Tuesday, April 30, 2002
A fascinating article in the most recent Atlantic (unfortunately, if you want to read it online, you have to pay for it; or you can just walk to a newstand and read it there, like I did) about how we all have very recent common ancestors. Go back a couple of thousand years, and everyone then living is either a common ancestor of everyone currently living or has no living descendants. This is based on mathematical models, not comprehensive genealogies. A simple mathematic model assuming equal-opportunity random mating converges on common ancestry for the entire world in a few hundred years; controlling for things like geographic boundaries and class pushes things back to a couple of thousand years. I doubt any of this is literally true - after all, the same mathematical models would probably have predicted in 1491 that everyone in the world had common ancestors circa 500 B.C., which would surely be untrue since America and Australia were still then terra incognita. But be that as it may, it's an interesting modelling exercise. And it sounds like a very valid model for populations that are in regular contact with one another.
And it got me to thinking: one of the things that seems most implausible about the sojourn in Egypt is the notion that Jacob and his family of 70 souls are the progenitors of a mighty nation of 600,000 men of fighting age, plus women and children (and much cattle!). But if you follow the logic of these models, you don't need to mutter about "the wonders of compound interest" and hope that suffices. The notion of Jacob as the common ancestor of an entire nation is entirely reasonable. Assume that Jacob's family is one family among many in Egypt; assume (as we know from Egyptian records) that there's a large population of Asiatics living in Egypt in the era of Joseph (presumably the era of the Hyksos Pharaohs, themselves Asiatic conquerors). Jacob's family itself hailed from Mesopotamia, according to the biblical account, and the wives of the patriarchs all came from their home region. It's reasonable to assume that Jacob's family would similarly make marriages among the other Asiatic peoples in Egypt. 400 years pass and, based on the kinds of models the article describes, it's likely that the entire Asiatic population of Egypt would technically be descended from Jacob. And this could be a very large number of people even in the absence of population growth.
Of course, any number of unnamed Asiatic men and women would also have been common ancestors of that entire population. That's the thing about genealogy: it's a multi-dimensional matrix of inter-connections, not a tree, as commonly represented. But we remember the name of Jacob. And that's, ultimately, what it means to be a patriarch: that it is your name that is carried on by your descendants.