Dating Between Modern Humans and Neanderthals

Harvard and Max Planck Institute scientists have estimated the date when Neanderthals and modern Europeans last shared ancestors to discover why Neanderthals are most closely related to people outside of Africa.  The research, published in the journal PLoS Genetics, provides a historical context for the interbreeding between Neanderthals and modern Europeans.  The research suggests modern humans encountered Neanderthals as the modern human expanded out of Africa.

[caption id="" align="aligncenter" width="300" caption="Gene flow less than 100,000 years ago."][/caption]

When the Neanderthal genome was sequenced in 2010, it revealed that people outside of Africa share more genetic variants with the Neanderthals than Africans.  To explain this occurrence, they believe modern humans mixed with Neanderthals when they came out of Africa.  Another possibility is that the African populations ancestral to both Neanderthals and modern humans remained subdivided over a few hundred thousand years.  Subsequently, those more related to Neanderthals left Africa.

Dr. Sriram Sankararaman and colleagues measured the length of DNA pieces in the genomes of Europeans that are similar to Neanderthals.  The Neanderthal-related pieces should be smaller the longer they have spent in the genomes of present-day people.  They believe the last exchange between modern humans and Neanderthals was between 37,000 and 86,000 years ago.  This is well after modern humans appeared outside Africa, but before they started spreading across Eurasia.  The findings suggest that Neanderthals had children with the direct ancestors of present-day people outside of Africa.  While looking up information of the breeding of modern humans and Neanderthals, I came across various sources that conflicted with this study.  Other studies believe this mating between modern humans and Neanderthals happened very rarely, at most at a rate of 2%.  There is still more research that has to be done regarding this subject.  This study will open up new areas of research.  Hopefully, we will get a definite answer regarding the interbreeding between modern humans and neanderthals.