Drowning in DNA Matches

As recently as maybe three or four months ago, I was keeping up pretty well with my new DNA matches. At AncestryDNA, I had 800 or 900 matches at fourth cousin level and closer, and new matches at that level dribbled in at the rate of a half dozen or so a week, and I added them to my database more or less as they showed up. I had no idea how many "distant" matches (5C-8C) I had and didn't care, because I ignored all but the handful which sported shaky-leaf "ancestor hints" or showed up in my DNA Circles.

At MyHeritage DNA, I had a few thousand matches with no clear delineation between the "about 4C" and really distant levels, but I had about 250 in my database, having worked down through to about 30 cM, with some more distant cousins included when they triangulated with closer cousins. (Why, oh why, can't they come up with a category intermediate somewhere between "extended family" – which seems to cut off around 90 cM – and so-called "distant relatives"?) Again, new matches were slow in coming, though harder to detect than for Ancestry since there isn't a "not looked at yet" flag.

Then, early this year, it was as if a floodgate opened. Suddenly I was getting a half dozen or more new matches each day at Ancestry, and next thing I knew I had a backlog of 50 or so that I hadn't been able to get into my database. The pace picked up at MyHeritage as well, though not as drastically.

Well, then DNA Painter came along, followed by Genetic Affairs's Auto-Clusters for Ancestry. Ancestry switched from the languishing DNA Circles and ancestor hints only for public trees, to ThruLines and "common ancestors" drawing on public, private, and unlinked trees. MyHeritage introduced their Theory of Family Relativity and an integrated Auto-Cluster tool. Between painting all those MyHeritage matches (and GEDmatch as well) plus their triangulated matches; analyzing clusters; and checking out dozens of proposed ThruLines and Family Relativity relationships, it's become even more difficult to keep up with the onslaught of new matches.

Right now, as of 10 PM on May 9, I have at AncestryDNA 1309 matches of 4C and closer level. (I also have an utterly incredible 55,962 distant matches!) I now have a backlog of 86 4C-and-closer matches to enter into my database.

At MyHeritage DNA, I have a total of 10,552 matches. Of those, 443 match with 25 cM or more, which is probably very roughly equivalent to Ancestry's 20 cM cutoff (Ancestry's reported total cMs are nearly always lower than for the same individuals who have their results at other sites). I seem to have only about 230 of those 443 in my database, however, so clearly I have a lot of catching up to do there, too.

Oh, and these numbers are only for my own test – I also manage my two brothers' tests, and I've never gotten anywhere close to getting all their matches in my database.

Is it any wonder I haven't blogged in three months? I need to back off on my DNA painting and visual phasing and auto-clustering, and get back to my research and writing.

What Were the Chances? A Tale of DNA

About two and a half years ago, I took an AncestryDNA autosomal DNA test, and linked the results to an Ancestry member tree. I looked over my matches now and then, but practically all of them were in fourth cousin range and beyond, most of them had no tree or only a private one, and few of the ones who did have public trees had any apparent connections to mine. There were a couple of matches around second cousin range and a bare handful at third, but I hadn't gotten around to investigating them further.

Then, a few weeks ago, two new matches, both female, popped up at the very top of my match list – still in 2nd-cousin territory (I have no full first cousins), but the highest yet. The top match (500 cM) was administered by the second match (299 cM), so they looked pretty much like a mother and daughter. And based on one of our shared matches (one of the few which I had been able to identify from their posted tree), the match had to be through my paternal grandfather. Trouble was, the surname was completely unknown to me, and the tree attached to the top match was private.

Even taking into account the possibility of an outlier at the extremes of observed shared DNA ranges, 500 cM is almost certainly in the class that includes first cousins once removed, half-first cousins, great-great-aunts, and half-great-aunts, with a second cousin just barely possible. Anyone at the great-aunt level or older would have been deceased long before atDNA testing began. And, since I have no full first cousins and my grandfather had no siblings who lived to adulthood, I have no (full) first cousins once removed or second cousins on his side.

That leaves half-first cousins. Well, that had potential; before his fifth and final marriage to my grandmother, my grandfather fathered five other children (that I know of) with four different mothers, all before the turn of the 20th century. Thus I had four half-uncles and a half-aunt who could in theory have given me half-first cousins. However, the reality is a bit more restricted in scope:

• Half-aunt Hazel – four sons with children; one daughter, unmarried and childless
• Half-uncle Kenneth – married twice, no children
• Half-uncle Leonard – one adopted son, no biological children
• Half-uncle Chester – no record after birth registration, assumed died as child
• Half-uncle Vinal – died as an infant

In other words, my only known female half-first cousin had no children, male or female – and she died in 1995 and was thus certainly not my 500 cM match! Which left, well, no leads at all.

Unless...

What about half-uncle Chester?

A couple of years ago, I posted some speculations here, entitled Whatever Happened to Chester L. Kirk?, in a 52 Ancestors post. Chester L., the son of my grandfather Chester F. Kirk and Nellie Crosman (who, as it happens, was not one of Chester's five wives), apparently dropped off the face of the earth after his birth was registered. No death record, no census records, no marriage record... he just disappeared. It seemed likely he had died as a child and the record was lost or misfiled.

Research into Nellie's subsequent whereabouts eventually found her in Gloucester, Massachusetts, married to a William Mitchell, with a son Linwood Arthur Mitchell, but no sign of Chester L. However, certain interesting coincidences led me to conjecture that Linwood might actually be Chester, informally adopted and renamed, with a delayed birth certificate naming William Mitchell as his father, and stating a birth date exactly two years (to the day!) after Chester's actual birth.

But, as I said in that post, "Of course, I can't prove (lacking DNA evidence) that any of this is more than just speculation."

What were the chances?

No, there had to be some other explanation. Probably the shared DNA amounts were misleading for some reason (some kind of double-cousin relationship? IBS?) and it really was one of the descendants of my half-aunt Hazel. For that matter, it was hardly out of the question that grandpa could have had additional off-spring that just never came to light before. So I never gave Uncle Chester any serious thought, and with no other apparent possibilities, I started researching Hazel's grandchildren to see if one of them had married into the surname of my new matches.

Two days later, I received an email from a young women who was doing some genealogical research for her grandmother and mother. A couple of months before, she had stumbled across this blog, with its two-year-old post idly speculating about the fate of one Chester L. Kirk. It made for eerie reading, she said, because her family lore held a rumor that her great-grandfather wasn't the biological son of his nominal father.

Her great-grandfather was named Linwood Arthur Mitchell.

Her grandmother – Linwood's daughter – and her mother had just received their DNA test matches.

To a half-first cousin, and a half-first cousin once removed, respectively.

To me.

What were the chances?