There is a king back there

kw: musings, genealogy

I just spent a long evening tuning up some of the Hints in my family tree at Ancestry.com. I also numbered all the people in the primary reference I used to begin the online tree, titled "Genealogy of the Lindsey Family", compiled in 1901 by my great-grandfather's sister, and updated by an aunt in 1962. It really gave us a leg up on the family tree my mother and I worked on through the 1960s and 1970s, and which she continued to compile through the 1990s.

One thing about genealogy as a hobby: it is a huge consumer of time. The online experience just makes it more intense. I "discovered" several new ancestors tonight, back in the mid 1600s. At the genealogy club my mother belonged to, they would hold a party every time someone found a new ancestor. When we found in the library a book with a complete family history of the Nantucketers from the founding in 1659 to about 1950, we "discovered" forty or more ancestors of one Joseph Macy, the one who first moved from Nantucket to the Carolinas. He is six generations back in my tree, while the founders are nine generations back, and many of them have three or four more generations that are known.

Then a few years later, someone who gave a talk at the club asked my mother, "Nantucketers? Are you descended from Dorcas Gayer? Then you're descended from Charlemagne!" There is still debate whether one of the links in the Gayer family tree is genuine, but if so, then Charlemagne is back there, 39 generations. I have my tree traced back to Edward I Plantagenet, who is 23 generations back, and I figure that is about far enough. The connection is almost meaningless.

Almost anyone of European ancestry is descended from the kings somewhere (though tracing it is another matter). Considering that the early "royalty" were just the biggest bullies around, it is a dubious distinction. Anyway, there is a numerical point that interests me here.

The human genome contains about 25,000 genes. If you divide 25,000 by two fifteen times, you get 0.76, which means you have a 76% chance that a single gene that was present in a particular ancestor fifteen generations ago is present in you. Of course, in that generation, you have about 32,000 ancestors, so there are plenty of people for every single gene to come from. But what about 23 generations? 2²³ is 8,388,608. Divide that by 25,000 and you get 336. There is one chance in 336 that any single gene from Edward I would be found in my genome.

Of course, as kings do, he had lots of children, most of them illegitimate, and in 23 generations, it is likely that some distant and not-so-distant cousins married one another, so there are more chances than exactly 1/336. But it is still not too likely.

I find the stories closer to this time of more interest. I am lucky to know who all of my great-great grandparents are, and well over half of the generation before that. Several of these were immigrants to America, and one was a Cherokee, so the immigrant there is about 500 generations back. The line I was researching today all lived and died in Salem, New Jersey. Any living descendants are about eighth cousins.

By the way, here is how I figure "Nth Cousin" and how many times removed. It is the rule of G's. First cousins share a grandparent. That is the first "G". Count the G's in the shortest line. For example, if two people share a great-great grandparent, that is three G's so they are third cousins. But if they are of different generations, the extra G's in the longer line are the "times removed". So, my third cousin and I are descended from a particular great-great grandmother. We are of the same generation. But his daughter is once removed, and her daughter is twice removed, from me. I have a son, and the daughter is his fourth cousin, while the daughter's daughter is his fourth cousin once removed.

For those of us who know lots of our ancestors, and perhaps lots of cousins, at various removes, we know that, when people say, "Family matters", it means, "Close family matters." An eighth cousin relationship is possibly interesting, but hardly significant.