromosome.

All of these cousins descend from Barbara’s paternal side, from the same family line, so the chances are pretty good that they do all triangulate, but let’s see.

Installing the Triangulator

First, you’ll need to install the triangulator.

My choice is to utilize the tool in Chrome, as I had difficulties with Internet Explorer compatibility. Chrome works just fine.

Goran has provided installation instructions for various browsers here.

If you’re installing this tool in Chrome, be sure to sign in to the Chrome web store while using Chrome to install the free app, or the store will ask you to download Chrome.

The installation is super easy – just one click, literally.

Triangulating

Ok, now the hardest part is over and we can get busy triangulating right away.

Sign in to your account at Family Tree DNA, using the browser where you just installed the tool.

Click on your Family Finder matches.

You’ll notice something new right away, a new icon that says “dnagen tools” at the top of your Family Finder matches. That’s the Triangulator.

On your match list, select the people you want to triangulate, just like you were selecting the people to compare in the chromosome browser.

Your comparison list will be built, like always, on the lower left hand side of your screen.

To triangulate, instead of clicking on the Chromosome Browser button, you’re going to click on the new dnagentools icon.

You’ll see a little dropdown box that says “Triangulator.”

Just click on “Triangulator.”

That’s it.

Processing…

You’ll see the progress bar as the tool calculates the relationships of the people you are triangulating to each other.

When the tool finishes, it switches to the Triangulated Segment tab, which is what everyone wants to see first, but you can always click on the Relationships tab to view the various relationships of the people you selected to each other.

All of the genetically estimated relationship of all of the people you’ve triangulated to every other person in the group are displayed.

Triangulated Segments

When the Triangulator is finished, you’ll see the “Triangulated Segments,” tab displayed, assuming some segments do triangulate, with a small image of the chromosome beneath each triangulated segment.  The area where the segments match to you is colored in orange and where the segments all triangulate is colored in red.

Additionally, the tool shows you the actual overlap range, the number of matching positions and the overlapping number of SNPs as well.

If you think you’ve died and gone to triangulation heaven, you have.

Downloadable Data

In order for you to easily transfer this information to your spreadsheets where you are triangulating your segments (you are, aren’t you???) and assigning segments to ancestors, Goran has provided a nifty tool for that too.

At the bottom, Goran has included downloads of:

  • All matching segments for these people
  • The triangulated segments for these people over the match threshold selected, which defaults to 5, same as the chromosome browser
  • The relationships of these people to each other

Yes, you can lower the threshold, but just remember that as you do, the chances of the segments being identical by chance increases.

The Answer to Our Problem – Triangulation is Critical

In case you’ve gotten all excited about triangulating and forgotten that we were in the middle of a story problem, let’s look at our answer.

If you recall, there were three candidate regions for triangulating between Barbara’s known cousins on chromosome 3.

However, the Triangulator only shows two triangulating segments, the first and third. That means that the second of these large segments does NOT triangulate. That means that one of these third cousins matches Barbara on that segment in one of these three ways:

  • By chance
  • Because the overlapping matching region is too small to be considered a match
  • One person matches from Barbara’s mother’s side and one from her father’s side – as unlikely as that seems with third cousins.

The most likely reason for non-triangulation is the third reason, given those large matching segment segment sizes.

While the first and third (grey and blue) segment match groups both triangulate, the middle (gold) region does not.

If you’re shocked, just remember that no matter how intuitive a match seems, and no matter how “sure” you are that two people from the same line of your family certainly must triangulate because they both match you on the same segment, without triangulation, you REALLY DON’T KNOW!

And you all know about assume, right? Been there, done that, got educated!

Triangulate removes the assume from the equation.

In this case, triangulation tells me that I need to look on Barbara’s mother’s side for a second common ancestor with either C. Lentz or W. Lentz.

Just so you know, I was suspicious of this result, but given that I have access directly to the kits of both C. and W. Lentz, because I tested them both, I verified that they don’t match each other on this segment, both at Family Tree DNA and at GedMatch.  So this is no mistake.

Support

This triangulation tool is a “goodness of heart” free application shared with the genetic genealogy community, and while Goran is willing to share, he doesn’t really want his inbox to be swamped. In the tool, he provides the following support information.

Goran follows the ISOGG Facebook group, so posting questions there will provide answers for you, and maybe for someone else following along too.

What if I Haven’t Tested at Family Tree DNA?

The Triangulator tool requires chromosome segment data, thankfully provided by Family Tree DNA. Therefore, this tool is not available for use with Ancestry data at Ancestry. You can, however, download your Ancestry DNA file to Family Tree DNA. Not everyone who tests at each vendor uploads to other places, so be sure to fish in all of the ponds, one way or another.

You can read about which vendors’ files are compatible to transfer to Family Tree DNA (and other places too) in the article Autosomal DNA Transfers – Which Companies Accept Which Tests?

The following chart shows transfer Files Accepted at Family Tree DNA.

Vendor Fully Compatible Version Partially Compatible Version Incompatible Version
Ancestry V1 – until May 2016 V2 – after May 2016 to present
23andMe V3 – until Nov. 2013 V4 – Nov. 2013 – Aug. 2017 V5 – Aug. 2017 to present
MyHeritage All

Keep in mind that the current V5 version of the 23andMe test is not compatible at all at Family Tree DNA. The 23andMe V4 version, in use between November of 2013 and August of 2017 is only partially compatible, as is the Ancestry V2 version in use since May 2016.

If you upload partially compatible versions, you’ll receive your closest (meaning largest) matches, generally about 20-25 % of your matches that you would receive if you tested on the Family Tree DNA platform.  However, you’ll be missing most of your matches, and you never know where that match you desperately need is hiding.

Note that this isn’t an artificial restriction imposed by Family Tree DNA, it’s a function of the other vendor’s chips only being partially compatible with the DNA processing chip used by Family Tree DNA.

If you want to see all of your matches and all of your segments, purchase the Family Finder test at Family Tree DNA.

Thank You

A really big thank you to Goran and the user interface developer, Jonas, for this wonderful tool.

_____________________________________________________________________

Standard Disclosure

This standard disclosure appears at the bottom of every article in compliance with the FTC Guidelines.

Hot links are provided to Family Tree DNA, where appropriate. If you wish to purchase one of their products, and you click through one of the links in an article to Family Tree DNA, or on the sidebar of this blog, I receive a small contribution if you make a purchase. Clicking through the link does not affect the price you pay. This affiliate relationship helps to keep this publication, with more than 850 articles about all aspects of genetic genealogy, free for everyone.

I do not accept sponsorship for this blog, nor do I write paid articles, nor do I accept contributions of any type from any vendor in order to review any product, etc. In fact, I pay a premium price to prevent ads from appearing on this blog.

When reviewing products, in most cases, I pay the same price and order in the same way as any other consumer. If not, I state very clearly in the article any special consideration received. In other words, you are reading my opinions as a long-time consumer and consultant in the genetic genealogy field.

I will never link to a product about which I have reservations or qualms, either about the product or about the company offering the product. I only recommend products that I use myself and bring value to the genetic genealogy community. If you wonder why there aren’t more links, that’s why and that’s my commitment to you.

Thank you for your readership, your ongoing support and for purchasing through the affiliate link if you are interested in making a purchase at Family Tree DNA.

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.

Glossary – DNA – Deoxyribonucleic Acid

What is DNA and why do I care?

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

The Recipe for You

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

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

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

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

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

Using DNA for Genetic Genealogy

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

Genetic genealogy makes use of 4 different types of DNA.

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

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

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

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

Receiving What Kind of DNA from Whom

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

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

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

The Y chromosome is what makes males male.

No Y chromosome?  You’re a female.

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

Autosomal DNA and Genetic Genealogy

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

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

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

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

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

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

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

More Info

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

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

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

If You Want to Test

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

Right now, the Y DNA, mitochondrial and autosomal (Family Finder) tests are on sale at Family Tree DNA, through the end of August, 2017.

______________________________________________________________________

Standard Disclosure

This standard disclosure will now appear at the bottom of every article in compliance with the FTC Guidelines.

Hot links are provided to Family Tree DNA, where appropriate. If you wish to purchase one of their products, and you click through one of the links in an article to Family Tree DNA, or on the sidebar of this blog, I receive a small contribution if you make a purchase. Clicking through the link does not affect the price you pay. This affiliate relationship helps to keep this publication, with more than 850 articles about all aspects of genetic genealogy, free for everyone.

I do not accept sponsorship for this blog, nor do I write paid articles, nor do I accept contributions of any type from any vendor in order to review any product, etc. In fact, I pay a premium price to prevent ads from appearing on this blog.

When reviewing products, in most cases, I pay the same price and order in the same way as any other consumer. If not, I state very clearly in the article any special consideration received. In other words, you are reading my opinions as a long-time consumer and consultant in the genetic genealogy field.

I will never link to a product about which I have reservations or qualms, either about the product or about the company offering the product. I only recommend products that I use myself and bring value to the genetic genealogy community. If you wonder why there aren’t more links, that’s why and that’s my commitment to you.

Thank you for your readership, your ongoing support and for purchasing through the affiliate link if you are interested in making a purchase at Family Tree DNA.

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?

______________________________________________________________________

Standard Disclosure

This standard disclosure will now appear at the bottom of every article in compliance with the FTC Guidelines.

Hot links are provided to Family Tree DNA, where appropriate. If you wish to purchase one of their products, and you click through one of the links in an article to Family Tree DNA, or on the sidebar of this blog, I receive a small contribution if you make a purchase. Clicking through the link does not affect the price you pay. This affiliate relationship helps to keep this publication, with more than 850 articles about all aspects of genetic genealogy, free for everyone.

I do not accept sponsorship for this blog, nor do I write paid articles, nor do I accept contributions of any type from any vendor in order to review any product, etc. In fact, I pay a premium price to prevent ads from appearing on this blog.

When reviewing products, in most cases, I pay the same price and order in the same way as any other consumer. If not, I state very clearly in the article any special consideration received. In other words, you are reading my opinions as a long-time consumer and consultant in the genetic genealogy field.

I will never link to a product about which I have reservations or qualms, either about the product or about the company offering the product. I only recommend products that I use myself and bring value to the genetic genealogy community. If you wonder why there aren’t more links, that’s why and that’s my commitment to you.

Thank you for your readership, your ongoing support and for purchasing through the affiliate link if you are interested in making a purchase at Family Tree DNA.

Concepts – Why Genetic Genealogy and Triangulation?

One of the questions often asked is why triangulation in genetic genealogy is so important.

Before I answer that, let’s take a look at why genealogists use autosomal DNA for genetic genealogy in the first place.

Why Genetic Genealogy?

Aside from ethnicity testing, genetic genealogists utilize autosomal DNA testing to further their genealogical research or confirm the research they have already performed. Genetic genealogy cannot stand alone on DNA evidence, but must include traditional genealogical research. DNA is simply another tool in the genealogist’s tool box – albeit a critical one.

There are three established primary vendors in this field, Family Tree DNA, Ancestry and 23andMe, plus a few newcomers. All three vendors offer autosomal DNA tests utilized by genetic genealogists in various ways. If you want to learn more about the differences between these vendors’ offerings, please read the article, “Which DNA Test is Best?”

In order to achieve genealogical goals, there are four criteria that need to be met. All are required to achieve triangulation which is the only way to confirm a genealogical ancestral match to a specific ancestor.

  • DNA Matching – The tester’s DNA matches that of other testers at the company where they tested, or at GedMatch. All three vendors provide matching information, along with GedMatch, a third-party tool utilized by genetic genealogists.

Family Tree DNA assigns matches to either maternal, paternal or both sides of the tester’s tree based on connecting the DNA of relatives, up through third cousins, who have tested to their appropriate location in the tester’s tree.

In the example above, you can see the individuals linked to my tree include my mother with her Family Finder test, plus her two first cousins, Donald and Cheryl Ferverda who have also tested.

  • Ancestor Matching – The testers identify a common ancestor or ancestral line based on their previous work, aka, genealogy and family trees.  In the example above, the common ancestors are the parents of the brothers, John and Roscoe Ferverda.  Identifying a common ancestor is an easy task with known close relatives, but becomes more challenging the more distant the common ancestor.

Of the vendors, 23andMe does not have a Gedcom upload or ability for testers to display trees and for the vendor to utilize to match surnames, although they can link to external trees. Ancestry provides “tree matching,” shown above, and Ancestry and Family Tree DNA, shown below, both provide surname matching.

  • Segment Matching – Utilizing chromosome browsers or downloaded match lists including segment information to identify actual DNA segments that match other testers.

Family Tree DNA’s chromosome browser is shown above.

Each individual tester will have two groups of matches on the same segment, one group from their mother’s side of the tree and one from their father’s side of the tree. Each tester carries DNA inherited from both parents on two different “sides” of each chromosome. You can read more about that in the article, One Chromosome, Two Sides, No Zipper – ICW and the Matrix.

Of the three vendors, Ancestry does not provide segment matching, a chromosome browser, nor any segment information, so testers cannot perform this step at Ancestry.

23andMe does provide this information, but each tester must individually “opt in” to data sharing, and many do not. If testers do not globally “opt in” they must authorize sharing individually for every match, so testers will not be able to see the chromosome segment information for many 23andMe matches. In my case, only about 60% are sharing.

Family Tree DNA provides a chromosome browser, the file download capability with segment information, and everyone authorizes sharing of information when they initially test – so there is no opt-in confusion.

Ancestry and 23andMe raw DNA data files can be transferred to both Family Tree DNA and GedMatch where chromosome browsers and other tools are available. For more information about transferring files, please read Autosomal DNA Transfers – Which Companies Accept Which Tests?

Triangulation – The process used to combine all three of the above steps in order to assign specific segments of the tester’s DNA to specific ancestors, by virtue of:

  • The tester’s DNA matching the DNA of other testers on a specific segment.
  • Identifying that the individuals who match the tester on that segment also match each other. This is part of the methodology employed to group the testers matches into two groups, the maternal and paternal groupings.
  • Identifying which ancestor contributed that segment to all of the people who match the tester and each other on that same segment.

In order for a group of matches to triangulate, they must match each other on the same segment of DNA and they must all share a common ancestor.

Triangulation is part DNA, meaning the inheritance, part technology, meaning the ability to show that all testers in a match group all match each other and on the same segment, and part genealogy, meaning the ability to identify the common ancestor of the group of individuals.

The following chart shows a portion of my match download file on chromosome 5 from Family Tree DNA.

As you can see, these matches all cover significant portions of the same segment on chromosome 5.

Without further investigation, we know that I match all of these people, but we don’t know what that information is telling us about my genealogy. We don’t know who matches each other, and we can’t tell which people are from my mother’s and father’s sides. We also don’t know who the common ancestor is or common ancestors are.

However, looking at the trees of the individuals involved, or contacting them for further information, and/or recognizing known cousins from a specific line all combine to contribute to the identification of our common ancestors.

Below is the same spreadsheet, now greatly enriched after my genealogy work is applied to the DNA matches in two additional columns.

I’ve colored my triangulated groups pink for my mother’s side and blue for my father’s side.

In this case, I also have access to my cousins’ DNA match results, so I can view their matches as well, looking for common matches on my match list.

One of the reasons genealogists always suggest testing older family members and as many cousins as possible is because triangulation becomes much easier with known cousins from particular lines to point the way to the common ancestor. In this case, one cousin, Joe, is from my mother’s side and one, Lou, is from my father’s side.

By looking at my matches’ genealogy, I’ve now been able to assign this particular segment on chromosome 5, on my mother’s side to ancestors Johann Michael Miller and his wife Susanna Berchtol. The same segment, on my father’s side is inherited from Charles Dodson and his wife, Ann, last name unknown.

In order to achieve triangulation, the common ancestor must be determined for the match group. Once triangulation is achieved, descent from the common ancestor is confirmed.

Unless you are dealing with very close known relatives, like the Ferverda first cousins, there is no other way to prove a genetic connection to a specific ancestor.

At Family Tree DNA, I can utilize the chromosome browser and the ICW and matrix tools to determine which of this group matches each other. At 23andMe, I can utilize their shared DNA matching tool. This information can then be recorded in my DNA spreadsheet, as illustrated above.

Triangulation cannot be achieved at Ancestry or utilizing their tools. Ancestry’s DNA Circles provide extended match groups, indicating who matches whom for a particular ancestor shown in a tester’s tree, but do not indicate that the matches are on the same segment. Circles do not guarantee that Circle members are matching on DNA from that ancestor, only that they do match and show a common ancestor in their tree.  The third triangulation step of segment matching is missing.  Ancestry does not provide segment information in any format, so Ancestry customers who want to triangulate can either retest elsewhere or download their data files to either Family Tree DNA or GedMatch for free.

Summary

Before the advent of genetic genealogy, genealogists had to take it on faith that the paper trail was accurate, and that there was no misattributed parentage – either through formal or informal adoption or hanky-panky.  That’s not the case anymore.

Today, DNA through triangulation can prove ancestry for groups of people to a common ancestor by identifying segments that have descended from that ancestor and are found in multiple descendants today.

Of course, the next step is to break down those remaining brick walls. For example, what is the birth name of Ann, wife of Charles Dodson, whose surname is unknown? Logically, the DNA descended from a couple, meaning Charles and Ann, contains DNA from both individuals. We don’t know if that segment on chromosome 5 is from Ann, Charles, or parts from both, BUT, if we begin to see a further breakdown to another, unknown family line among the Charles and Ann segments, that might be a clue.

One day, in the future, we’ll be able to identify our unknown family lines through DNA matches and other people’s triangulation. That indeed, is the Holy Grail.

Additional Resources

If you’d like to read more specific information about autosomal DNA matching and triangulation, be sure to read the links in the article, above. The following articles may be of interest as well:

DeMystifying Autosomal DNA Matching

Autosomal DNA Testing 101 – What Now?

Autosomal DNA Matching Confidence Spectrum

Concepts – Segment Size, Legitimate and False Matches

How Your Autosomal DNA Identifies Your Ancestors

Concepts – Identical by Descent, State, Population and Chance

Nine Autosomal Tools at Family Tree DNA

If you think you might come up short, because you have only one known cousin who has tested, well, think again.

Just One Cousin

Here’s wishing you lots of triangulated matches!!!

Which DNA Test is Best?

If you’re reading this article, congratulations. You’re a savvy shopper and you’re doing some research before purchasing a DNA test. You’ve come to the right place.

The most common question I receive is asking which test is best to purchase. There is no one single best answer for everyone – it depends on your testing goals and your pocketbook.

Testing Goals

People who want to have their DNA tested have a goal in mind and seek results to utilize for their particular purpose. Today, in the Direct to Consumer (DTC) DNA market space, people have varied interests that fall into the general categories of genealogy and medical/health.

I’ve approached the question of “which test is best” by providing information grouped into testing goal categories.  I’ve compared the different vendors and tests from the perspective of someone who is looking to test for those purposes – and I’ve created separate sections of this article for each interest..

We will be discussing testing for:

  • Ethnicity – Who Am I? – Breakdown by Various World Regions
  • Adoption – Finding Missing Parents or Close Family
  • Genealogy – Cousin Matching and Ancestor Search/Verification
  • Medical/Health

We will be reviewing the following test types:

  • Autosomal
  • Y DNA (males only)
  • Mitochondrial DNA

I have included summary charts for each section, plus an additional chart for:

  • Additional Vendor Considerations

If you are looking to select one test, or have limited funds, or are looking to prioritize certain types of tests, you’ll want to read about each vendor, each type of test, and each testing goal category.

Each category reports information about the vendors and their products from a different perspective – and only you can decide which of these perspectives and features are most important to you.

You might want to read this short article for a quick overview of the 4 kinds of DNA used for genetic genealogy and DTC testing and how they differ.

The Big 3

Today, there are three major players in the DNA testing market, not in any particular order:

Each of these companies offers autosomal tests, but each vendor offers features that are unique. Family Tree DNA and 23andMe offer additional tests as well.

In addition to the Big 3, there are a couple of new kids on the block that I will mention where appropriate. There are also niche players for the more advanced genetic genealogist or serious researcher, and this article does not address advanced research.

In a nutshell, if you are serious genealogist, you will want to take all of the following tests to maximize your tools for solving genealogical puzzles. There is no one single test that does everything.

  • Full mitochondrial sequence that informs you about your matrilineal line (only) at Family Tree DNA. This test currently costs $199.
  • Y DNA test (for males only) that informs you about your direct paternal (surname) line (only) at Family Tree DNA. This test begins at $169 for 37 markers.
  • Family Finder, an autosomal test that provides ethnicity estimates and cousin matching at Family Tree DNA. This test currently costs $89.
  • AncestryDNA, an autosomal test at Ancestry.com that provides ethnicity estimates and cousin matching. (Do not confuse this test with Ancestry by DNA, which is not the same test and does not provide the same features.) This test currently costs $99, plus the additional cost of a subscription for full feature access. You can test without a subscription, but nonsubscribers can’t access all of the test result features provided to Ancestry subscribers.
  • 23andMe Ancestry Service test, an autosomal test that provides ethnicity estimates and cousin matching. The genealogy version of this test costs $99, the medical+genealogy version costs $199.

A Word About Third Party Tools

A number of third party tools exist, such as GedMatch and DNAGedcom.com, and while these tools are quite useful after testing, these vendors don’t provide tests. In order to use these sites, you must first take an autosomal DNA test from a testing vendor. This article focuses on selecting your DNA testing vendor based on your testing goals.

Let’s get started!

Ethnicity

Many people are drawn to DNA testing through commercials that promise to ‘tell you who you are.” While the allure is exciting, the reality is somewhat different.

Each of the major three vendors provide an ethnicity estimate based on your autosomal DNA test, and each of the three vendors will provide you with a different result.

Yep, same person, different ethnicity breakdowns.

Hopefully, the outcomes will be very similar, but that’s certainly not always the case. However, many people take one test and believe those results wholeheartedly. Please don’t. You may want to read Concepts – Calculating Ethnicity Percentages to see how varied my own ethnicity reports are at various vendors as compared to my known genealogy.

The technology for understanding “ethnicity” from a genetic perspective is still very new. Your ethnicity estimate is based on reference populations from around the world – today. People and populations move, and have moved, for hundreds, thousands and tens of thousands of years. Written history only reaches back a fraction of that time, so the estimates provided to people today are not exact.

That isn’t to criticize any individual vendor. View each vendor’s results not as gospel, but as their opinion based on their reference populations and their internal proprietary algorithm of utilizing those reference populations to produce your ethnicity results.

To read more about how ethnicity testing works, and why your results may vary between vendors or not be what you expected, click here.

I don’t want to discourage anyone from testing, only to be sure consumers understand the context of what they will be receiving. Generally speaking, these results are accurate at the continental level, and less accurate within continents, such as European regional breakdowns.

All three testing companies provide additional features or tools, in addition to your ethnicity estimates, that are relevant to ethnicity or population groups.

Let’s look at each company separately.

Ethnicity – Family Tree DNA

Family Tree DNA’s ethnicity tool is called myOrigins and provides three features or tools in addition to the actual ethnicity estimate and associated ethnicity map.

Please note that throughout this article you can click on any image to enlarge.

On the myOrigins ethnicity map page, above, your ethnicity percentages and map are shown, along with two additional features.

The Shared Origins box to the left shows the matching ethnic components of people on your DNA match list. This is particularly useful if you are trying to discover, for example, where a particular minority admixture comes from in your lineage. You can select different match types, for example, immediate relatives or X chromosome matches, which have special inheritance qualities.

Clicking on the apricot (mitochondrial DNA) and green (Y DNA) pins in the lower right corner drops the pins in the locations on your map of the most distant ancestral Y and mitochondrial DNA locations of the individuals in the group you have selected in the Shared Origins match box. You may or may not match these individuals on the Y or mtDNA lines, but families tend to migrate in groups, so match hints of any kind are important.

A third unique feature provided by Family Tree DNA is Ancient Origins, a tool released with little fanfare in November 2016.

Ancient Origins shows the ancient source of your European DNA, based on genome sequencing of ancient DNA from the locations shown on the map.

Additionally, Family Tree DNA hosts an Ancient DNA project where they have facilitated the upload of the ancient genomes so that customers today can determine if they match these ancient individuals.

Kits included in the Ancient DNA project are shown in the chart below, along with their age and burial location. Some have matches today, and some of these samples are included on the Ancient Origins map.

Individual Approx. Age Burial Location Matches Ancient Origins Map
Clovis Anzick 12,500 Montana (US) Yes No
Linearbandkeramik 7,500 Stuttgart, Germany Yes Yes
Loschbour 8,000 Luxembourg Yes Yes
Palaeo-Eskimo 4,000 Greenland No No
Altai Neanderthal 50,000 Altai No No
Denisova 30,000 Siberia No No
Hinxton-4 2,000 Cambridgeshire, UK No No
BR2 3,200 Hungary Yes Yes
Ust’-Ishim 45,000 Siberia Yes No
NE1 7,500 Hungary Yes Yes

Ethnicity – Ancestry

In addition to your ethnicity estimate, Ancestry also provides a feature called Genetic Communities.

Your ethnicity estimate provides percentages of DNA found in regions shown on the map by fully colored shapes – green in Europe in the example above. Genetic Communities show how your DNA clusters with other people in specific regions of the world – shown with dotted clusters in the US in this example.

In my case, my ethnicity at Ancestry shows my European roots, illustrated by the green highlighted areas, and my two Genetic Communities are shown by yellow and red dotted regions in the United States.

My assigned Genetic Communities indicate that my DNA clusters with other people whose ancestors lived in two regions; The Lower Midwest and Virginia as well as the Alleghenies and Northeast Indiana.

Testers can then view their DNA matches within that community, as well as a group of surnames common within that community.

The Genetic Communities provided for me are accurate, but don’t expect all of your genealogical regions to be represented in Genetic Communities. For example, my DNA is 25% German, and I don’t have any German communities today, although ancestry will be adding new Genetic Communities as new clusters are formed.

You can read more about Genetic Communities here and here.

Ethnicity – 23andMe

In addition to ethnicity percentage estimates, called Ancestry Composition, 23andMe offers the ability to compare your Ancestry Composition against that of your parent to see which portions of your ethnicity you inherited from each parent, although there are problems with this tool incorrectly assigning parental segments.

Additionally, 23andMe paints your chromosome segments with your ethnic heritage, as shown below.

You can see that my yellow Native American segments appear on chromosomes 1 and 2.

In January 2017, 23andMe introduced their Ancestry Timeline, which I find to be extremely misleading and inaccurate. On my timeline, shown below, they estimate that my most recent British and Irish ancestor was found in my tree between 1900 and 1930 while in reality my most recent British/Irish individual found in my tree was born in England in 1759.

I do not view 23andMe’s Ancestry Timeline as a benefit to the genealogist, having found that it causes people to draw very misleading conclusions, even to the point of questioning their parentage based on the results. I wrote about their Ancestry Timeline here.

Ethnicity Summary

All three vendors provide both ethnicity percentage estimates and maps. All three vendors provide additional tools and features relevant to ethnicity. Vendors also provide matching to other people which may or may not be of interest to people who test only for ethnicity. “Who you are” only begins with ethnicity estimates.

DNA test costs are similar, although the Family Tree DNA test is less at $89. All three vendors have sales from time to time.

Ethnicity Vendor Summary Chart

Ethnicity testing is an autosomal DNA test and is available for both males and females.

Family Tree DNA Ancestry 23andMe
Ethnicity Test Included with $89 Family Finder test Included with $99 Ancestry DNA test Included with $99 Ancestry Service
Percentages and Maps Yes Yes Yes
Shared Ethnicity with Matches Yes No Yes
Additional Feature Y and mtDNA mapping of ethnicity matches Genetic Communities Ethnicity phasing against parent (has issues)
Additional Feature Ancient Origins Ethnicity mapping by chromosome
Additional Feature Ancient DNA Project Ancestry Timeline

 

Adoption and Parental Identity

DNA testing is extremely popular among adoptees and others in search of missing parents and grandparents.

The techniques used for adoption and parental search are somewhat different than those used for more traditional genealogy, although non-adoptees may wish to continue to read this section because many of the features that are important to adoptees are important to other testers as well.

Adoptees often utilize autosomal DNA somewhat differently than traditional genealogists by using a technique called mirror trees. In essence, the adoptee utilizes the trees posted online of their closest DNA matches to search for common family lines within those trees. The common family lines will eventually lead to the individuals within those common trees that are candidates to be the parents of the searcher.

Here’s a simplified hypothetical example of my tree and a first cousin adoptee match.

The adoptee matches me at a first cousin level, meaning that we share at least one common grandparent – but which one? Looking at other people the adoptee matches, or the adoptee and I both match, we find Edith Lore (or her ancestors) in the tree of multiple matches. Since Edith Lore is my grandmother, the adoptee is predicted to be my first cousin, and Edith Lore’s ancestors appear in the trees of our common matches – that tells us that Edith Lore is also the (probable) grandmother of the adoptee.

Looking at the possibilities for how Edith Lore can fit into the tree of me and the adoptee, as first cousins, we fine the following scenario.

Testing the known child of daughter Ferverda will then provide confirmation of this relationship if the known child proves to be a half sibling to the adoptee.

Therefore, close matches, the ability to contact matches and trees are very important to adoptees. I recommend that adoptees make contact with www.dnaadoption.com. The volunteers there specialize in adoptions and adoptees, provide search angels to help people and classes to teach adoptees how to utilize the techniques unique to adoption search such as building mirror trees.

For adoptees, the first rule is to test with all 3 major vendors plus MyHeritage. Family Tree DNA allows you to test with both 23andMe and Ancestry and subsequently transfer your results to Family Tree DNA, but I would strongly suggest adoptees test on the Family Tree DNA platform instead. Your match results from transferring to Family Tree DNA from other companies, except for MyHeritage, will be fewer and less reliable because both 23andMe and Ancestry utilize different chip technology.

For most genealogists, MyHeritage is not a player, as they have only recently entered the testing arena, have a very small data base, no tools and are having matching issues. I recently wrote about MyHeritage here. However, adoptees may want to test with MyHeritage, or upload your results to MyHeritage if you tested with Family Tree DNA, because your important puzzle-solving match just might have tested there and no place else. You can read about transfer kit compatibility and who accepts which vendors’ tests here.

Adoptees can benefit from ethnicity estimates at the continental level, meaning that regional (within continent) or minority ethnicity should be taken with a very large grain of salt. However, knowing that you have 25% Jewish heritage, for example, can be a very big clue to an adoptee’s search.

Another aspect of the adoptees search that can be relevant is the number of foreign testers. For many years, neither 23andMe, nor Ancestry tested substantially (or at all) outside the US. Family Tree DNA has always tested internationally and has a very strong Jewish data base component.

Not all vendors report X chromosome matches. The X chromosome is important to genetic genealogy, because it has a unique inheritance path. Men don’t inherit an X chromosome from their fathers. Therefore, if you match someone on the X chromosome, you know the relationship, for a male, must be from their mother’s side. For a female, the relationship must be from the mother or the father’s mother’s side. You can read more about X chromosome matching here.

Neither Ancestry nor MyHeritage have chromosome browsers which allow you to view the segments of DNA on which you match other individuals, which includes the X chromosome.

Adoptee Y and Mitochondrial Testing

In addition to autosomal DNA testing, adoptees will want to test their Y DNA (males only) and mitochondrial DNA.

These tests are different from autosomal DNA which tests the DNA you receive from all of your ancestors. Y and mitochondrial DNA focus on only one specific line, respectively. Y DNA is inherited by men from their fathers and the Y chromosome is passed from father to son from time immemorial. Therefore, testing the Y chromosome provides us with the ability to match to current people as well as to use the Y chromosome as a tool to look far back in time. Adoptees tend to be most interested in matching current people, at least initially.

Working with male adoptees, I have a found that about 30% of the time a male will match strongly to a particular surname, especially at higher marker levels. That isn’t always true, but adoptees will never know if they don’t test. An adoptee’s match list is shown at 111 markers, below.

Furthermore, utilizing the Y and mitochondrial DNA test in conjunction with autosomal DNA matching at Family Tree DNA helps narrows possible relatives. The Advanced Matching feature allows you to see who you match on both the Y (or mitochondrial) DNA lines AND the autosomal test, in combination.

Mitochondrial DNA tests the matrilineal line only, as women pass their mitochondrial DNA to all of their children, but only females pass it on. Family Tree DNA provides matching and advanced combination matching/searching for mitochondrial DNA as well as Y DNA. Both genders of children carry their mother’s mitochondrial DNA. Unfortunately, mitochondrial DNA is more difficult to work with because of the surname changes in each generation, but you cannot be descended from a woman, or her direct matrilineal ancestors if you don’t substantially match her mitochondrial DNA.

Some vendors state that you receive mitochondrial DNA with your autosomal results, which is only partly accurate. At 23andMe, you receive a haplogroup but no detailed results and no matching. 23andMe does not test the entire mitochondria and therefore cannot provide either advanced haplogroup placement nor Y or mitochondrial DNA matching between testers.

For additional details on the Y and Mitochondrial DNA tests themselves and what you receive, please see the Genealogy – Y and Mitochondrial DNA section.

Adoption Summary

Adoptees should test with all 4 vendors plus Y and mitochondrial DNA testing.

  • Ancestry – due to their extensive data base size and trees
  • Family Tree DNA – due to their advanced tools, chromosome browser, Y and mitochondrial DNA tests (Ancestry and 23andMe participants can transfer autosomal raw data files and see matches for free, but advanced tools require either an unlock fee or a test on the Family Tree DNA platform)
  • 23andMe – no trees and many people don’t participate in sharing genetic information
  • MyHeritage – new kid on the block, working through what is hoped are startup issues
  • All adoptees should take the full mitochondrial sequence test.
  • Male adoptees should take the 111 marker Y DNA test, although you can start with 37 or 67 markers and upgrade later.
  • Y and mitochondrial tests are only available at Family Tree DNA.

Adoptee Vendor Feature Summary Chart

Family Tree DNA Ancestry 23andMe MyHeritage
Autosomal DNA – Males and Females
Matching Yes Yes Yes Yes – problems
Relationship Estimates* Yes – May be too close Yes – May be too distant Yes – Matches may not be sharing Yes –  problematic
International Reach Very strong Not strong but growing Not strong Small but subscriber base is European focused
Trees Yes Yes No Yes
Tree Quantity 54% have trees, 46% no tree (of my first 100 matches) 56% have trees, 44% no tree or private (of my first 100 matches) No trees ~50% don’t have trees or are private (cannot discern private tree without clicking on every tree)
Data Base Size Large Largest Large – but not all opt in to matching Very small
My # of Matches on 4-23-2017 2,421 23,750 1,809 but only 1,114 are sharing 75
Subscription Required No No for partial, Yes for full functionality including access to matches’ trees, minimal subscription for $49 by calling Ancestry No No for partial, Yes for full functionality
Other Relevant Tools New Ancestor Discoveries
Autosomal DNA Issues Many testers don’t have trees Many testers don’t have trees Matching opt-in is problematic, no trees at all Matching issues, small data base size is problematic, many testers don’t have trees
Contact Methodology E-mail address provided to matches Internal message system – known delivery issues Internal message system Internal message system
X Chromosome Matching Yes No Yes No
Y-DNA – Males Only
Y DNA STR Test Yes- 37, 67, and 111 markers No No No
Y Haplogroup Yes as part of STR test plus additional testing available No Yes, basic level but no additional testing available, outdated haplogroups No
Y Matching Yes No No No
Advanced Matching Between Y and Autosomal Yes No No No
Mitochondrial DNA- Males and Females
Test Yes, partial and full sequence No No No
Mitochondrial DNA Haplogroup Yes, included in test No Yes, basic but full haplogroup not available, haplogroup several versions behind No
Advanced Matching Between Mitochondrial and Autosomal Yes No No No

Genealogy – Cousin Matching and Ancestor Search/Verification

People who want to take a DNA test to find cousins, to learn more about their genealogy, to verify their genealogy research or to search for unknown ancestors and break down brick walls will be interested in various types of testing

Test Type Who Can Test
Y DNA – direct paternal line Males only
Mitochondrial DNA – direct matrilineal line Males and Females
Autosomal – all lines Males and Females

Let’s begin with autosomal DNA testing for genealogy which tests your DNA inherited from all ancestral lines.

Aside from ethnicity, autosomal DNA testing provides matches to other people who have tested. A combination of trees, meaning their genealogy, and their chromosome segments are used to identify (through trees) and verify (through DNA segments) common ancestor(s) and then to assign a particular DNA segment(s) to that ancestor or ancestral couple. This process, called triangulation, then allows you to assign specific segments to particular ancestors, through segment matching among multiple people. You then know that when another individual matches you and those other people on the same segment, that the DNA comes from that same lineage. Triangulation is the only autosomal methodology to confirm ancestors who are not close relatives, beyond the past 2-3 generations or so.

All three vendors provide matching, but the tools they include and their user interfaces are quite different. 

Genealogy – Autosomal –  Family Tree DNA

Family Tree DNA entered DNA testing years before any of the others, initially with Y and mitochondrial DNA testing.

Because of the diversity of their products, their website is somewhat busier, but they do a good job of providing areas on the tester’s personal landing page for each of the products and within each product, a link for each feature or function.

For example, the Family Finder test is Family Tree DNA’s autosomal test. Within that product, tools provided are:

  • Matching
  • Chromosome Browser
  • Linked Relationships
  • myOrigins
  • Ancient Origins
  • Matrix
  • Advanced Matching

Unique autosomal tools provided by Family Tree DNA are:

  • Linked Relationships that allows you to connect individuals that you match to their location in your tree, indicating the proper relationship. Phased Family Matching uses these relationships within your tree to indicate which side of your tree other matches originate from.
  • Phased Family Matching shows which side of your tree, maternal, paternal or both, someone descends from, based on phased DNA matching between you and linked relationship matches as distant as third cousins. This allows Family Tree DNA to tell you whether matches are paternal (blue icon), maternal (red icon) or both (purple icon) without a parent’s DNA. This is one of the best autosomal tools at Family Tree DNA, shown below.

  • In Common With and Not In Common With features allow you to sort your matches in common with another individual a number of ways, or matches not in common with that individual.
  • Filtered downloads provide the downloading of chromosome data for your filtered match list.
  • Stackable filters and searches – for example, you can select paternal matches and then search for a particular surname or ancestral surname within the paternal matches.
  • Common ethnicity matching through myOrigins allows you to see selected groups of individuals who match you and share common ethnicities.
  • Y and mtDNA locations of autosomal matches are provided on your ethnicity map through myOrigins.
  • Advanced matching tool includes Y, mtDNA and autosomal in various combinations. Also includes matches within projects where the tester is a member as well as by partial surname.
  • The matrix tool allows the tester to enter multiple people that they match in order to see if those individuals also match each other. The matrix tool is, in combination with the in-common-with tool and the chromosome browser is a form of pseudo triangulation, but does not indicate that the individuals match on the same segment.

  • Chromosome browser with the ability to select different segment match thresholds to display when comparing 5 or fewer individuals to your results.
  • Projects to join which provide group interaction and allow individuals to match only within the project, if desired.

To read more about how to utilize the various autosomal tools at Family Tree DNA, with examples, click here.

Genealogy – Autosomal – Ancestry

Ancestry only offers autosomal DNA testing to their customers, so their page is simple and straightforward.

Ancestry is the only testing vendor (other than MyHeritage who is not included in this section) to require a subscription for full functionality, although if you call the Ancestry support line, a minimal subscription is available for $49. You can see your matches without a subscription, but you cannot see your matches trees or utilize other functions, so you will not be able to tell how you connect to your matches. Many genealogists have Ancestry subscriptions, so this is minimally problematic for most people.

However, if you don’t realize you need a subscription initially, the required annual subscription raises the effective cost of the test quite substantially. If you let your subscription lapse, you no longer have access to all DNA features. The cost of testing with Ancestry is the cost of the test plus the cost of a subscription if you aren’t already a subscriber.

This chart, from the Ancestry support center, provides details on which features are included for free and which are only available with a subscription.

Unique tools provided by Ancestry include:

  • Shared Ancestor Hints (green leaves) which indicate a match with whom you share a common ancestor in your tree connected to your DNA, allowing you to display the path of you and your match to the common ancestor. In order to take advantage of this feature, testers must link their tree to their DNA test. Otherwise, Ancestry can’t do tree matching.  As far as I’m concerned, this is the single most useful DNA tool at Ancestry. Subscription required.

  • DNA Circles, example below, are created when several people whose DNA matches also share a common ancestor. Subscription required.

  • New Ancestor Discoveries (NADs), which are similar to Circles, but are formed when you match people descended from a common ancestor, but don’t have that ancestor in your tree. The majority of the time, these NADs are incorrect and are, when dissected and the source can be determined, found to be something like the spouse of a sibling of your ancestor. I do not view NADs as a benefit, more like a wild goose chase, but for some people these could be useful so long as the individual understands that these are NOT definitely ancestors and only hints for research. Subscription required.
  • Ancestry uses a proprietary algorithm called Timber to strip DNA from you and your matches that they consider to be “too matchy,” with the idea that those segments are identical by population, meaning likely to be found in large numbers within a population group – making them meaningless for genealogy. The problem is that Timber results in the removal of valid segments, especially in endogamous groups like Acadian families. This function is unique to Ancestry, but many genealogists (me included) don’t consider Timber a benefit.
  • Genetic Communities shows you groups of individuals with whom your DNA clusters. The trees of cluster members are then examined by Ancestry to determine connections from which Genetic Communities are formed. You can filter your DNA match results by Genetic Community.

Genealogy – Autosomal – 23and Me

Unfortunately, the 23andMe website is not straightforward or intuitive. They have spent the majority of the past two years transitioning to a “New Experience” which has resulted in additional confusion and complications when matching between people on multiple different platforms. You can take a spin through the New Experience by clicking here.

23andMe requires people to opt-in to sharing, even after they have selected to participate in Ancestry Services (genealogy) testing, have opted-in previously and chosen to view their DNA Relatives. Users on the “New Experience” can then either share chromosome data and results with each other individually, meaning on a one by one basis, or globally by a one-time opt-in to “open sharing” with matches. If a user does not opt-in to both DNA Relatives and open sharing, sharing requests must be made individually to each match, and they must opt-in to share with each individual user. This complexity and confusion results in an approximate sharing rate of between 50 and 60%. One individual who religiously works their matches by requesting sharing now has a share rate of about 80% of their matches in the data base who HAVE initially selected to participate in DNA Relatives. You can read more about the 23andMe experience at this link.

Various genetic genealogy reports and tools are scattered between the Reports and Tools tabs, and within those, buried in non-intuitive locations. If you are going to utilize 23andMe for matching and genealogy, in addition to the above link, I recommend Kitty Cooper’s blogs about the new DNA Relatives here and on triangulation here. Print the articles, and use them as a guide while navigating the 23andMe site.

Note that some screens (the Tools, DNA Relatives, then DNA tab) on the site do not display/work correctly utilizing Internet Explorer, but do with Edge or other browsers.

The one genealogy feature unique to 23andMe is:

  • Triangulation at 23andMe allows you to select a specific match to compare your DNA against. Several pieces of information will be displayed, the last of which, scrolling to the bottom, is a list of your common relatives with the person you selected.

In the example below, I’ve selected to see the matches I match in common with known family member, Stacy Den (surnames have been obscured for privacy reasons.)  Please note that the Roberta V4 Estes kit is a second test that I took for comparison purposes when the new V4 version of 23andMe was released.  Just ignore that match, because, of course I match myself as a twin.

If an individual does not match both you and your selected match, they will not appear on this list.

In the “relatives in common” section, each person is listed with a “shared DNA” column. For a person to be shown on this “in common” list, you obviously do share DNA with these individuals and they also share with your match, but the “shared DNA” column goes one step further. This column indicates whether or not you and your match both share a common DNA segment with the “in common” person.

I know this is confusing, so I’ve created this chart to illustrate what will appear in the “Shared DNA” column of the individuals showing on the list of matches, above, shared between me and Stacy Den.

Clicking on “Share to see” sends Sarah a sharing request for her to allow you to see her segment matches.

Let’s look at an example with “yes” in the Shared DNA column.

Clicking on the “Yes” in the Shared DNA column of Debbie takes us to the chromosome browser which shows both your selected match, Stacy in my case, and Debbie, the person whose “yes” you clicked.

All three people, meaning me, Stacy and Debbie share a common DNA segment, shown below on chromosome 17.

What 23andMe does NOT say is that these people. Stacy and Debbie, also match each other, in addition to matching me, which means all three of us triangulate.

Because I manage Stacy’s kit at 23andMe, I can check to see if Debbie is on Stacy’s match list, and indeed, Debbie is on Stacy’s match list and Stacy does match both Debbie and me on chromosome 17 in exactly the same location shown above, proving unquestionably that the three of us all match each other and therefore triangulate on this segment. In our case, it’s easy to identify our common relative whose DNA all 3 of us share.

Genealogy – Autosomal Summary

While all 3 vendors offer matching, their interfaces and tools vary widely.

I would suggest that Ancestry is the least sophisticated and has worked hard to make their tools easy for the novice working with genetic genealogy. Their green leaf DNA+Tree Matching is their best feature, easy to use and important for the novice and experienced genealogist alike.  Now, if they just had that chromosome browser so we could see how we match those people.

Ancestry’s Circles, while a nice feature, encourage testers to believe that their DNA or relationship is confirmed by finding themselves in a Circle, which is not the case.

Circles can be formed as the result of misinformation in numerous trees. For example, if I were to inaccurately list Smith as the surname for one of my ancestor’s wives, I would find myself in a Circle for Barbara Smith, when in fact, there is absolutely no evidence whatsoever that her surname is Smith. Yet, people think that Barbara Smith is confirmed due to a Circle having been formed and finding themselves in Barbara Smith’s Circle. Copying incorrect trees equals the formation of incorrect Circles.

It’s also possible that I’m matching people on multiple lines and my DNA match to the people in any given Circle is through another common ancestor entirely.

A serious genealogist will test minimally at Ancestry and at Family Tree DNA, who provides a chromosome browser and other tools necessary to confirm relationships and shared DNA segments.

Family Tree DNA is more sophisticated, so consequently more complex to use.  They provide matching plus numerous other tools. The website and matching is certainly friendly for the novice, but to benefit fully, some experience or additional education is beneficial, not unlike traditional genealogy research itself. This is true not just for Family Tree DNA, but GedMatch and 23andMe who all three utilize chromosome browsers.

The user will want to understand what a chromosome browser is indicating about matching DNA segments, so some level of education makes life a lot easier. Fortunately, understanding chromosome browser matching is not complex. You can read an article about Match Groups and Triangulation here. I also have an entire series of Concepts articles, Family Tree DNA offers a webinar library, their Learning Center and other educational resources are available as well.

Family Tree DNA is the only vendor to provide Phased Family Matches, meaning that by connecting known relatives who have DNA tested to your tree, Family Tree DNA can then identify additional matches as maternal, paternal or both. This, in combination with pseudo-phasing are very powerful matching tools.

23andMe is the least friendly of the three companies, with several genetic genealogy unfriendly restrictions relative to matching, opt-ins, match limits and such. They have experienced problem after problem for years relative to genetic genealogy, which has always been a second-class citizen compared to their medical research, and not a priority.

23andMe has chosen to implement a business model where their customers must opt-in to share segment information with other individuals, either one by one or by opting into open sharing. Based on my match list, roughly 60% of my actual DNA matches have opted in to sharing.

Their customer base includes fewer serious genealogists and their customers often are not interested in genealogy at all.

Having said that, 23andMe is the only one of the three that provides actual triangulated matches for users on the New Experience and who have opted into sharing.

If I were entering the genetic genealogy testing space today, I would test my autosomal DNA at Ancestry and at Family Tree DNA, but I would probably not test at 23andMe. I would test both my Y DNA (if a male) and mitochondrial at Family Tree DNA.

Thank you to Kitty Cooper for assistance with parent/child matching and triangulation at 23andMe.

Genealogy Autosomal Vendor Feature Summary Chart

Family Tree DNA Ancestry 23andMe
Matching Yes Yes Yes – each person has to opt in for open sharing or authorize sharing individually, many don’t
Estimated Relationships Yes Yes Yes
Chromosome Browser Yes No – Large Issue Yes
Chromosome Browser Threshold Adjustment Yes No Chromosome Browser No
X Chromosome Matching Yes No Yes
Trees Yes Yes – subscription required so see matches’ trees No
Ability to upload Gedcom file Yes Yes No
Ability to search trees Yes Yes No
Subscription in addition to DNA test price No No for partial, Yes for full functionality, minimal subscription for $49 by calling Ancestry No
DNA + Ancestor in Tree Matches No Yes – Leaf Hints – subscription required – Best Feature No
Phased Parental Side Matching Yes – Best Feature No No
Parent Match Indicator Yes No Yes
Sort or Group by Parent Match Yes Yes Yes
In Common With Tool Yes Yes Yes
Not In Common With Tool Yes No No
Triangulated Matches No – pseudo with ICW, browser and matrix No Yes – Best Feature
Common Surnames Yes Yes – subscription required No
Ability to Link DNA Matches on Tree Yes No No
Matrix to show match grid between multiple matches Yes No No
Match Filter Tools Yes Minimal Some
Advanced Matching Tool Yes No No
Multiple Test Matching Tool Yes No multiple tests No multiple tests
Ethnicity Matching Yes No Yes
Projects Yes No No
Maximum # of Matches Restricted No No Yes – 2000 unless you are communicating with the individuals, then they are not removed from your match list
All Customers Participate Yes Yes, unless they don’t have a subscription No – between 50-60% opt-in
Accepts Transfers from Other Testing Companies Yes No No
Free Features with Transfer Matching, ICW, Matrix, Advanced Matching No transfers No transfers
Transfer Features Requiring Unlock $ Chromosome Browser, Ethnicity, Ancient Origins, Linked Relationships, Parentally Phased Matches No Transfers No transfers
Archives DNA for Later Testing Yes, 25 years No, no additional tests available No, no additional tests available
Additional Tool DNA Circles – subscription required
Additional Tool New Ancestor Discoveries – subscription required
Y DNA Not included in autosomal test but is additional test, detailed results including matching No Haplogroup only
Mitochondrial DNA Not included in autosomal test but is additional test, detailed results including matching No Haplogroup only
Advanced Testing Available Yes No No
Website Intuitive Yes, given their many tools Yes, very simple No
Data Base Size Large Largest Large but many do not test for genealogy, only test for health
Strengths Many tools, multiple types of tests, phased matching without parent DNA + Tree matching, size of data base Triangulation
Challenges Website episodically times out No chromosome browser or advanced tools Sharing is difficult to understand and many don’t, website is far from intuitive

 

Genealogy – Y and Mitochondrial DNA

Two indispensable tools for genetic genealogy that are often overlooked are Y and mitochondrial DNA.

The inheritance path for Y DNA is shown by the blue squares and the inheritance path for mitochondrial DNA is shown by the red circles for the male and female siblings shown at the bottom of the chart.

Y-DNA Testing for Males

Y DNA is inherited by males only, from their father. The Y chromosome makes males male. Women instead inherit an X chromosome from their father, which makes them female. Because the Y chromosome is not admixed with the DNA of the mother, the same Y chromosome has been passed down through time immemorial.

Given that the Y chromosome follows the typical surname path, Y DNA testing is very useful for confirming surname lineage to an expected direct paternal ancestor. In other words, an Estes male today should match, with perhaps a few mutations, to other descendants of Abraham Estes who was born in 1647 in Kent, England and immigrated to the colony of Virginia.

Furthermore, that same Y chromosome can look far back in time, thousands of years, to tell us where that English group of Estes men originated, before the advent of surnames and before the migration to England from continental Europe. I wrote about the Estes Y DNA here, so you can see an example of how Y DNA testing can be used.

Y DNA testing for matching and haplogroup identification, which indicates where in the world your ancestors were living within the past few hundred to few thousand years, is only available from Family Tree DNA. Testing can be purchased for either 37, 67 or 111 markers, with the higher marker numbers providing more granularity and specificity in matching.

Family Tree DNA provides three types of Y DNA tests.

  • STR (short tandem repeat) testing is the traditional Y DNA testing for males to match to each other in a genealogically relevant timeframe. These tests can be ordered in panels of 37, 67 or 111 markers and lower levels can be upgraded to higher levels at a later date. An accurate base haplogroup prediction is made from STR markers.
  • SNP (single nucleotide polymorphism) testing is a different type of testing that tests single locations for mutations in order to confirm and further refine haplogroups. Think of a haplogroup as a type of genetic clan, meaning that haplogroups are used to track migration of humans through time and geography, and are what is utilized to determine African, European, Asian or Native heritage in the direct paternal line. SNP tests are optional and can be ordered one at a time, in groups called panels for a particular haplogroup or a comprehensive research level Y DNA test called the Big Y can be ordered after STR testing.
  • The Big Y test is a research level test that scans the entire Y chromosome to determine the most refined haplogroup possible and to report any previously unknown mutations (SNPs) that may define further branches of the Y DNA tree. This is the technique used to expand the Y haplotree.

You can read more about haplogroups here and about the difference between STR markers and SNPs here, here and here.

Customers receive the following features and tools when they purchase a Y DNA test at Family Tree DNA or the Ancestry Services test at 23andMe. The 23andMe Y DNA information is included in their Ancestry Services test. The Family Tree DNA Y DNA information requires specific tests and is not included in the Family Finder test. You can click here to read about the difference in the technology between Y DNA testing at Family Tree DNA and at 23andMe. Ancestry is not included in this comparison because they provide no Y DNA related information.

Y DNA Vendor Feature Summary Chart

Family Tree DNA 23andMe
Varying levels of STR panel marker testing Yes, in panels of 37, 67 and 111 markers No
Test panel (STR) marker results Yes Not tested
Haplogroup assignment Yes – accurate estimate with STR panels, deeper testing available Yes –base haplogroup by scan – haplogroup designations are significantly out of date, no further testing available
SNP testing to further define haplogroup Yes – can purchase individual SNPs, by SNP panels or Big Y test No
Matching to other participants Yes No
Trees available for your matches Yes No
E-mail of matches provided Yes No
Calculator tool to estimate probability of generational distance between you and a match Yes No
Earliest known ancestor information Yes No
Projects Surname, haplogroup and geographic projects No
Ability to search Y matches Yes No Y matching
Ability to search matches within projects Yes No projects
Ability to search matches by partial surname Yes No
Haplotree and customer result location on tree Yes, detailed with every branch Yes, less detailed, subset
Terminal SNP used to determine haplogroup Yes Yes, small subset available
Haplogroup Map Migration map Heat map
Ancestral Origins – summary by ancestral location of others you match, by test level Yes No
Haplogroup Origins – match ancestral location summary by haplogroup, by test level Yes No
SNP map showing worldwide locations of any selected SNP Yes No
Matches map showing mapped locations of your matches most distant ancestor in the paternal line, by test panel Yes No
Big Y – full scan of Y chromosome for known and previously unknown mutations (SNPs) Yes No
Big Y matching Yes No
Big Y matching known SNPs Yes No
Big Y matching novel variants (unknown or yet unnamed SNPs) Yes No
Filter Big Y matches Yes No
Big Y results Yes No
Advanced matching for multiple test types Yes No
DNA is archived so additional tests or upgrades can be ordered at a later date Yes, 25 years No

Mitochondrial DNA Testing for Everyone

Mitochondrial DNA is contributed to both genders of children by mothers, but only the females pass it on. Like the Y chromosome, mitochondrial DNA is not admixed with the DNA of the other parent. Therefore, anyone can test for the mitochondrial DNA of their matrilineal line, meaning their mother’s mother’s mother’s lineage.

Matching can identify family lines as well as ancient lineage.

You receive the following features and tools when you purchase a mitochondrial DNA test from Family Tree DNA or the Ancestry Services test from 23andMe. The Family Tree DNA mitochondrial DNA information requires specific tests and is not included in the Family Finder test. The 23andMe mitochondrial information is provided with the Ancestry Services test. Ancestry is omitted from this comparison because they do not provide any mitochondrial information.

Mitochondrial DNA Vendor Feature Summary Chart

Family Tree DNA 23andMe
Varying levels of testing Yes, mtPlus and Full Sequence No
Test panel marker results Yes, in two formats, CRS and RSRS No
Rare mutations, missing and extra mutations, insertions and deletions reported Yes No
Haplogroup assignment Yes, most current version, Build 17 Yes, partial and out of date version
Matching to other participants Yes No
Trees of matches available to view Yes No
E-mail address provided to matches Yes No
Earliest known ancestor information Yes No
Projects Surname, haplogroup and geographic available No
Ability to search matches Yes No
Ability to search matches within project Yes No projects
Ability to search match by partial surname Yes No
Haplotree and customer location on tree No Yes
Mutations used to determine haplogroup provided Yes No
Haplogroup Map Migration map Heat map
Ancestral Origins – summary by ancestral location of others you match, by test level Yes No
Haplogroup Origins –match ancestral location summary by haplogroup Yes No
Matches map showing mapped locations of your matches most distant ancestor in the maternal line, by test level Yes No
Advanced matching for multiple test types Yes No
DNA is archived so additional tests or upgrades can be ordered at a later date Yes, 25 years No

 

Overall Genealogy Summary

Serious genealogists should test with at least two of the three major vendors, being Family Tree DNA and Ancestry, with 23andMe coming in as a distant third.

No genetic genealogy testing regimen is complete without Y and mitochondrial DNA for as many ancestral lines as you can find to test. You don’t know what you don’t know, and you’ll never know if you don’t test.

Unfortunately, many people, especially new testers, don’t know Y and mitochondrial DNA testing for genetic genealogy exists, or how it can help their genealogy research, which is extremely ironic since these were the first tests available, back in 2000.

You can read about finding Y and mitochondrial information for various family lines and ancestors and how to assemble a DNA Pedigree Chart here.

You can also take a look at my 52 Ancestors series, where I write about an ancestor every week. Each article includes some aspect of DNA testing and knowledge gained by a test or tests, DNA tool, or comparison. The DNA aspect of these articles focuses on how to use DNA as a tool to discover more about your ancestors.

 

Testing for Medical/Health or Traits

The DTC market also includes health and medical testing, although it’s not nearly as popular as genetic genealogy.

Health/medical testing is offered by 23andMe, who also offers autosomal DNA testing for genealogy.

Some people do want to know if they have genetic predispositions to medical conditions, and some do not. Some want to know if they have certain traits that aren’t genealogically relevant, but might be interesting – such as whether they carry the Warrior gene or if they have an alcohol flush reaction.

23andMe was the first company to dip their toes into the water of Direct to Consumer medical information, although they called it “health,” not medicine, at that time. Regardless of the terminology, information regarding Parkinson’s and Alzheimer’s, for example, were provided for customers. 23andMe attempted to take the raw data and provide the consumer with something approaching a middle of the road analysis, because sometimes the actual studies provide conflicting information that might not be readily understood by consumers.

The FDA took issue with 23andMe back in November of 2013 when they ordered 23andMe to discontinue the “health” aspect of their testing after 23andMe ignored several deadlines. In October 2015, 23andMe obtained permission to provide customers with some information, such as carrier status, for 36 genetic disorders.

Since that time, 23andMe has divided their product into two separate tests, with two separate prices. The genealogy only test called Ancestry Service can be purchased separately for $99, or the combined Health + Ancestry Service for $199.

If you are interested in seeing what the Health + Ancestry test provides, you can click here to view additional information.

However, there is a much easier and less expensive solution.

If you have taken the autosomal test from 23andMe, Ancestry or Family Tree DNA, you can download your raw data file from the vendor and upload to Promethease to obtain a much more in-depth report than is provided by 23andMe, and much less expensively – just $5.

I reviewed the Promethease service here. I found the Promethease reports to be very informative and I like the fact that they provide information, both positive and negative for each SNP (DNA location) reported. Promethease avoids FDA problems by not providing any interpretation or analysis, simply the data and references extracted from SNPedia for you to review.

I would be remiss if I didn’t mention that you should be sure you really want to know before you delve into medical testing. Some mutations are simply indications that you could develop a condition that you will never develop or that is not serious. Other mutations are not so benign. Promethease provides this candid page before you upload your data.

Different files from different vendors provide different results at Promethease, because those vendors test different SNP locations in your DNA. At the Promethease webpage, you can view examples.

Traits

Traits fall someplace between genealogy and health. When you take the Health + Ancestry test at 23andMe, you do receive information about various traits, as follows:

Of course, you’ll probably already know if you have several of these traits by just taking a look in the mirror, or in the case of male back hair, by asking your wife.

At Family Tree DNA, existing customers can order tests for Factoids (by clicking on the upgrade button), noted as curiosity tests for gene variants.

Family Tree DNA provides what I feel is a great summary and explanation of what the Factoids are testing on their order page:

“Factoids” are based on studies – some of which may be controversial – and results are not intended to diagnose disease or medical conditions, and do not serve the purpose of medical advice. They are offered exclusively for curiosity purposes, i.e. to see how your result compared with what the scientific papers say. Other genetic and environmental variables may also impact these same physiological characteristics. They are merely a conversational piece, or a “cocktail party” test, as we like to call it.”

Test Price Description
Alcohol Flush Reaction $19 A condition in which the body cannot break down ingested alcohol completely. Flushing, after consuming one or two alcoholic beverages, includes a range of symptoms: nausea, headaches, light-headedness, an increased pulse, occasional extreme drowsiness, and occasional skin swelling and itchiness. These unpleasant side effects often prevent further drinking that may lead to further inebriation, but the symptoms can lead to mistaken assumption that the people affected are more easily inebriated than others.
Avoidance of Errors $29 We are often angry at ourselves because we are unable to learn from certain experiences. Numerous times we have made the wrong decision and its consequences were unfavorable. But the cause does not lie only in our thinking. A mutation in a specific gene can also be responsible, because it can cause a smaller number of dopamine receptors. They are responsible for remembering our wrong choices, which in turn enables us to make better decisions when we encounter a similar situation.
Back Pain $39 Lumbar disc disease is the drying out of the spongy interior matrix of an intervertebral disc in the spine. Many physicians and patients use the term lumbar disc disease to encompass several different causes of back pain or sciatica. A study of Asian patients with lumbar disc disease showed that a mutation in the CILP gene increases the risk of back pain.
Bitter Taste Perception $29 There are several genes that are responsible for bitter taste perception – we test 3 of them. Different variations of this gene affect ability to detect bitter compounds. About 25% of people lack ability to detect these compounds due to gene mutations. Are you like them? Maybe you don’t like broccoli, because it tastes too bitter?
Caffeine Metabolism $19 According to the results of a case-control study reported in the March 8, 2006 issue of JAMA, coffee is the most widely consumed stimulant in the world, and caffeine consumption has been associated with increased risk for non-fatal myocardial infarction. Caffeine is primarily metabolized by the cytochrome P450 1A2 in the liver, accounting for 95% of metabolism. Carriers of the gene variant *1F allele are slow caffeine metabolizers, whereas individuals homozygous for the *1A/*1A genotype are rapid caffeine metabolizers.
Earwax Type $19 Whether your earwax is wet or dry is determined by a mutation in a single gene, which scientists have discovered. Wet earwax is believed to have uses in insect trapping, self-cleaning and prevention of dryness in the external auditory canal of the ear. It also produces an odor and causes sweating, which may play a role as a pheromone.
Freckling $19 Freckles can be found on anyone no matter what the background. However, having freckles is genetic and is related to the presence of the dominant melanocortin-1 receptor MC1R gene variant.
Longevity $49 Researchers at Harvard Medical School and UC Davis have discovered a few genes that extend lifespan, suggesting that the whole family of SIR2 genes is involved in controlling lifespan. The findings were reported July 28, 2005 in the advance online edition of Science.
Male Pattern Baldness $19 Researchers at McGill University, King’s College London and GlaxoSmithKline Inc. have identified two genetic variants in Caucasians that together produce an astounding sevenfold increase of the risk of male pattern baldness. Their results were published in the October 12, 2008 issue of the Journal of Nature Genetics.
Monoamine Oxidase A (Warrior Gene) $49.50 The Warrior Gene is a variant of the gene MAO-A on the X chromosome. Recent studies have linked the Warrior Gene to increased risk-taking and aggressive behavior. Whether in sports, business, or other activities, scientists found that individuals with the Warrior Gene variant were more likely to be combative than those with the normal MAO-A gene. However, human behavior is complex and influenced by many factors, including genetics and our environment. Individuals with the Warrior Gene are not necessarily more aggressive, but according to scientific studies, are more likely to be aggressive than those without the Warrior Gene variant. This test is available for both men and women, however, there is limited research about the Warrior Gene variant amongst females. Additional details about the Warrior Gene genetic variant of MAO-A can be found in Sabol et al, 1998.
Muscle Performance $29 A team of researchers, led by scientists at Dartmouth Medical School and Dartmouth College, have identified and tested a gene that dramatically alters both muscle metabolism and performance. The researchers say that this finding could someday lead to treatment of muscle diseases, including helping the elderly who suffer from muscle deterioration and improving muscle performance in endurance athletes.
Nicotine Dependence $19 In 2008, University of Virginia Health System researchers have identified a gene associated with nicotine dependence in both Europeans and African Americans.

Many people are interested in the Warrior Gene, which I wrote about here.

At Promethease, traits are simply included with the rest of the conditions known to be associated with certain SNPs, such as baldness, for example, but I haven’t done a comparison to see which traits are included.

 

Additional Vendor Information to Consider

Before making your final decision about which test or tests to purchase, there are a few additional factors you may want to consider.

As mentioned before, Ancestry requires a subscription in addition to the cost of the DNA test for the DNA test to be fully functional.

One of the biggest issues, in my opinion, is that both 23andMe and Ancestry sell customer’s anonymized DNA information to unknown others. Every customer authorizes the sale of their information when they purchase or activate a kit – even though very few people actually take the time to read the Terms and Conditions, Privacy statements and Security documents, including any and all links. This means most people don’t realize they are authorizing the sale of their DNA.

At both 23andMe and Ancestry, you can ALSO opt in for additional non-anonymized research or sale of your DNA, which you can later opt out of. However, you cannot opt out of the lower level sale of your anonymized DNA without removing your results from the data base and asking for your sample to be destroyed. They do tell you this, but it’s very buried in the fine print at both companies. You can read more here.

Family Tree DNA does not sell your DNA or information.

All vendors can change their terms and conditions at any time. Consumers should always thoroughly read the terms and conditions including anything having to do with privacy for any product they purchase, but especially as it relates to DNA testing.

Family Tree DNA archives your DNA for later testing, which has proven extremely beneficial when a family member has passed away and a new test is subsequently introduced or the family wants to upgrade a current test.  Had my mother’s DNA not been archived at Family Tree DNA, I would not have Family Finder results for her today – something I thank Mother and Family Tree DNA for every single day.

Family Tree DNA also accepts transfer files from 23andMe, Ancestry and very shortly, MyHeritage – although some versions work better than others. For details on which companies accept which file versions, from which vendors, and why, please read Autosomal DNA Transfers – Which Companies Accept Which Tests?

If you tested on a compatible version of the 23andMe Test (V3 between December 2010 and November 2013) or the Ancestry V1 (before May 2016) you may want to transfer your raw data file to Family Tree DNA for free and pay only $19 for full functionality, as opposed to taking the Family Finder test. Family Tree DNA does accept later versions of files from 23andMe and Ancestry, but you will receive more matches if you test on the same chip platform that Family Tree DNA utilizes instead of doing a transfer.

Additional Vendor Considerations Summary Chart

Family Tree DNA Ancestry 23andMe
Subscription required in addition to cost of DNA test No Yes for full functionality, partial functionality is included without subscription, minimum subscription is $49 by calling Ancestry No
Customer Support Good and available Available, nice but often not knowledgeable about DNA Poor
Sells customer DNA information No Yes Yes
DNA raw data file available to download Yes Yes Yes
DNA matches file available to download including match info and chromosome match locations Yes No Yes
Customers genealogically focused Yes Yes Many No
Accepts DNA raw data transfer files from other companies Yes, most, see article for specifics No No
DNA archived for later testing Yes, 25 years No No
Beneficiary provision available Yes No No

 

Which Test is Best For You?

I hope you now know the answer as to which DNA test is best for you – or maybe it’s multiple tests for you and other family members too!

DNA testing holds so much promise for genealogy. I hesitate to call DNA testing a miracle tool, but it often is when there are no records. DNA testing works best in conjunction with traditional genealogical research.

There are a lot of tests and options.  The more tests you take, the more people you match. Some people test at multiple vendors or upload their DNA to third party sites like GedMatch, but most don’t. In order to make sure you reach those matches, which may be the match you desperately need, you’ll have to test at the vendor where they tested. Otherwise, they are lost to you. That means, of course, that eventually, if you’re a serious genealogist, you’ll be testing at all 3 vendors.  Don’t forget about Y and mitochondrial tests at Family Tree DNA.

Recruit family members to test and reach out to your matches.  The more you share and learn – the more is revealed about your ancestors. You are, after all, the unique individual that resulted from the combination of all of them!

Update: Vendor prices updated June 22, 2017.

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I do not accept sponsorship for this blog, nor do I write paid articles, nor do I accept contributions of any type from any vendor in order to review any product, etc. In fact, I pay a premium price to prevent ads from appearing on this blog.

When reviewing products, in most cases, I pay the same price and order in the same way as any other consumer. If not, I state very clearly in the article any special consideration received. In other words, you are reading my opinions as a long-time consumer and consultant in the genetic genealogy field.

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Concepts – Segment Size, Legitimate and False Matches

Matchmaker, matchmaker, make me a match!

One of the questions I often receive about autosomal DNA is, “What, EXACTLY, is a match?”  The answer at first glance seems evident, meaning when you and someone else are shown on each other’s match lists, but it really isn’t that simple.

What I’d like to discuss today is what actually constitutes a match – and the difference between legitimate or real matches and false matches, also called false positives.

Let’s look at a few definitions before we go any further.

Definitions

  • A Match – when you and another person are found on each other’s match lists at a testing vendor. You may match that person on one or more segments of DNA.
  • Matching Segment – when a particular segment of DNA on a particular chromosome matches to another person. You may have multiple segment matches with someone, if they are closely related, or only one segment match if they are more distantly related.
  • False Match – also known as a false positive match. This occurs when you match someone that is not identical by descent (IBD), but identical by chance (IBC), meaning that your DNA and theirs just happened to match, as a happenstance function of your mother and father’s DNA aligning in such a way that you match the other person, but neither your mother or father match that person on that segment.
  • Legitimate Match – meaning a match that is a result of the DNA that you inherited from one of your parents. This is the opposite of a false positive match.  Legitimate matches are identical by descent (IBD.)  Some IBD matches are considered to be identical by population, (IBP) because they are a result of a particular DNA segment being present in a significant portion of a given population from which you and your match both descend. Ideally, legitimate matches are not IBP and are instead indicative of a more recent genealogical ancestor that can (potentially) be identified.

You can read about Identical by Descent and Identical by Chance here.

  • Endogamy – an occurrence in which people intermarry repeatedly with others in a closed community, effectively passing the same DNA around and around in descendants without introducing different/new DNA from non-related individuals. People from endogamous communities, such as Jewish and Amish groups, will share more DNA and more small segments of DNA than people who are not from endogamous communities.  Fully endogamous individuals have about three times as many autosomal matches as non-endogamous individuals.
  • False Negative Match – a situation where someone doesn’t match that should. False negatives are very difficult to discern.  We most often see them when a match is hovering at a match threshold and by lowing the threshold slightly, the match is then exposed.  False negative segments can sometimes be detected when comparing DNA of close relatives and can be caused by read errors that break a segment in two, resulting in two segments that are too small to be reported individually as a match.  False negatives can also be caused by population phasing which strips out segments that are deemed to be “too matchy” by Ancestry’s Timber algorithm.
  • Parental or Family Phasing – utilizing the DNA of your parents or other close family members to determine which side of the family a match derives from. Actual phasing means to determine which parts of your DNA come from which parent by comparing your DNA to at least one, if not both parents.  The results of phasing are that we can identify matches to family groups such as the Phased Family Finder results at Family Tree DNA that designate matches as maternal or paternal based on phased results for you and family members, up to third cousins.
  • Population Based Phasing – In another context, phasing can refer to academic phasing where some DNA that is population based is removed from an individual’s results before matching to others. Ancestry does this with their Timber program, effectively segmenting results and sometimes removing valid IBD segments.  This is not the type of phasing that we will be referring to in this article and parental/family phasing should not be confused with population/academic phasing.

IBD and IBC Match Examples

It’s important to understand the definitions of Identical by Descent and Identical by Chance.

I’ve created some easy examples.

Let’s say that a match is defined as any 10 DNA locations in a row that match.  To keep this comparison simple, I’m only showing 10 locations.

In the examples below, you are the first person, on the left, and your DNA strands are showing.  You have a pink strand that you inherited from Mom and a blue strand inherited from Dad.  Mom’s 10 locations are all filled with A and Dad’s locations are all filled with T.  Unfortunately, Mother Nature doesn’t keep your Mom’s and Dad’s strands on one side or the other, so their DNA is mixed together in you.  In other words, you can’t tell which parts of your DNA are whose.  However, for our example, we’re keeping them separate because it’s easier to understand that way.

Legitimate Match – Identical by Descent from Mother

matches-ibd-mom

In the example above, Person B, your match, has all As.  They will match you and your mother, both, meaning the match between you and person B is identical by descent.  This means you match them because you inherited the matching DNA from your mother. The matching DNA is bordered in black.

Legitimate Match – Identical by Descent from Father

In this second example, Person C has all T’s and matches both you and your Dad, meaning the match is identical by descent from your father’s side.

matches-ibd-dad

You can clearly see that you can have two different people match you on the same exact segment location, but not match each other.  Person B and Person C both match you on the same location, but they very clearly do not match each other because Person B carries your mother’s DNA and Person C carries your father’s DNA.  These three people (you, Person B and Person C) do NOT triangulate, because B and C do not match each other.  The article, “Concepts – Match Groups and Triangulation” provides more details on triangulation.

Triangulation is how we prove that individuals descend from a common ancestor.

If Person B and Person C both descended from your mother’s side and matched you, then they would both carry all As in those locations, and they would match you, your mother and each other.  In this case, they would triangulate with you and your mother.

False Positive or Identical by Chance Match

This third example shows that Person D does technically match you, because they have all As and Ts, but they match you by zigzagging back and forth between your Mom’s and Dad’s DNA strands.  Of course, there is no way for you to know this without matching Person D against both of your parents to see if they match either parent.  If your match does not match either parent, the match is a false positive, meaning it is not a legitimate match.  The match is identical by chance (IBC.)

matches-ibc

One clue as to whether a match is IBC or IBD, even without your parents, is whether the person matches you and other close relatives on this same segment.  If not, then the match may be IBC. If the match also matches close relatives on this segment, then the match is very likely IBD.  Of course, the segment size matters too, which we’ll discuss momentarily.

If a person triangulates with 2 or more relatives who descend from the same ancestor, then the match is identical by descent, and not identical by chance.

False Negative Match

This last example shows a false negative.  The DNA of Person E had a read error at location 5, meaning that there are not 10 locations in a row that match.  This causes you and Person E to NOT be shown as a match, creating a false negative situation, because you actually do match if Person E hadn’t had the read error.

matches-false-negative

Of course, false negatives are by definition very hard to identify, because you can’t see them.

Comparisons to Your Parents

Legitimate matches will phase to your parents – meaning that you will match Person B on the same amount of a specific segment, or a smaller portion of that segment, as one of your parents.

False matches mean that you match the person, but neither of your parents matches that person, meaning that the segment in question is identical by chance, not by descent.

Comparing your matches to both of your parents is the easiest litmus paper test of whether your matches are legitimate or not.  Of course, the caveat is that you must have both of your parents available to fully phase your results.

Many of us don’t have both parents available to test, so let’s take a look at how often false positive matches really do occur.

False Positive Matches

How often do false matches really happen?

The answer to that question depends on the size of the segments you are comparing.

Very small segments, say at 1cM, are very likely to match randomly, because they are so small.  You can read more about SNPs and centiMorgans (cM) here.

As a rule of thumb, the larger the matching segment as measured in cM, with more SNPs in that segment:

  • The stronger the match is considered to be
  • The more likely the match is to be IBD and not IBC
  • The closer in time the common ancestor, facilitating the identification of said ancestor

Just in case we forget sometimes, identifying ancestors IS the purpose of genetic genealogy, although it seems like we sometimes get all geeked out by the science itself and process of matching!  (I can hear you thinking, “speak for yourself, Roberta.”)

It’s Just a Phase!!!

Let’s look at an example of phasing a child’s matches against those of their parents.

In our example, we have a non-endogamous female child (so they inherit an X chromosome from both parents) whose matches are being compared to her parents.

I’m utilizing files from Family Tree DNA. Ancestry does not provide segment data, so Ancestry files can’t be used.  At 23andMe, coordinating the security surrounding 3 individuals results and trying to make sure that the child and both parents all have access to the same individuals through sharing would be a nightmare, so the only vendor’s results you can reasonably utilize for phasing is Family Tree DNA.

You can download the matches for each person by chromosome segment by selecting the chromosome browser and the “Download All Matches to Excel (CSV Format)” at the top right above chromosome 1.

matches-chromosomr-browser

All segment matches 1cM and above will be downloaded into a CSV file, which I then save as an Excel spreadsheet.

I downloaded the files for both parents and the child. I deleted segments below 3cM.

About 75% of the rows in the files were segments below 3cM. In part, I deleted these segments due to the sheer size and the fact that the segment matching was a manual process.  In part, I did this because I already knew that segments below 3 cM weren’t terribly useful.

Rows Father Mother Child
Total 26,887 20,395 23,681
< 3 cM removed 20,461 15,025 17,784
Total Processed 6,426 5,370 5,897

Because I have the ability to phase these matches against both parents, I wanted to see how many of the matches in each category were indeed legitimate matches and how many were false positives, meaning identical by chance.

How does one go about doing that, exactly?

Downloading the Files

Let’s talk about how to make this process easy, at least as easy as possible.

Step one is downloading the chromosome browser matches for all 3 individuals, the child and both parents.

First, I downloaded the child’s chromosome browser match file and opened the spreadsheet.

Second, I downloaded the mother’s file, colored all of her rows pink, then appended the mother’s rows into the child’s spreadsheet.

Third, I did the same with the father’s file, coloring his rows blue.

After I had all three files in one spreadsheet, I sorted the columns by segment size and removed the segments below 3cM.

Next, I sorted the remaining items on the spreadsheet, in order, by column, as follows:

  • End
  • Start
  • Chromosome
  • Matchname

matches-both-parents

My resulting spreadsheet looked like this.  Sorting in the order prescribed provides you with the matches to each person in chromosome and segment order, facilitating easy (OK, relatively easy) visual comparison for matching segments.

I then colored all of the child’s NON-matching segments green so that I could see (and eventually filter the matchname column by) the green color indicating that they were NOT matches.  Do this only for the child, or the white (non-colored) rows.  The child’s matchname only gets colored green if there is no corresponding match to a parent for that same person on that same chromosome segment.

matches-child-some-parents

All of the child’s matches that DON’T have a corresponding parent match in pink or blue for that same person on that same segment will be colored green.  I’ve boxed the matches so you can see that they do match, and that they aren’t colored green.

In the above example, Donald and Gaff don’t match either parent, so they are all green.  Mess does match the father on some segments, so those segments are boxed, but the rest of Mess doesn’t match a parent, so is colored green.  Sarah doesn’t match any parent, so she is entirely green.

Yes, you do manually have to go through every row on this combined spreadsheet.

If you’re going to phase your matches against your parent or parents, you’ll want to know what to expect.  Just because you’ve seen one match does not mean you’ve seen them all.

What is a Match?

So, finally, the answer to the original question, “What is a Match?”  Yes, I know this was the long way around the block.

In the exercise above, we weren’t evaluating matches, we were just determining whether or not the child’s match also matched the parent on the same segment, but sometimes it’s not clear whether they do or do not match.

matches-child-mess

In the case of the second match with Mess on chromosome 11, above, the starting and ending locations, and the number of cM and segments are exactly the same, so it’s easy to determine that Mess matches both the child and the father on chromosome 11. All matches aren’t so straightforward.

Typical Match

matches-typical

This looks like your typical match for one person, in this case, Cecelia.  The child (white rows) matches Cecelia on three segments that don’t also match the child’s mother (pink rows.)  Those non-matching child’s rows are colored green in the match column.  The child matches Cecelia on two segments that also match the mother, on chromosome 20 and the X chromosome.  Those matching segments are boxed in black.

The segments in both of these matches have exact overlaps, meaning they start and end in exactly the same location, but that’s not always the case.

And for the record, matches that begin and/or end in the same location are NOT more likely to be legitimate matches than those that start and end in different locations.  Vendors use small buckets for matching, and if you fall into any part of the bucket, even if your match doesn’t entirely fill the bucket, the bucket is considered occupied.  So what you’re seeing are the “fuzzy” bucket boundaries.

(Over)Hanging Chad

matches-overhanging

In this case, Chad’s match overhangs on each end.  You can see that Chad’s match to the child begins at 52,722,923 before the mother’s match at 53,176,407.

At the end location, the child’s matching segment also extends beyond the mother’s, meaning the child matches Chad on a longer segment than the mother.  This means that the segment sections before 53,176,407 and after 61,495,890 are false negative matches, because Chad does not also match the child’s mother of these portions of the segment.

This segment still counts as a match though, because on the majority of the segment, Chad does match both the child and the mother.

Nested Match

matches-nested

This example shows a nested match, where the parent’s match to Randy begins before the child’s and ends after the child’s, meaning that the child’s matching DNA segment to Randy is entirely nested within the mother’s.  In other words, pieces got shaved off of both ends of this segment when the child was inheriting from her mother.

No Common Matches

matches-no-common

Sometimes, the child and the parent will both match the same person, but there are no common segments.  Don’t read more into this than what it is.  The child’s matches to Mary are false matches.  We have no way to judge the mother’s matches, except for segment size probability, which we’ll discuss shortly.

Look Ma, No Parents

matches-no-parents

In this case, the child matches Don on 5 segments, including a reasonably large segment on chromosome 9, but there are no matches between Don and either parent.  I went back and looked at this to be sure I hadn’t missed something.

This could, possibly, be an instance of an unseen a false negative, meaning perhaps there is a read issue in the parent’s file on chromosome 9, precluding a match.  However, in this case, since Family Tree DNA does report matches down to 1cM, it would have to be an awfully large read error for that to occur.  Family Tree DNA does have quality control standards in place and each file must pass the quality threshold to be put into the matching data base.  So, in this case, I doubt that the problem is a false negative.

Just because there are multiple IBC matches to Don doesn’t mean any of those are incorrect.  It’s just the way that the DNA is inherited and it’s why this type of a match is called identical by chance – the key word being chance.

Split Match

matches-split

This split match is very interesting.  If you look closely, you’ll notice that Diane matches Mom on the entire segment on chromosome 12, but the child’s match is broken into two.  However, the number of SNPs adds up to the same, and the number of cM is close.  This suggests that there is a read error in the child’s file forcing the child’s match to Diane into two pieces.

If the segments broken apart were smaller, under the match threshold, and there were no other higher matches on other segments, this match would not be shown and would fall into the False Negative category.  However, since that’s not the case, it’s a legitimate match and just falls into the “interesting” category.

The Deceptive Match

matches-surname

Don’t be fooled by seeing a family name in the match column and deciding it’s a legitimate match.  Harrold is a family surname and Mr. Harrold does not match either of the child’s parents, on any segment.  So not a legitimate match, no matter how much you want it to be!

Suspicious Match – Probably not Real

matches-suspicious

This technically is a match, because part of the DNA that Daryl matches between Mom and the child does overlap, from 111,236,840 to 113,275,838.  However, if you look at the entire match, you’ll notice that not a lot of that segment overlaps, and the number of cMs is already low in the child’s match.  There is no way to calculate the number of cMs and SNPs in the overlapping part of the segment, but suffice it to say that it’s smaller, and probably substantially smaller, than the 3.32 total match for the child.

It’s up to you whether you actually count this as a match or not.  I just hope this isn’t one of those matches you REALLY need.  However, in this case, the Mom’s match at 15.46 cM is 99% likely to be a legitimate match, so you really don’t need the child’s match at all!!!

So, Judge Judy, What’s the Verdict?

How did our parental phasing turn out?  What did we learn?  How many segments matched both the child and a parent, and how many were false matches?

In each cM Size category below, I’ve included the total number of child’s match rows found in that category, the number of parent/child matches, the percent of parent/child matches, the number of matches to the child that did NOT match the parent, and the percent of non-matches. A non-match means a false match.

So, what the verdict?

matches-parent-child-phased-segment-match-chart

It’s interesting to note that we just approach the 50% mark for phased matches in the 7-7.99 cM bracket.

The bracket just beneath that, 6-6.99 shows only a 30% parent/child match rate, as does 5-5.99.  At 3 cM and 4 cM few matches phase to the parents, but some do, and could potentially be useful in groups of people descended from a known common ancestor and in conjunction with larger matches on other segments. Certainly segments at 3 cM and 4 cM alone aren’t very reliable or useful, but that doesn’t mean they couldn’t potentially be used in other contexts, nor are they always wrong. The smaller the segment, the less confidence we can have based on that segment alone, at least below 9-15cM.

Above the 50% match level, we quickly reach the 90th percentile in the 9-9.99 cM bracket, and above 10 cM, we’re virtually assured of a phased match, but not quite 100% of the time.

It isn’t until we reach the 16cM category that we actually reach the 100% bracket, and there is still an outlier found in the 18-18.99 cM group.

I went back and checked all of the 10 cM and over non-matches to verify that I had not made an error.  If I made errors, they were likely counting too many as NON-matches, and not the reverse, meaning I failed to visually identify matches.  However, with almost 6000 spreadsheet rows for the child, a few errors wouldn’t affect the totals significantly or even noticeably.

I hope that other people in non-endogamous populations will do the same type of double parent phasing and report on their results in the same type of format.  This experiment took about 2 days.

Furthermore, I would love to see this same type of experiment for endogamous families as well.

Summary

If you can phase your matches to either or both of your parents, absolutely, do.  This this exercise shows why, if you have only one parent to match against, you can’t just assume that anyone who doesn’t match you on your one parent’s side automatically matches you from the other parent. At least, not below about 15 cM.

Whether you can phase against your parent or not, this exercise should help you analyze your segment matches with an eye towards determining whether or not they are valid, and what different kinds of matches mean to your genealogy.

If nothing else, at least we can quantify the relatively likelihood, based on the size of the matching segment, in a non-endogamous population, a match would match a parent, if we had one to match against, meaning that they are a legitimate match.  Did you get all that?

In a nutshell, we can look at the Parent/Child Phased Match Chart produced by this exercise and say that our 8.5 cM match has about a 66% chance of being a legitimate match, and our 10.5 cM match has a 95% change of being a legitimate match.

You’re welcome.

Enjoy!!