Unlike Homo sapiens of African descent who have little or no Neanderthal DNA, current humans European and Asian origin have inherited an average of 1 to 3% of the genome of their cousins, whose species went out there about 30 000 years.
Unlike Homo sapiens of African descent who have little or no Neanderthal DNA, current humans European and Asian origin have inherited an average of 1 to 3% of the genome of their cousins, whose species went out there about 30 000 years. The reason is simple: there was no cross between Homo sapiens of African descent, who lived in Eurasia, and their ancestors
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According to a study released Wednesday, Jan. 29 in the journal Science , if we put end to end all the pieces Neanderthal DNA scattered throughout the European or Asian individuals this would total 20% of the Neanderthal genome that would remain broadly in modern populations. The British journal Nature , the same day, another study published on the legacy of Neanderthal, led by David Reich (Harvard University, USA). With his colleagues, he analyzed the genetic variations of 846 people of non-African descent, 176 people in sub-Saharan Africa and an old Neanderthal 50 000 years, whose genome sequence was published in 2013.
Both teams found, despite separate and different methods work, large parts of the modern non-African genome devoid of Neanderthal DNA, and others where, conversely, the legacy of the Neanderthal man was richer than expected. According to these researchers, this distribution is the result of natural selection: the modern man would have ousted its genetic elements of the Neanderthals who were his “harmful”. However, what remains of Neanderthal had to bring an adaptive advantage.
Both studies cite in particular inheritance in genes that influence the characteristics of the skin. According to David Reich, “it is tempting to think that Neanderthals were already adapted to a non-African environment and passed on this genetic advantage to man.” His team has shown that heredity Neanderthal is more pronounced in the genes associated with keratin, a fibrous protein that gives skin its strength, hair and nails and provides better protection in colder environments, writes World .
According
team David Reich, genetic mutations known to be associated with specific traits in Homo sapiens could also find a home in the Neanderthals. This would be the case for diseases with a genetic component, such as diabetes or Crohn’s disease.
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