Should We Develop A Genetic Genealogy Strategy For Future Testing Advancements?

When it comes to autosomal DNA testing, the smart advice is to test your eldest living family members.

None of us are going to be around forever. Life is short and we must gather, while it's available, the irreplaceable spit data that can provide deeper insights into our family's history.

But how do we prepare for future advancements in genetic genealogical testing?

Surely the autosomal testing that currently dominates (e.g. AncestryDNA, 23andMe, MyHeritage, and FTDNA) won't be here for the duration. Something new and presumably better (meaning technologically more advanced) will eventually bound onto the scene replacing the current iteration of autosomal tests.

In preparation for that anticipated new product, should genetic genealogists act now to preserve their eldest family's data, so it can be examined by whatever newfangled test comes to market?

DNA storage for genealogical purposes is possible. One company, FamilyTree DNA, stores customers' DNA samples (purportedly for 25 years). To my knowledge, none of the other genealogically-focused providers currently offer this service.

Is a smart strategy to test older relatives with companies like FamilyTree DNA to preserve a copy of their DNA sample? This way, when new technology is available (and affordable), the sample can be examined by the latest test.

It seems prudent to be forward thinking with our DNA testing strategies both now and in the years ahead - particularly when our eldest family members may no longer be around to provide testing samples.

On the surface, this seems quite sensible. But we haven't even touched on the ethical considerations of preserving and testing DNA samples of family members after they've passed away. Clearly, it's a complicated issue that requires measured consideration.

I'm curious what others think about the matter and what steps, if any, you're undertaking to protect samples for future testing.

What's your take on developing a genetic genealogy strategy for future testing advancements? What other considerations should come into play?

The Limits of Triangulation

I recently wrote about my difficulties with triangulating DNA cousin matches (see The Trials and Tribulations of Triangulation). Among my challenges were that:

• Most of my DNA matches tested with AncestryDNA, which does not presently give access to the segment data necessary for triangulation.

• Encouraging these cousins to transfer their data to a third-party site that does provide access to segment data is sloooow going. 

I really stepped in it, though, when I said that triangulation was the gold standard for identifying a common ancestor among genetic cousins.

While these challenges are real and resonated with many, genetic genealogists were quick to flag that triangulation “was never the gold standard.”

I’ve spent the last couple weeks boning up on the shortcomings of triangulation to better understand its limits.

Let’s look at those limits in the context of the research question I am investigating.

An 18th Century Siblingship Hypothesis

I believe my fifth great-grandfather Thomas Kirk (1778-1846) was the younger brother of his neighbor Mary (Kirk) Geiger (1774-1832).

From beginning to end, their lives followed similar geographical trajectories:

• Both were born in Virginia
• Both settled in the southern part of Licking County shortly after Ohio gained statehood 
• Both are buried in a small cemetery just yards apart 

I've blogged a considerable amount about Thomas and Mary and the many curious tangential links that led to speculation about a family relationship. Recently, I've turned to genetic genealogy to complement the traditional research.

With more than 40 one-to-one autosomal DNA matches between descendants of Thomas and Mary – and each of those matches sharing amounts of DNA expected for their speculated relationship level if Thomas and Mary were in fact siblings – it seemed there was strong supporting evidence for my theory within reach.

Was there a more conclusive way to interpret what the DNA was telling me and credibly substantiate my hypothesis?

An Example Case Study

I got an idea after I read a case study published in the National Genealogical Society Quarterly.

In a nutshell, a professional genealogist was trying to identify the father of a woman born in 1789. Although traditional genealogy had surfaced a candidate for paternity within her small community, it failed to provide a definitive answer. Turning to genetics, there were significant amounts of shared autosomal DNA between descendants of the woman and her suspected paternal family. To reinforce the argument, these one-to-one matches were supplemented with a handful of triangulated matches among third to sixth great-grandchildren of the alleged father. The case study concluded that the paired and triangulated DNA matches supported the theory that the woman was the daughter of the possible paternal candidate.

This example seemed like a perfect fit that was analogous to my own research hypothesis. If this approach was good enough for a professional case study, then surely it could help me conclude that Thomas and Mary were siblings. I determined I would replicate the model, and search for triangulated matches among the dozens of paired matches already found between Thomas and Mary.

That’s when I crashed head-on with the triangulation trials and tribulations and realized that - while the methodology offers potential value - it was not a gold standard.

Approach with Caution

The odds for finding a triangulated match between descendants of my 5th great-grandfather and his possible sister are not in my favor. In fact, they're downright daunting. I knew that would be the case, but I didn’t realize how poor my chances were.

My DNA is too far removed from Thomas and Mary and their parents, the Most Recent Common Ancestor (MRCA), to be an effective magnet for cousins. As a fifth great-grandson, I could expect – on average - to share less than 1% of Thomas’ DNA (0.78% to be exact).¹ It's easy to imagine how grim the odds are for inheriting any DNA from his parents, my sixth great-grandparents. They're edging on genealogical ancestors who no longer have an imprint on my genetic family tree.²

I needed proxies closer in time to Thomas and Mary who inherited more of their DNA and could boost the odds for matches. Fortunately, several third great-grandchildren of Thomas and Mary are still alive and have tested (all would be fourth great-grandchildren to the parents of Thomas and Mary - the MRCA).

Odds of Inheriting DNA

According to AncestryDNA,³ there's a 100% likelihood that we've inherited DNA from our ancestors up to five generations removed. This means that the tested descendants almost certainly inherited some of their DNA from Thomas and Mary. Although we’re only talking about, on average, 3.12%.

At six generations, AncestryDNA estimates that there’s still a 99.99% chance that we’ve inherited DNA from our ancestors (meaning it’s probable that the tested descendants have inherited DNA from the parents of Thomas and Mary).

Knowing that there’s a 99.99% chance that we inherited DNA dating back at least six generations, but mindful that it’s a slim amount, how likely are these fourth great-grandchildren of the MRCA to share DNA with each other?

Odds of Sharing DNA

According to AncestryDNA, there's a 100% chance that you'll share DNA with siblings through second cousins. Beginning with third cousins there’s a 98% chance, but then the odds dip and decline dramatically for each subsequent generation:

• fourth cousins (71%)
• fifth cousins (32%) 
• sixth cousins (11%) 
• seventh cousins (3.2%) 

Fourth great-grandchildren of the Kirk MRCA would be fifth cousins and, at least at AncestryDNA as a result of their phasing methodologies,⁴ would have a 32% chance of sharing DNA.

While the odds aren't great, they're not entirely insignificant and may explain why I’ve found over 40 one-to-one matches between descendants of Thomas and Mary at AncestryDNA.

Odds of a Triangulated DNA Match

When it comes to triangulation, however, it’s not enough to just find a match. It requires that a group of cousins share the same segments of DNA.

What are the chances of that happening?

Not good.

The process of recombination – how our DNA is randomly mixed up before it’s passed to each new generation – ensures we inherit a mishmash of our parents’ DNA.⁵

This amalgamation of DNA passed from one generation to the next makes it unlikely that three fourth great-grandchildren of the Kirk MRCA would all share overlapping DNA segments.

AncestryDNA found - with a threshold of five centiMorgans (cM) - that three random first cousins shared the same DNA segment 84% of the time. However, when five first cousins were compared, there was only a 40% chance that they each shared the same segment. The likelihood of sharing the same DNA segment among ten first cousins plummeted to 0%.

Even though first cousins will share DNA 100% of the time, the recombination process keeps us on our toes and makes it unlikely that cousins will inherit the exact same pieces of DNA.

Bottom line, the odds are daunting and not in favor of triangulation for recent relationships. Imagine how much grimmer the prospects are for finding triangulated segments among descendants of the Kirk MRCA.

The lesson learned, according to AncestryDNA's computational scientist was that, "We can't rely on those pieces of [matching segments of] DNA in order to bring people together." The odds aren’t in our favor.

And this doesn’t even touch on other complicating factors like

• larger shared segments potentially coming from more distant ancestors, or
• the DNA match actually coming from shared ancestors who are not currently known nor mapped out in the pedigree, or 
• misleading pile ups on certain DNA segments. 

Clearly, triangulation is not the gold standard for identifying and verifying ancestral matches.

The dim probabilities (coupled with challenges inherent to DNA-testing at AncestryDNA) likely explain why I’ve only found, to-date, two triangulated matches between descendants of Thomas and Mary from the 40+ paired matches.

I'm not discounting these triangulated matches or the value of triangulation in certain cases, but I am meditating on alternative approaches to determine how best to leverage these DNA matches to prove or disprove that Thomas Kirk and Mary (Kirk) Geiger were siblings.

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[1] https://dna-explained.com/2017/06/27/ancestral-dna-percentages-how-much-of-them-is-in-you/
[2] https://gcbias.org/2013/11/11/how-does-your-number-of-genetic-ancestors-grow-back-over-time/
[3] https://www.ancestry.com/academy/course/ancestry-dna-circles
[4] https://cruwys.blogspot.com/2016/01/autosomal-dna-triangulation-part-2.html
[5] https://cruwys.blogspot.com/2016/01/autosomal-dna-triangulation-part-1.html

The Trials and Tribulations of Triangulation

There are millions of consumers spitting and swabbing their way to family history. An entire industry is on the rise, eager to be the spittoon to the masses and their gateway to genetic genealogy.¹

Ethnicity estimates, of course, are a huge draw for the average Joe (“Kiss me, I’m 21% or 39% or 53.9% or 21.9% Irish!).² My head’s already spinning, and I haven’t even had a pint of Guinness, yet.

Test-takers (particularly Americans where market penetration is greatest) are racking up cousin matches by the thousands. This overload abundance of unidentified relationships makes for Mission Impossible when you just want to pinpoint your link to William the Conqueror and make a better case for Liz’s crown.

Serious family historians fight the good fight, trudging through hordes of matches hoping for public trees that align with their own. If they’re lucky they’ll find a paired match with Average Joe who has a well-documented pedigree making it easy to pinpoint a shared ancestor.

While offering important clues to possible family relationships, these one-to-one matches are not entirely conclusive on their own.

Try Triangulation

What if you’re looking for more substantial evidence to untangle a tightly knotted family mystery? Can you do something a little more sophisticated with those DNA results?

Perhaps.

One approach is called triangulation. Genetic genealogist Blaine Bettinger defines it as, "a process or method by which three or more people all sharing an overlapping segment of DNA in common compare their family trees in order to identify a common ancestor or ancestral couple shared by all."³

Triangulation is often touted as the gold standard for verifying a common ancestor among genetic cousins.

I have my own case study where triangulation may provide an answer for a theory of mine. 

Theory: My fifth great-grandfather Thomas Kirk (1778-1846) of Licking County, Ohio was the younger brother to Mary (Kirk) Geiger (1774-1832) also of Licking County. 

I really think they were brother and sister. I've found more than 40 one-to-one DNA matches between descendants of Thomas and Mary. The amounts of shared DNA between those paired matches aligns with the projected relationship-level (usually 5th cousins or 5th cousins once removed) that I would expect to see for the matches if Thomas and Mary were siblings and their parents were the common ancestors for all testers.⁴

Could triangulation provide more substantive, respected evidence so I could confidently conclude that they were siblings?

All I have to do is find living descendants of Thomas and Mary, test their DNA, and compare for overlapping segments. And those first two steps are mostly done. There's just step three to tackle.

Sounds worthwhile and easy enough, right?

Why is it so difficult to triangulate?

I quickly learned that triangulating autosomal DNA was easier said than done. In fact, I think Euclid had an easier go of it.

The first obstacle I encountered was getting access to the information needed to properly triangulate matches.

Nearly all of those 40+ paired matches were discovered on one monolithic genealogy site.

Guess which site does not provide information on whether matches triangulate nor does it give access to the segment data necessary to triangulate? The big monolithic one, of course.

To triangulate, I would need to persuade my genetic cousins to download their data from the monolith and upload to another entity that offers triangulation capabilities. Not impossible, of course, but frustrating that the approach can't be undertaken at the monolith.

The second obstacle I encountered was where to persuade the matches to transfer their results.

A couple years ago, this would have been a straightforward answer. There's one third party website that was the go-to site for testers to upload their data from most of the consumer DNA websites, especially the monolith.

However, following the apprehending of the Golden State Killer and other violent criminals thanks in part to a lead from a consumer genealogy test uploaded at this third party site, sensational headlines have raised privacy concerns.⁵ The subsequent spotlight on the use of the site by investigative authorities and a robust dialogue within the genetic genealogy community has been withering.

Was law enforcement surreptitiously mining users' data without their knowledge and consent? While this conversation is ongoing, concerns around ethics and privacy have created an unease that makes testers more cautious with their data.

Seeking a site that largely escaped the clickbait headlines, I settled on a popular genealogy platform based out of Israel that has proven an innovative player in the consumer DNA game and - most importantly to my case study - has a tool that identifies triangulated matches. Opportunely, they offer FREE uploads of DNA data from other companies (although there's a nominal fee to gain access to tools like the triangulation feature), and their Terms and Conditions of service attempt to put at ease concerns about law enforcement access:

"...using the DNA Services for law enforcement purposes, forensic examinations, criminal investigations, "cold case" investigations, identification of unknown deceased people, location of relatives of deceased people using cadaver DNA, and/or all similar purposes, is strictly prohibited, unless a court order is obtained. It is our policy to resist law enforcement inquiries to protect the privacy of our customers."⁶

The third obstacle I am now encountering has more to do with the science of how DNA is inherited and fades with each subsequent generation, drastically reducing the amount of genetic overlap needed for triangulation. The eldest living generation of Kirk descendants who have tested are 4th and 5th great-grandchildren of Thomas and Mary Kirk's parents.

At this level, there's very little DNA inherited from 4th and 5th great-grandparents: 1.56% and 0.78% respectively.⁷ The odds that the tested matches have inherited any DNA from Thomas and Mary's parents are slim, and the chance that they have inherited the same, overlapping bits of DNA required to triangulate a match are even slimmer!

And yet, despite all of these obstacles, I have identified my first triangulated match.

Two 4th great-grandchildren of Thomas Kirk - each descended from a different line - triangulate with a single descendant of Mary (Kirk) Geiger. It's a small 10.3 cM triangulated match, but, right now, it's my beloved inspiration and motivation to persevere through the trials and tribulations of triangulation.

While I wait for more Kirk and Geiger descendants to transfer their data and pray for overlapping segments, I find myself asking, "Why is triangulation so difficult if the rewards are potentially so great?" Surely it doesn't have to be this hard (shaking fist at that monolith).

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[1] https://thednageek.com/genealogical-database-growth-slows/

[2] https://www.familysleuther.com/2018/11/the-amalgamation-of-me-dna-ethnicity.html
[3] https://thegeneticgenealogist.com/2016/06/19/a-triangulation-intervention/

[4] https://dnapainter.com/tools/sharedcmv4
[5] https://www.wired.com/story/the-meteoric-rise-of-family-tree-forensics-to-fight-crimes/
[6] https://www.myheritage.com/FP/Company/popup.php?p=terms_conditions
[7] https://dna-explained.com/2017/06/27/ancestral-dna-percentages-how-much-of-them-is-in-you/

Family Rumors Beget A Genetic Conundrum

Who was my grandfather Frank's mother?

Two long-simmering family rumors offer conflicting stories. With none of the parties still alive, it's no longer possible to question anyone who had firsthand knowledge.

Charles and Angela raised Frank as if he were their own child. But was he?

While it's true that Angela was married to Charles, recent DNA testing confirmed that Frank was not his son.

Perhaps DNA could offer clarity nearly ninety years after Frank's birth and almost three decades since his passing.

Let's take a closer look at the two rumors.

Family Rumor #1

The first family rumor was that Angela had an extramarital relationship with a man named Sam, and that Sam was Frank's biological father.

A granddaughter of Angela and Charles remembers her mother saying that Charles, "slept in a separate room from Angela because of the affair and that Frank's biological father was some guy that worked on the water reservoir by their house."

Another granddaughter remembers signs of estrangement between Angela and Charles. She recalled that, "Charles slept in a separate room from Angela, first in the smaller room upstairs and then in the basement when they finished a room in that area."

Family Rumor #1: Frank is the son of Angela and Sam

DNA testing (both autosomal and Y) has confirmed that Charles is not the father and that Sam (or one of his brothers) is the father (see A Family History Mystery Revealed). The nature of the relationship between Angela and Sam remains a mystery.

Family Rumor #2

Both granddaughters also remember a second rumor, which conflicted with the first.

In this story, Frank was allegedly the son of Julia - a daughter of Charles and Angela.

At the time of Frank's birth, Julia was just 16 years old and already married to a man named Earl. Julia and Earl had lost a baby a year and a half before Frank's birth when she was only 15 years old. 

Family Rumor #2: Frank is the son of Julia and Sam

Distilling Truth From The Paper Trail

Frank's original birth certificate hints at the validity of Family Rumor #1.

Shockingly, Frank's surname matched Sam's and not Charles'.

But there were also possible attempts to obfuscate the truth perhaps in a bid for discretion.

The father's first name was listed as a diminutive of Sam's middle name.

Also, the first name of the mother was listed as Agnes instead of Angela, and the mother's surname was Angela's maiden name not her married name. Was she trying to afford herself some cover for the birth of a child outside of her marriage?

The mother's age at last birthday was listed as 37. This matched Angela's age when she conceived, but she was actually three months into her 38th year when Frank was born. In any case, it seems unlikely that a hospital registrar would mistake a 38-year-old woman for a 16-year-old teenager.

Frank's birth certificate also included the prior number of children born to the mother: four total but only three living. This correctly matched the number of children Angela had given birth to and lost.

Lastly, an address was provided for the mother. It was Angela's home address.

Genetic Conundrum

While the paper trail hinted at a preferred family rumor, I wondered if I could eliminate Family Rumor #2 as a contender.

The best way to pinpoint Frank's mother would be with DNA.

Family Rumor #1 by the DNA

Three of Frank's children have completed autosomal DNA tests. Charles and Angela had a son; a daughter of this son has also tested. If Family Rumor #1 was true, Frank's three children would be half first cousins to this granddaughter of Charles and Angela.

Alleged family relationship per Family Rumor #1

How did their results compare? Let's have a look.

Curiously, there was quite a spread between Frank's three children and the amount of centimorgans they each shared with the granddaughter. 

Across the board, they were all below the average amount of shared DNA commonly seen with half first cousin relationships (per Blaine Bettinger's Shared cM Project). However, all three fell comfortably within the range of shared DNA for this relationship level.

Takeaway? Family Rumor #1 was genetically possible.

Family Rumor #2 by the DNA

If Family Rumor #2 were true, Frank's three children would be first cousins once removed with the granddaughter.

Alleged family relationship per Family Rumor #2

How did their shared amounts of DNA compare with averages for that relationship level as tallied by the Shared cM Project?

Across the board, the amount of DNA they each shared was below the average for first cousins once removed. Once again, the amount of DNA they shared fell within the range for the relationship level of Family Rumor #2.

Takeaway? Family Rumor #2 also appeared to be genetically possible.

Dueling Rumors Linger

I hoped for a more definitive answer that would knock Family Rumor #2 out of the running, but it seems I cannot comfortably do that on numbers alone.

The birth certificate adds credibility to the first rumor, but was it possible that Angela could have had her name added as the mother's to spare her daughter marital angst and public shame? I don't know when, where or by whom the birth record was completed (although it was signed by a Dr. Felix affirming he attended the birth of the child). If it was at the hospital then that lends credibility to Family Rumor #1. If not, a gap opens up where Family Rumor #2 could slip in.

How else might I resolve this genetic conundrum and finally settle which family rumor was fact?

Were They Brother and Sister? Verifying an 18th Century Relationship with Autosomal DNA

Were Thomas Kirk, my fifth great-grandfather, and Mary (Kirk) Geiger siblings?

I believe DNA has finally given me an answer.

A Web of Parallels

Setting DNA aside for just a moment, there were a few curious facts that initially made the siblingship case worth considering, including:

Name:  Given my extensive research into Thomas Kirk, any Kirk who crossed his path or simply toe-tapped into his proximity was an immediate person of interest and required a full-fledged investigation. Naturally, when Mary Kirk, who married Anthony Geiger in 1797 in Martinsburg, Virginia (now West Virginia), appeared in the same Ohio neighborhood, the sleuthing commenced with an excited fury.

Age:  They shared a close proximity in age. Born in 1778 in Virginia, Thomas was just four years younger than Mary who was born in 1774. 

Time and Space:  They both lived in the same geography and timeline. Tax records confirmed that Thomas, my fifth great-grandfather, was in Licking County, Ohio by 1805. Meanwhile, a 1901 biography of Mary's grandson Richard Geiger, recalled that "In 1804 he [Mary's husband Anthony Geiger] came to Ohio, the year following the admission of the state into the Union, and located in Licking County..." Mary was even buried in the same cemetery as Thomas. Only a few yards separate them in their eternal rest.

Although these facts coalesced around my theory, there was still no explicit evidence of a family relationship.

Finding Family With Saliva

What, if anything, could DNA tell me about their possible connection?

The first challenge with autosomal DNA is that the genetic material inherited from a given ancestor fades with each subsequent generation. As a result, the strength of autosomal DNA matching only goes back about five, six or maybe seven generations.

To put this another way, consider approximately how much DNA we inherit from each preceding generation: 50% of our DNA came from our fathers and the other half from our mothers. Jump back another generation, and we've inherited 25% of each of our grandparents' DNA. As you climb back each generation, the average amount of inherited DNA decreases by half. The further back you go, the numbers slim proportionally until the DNA is virtually indiscernible.

Exactly how much of Thomas Kirk's DNA should I have? As a fifth great-grandson, I could expect to share less than 1% of his DNA (0.78% to be exact). If we were to graph my DNA, Thomas would represent a slim sliver.

Of course, DNA is rarely that straightforward. The process is further complicated because we don't necessarily inherit DNA from all of our ancestors at this distance. For a more detailed explanation on this quandary, I defer to genetic genealogist Roberta Estes who has addressed this issue in her blog Ancestral DNA Percentages - How Much of Them is in You.

Mindful of the pittance of autosomal DNA that I've inherited from Thomas, I'm fortunate to have a first cousin twice removed - two generations closer to Thomas than me - who tested her autosomal DNA. As a third great-granddaughter of Thomas, she's inherited approximately 3.12% of his DNA.

More DNA, of course, means increased odds for matching genetic Kirk cousins. Could we link her to any of Mary (Kirk) Geiger's descendants?

I searched my Kirk cousin's DNA matches for the surname Geiger and found six individuals who had a pedigree that traced back to Anthony and Mary (Kirk) Geiger. At first blush, it seemed there was indeed a genetic relationship between descendants of Thomas Kirk and Mary (Kirk) Geiger.

Crunching the CentiMorgans to Verify Relationships

My next step was to evaluate the accuracy of these six genetic matches, and determine whether the amount of shared DNA corroborated a sibling relationship between Thomas and Mary.

I do this by making the assumption that Thomas and Mary were siblings and calculating the descending relationships between my Kirk cousin and her Geiger matches accordingly.

Next, I examine how much DNA each match shares and whether this falls within the verified range for similar family relationships.

To make this assessment, I rely on The Shared cM Project, an invaluable tool developed by genetic genealogist Blaine Bettinger.

Bettinger has polled an enormous number of DNA testers and their known relationships to determine the average amount of centiMorgans (a DNA measurement) an individual could expect to share with cousins at various levels. The expansive chart details both the average amount of centiMorgans (cM) common for a particular relationship as well as the range of cM that exists for that particular relationship.

If Thomas Kirk and Mary (Kirk) Geiger were in fact siblings, the published pedigrees indicate that four of the six individuals would be fifth cousins with my Kirk cousin. Their relationship would look like this:

(*Note that the Geiger relationship is not a direct paternal line of descent,
the surname is used for illustrative purposes only.)

According to the Shared cM Project, fifth cousins share, on average, 25 centiMorgans (cM), but the amount of shared DNA can range anywhere from 0 to 94 cM. So, where do each of those four 5th cousins fall?

• 18.2 cMs over 2 segments
• 33 cMs over 2 segments
• 35 cMs over 2 segments
• 12.8 cMs over 1 segment

While there is some variation among the four and none individually match the average, all fall well within the range that you would expect to see for a fifth cousin relationship. The average cMs for these four is 24.75 - a near exact match to the fifth cousin average.

Two of the six Geiger matches would be fifth cousins once removed. Assuming Thomas and Mary are siblings, their relationship to my Kirk cousin would look like this:

(*Note that the Geiger relationship is not a direct paternal line of descent,
the surname is used for illustrative purposes only.)

According to the Shared cM Project, 5th cousins once removed share, on average, 21 centiMorgans (cM), but the amount of shared DNA can range anywhere from 0 to 79 cM. Here's how the two 5th cousins once removed stack up:

• 8.6 cMs over 1 segment
• 24.1 cMs over 2 segments

Again, the shared DNA falls within the established ranges we could expect to see for fifth cousins once removed.

Taking Stock of the Genetic Relationship

Six people who descend from Mary (Kirk) Geiger are genetic matches to a descendant of Thomas Kirk. 

The amount of shared centiMorgans between them all supports the claim that they are fifth cousins (or fifth cousins once removed), which in turn indicates that Thomas and Mary were siblings. This is, of course, assuming there's no other shared ancestry between the matches, which would skew my results. To my eye, there is no other obvious overlap in the family trees.

While the evidence doesn't contradict my theory, I do recognize that the cM range for these distant family relationships are quite expansive. The shared cMs for the six cousins could just as easily be used to indicate a 6th or even 7th cousin relationship, putting another generation or two between Thomas and Mary. But what's the likelihood that six matches would show up for a single 6th or 7th cousin relationship?

All of these matches are in the largest DNA database in the family history market, which means there's currently no access to additional tools like a chromosome browser to further scrutinize the connections. 

How else could I leverage these matches to determine definitively - should that be possible - that Thomas Kirk and Mary (Kirk) Geiger were brother and sister? 

In the meantime, I'm increasingly confident that Thomas and Mary were siblings.

The Genetic Family Tree Grows New Buds

Genetics are now tightly intertwined with genealogy. The powerful role DNA plays in revealing family history has been nothing short of revolutionary, says the guy who unraveled a Not-the-Parent-Expected (NPE) event thanks to DNA.

DNA testing for genealogy has gone mainstream, catching the imagination of consumers who aren't ardent genealogists (for better or worse).

Databases of DNA-tested consumers are experiencing exponential growth (check out the latest numbers at Leah Larkin's The DNA Geek blog). More testers means increased potential to connect with genetic cousins who may expand our family trees, perhaps even knock down a few brick walls.

Genetic Haplogroup Family Tree
A year ago, I wrote about the creation of a new kind of family tree - one based on genetics and not names.

The Haplogroup Family Tree is a pedigree of paternal and maternal haplogroups.

What's a haplogroup? The International Society of Genetic Genealogy defines it as, "a genetic population group of people who share a common ancestor on the patrilineal or matrilineal line. Haplogroups are assigned letters of the alphabet, and refinements consist of additional number and letter combinations."

In the past year, my genetic family tree has seen two primary changes: an evolution of my paternal Y-DNA haplogroup and a newly-tested family line.

Family Sleuther's genetic family tree

My primary attention has been on my paternal line, using Family Tree DNA's Big-Y test to refine my patrilineal haplogroup to a more recent timeline (but more on this in a future post). In the last year, my paternal haplogroup has narrowed from R-A664 to R-BY30547 - a branch (or, more appropriately, a twig) of mankind's Y-DNA tree that is unique to my relatively recent paternal ancestors.

The second update is that my mother's brother recently agreed to Y-DNA test, which will provide me that line's Y-DNA haplogroup. When those results arrive, I'll need just two great-grandmothers' maternal haplogroups: great-grandmothers Ruoti and Wagnon.

Fishing For Cousins

Roberta Estes, author of the wonderful DNAeXplained - Genetic Genealogy blog, just featured her own genetic pedigree in a recent post. She's detailed her paternal and maternal haplogroups back to her great-grandparents. Like me, she needs to identify just two great-grandmothers' maternal haplogroups.

To fill those gaps, Estes offers to provide free DNA tests to qualified descendants of those ancestors. I think that's a fantastic idea. 

So ping me if you're a descendant with a direct maternal connection to either of the women below:

• Maria Filomena (La Rocca) Ruoti, 1875-1929, Potenza, Italy and Denver, Colorado: this is actually my second great-grandmother, but her daughter, my great-grandmother, had no female descendants to carry on the matrilineal haplogroup, so I have to take it back a generation.

• Mary Pauline (Wagnon) Upton, 1906-1992, Muskogee, Oklahoma.

A lot can happen in a year. We'll see how fulsome the tree looks in twelve months. 

Building A Genetic Haplogroup Family Tree

The introduction of DNA into genealogy has been revolutionary for the hobby.

What was once a seemingly straightforward process of tracing family names through paper trails and family lore - where they existed - has been made more nuanced (some would argue complicated) by the ability to identify and establish family bonds using the invisible genetic signatures inside each of us.

The Power of Genetic Genealogy
I am thankful for the insight that genetic genealogy affords the family historian. I witnessed firsthand just how powerful a truth rests in the blood. DNA helped me uncover a long-forgotten family secret (follow that wee little adventure in my four-part series A Family History Mystery Revealed).

Uncovering a Non-Paternal Event (NPE) and learning the identity of my biological paternal great-grandfather was an eyeopening experience. While it didn't change the love for the family who raised my grandfather, it certainly expanded the branches of my family tree in unanticipated ways. There were new relatives with new surnames to research.

Above all, there was a new appreciation for the genetic family tree.

A New Kind of Family Tree
In late January, I read Lara Diamond's blog about her Updated Haplogroup Tree with great interest. She built a pedigree that documents not names of family members but rather the haplogroup of her ancestors.

Perhaps you're wondering what is a haplogroup?

The International Society of Genetic Genealogy defines it as, "a genetic population group of people who share a common ancestor on the patrilineal or matrilineal line. Haplogroups are assigned letters of the alphabet, and refinements consist of additional number and letter combinations."

Using the Y-DNA (paternal line) and mtDNA (maternal line) test results for family members tested with both FamilyTreeDNA.com and 23andMe.com, I plugged my ancestors' known haplogroups into my first Genetic Haplogroup Family Tree.

Family Sleuther's Genetic Haplogroup Family Tree

It's a fledgling set of results with haplogroups known for 11 of the 15 family members depicted in my genetic pedigree. 

There remains work to be done. I don't yet know my maternal grandfather's Y-DNA haplogroup or his mother's. I also don't know my paternal great-grandmother's haplogroup. Fortunately, I'm certain there are descendants of these individuals who can test and provide this data. The clock is ticking. We'll check-in in a year to see what progress I make.

What about your Genetic Haplogroup Family Tree? Have you started mapping out your ancestors' haplogroups?

What's In A Name: DNA & Naming Customs

Who was Thomas Kirk's father? A burned county courthouse, destroyed census enumerations, and lost family lore have complicated the question. Understandably, all research options are on the table as I try to uncover my fifth great-grandfather's ancestral origins.

Born in 1778 in - most likely - Virginia, Thomas settled in Licking County, Ohio where he died in 1846. Most genealogies conclude that Thomas married Sarah Louise Bonar in about 1804. Together they had at least twelve children of whom ten survived to adulthood. The eldest child was their son Vachel (my fourth great-grandfather) who was born in approximately 1805.

What can Vachel Kirk tell me about his paternal grandfather?

Traditional Naming Customs
If the Kirk family followed traditional Scottish or even Irish naming patterns, the first son was named after the father's father. Was Thomas a man of tradition? Did he name his son Vachel after his own father?

A clue to Thomas' inclinations can be found by using his eldest daughter Jane Kirk as an example. Naming customs typically stipulated that the eldest daughter be named after the mother's mother. We know that Sarah (Bonar) Kirk's mother's name was Jane (McCulloch) Bonar. It seems - at least in the case of his daughter - Thomas did stick to tradition.

Vachel certainly was an unusual name. How many could be out there? Surely I could locate them all and quickly discern whether there was any family connection to my Thomas.

Broad name research is complicated in the early 19th century census records. Only heads of household were enumerated before 1850, eliminating any Vachels who were still living with their parents. Also, many states' census records were lost, including Virginia's 1790 enumeration (this is of particular concern since some of Thomas' children indicated on later censuses that he was born in Virginia).

Ultimately, I found two other Vachel Kirks, both in Ohio, who were near contemporaries of my Thomas Kirk, although not old enough to be his father. Given the shared unusual name and location, they required further scrutiny.

Vachel Kirk from Fayette Co, PA buys
land in Knox Co, OH in November 1809.

Will Vachel Kirk Please Stand Up
Vachel Kirk #1 was born in June 1783 in Pennsylvania and died April 6, 1836 in Butler County, Ohio. His death and approximate birth dates come from his headstone. His birth location was reported by his daughter Nancy on the 1880 census.

This Vachel Kirk would have been five years younger than my Thomas Kirk. Obviously this wasn't a father son relationship. However, it's possible that they were siblings or cousins.

A Vachel Kirk was enumerated in Fayette County, Pennsylvania in the 1810 census. The eldest male enumerated in that census was between the ages of 26 and 44. If Vachel was born in 1783 he would have been 27 in 1810 and would have fit this broad age range.

In November 1809, a Vachel Kirk from Fayette County, Pennsylvania bought land in Knox County, Ohio for $100. Knox County borders Licking County to the south. This land purchase put Vachel Kirk #1 within proximity of my Thomas Kirk.

Vachel Kirk #2 is a murkier fellow. He was perhaps born in the late 1790s or early 1800s in Virginia or Ohio. There were minor discrepancies between the census records. The one common fact that helped pinpoint him was his spouse, Susanna Allstaff, and children.

This Vachel Kirk married Susanna Allstaff on December 1, 1825 in Belmont County, Ohio. To-date, his last documented appearance that I've uncovered was in the 1870 census. He was living with his wife and daughter Sarah in Clay Township, Hendricks County, Indiana. I haven't discovered a grave or other evidence of when or where he died.

Following the Genetic Code
When the paper trail doesn't cooperate, I advocate turning to the genetic code. Underscoring the value of investigating people of shared unusual family names, I've just identified a genetic link between descendants of Thomas Kirk and both of the above-mentioned Vachel Kirks. However, I still haven't determined our shared common ancestor.

I mapped out a direct male descendant of Vachel Kirk #1. He agreed to take a Y-DNA test. The results - at 37 markers - came back as a match with a genetic distance of two. Family Tree DNA estimates that, at this level, there's more than an 88% chance that we share a common ancestor within the past eight generations.

If Vachel #1 was a sibling to my Thomas Kirk, that means the common ancestor - their father - would be eight generations ago. I'm hopeful we can upgrade this Y-DNA test to include more markers and yield more refined estimates.

Meanwhile, from a different lab, a first cousin twice removed on my Kirk line recently had a new 5th to 8th cousin match appear on Ancestry. This matching cousin is a descendant of (drum roll please...) Vachel Kirk #2.

This match estimate suggests that their shared ancestor was in the range of a 4th to 7th great-grandparent. In their case, the fourth great-grandparent level begins with Thomas Kirk's parents.

It seems highly unlikely that Thomas Kirk's parents would have named two sons Vachel Kirk who both lived to adulthood, so I currently hypothesize - based largely on birth year - that one of them was a sibling to Thomas (Vachel #1) and the other was a cousin or nephew (Vachel #2). Of course, there's much more research required to confirm these theories.

I'm excited to identify new Kirk family members who were contemporaries to my Thomas Kirk. It creates new research avenues to pursue. If the records are snuffed out on Thomas' line, perhaps results for the two Vachel Kirks will help shed light on our shared paternal ancestral origins.

A Birthday of Genealogy Serendipity

The Author's Maternal Grandmother

This was a week of milestones. Sunday was the two year anniversary of my maternal grandmother's passing. Thursday was my birthday.

While I'm not one to usually look for signs from above, it seemed like more than just a coincidence when the bill for my birthday breakfast came back matching the last two digits of each of our birth years: hers the dollars and mine the cents.

The chance pairing of those numbers stuck in my head and set the tone for the rest of my birthday.

A DNA Research Project
Readers of this blog know that I am researching my 5th great-grandfather Thomas Kirk. He represents a brick wall for my paternal line. I want to learn the identities of his parents and their ancestral origins. Given the spotty 18th century paper trail, I've turned to genetic genealogy.

Thomas had a large family with at least twelve children. Seven of his children were sons who lived to adulthood and had sons of their own. To accurately recreate Thomas' Y-DNA, I've been searching for male descendants of each of his seven sons.

After months of research and outreach, four men - descendants of four of his seven sons - agreed to participate in the Y-DNA initiative and tested. However, I still wanted to find male testers descending from the remaining three sons. I had feelers out to several men.

Genealogy Serendipity
Stopping by the mailbox on my birthday, I saw there was a letter from a gentleman who was a descendant of one of those three remaining sons. He's not online and doesn't have an email address, so we've been corresponding about our shared Kirk ancestry through letters.

I ripped open the envelope and pulled out his note: "Yes I would be willing to do a DNA test."

I was ecstatic! Testing another descendant of one of Thomas' sons was a fantastic birthday present. I quickly loaded up the DNA website and ordered his kit. Five sons tested only two sons to go.

When I logged into my own account, I saw that I had a new Y-DNA match. The match's surname was Kirk. I quickly recognized that the first name belonged to a gentleman I spoke with this past winter about testing. Months of radio silence later, here I was staring at another genetic match and, best of all, the descendant of one of the two remaining sons.

Chart of Y-DNA-tested descendants of Thomas Kirk's sons. 

What were the odds that two more men - much sought-after descendants of two of Thomas' sons - would both contribute to the Y-DNA research project on the same day? And my birthday to boot! It felt rather serendipitous. As a genealogist, I couldn't ask for a better gift, and I can't help but wonder if my grandmother had a hand in it.

My focus is now on Thomas' last remaining son. William Kirk, you're next!

Family Mystery Part IV: DNA Doesn't Lie

A couple years ago, I stumbled onto a non-paternal event after discovering a birth certificate for my paternal grandfather that listed his father as Jimmy Kirk. Jimmy Kirk was not my great-grandfather's name. At least not the name of the man I believed to be my great-grandfather.

Shortly after this discovery, I heard a family rumor that my great-grandmother had a relationship with a man who worked at the water reservoir beside her home. 

I've blogged my way through this mystery. Catch up on all of the sordid details to-date:

• A Family History Mystery Revealed
• Family Mystery Part II: Identifying the Watchman
• Family Mystery Part III: Are You My Grandpa?

I identified Samuel James Kirk as the likely candidate for my biological paternal great-grandfather, but I still needed something more than conjecture, rumor, and hunches to give me solid answers on which I could stake my surname.

Could there be a role for DNA?

Samuel James Kirk was the son of William Frank Kirk. In total, Samuel had ten siblings (six brothers and four sisters). Unfortunately, they're all deceased. To find answers, I would have to move on to the next generation. One of Samuel's brothers had a daughter who is still alive. 

Autosomal DNA Test

I found an address for her, wrote her a letter, and over the course of several months she shared information on her Kirk family history. In November 2014, she agreed to take an autosomal DNA test with Ancestry.com. 

An email finally arrived with the long-awaited news that her results were in; however, it took a full day for her genetic matches to populate. The wait was torture thrilling! 

Her four closest matches were (drum roll, please...) my father, my aunt, my uncle, and myself.

Bingo! DNA had confirmed a winner.

Ancestry.com estimated her relationship to my dad and his siblings as second cousins. In actual fact, they would be first cousins once removed. This relationship prediction aligned exactly how I would expect it to if Samuel James Kirk was my great-grandfather. 

Based on this genetic evidence, I had finally latched onto the correct Kirk family. Great-grandma did indeed have a very friendly relationship with the reservoir watchman!

Y-DNA Test
After the autosomal DNA test connected me to the correct Kirk family, I began mapping out the family tree. I wanted to locate a direct male Kirk descendant to further confirm the initial DNA results. In preparation, both my father and I took Y-DNA tests with FamilyTreeDNA. 

My Kirk genealogy determined that William Frank Kirk was the son of James Kirk (1830 - 1917). James and his wife Hester Griffith had eight children, including James Kirk, Jr. 

Following James Jr.'s descendants, I eventually landed on a male Kirk cousin living in the Midwest. Judging by our family tree, he would be my third cousin once removed. But would the DNA confirm the relationship?

I mailed him a letter explaining my interest in researching the Kirk family tree, and then I asked if he would take a DNA test. (It must be so odd to receive a request like that out of the blue!) He wasn't weirded out.

I received a phone call from the cousin. He was on board. I had a Y-DNA test kit shipped to him and after several months (it took him a while to actually take the test) the sample was at the lab for analysis.

In early July 2015, his results came back. He was a very close match with a genetic distance of 1 (on a fast changing marker) for 67 markers. Based on those results, it was safe to say that we did share a common male ancestor - James Kirk - as the paper trail suggested.

Again, DNA had reinforced the case for my link to the Kirk family.

How Far Can I Go?

While I was waiting for the Y-DNA results to arrive, I continued researching the Kirk family tree. I was able to push the paternal line as far back as the paper trail currently supports. 

The furthest my male Kirk line can be traced is to a man named Thomas Kirk (c.1778 - 1846) who was married to Sarah Louise Bonar and lived in Licking County, Ohio. 

After one non-paternal event, you get a bit skittish and begin to only trust the science. The truth DNA brings to genealogy is both refreshing and a confidence builder in the accuracy of your research. Could I genetically confirm Thomas as my 5th great-grandfather?

I would need to find and test another direct male descendant of one of his sons. Fortunately, Thomas had 12 children. Nine of them were boys. There was no shortage of Y-DNA to track down.

I descend from Thomas' eldest child Vachel Kirk. Zeroing in on Thomas' eighth son Greenberry Dorsa Kirk, I eventually found a direct male descendant who was willing to take a 67-marker Y-DNA test.

In late August, his results came back. He was a close match to my father with a genetic distance of two (the same fast changing marker mentioned above and a slow marker).

The test again reinforced the paper trail: I am a descendant of Thomas Kirk. 

Genetic Genealogy Is Here To Stay

The entire mystery of my grandfather's paternity would not have been solved with any level of confidence without the DNA tests.

Genetic genealogy is now a fundamental tool in the genealogist's toolkit. In fact, DNA will likely play a key role in helping to learn the ancestry of Thomas Kirk and his national origins. 

I look forward to the adventure and my newfound role as a citizen scientist. Now where did I put my lab coat?

AncestryDNA Ups Its Genetic Matching Game

Have you heard the good news? Genetic genealogists have cause to celebrate!

Ancestry.com took a step in a very positive direction this week by adding two new features to AncestryDNA that will help immensely with your genetic genealogy research.

Genetic Matches
With the addition of a "Shared Matches" button, you now have the ability to click on the profile for a DNA match and view a list of AncestryDNA users who are also genetic matches between you and the selected profile.

Why is this so cool?

Let's say that you've recently uncovered a non-paternal event (hypothetically) and  you want to zero in on only paternal line matches. If you've been fortunate enough to identify a potential biological paternal line cousin, you can now click on said cousin's profile and select the "Shared Matches" option.

A list will generate and you're off to the races. You no longer need to trawl through your own list of matches and then a cousin's list of matches to find the few shared common matches. The comparison is automated. Efficiency is cause to celebrate.

Of course, this isn't a chromosome browser. You can't, in this current format, verify which chromosome blip the matches all share in common. Subsequently, you can't identify - with 100% certainty - the common ancestor. It remains incumbent upon the diligent researcher to scrutinize the shared matches in order to suss out a likely common ancestor.

But let's not nitpick, for now, and celebrate this victory.

Mother and Father Filter
AncestryDNA also unveiled a new filter for users who have had either or both of their parents test. Once your parents' tests are in the system, a Mother and Father button will appear in your match view.

Click on either button to see matches that you share with your mother or your father. Again, another mighty helpful feature if you're looking to focus on a particular line of your ancestry.

To learn more, check out AncestryDNA's Anna Swayne as she walks users through the new features.