The Winding Path of DNA Descent

 

Genealogical puzzles, fortunately enough, can be approached in more ways than one. That is a good thing in my current case, while I'm puzzling over just who it might have been that was my second great-grandmother's father. The woman I was told was Sarah Catherine Laws, wife of Thomas Davis, showed up in so many records simply by the given name Catherine. I knew her maiden name was Laws—but which Catherine Laws? And which father would be the one for the right Catherine?

While I've spotted a possibility with William Laws—who, thankfully, gave three of his children un-missable names—it has been a rough go to pin him down as clearly the father of Catherine. For one thing, as we've seen, William moved around a lot. That pattern seemed to be adopted by his sons, making their unusual given names even more valuable to me. Although I can't seem to pin William down as to a date of death or place of burial yet—not to mention, a will would still be helpful—I realized there is another approach we can take: follow the winding path of his sons' DNA descent.

As you can imagine, even that approach has its challenges, as the family seemed to have a multi-generational way with moving from place to place, or appearing in multiple marriage records. But I decided to try my hand once again at the chase based on genetic genealogy this time.

If William Laws was my third great-grandfather, then right now I'd be seeking DNA matches at the approximate level of fourth cousin. A relationship that distant isn't likely to share much genetic material—the range, according to Blaine Bettinger's helpful Shared centiMorgan chart—could be up to 139 centiMorgans at the most, but 35 for a mid-range. Then again, it could be that my fourth cousins and I share absolutely no genetic material at all.

In the case of the ThruLines suggested DNA matches for my Laws ancestor at Ancestry.com, my top match for William's son Larkin's line shared a bit over ninety centiMorgans with me. The next closest match shared fifty five—and the further from the top of the list I got, the more precipitously the numbers dropped.

There was another problem with the Laws matches I found: that top match with over 90 cMs shared genetic material with me in four separate segments. I would have been far more encouraged to see those centiMorgans all contained within one segment. As the total centiMorgan count decreased, those many segments seemed to dilute the possibility of finding a verifiable match through corresponding documentation. But I tried my hand at it anyhow.

My first step was to look for Laws matches who shared one larger segment with me, rather than four or five smatterings of genetic material. For two matches who each shared one segment measuring twenty three cMs with me, I was able to confirm their line of descent. That was encouraging.

Then, I tried my hand at the names closer to the top of the list, the ones with the many segments shared. I had tried tracing those lines on paper several years ago without any success, but thankfully this year, the documentation was there to confirm the connections. Not that this was easy; many moves, many marriages, many incidents causing me to backtrack to pick up events hidden in between the census years made me wonder whether I'd ever find satisfactory confirmation of the connections.

So far, I've verified four out of seventeen matches in the ThruLines readout for William's son Larkin. I'll eventually work my way through the rest of that list. The work will certainly go more quickly, now that the trailblazing effort has laid out the patterns and the locations. From that point, I'll move on to confirm the four ThruLines matches descending from William's son Pine Dexter—a name which can't be missed, although one that has suffered much recorded abuse.

Then, unless I can find contradictory evidence that there was another William Laws out there during the same time period in that same northeastern Tennessee area—or another set of brothers named Larkin and Pine Dexter—I think it will be safe to assume my second great-grandmother Sarah Catherine was daughter of William Laws. It all comes down to doing the grunt work of building a solid paper trail—but DNA can certainly help point the way.