Friday, February 18, 2022

Sifting Through the Match List

 

I realize there are all sorts of approaches to sifting through those myriad DNA matches we receive in exchange for spitting in a tube mailed to a genetic genealogy company. Believe me, since my case involves a current count of over two thousand of what Ancestry calls "close matches"—fourth cousin or closer—and nearly thirty five thousand matches in total, I'm all for figuring out how to make sense of such a jumble of results.

Still, as we've already explored, simply using the tool Ancestry provides—their Thru-Lines listings—gives me only four puny matches linked specifically to my target ancestor, second great-grandmother Catherine Laws of northeastern Tennessee. Of those four matches, the one with the largest amount of genetic material in common with me amounts to a share of only twelve centiMorgans, hardly a sure lead—though I did determine exactly where she fits in my family tree.

Instead of relying solely on Thru-Lines, I try a different approach, one I've come to prefer, despite the added work to keep track of progress. I start by pulling up my entire match list and searching for those who have, in their affixed family tree, a specific surname in common with me. In this case, I entered the Laws surname in the search box, and pulled up twenty four matches who share at least twenty centiMorgans with me.

I record the names resulting from that family tree search—spreadsheet fans know where to go with this recordkeeping task—and also note the estimated relationship range, amount of centiMorgans in common, and how many segments that shared amount involves. Once I have that material listed, I then click through each Laws match candidate—I just open each one in quick succession by filling in a sequence of tabs across my computer screen so I can move quickly from one match to the next. The main point is to examine each candidate's "Shared Matches" for those lists which yield a cluster of repeated matches' names.

In that way, I spotted a few specific matches who kept showing up in a cluster. In particular, I zeroed in on those who met this criterion as well as being among those matches who shared only one segment with me. That is important because of the risk of finding matches who actually belong to the other interrelated lines from the small Tennessee communities where my ancestors lived. As became obvious during this process of elimination, some "shared matches" really connected with my Davis, Boothe, or Broyles lines, rather than specifically and solely pointing back to that Laws connection I am seeking.

Of the twenty four matches located through this process, three stood out as strong possibilities. They range from the largest match sharing ninety one centiMorgans to one with a single segment containing only twenty eight centiMorgans. I'll use these three as test cases, exploring the documentation they provide in their own trees, as well as building out a hypothetical tree upwards from my second great-grandmother to her parents and siblings.

While I'm in the midst of that (admittedly messy) process, on Monday, I'll explain what's behind my reasoning for focusing on one particular hypothesis for Catherine Laws' parents. I may be right. I may turn out to be wrong. But stuck as I am at this point, there isn't any possibility of forward movement without the willingness to experiment. In some ways, the way forward beyond a brick wall ancestor—at least with the assistance of DNA testing—is not much different than the techniques used by adoptees to find their birth parents.  

 

2 comments:

  1. Replies
    1. We'll see how it actually goes, Miss Merry. There's a lot of trial and error happening between now and Monday.

      Delete