MRCAs

by Laura

Most Recent Common Ancestors are the key to finding family, when you have nothing except a handful of DNA matches to go on. Fortunately, I had one (which I’ve mentioned beforenot too long ago). I mentioned that, in the beginning I thought for a long time that Catherine Wright was my 3rd Great Grandmother. But she wasn’t. She was my 3rd Great Aunt. That meant I had the correct family, but the wrong relationship. One of Catherine’s siblings was the Great (etc) Grandparent I was looking for.

So why is this important???

The methodology for adoptees using DNA to find family utilises a number of different tools. One of them, is building mirror trees (where you copy or “mirror” an existing tree for the person who is your MRCA) or speculative trees (where you begin to build a tree based on the supposed relationship between you and your MRCA).  These are, more or less, the same thing. You begin…or, at least, I did…by taking your top, closest DNA matches and matching the family trees to each other, looking for the same names in each of the trees you are looking at. In the beginning, it’s all speculative because you don’t actually know if these folk are in your tree or not and what your actual relationship to them is.  It’s an assumption; an educated guess based on the DNA being absolutely correct and the matches’ trees being more or less accurate.  In my case, I found Catherine in two separate trees: married to the same men, having the same children, who were also married to the same spouses, having the same children. Ancestry’s databases, being very large and very comprehensive, were very helpful at this point. I was able to verify, to the best of my limited ability that this person was the same person in both trees. Again, it’s speculative; you have to take a bit of a risk here and just go for it. Where the trees diverged from each other, was further down the tree…closer to our time…and in who Catherine was connected to and how she was connected (Grandmother or Aunt or Cousin). At one point, with about 500 people in this speculative tree, I found a huge mistake. So I deleted it. All of it. And started over from the beginning. Such is the nature of this sort of research.

The key to all of this is working down or forward in time until you get to where you would naturally fall in your own tree. Since Catherine had had two Husbands, it was pretty simple to separate the two trees between Husband A, and their progeny, and Husband 2 and their progeny. That’s when I started doing the other thing suggested for DNA genealogists:  connecting one’s DNA to someone (anyone, really, but one must be thoughtful about this…) in the tree. I played with this for months, connecting my DNA to everybody and their brother, literally!, male or female, dead or alive, until I finally got a huge breakthrough:

Johanna Wright.

I actually have three women with this name in my tree. One is a 1st cousin 3x removed; one is a 2nd great-aunt and they were born within five years of each other. They also were both born in Ballingarry, Ireland, emigrated to Pennsylvania, and died there. In the same town.

But the third Johanna Wright later proved to be my paternal Grandmother.  She was born in the same town where the other two Johannas had died.

I don’t believe in coincidences.

When I attached my DNA to her, I got green shaky leaf hints all over the place.

After six months of research, I had found my Father’s family; I still didn’t have a name.  Now it was time to fill in the blanks. Which, this being genealogy, turned out to be harder than I thought it would be.

Why do the Irish name everyone by the same. damn. names?