On Jun 29, 2006, at 1:03 PM, Schroeppel, Richard wrote:
I have a puzzle from c. 1970. Back then, it was science fiction, but now it looks less farfetched. Suppose we have a big computer with everyone's genome data. [Looking less farfetched every day, in fact.] What can we deduce about the genomes of our ancestors? Could we reconstruct an estimated genome of Fermat, Buddha, or Caesar? There's some information loss from generation to generation: Parents with N children will (on average) omit 2^-N of their genes from (the set of) their children. Some of that lost information could be deduced from knowing genomes of cousins (-> aunts & uncles -> grandparents), so it's hard to see exactly how much is erased. If we throw in present-day location information, we can probably figure our who moved where, when, and perhaps deduce population movements from long ago.
They are busy doing exactly this in Iceland, where the genealogies are carefully recorded. Needless to say, there are many embarrassing revelations. I'm not sure this would ever be allowed politically. There is too much to be lost by too many people and cultures. Imagine what the reaction to Hitler's jewishness would have been, for example.