> From: Julia Thompson <[EMAIL PROTECTED]> > Charlie Bell wrote: > > > ... and second, the > > maths of evolutionary genetics is against you - while direct chromosomal > > inheritance goes down exponentially by generation, family tree goes up > > exponentially by generation (to within population limits). Or do you > > really think you had 2,147,483.648 *individual* ancestors 30 generations > > ago? No, of course not - family trees converge as well as diverge. > > At the generation where you'd expect me to have 128 ancestors, I have > 122. (There was a first-cousin marriage at one point, and a > second-cousin marriage at another. And on top of that, I know someone > whose closest degree of relation to me is third cousin -- but he's also > more "closely related" to me than a second cousin, because we have > kinship in other ways, as well.)
It's expected that the farther you go back in a geneologic tree, the more the branches beging overlapping. After all, at only 40 generations, you would have to have had more than a trillion ancestors. Assuming 25 years per generation, that would have been roughly 1000ya. Assumming there are 10^85 sub atomic particles in the entire universe, you would have more ancestors than that at approxamately 283 generations. At 25 years per generation (an exeptionally conservate estimate that is probably twice or larger than average historical average generation times), that generation of ancestors would have lived approxamately 7075 years ago (~5069 BCE). _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
