Monday, May 11, 2020
Celebrating Mother's Day,
Genetic Genealogy Style
While yesterday was Mother's Day—which put far more people on the road, traveling to make a special visit, than these quarantine times might warrant—I didn't really have a mother to celebrate with. So I had to do a bit of my own celebrating in her memory. That consisted mostly of rehearsing memories of her life and her influence on mine, but it also included a hat tip to the genetics that allowed part of her to live on in her daughters' and granddaughters' efforts.
One of those tiny ways has been captured by a specific DNA test called, in typical unwieldy scientific manner, the mitochondrial DNA test. (Perhaps, seeing a name of that length, you can understand why people resort to the shorthand of calling it the mtDNA test.) While there have been literally millions of people who have had their DNA tested, I doubt much more than one percent of them has purchased this type of DNA test. Genealogy guinea pig that I am, of course I stepped up to be one of the ones to experiment with the mtDNA test.
The mtDNA test—so appropriate to review during Mother's Day, as you will see shortly—can help determine what is called the matriline: the mother's mother's mother's ancestral line. Each of us inherits that specific genetic signature from our mother, though only daughters pass that code along to their children. Thus, I can find out about my mother's ancestors, even though she is no longer with us, simply by testing my own mitochondrial DNA, which can be done at only one company at this point, FamilyTreeDNA in Houston, Texas.
Actually, I have managed to become administrator for three tests which utilize that mtDNA option. Having not visited those results in far too long a time, I took the opportunity during Mother's Day to check whether there were any updates to those three accounts.
Sadly, there weren't any new additions to the results for any of the mtDNA tests I administer. This is disappointing, but not unexpected. The higher price for the mtDNA test—particularly the most complete version of the test, which includes the two "hyper-variable regions" as well as a coding region—is less attractive to consumers than the more widely purchased autosomal test. And yet, it is the mtDNA test—along with its counterpart for the males in a family's line, the Y-DNA test—which is more powerful, when it comes to reaching deep, yet specifically, into one's ancestry.
For example, out of the four "exact match" tests in my own account, one belonged to a woman who had built her tree back to the late 1600s. There in her pedigree, I spotted a familiar surname, which turned out to be ten generations back in time—a considerable stretch, considering that an "exact match" means that there have been no mutations between then and now.
That discovery also did something extra for me: it confirmed my guess about my second great-grandmother on my matriline, whom I had been told was an orphan who had been adopted. How does one figure out how to break through an unfortunate brick wall like that? If it's on the matriline and two people test with an exact-match result, comparing notes can help bridge that information gap.
This, of course, is why two of my four mtDNA exact matches belonged to adoptees. They were hoping to find a clue to help them piece together their birth families. Regardless of the power of science, this, of course, can still be an immense undertaking, requiring persistence to achieve. But it is possible.
Every year, leading up to Mother's Day, the mtDNA test goes on sale—as does the Y-DNA test before Father's Day. Each year, I hope some unknown someone out there, who just happens to be an exact match to me or the other two people whose tests I administer, will spring for that pricey mtDNA full sequence test and show up in my results.
It doesn't take many such results to help build an ancestral line that reaches back three hundred years or more, so I suppose there's no need for a multitude of such responses, though I always am greedy for more validation. But it certainly is awe-inspiring to see the power of the genetics that go into making us who we are—and how that same detail went into connecting us with our own mother...and the ten generations preceding her in our family's history.