meehawl

2 Responses to “Sic Transit”

1. Dez // Dec 30, 2006 at 10:11:12

   Its funny, Saddam being executed on the Day of Arafat, thee holiest day for Muslims. Significant?

2. mike // Jan 6, 2007 at 10:11:12

   Given the length of time that has elapsed between Babylonian times and the modern day, and allowing for typical population dispersion and growth, I believe pretty much everyone in Asia, Europe, and Africa, and probably most in the Americas, can count Nebuchadnezzar II as an ancestor.

   Modelling the recent common ancestry of all living humans
   If a common ancestor of all living humans is defined as an individual who is a genealogical ancestor of all present-day people, the most recent common ancestor (MRCA) for a randomly mating population would have lived in the very recent past … we show that recent common ancestors also emerge from two models incorporating substantial population substructure. One model, designed for simplicity and theoretical insight, yields explicit mathematical results through a probabilistic analysis. A more elaborate second model, designed to capture historical population dynamics in a more realistic way, is analysed computationally through Monte Carlo simulations. These analyses suggest that the genealogies of all living humans overlap in remarkable ways in the recent past. In particular, the MRCA of all present-day humans lived just a few thousand years ago in these models. Moreover, among all individuals living more than just a few thousand years earlier than the MRCA, each present-day human has exactly the same set of genealogical ancestors.