Friday, November 03, 2017

Modern humans have been around a while

I don't find this topic all that interesting (it's a tad too complicated and rubbery, and I'm under no obligation to find every branch of science interesting, am I?), but a new paper in Science suggests an age range for modern humans that means they were stumbling around the place before building much for quite a long time:
Southern Africa is consistently placed as a potential region for the evolution of Homo sapiens. We present genome sequences, up to 13x coverage, from seven ancient individuals from KwaZulu-Natal, South Africa. The remains of three Stone Age hunter-gatherers (about 2000 years old) were genetically similar to current-day southern San groups, and those of four Iron Age farmers (300 to 500 years old) were genetically similar to present-day Bantu-language speakers. We estimate that all modern-day Khoe-San groups have been influenced by 9 to 30% genetic admixture from East Africans/Eurasians. Using traditional and new approaches, we estimate the first modern human population divergence time to between 350,000 and 260,000 years ago. This estimate increases the deepest divergence among modern humans, coinciding with anatomical developments of archaic humans into modern humans, as represented in the local fossil record.
I see from various websites that the previous estimate was a mere 200,000 years, so this pushes it back somewhat. 

1 comment:

John said...

Steve I have been following this since the days of Alan Wilson at Berkeley when the first "molecular time clocks" came into vogue. They keep changing their minds so it is rubbery. It is a very interesting area to read but I'm cautious of all these claims. So little data and that clock keeps changing time.