Saturday, May 17, 2014
Human evolution in North America or simple diversity?
Regular reader Dave sent this story in this morning and I thought it was worth commenting on.
Apparently the skeletal remains of a teen girl, and some 30 or so other animals including a saber-toothed tiger, were found in a water-submerged cave and are thought to be 15,000 years old. There are physical differences suggestive of evolutionary divergence from North American natives, but DNA evidence shows that the girl came from the same genetic stock as other Paleoamericans rather than from other immigration routes as previously thought.
My problem is that humans don't evolve that fast....over 15,000 years based on environmental pressures. Moreover, how could the environmental pressures have been that different between what is now Mexico and what is not the US?
The article doesn't say what the physical differences are, but I'll bet they can be accounted for by simple physical variation among individuals in a population, not evolution.