The DNA analysis of a jaw 40 thousand years old, found in 2002 in a cave in Romania, provides further evidence of cross between Homo sapiens and Neanderthals. The study of the fossil suggests that both species coexisted in Europe for at least 5,000 years. During that period, genetically he met on numerous occasions.
The scientists estimate suggests that Neanderthal ancestry bone carrier that dates back to between 4 and 6 generations in your family tree. Which it is a conclusive indication that early modern humans to reach Europe were mixed with Neanderthals that were already set in place.
To carry out this project, two of the world leaders in the field of ancient DNA David Reich of Harvard Medical School and Svante Paabo of the Max Planck Institute for Evolutionary Biology in Leipzig, in Germany they were allied. The result was published in the online edition of the scientific journal Nature.
The research team analyzed a jawbone found at the site Pestera cu Oase (Cave with Bones) in southwestern Romania, dating from about 37000-42000 years. There the oldest remains of Homo sapiens in Europe were detected and concluded that between 5% and 11% of the genome was linked to the Neanderthals.
The consensus theory holds that the first temporal coincidence between both species occurred about 60 thousand years ago in the Middle East when modern humans coming from Africa Neanderthals crossed from Eurasia.
“There is archaeological evidence that modern humans interacted with Neanderthals during the time they lived in Europe: changes in technology tool to make the funeral rituals, and body decoration involving a cultural exchange between groups. But we have very few skeletons from this period, “says Reich.
The jaw was found near the skull of another specimen, although no utensils were identified in the vicinity, so cavers have no other cultural clues. Chin Oase Guy dominated the physical characteristics of modern humans, but with some Neanderthal features. In the first instance it was thought that the bone may belong to a descendant of both groups.
But that was not the only problem. When Qiaomei Fu, Pääbo’s lab, got the DNA of bones, most were microbes living in the soil where it was found. Fu by a novel method enriched the proportion of human DNA in the sample, using genetic probes to retrieve DNA fragments encompassing 3.7 million any positions in the human genome to be useful in evaluating the variation between populations .
However, the results threw the fossil is genetically more like East Asians and current than modern European American natives.
To calculate the number of generations that had happened since the latest pairing between the two species, experts collated the length of the set of genes contained in the chromosomes. Since DNA fragments and recombine with each new generation, the more generations have passed since an ancestor, its genome is fragmented. Was so assessed who had spent less than 200 years among 4 and 6 descendants from the last Neanderthal ancestor of Homo sapiens in Romania.
This suggests that the individual was part of a population that was crossed with Neanderthals, but it did not contribute to the current European genome. “It could be a pioneer group of modern humans arrived in Europe, but was later replaced by other groups” Pääbo suggests.
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