The Neanderthal - modern human connection?

The Neanderthal - modern human connection?

A sixty percent complete, “first draft” of the Neanderthal genome has been prepared by scientists with the Max Planck Institute in Germany and there is evidence there was interbreeding between Neanderthals and modern humans about 80,000 years ago in the Levant. This announcement appeared in the journal Science on May 8 and has had a mixed reception.

Colleagues of the Max Planck team are delighted so much progress has been made in defining the Neanderthal genome, so soon after the announcement, a few years ago, of the complete human genome but key figures in the fields of evolutionary biology and paleoanthropology question whether the complex statistical analysis outlined in the paper in fact supports the hypothesis there was interbreeding between the two species.

The authors’ genetic analysis also challenges the “out of Africa” hypothesis which posits we modern humans, Homo sapiens, throughout the world trace our ancestry to anatomically modern humans who migrated out of Africa around 50,000 years ago.

The paper’s Abstract reads:
“Neandertals, the closest evolutionary relatives of present-day humans, lived in large parts of Europe and western Asia before disappearing 30,000 years ago. We present a draft sequence of the Neandertal genome composed of more than 4 billion nucleotides from three individuals. Comparisons of the Neandertal genome to the genomes of five present-day humans from different parts of the world identify a number of genomic regions that may have been affected by positive selection in ancestral modern humans, including genes involved in metabolism and in cognitive and skeletal development. We show that Neandertals shared more genetic variants with present-day humans in Eurasia than with present-day humans in sub-Saharan Africa, suggesting that gene flow from Neandertals into the ancestors of non-Africans occurred before the divergence of Eurasian groups from each other.”

Science has published a special section, available without the usual subscription requirement. Also the New York Times has an informative account of the Science announcement.

The Neanderthals (Homo neanderthalensis) ranged from Spain to southern Siberia and as far south as modern day Israel and Palestine, according to this map, and lived from about 130,000 years ago until their extinction 28,000 years ago.