First of all, it’s science. Not simple science. Complicated science. This old woman can’t remember what she learned 150 years ago in high school!
Second, I do better with the dead, long-gone ancestors. We get along really well. I chase them through centuries of various documents and I usually catch them.
They don’t mind.
Finally, in the work I do for others, I deal far more with direct line ancestors than I do collateral ancestors and I rarely encounter much trouble in the chase until the early 1800’s.
I thought about how DNA might help me find relatives I would have no other way of making a connection to, but never got farther in my personal research than taking the autosomal test Ancestry.com offers.
Honestly, until I attended a seminar hosted by the Louisville Free Public Library this summer, I rather ignored DNA.
The facilitator of the DNA seminar I selected, Debra Smith Renard, was extremely knowledgeable. She made it clear DNA testing is not a replacement for traditional research. I now see it as another evidence avenue. She also explained just how much DNA can bring to the genealogical table in a way that I was able to understand. As a result, I feel comfortable bringing it aboard my ship. It’s still not in my wheelhouse—yet—but I’m not leaving it on the dock anymore.
And just in time.
A couple of weeks ago, I was contacted by an Ancestry match. She was new to the genealogy game and wanted to know if we were, in fact, third cousins.
Being third cousins indicates we share great-great grandparents. Ancestry indicated “extremely high” confidence about this. Of course, we could be second cousins once removed, or fourth cousins....
Instead of ignoring the email, as I have done with others in the past (I know, shame on me!), I replied to her with the names of all eight sets of my great-great grandparents.
She indicated she was just beginning her tree and that she’d look for some same-name overlap.
Then, the question:
If she and I match, why wasn’t I a match to her full sister or her mother?
Well, here we go!
AncestryDNA is an autosomal, or atDNA, test. This means it looks at what we inherit from ALL our ancestors through our mother AND our father.
The percentage of atDNA inherited is halved with each generation, so when you look at the first generation, half of my atDNA is from my mother and half is from my father. Because they each got half from their respective parents, I wind up with about 25% of each grandparent’s atDNA, 12.5% of each of my great-grandparents’, and so on.
You can only go back so far until atDNA simply peters out and is no longer helpful.
...there are a number of reasons why two people’s DNA could be identical. This is what makes DNA matching a complicated scientific problem.... Pieces of DNA could be identical between two people because they are both human, because they are of the same ethnicity or come from the same region, because they share some other more ancient shared history, or other reasons. We call these identical pieces of DNA identical by state (IBS), because the DNA is identical for a reason other than having a recent shared common ancestor.
So are we cousins or not?
The time period our ancestors with same last names both resided in the same county in Virginia indicate we may be cousins but because it is so far back, we’ll need documentation to prove it.
Good old traditional genealogical research, substantiated to a point by DNA results, will prove or disprove our relationship.
Back to my wheelhouse!