MADRID. More and more scientific data to support the process of the human evolution is more like a mosaic, more complex than expected, and hybridization between Neanderthals and sapiens is one of their keys. Now a team of scientists found that these were crossed more than 100,000 years ago.
This is an earlier date established so far that shows that there were at least two different crossings between the two species, which was already known, some 60,000 or 65,000 years ago, and another that he makes between 100,000 and 120,000 years, confirmed to Efe Carles Lalueza-Fox of the Institute of Evolutionary Biology (a joint CSIC and Pompeu Fabra University).
This ancient genetic exchange could have taken place in the Middle East, according to a study published today in “Nature”.
through the use of different analytical techniques DNA (genomic fragments are shorter the farther has been the crossroads), scientists identified thus hybridization between Neanderthals and modern humans tens of thousands of years (50,000) before documented previously.
this suggests, as has been published in recent studies that modern humans left Africa earlier and mixed with Neanderthal . These modern humans became extinct, so their genetics are not the ancestors of today’s modern man.
The work is led by the Max Planck Institute for Evolutionary Anthropology (Germany ) and
involved several Spanish centers, this article describes the find first genetic sequence sapiens chromosomes of Neanderthals.
to reach these conclusions, were studied and compared the entire genomes of a Neanderthal and denisovan (Denisovan) of Siberia, and the sequence of chromosome 21 of a Neanderthal cave Asturian the Sidrón and other Vindija (Croatia), according to a note from the CSIC.
experts already knew since 2010, thanks to the Neanderthal Genome project is that 60,000 years ago, human population ancestor of the Europeans and the current Asian, after migration out of Africa, crossed with Neanderthals.
As a result of that gene flow, non-African modern humans carry a 2% Neanderthal genetic sequence, but not the sub-Saharan populations who were never in contact with Neanderthals and do not carry these archaic genes.
in the new study, found evidence of the contribution of a modern human in the genome of a Neanderthal, he said in a note from the Max Planck Sergi Castilian, another of the authors.
evidence of this flow of genes were found in a Neanderthal individual whose remains were found in a cave in the Altai mountains in southern Siberia, near the border between Russia and Mongolia. They found genetic evidence of modern humans or Neanderthals El Sidrón and Vindija or the Denisovan.
This does not mean that modern humans have not been crossed with Denisovans or European Neanderthals, but the signal Neanderthal genetics observed in the Altai probably comes from a cross occurred after this Neanderthal lineage diverged from their “cousins Europeans,” just over 100,000 years ago, Adam Siepel details of the Simons Center for Quantitative Biology (USA).
to Antonio Rosas, of the National Museum of Natural Sciences, these findings have implications for the evolutionary model.
“We knew for decades that there was an early exit from sapiens outside Africa, by the remains found in Israeli fields Skhul and Qafzeh, but having no paleontological data this output was seen by many as a failed migration, not having gone beyond the Middle East “.
data this study coincide with the new archaeological evidence: recently, for example, another study published in the presence of Homo sapiens in China about 100,000 years ago, remember Lalueza, who points out that this and other evidence may well correspond to these sapiens who left their genes into the branch Neanderthals migrated eastward.
for the scientist, if he were older genomes more crosses between species would be found because, as this study shows, “evolution human is more complex than we thought, more like a network with many branches “
Source:. EFE
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