Wednesday, May 20, 2015

D N A: Not as Easy as A B C

As we’ll be discussing in a few more days, I’ve been diligently chipping away at my genetic genealogy test results. I’ve been pursuing outcomes in two tracks: one is on my matrilineal line, where my only mtDNA exact match is with an adoptee for whom I can find no nexus in my to-date two hundred year long paper trail; the other is awash in my well-over-eight-hundred matches from my autosomal DNA test.

I’ve been doing this since midway through last December. I suppose five months of steady work on this project does not bring me anywhere near expert status. But it does grant me a modicum of knowledge—just enough to jack up the frustration level when things that seem like they ought to work one way stubbornly resist cooperating with the expected.

The most recent problem is this: my one and only exact match through my mtDNA test results recently received news that he has another exact match. He kindly passed along the word to me, thinking I would have received that news as well.

I hadn’t.

This, of course, was puzzling, because if someone is an exact match to a person who is an exact match to someone else, well…

It brings to mind such previously disdained elementary-grade math class rules as “The Transitive Property of Equality.” You know:

If a = b and b = c, then a = c



Yeah, I know: I wasn’t always a cherub in math class. But I did remember that rule—even if I had to go back and look up what it was officially called.

So, here I am: stuck at the part that says, “then a = c.” In other words, if I equal my mystery cousin, and my mystery cousin equals this other guy, then why don’t I?

Never one to wait for an answer to come to him, my mystery cousin went straight to the source: a project administrator for Family Tree DNA, where we took our DNA tests.

The answer? “Never seen anything like it.”

This will take some “looking into.”

Now, on the cusp of realizing a second exact match, I’m having to sit back and wait. Hold my breath.

This is near impossible for me, as I’m sure you can imagine. After all, according to the International Society of Genetic Genealogy, an “exact match”—at least at the level of the full mitochondrial sequence, as we’ve taken—means it “usually indicates a shared common ancestor within a genealogical timeframe.”

But…are we a match? Or aren’t we?

That is the question that’s awaiting an answer.


  1. Wow! How puzzling. I hope you get the answer to your DNA question very soon.

    1. Jana, I'm sure there will be some explanation forthcoming, soon--whether computer glitch or test result anomaly. There's always something more to learn, when it comes to DNA testing!

  2. Frustrating that even when we get into the more exact sciences, it appears for every answer there are more questions. I am beginning to wonder if the real lesson in genealogy is seems to be required at every level of every type of search.

    1. Excellent thought, Michelle! Patience!

      I am glad to say, though, that we've received an update rather quickly from the testing company. Calling it a "glitch," Family Tree DNA promised to look into the issue, and by this afternoon, had resolved the problem. I now have two "exact match" names on my mtDNA results.

  3. I think Michelle has a very good point! Patience grasshopper!

    I remember “The Transitive Property of Equality.” Lot of math in genealogy actually with "halving" and "doubling" to boot.

    I got to love that "within a genealogical timeframe” phrase... goodness is that ever vague!

  4. Being patient is hard...I cannot believe they "Never seen anything like it."

    1. As I suspected when I first heard about it, the "never seen" part turned out to be about a computer glitch, rather than any testing aspect. Thankfully. Otherwise, I might be concerned about being some sort of three headed monster...


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