Contributed by: filbert Tuesday, December 11 2007 @ 05:36 AM CST
“Ten thousand years ago, no one on planet Earth had blue eyes,” Hawks notes, because that gene—OCA2—had not yet developed. “We are different from people who lived only 400 generations ago in ways that are very obvious; that you can see with your eyes.”
Comparing the amount of genetic differentiation between humans and our closest relatives, chimpanzees, suggests that the pace of change has accelerated to 10 to 100 times the average long-term rate, the researchers write in Proceedings of the National Academy of Sciences USA.
Not all populations show the same evolutionary speed. For example, Africans show a slightly lower mutation rate. “Africans haven’t had to adapt to a fundamentally new climate,” because modern humanity evolved where they live, Cochran says. “Europeans and East Asians, living in environments very different from those of their African ancestors and early adopters of agriculture, were more maladapted, less fitted to their environments.”
And this speedy pace of evolution will not slow until every possible beneficial mutation starts to happen—the maximum rate of adaptation. This has already begun to occur in such areas as skin color in which different sets of genes are responsible for the paler shades of Europeans and East Asians, according to the researchers.
Kinda sorta via FuturePundit[*2]