Thursday, May 06, 2010
WE ARE (SOME OF US) CAVE MEN!
The current issue of Science Magazine (May 7, 2010) includes an article comparing a completely sequenced Neanderthal Genome with genomes of 5 Modern Humans.
Four of the five Modern Humans seemed to have an overlap (small) in their genomes with Neanderthal DNA. The human of African descent did not show evidence of Neanderthal DNA.
The conclusion is that some Modern Humans interbred with some Neanderthals. The fact that this evidence is in individuals of Asian descent (where no Neanderthal traces have been found) as well as European descent suggests that the interbreeding occured before Modern Humans spread into the European and Asian areas.
One model is that modern humans moved out of Africa two to three hundred thousand years ago, interbred (lightly) with Neanderthals in the Middle East from 30-60 thousand years ago, and then continued to spread around the world (eventually replacing any other hominid variants -- including Neanderthals -- that may have existed).
This is the first evidence of interbreeding between any of the ancestors of today's humans and Neanderthals.
One Neanderthal and 5 Modern Humans is not a large sample! Clearly, the continued study of Neanderthal and Modern Human DNA is of the utmost interest in understanding who we are and how we got that way.
This discovery of our heritage should provide a big boost to Spelunkers!