It was a bone fragment in 2012 at the Altai Mountains of Siberia , whose DNA was extracted and analyzed, giving the researchers the surprise of finding themselves in front of an individual son of two different hominids.
That bone fragment in fact belonged to a young girl, about 13 years old , who lived more than 50 thousand years ago, daughter of a Neanderthal and a man from Denisova .
The direct evidence that the two met, recount today the researchers led by Viviane Slon and Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology, Leipzig, on the pages of Nature.
In fact, the authors themselves admit, that Neanderthal and Denisova they could have met was already known and the discovery of traces of Neanderthal DNA in the first examples of Denisova also suggested it. It was a real stroke of luck that in their hunt and in their analyzes the anthropologists could stumble upon a direct son of these encounters.
The parents of “ Denisova 11 ”(The name of the find belonging to the girl who lived about 50 thousand years ago , found in Denisova's cave), are extinct groups of hominids - cousins of Homo sapiens, we might venture - who separated about 390 thousand years ago and inhabited Eurasia until about 40 thousand years ago .
If Neanderthals were mostly light-skinned and red-haired, the Denisovan they probably had darker skin and brown eyes.
These two hominids met and although the opportunities may not have been many, when it happened, Pääbo explains, “they mated frequently, more than previously believed”.
This is suggested by the stroke of luck itself, namely the discovery of evidence of the first generation of Neanderthal-Denisova among a limited number of ancient finds.
The morphology and genomic analysis of the Denisova 11 fragment not only shows that the mother was Neanderthal and dad Denisovano , but it also allows us to make considerations on the very origin of the parents and on the routes taken by these hominids. The father, for example, was a Denisova , but in turn it could boast some Neanderthal ancestors in the family tree.
Mom, on the other hand, was genetically close to the Neanderthals who lived in the westernmost areas of Eurasia (such as Croatia) compared to those who reached the easternmost areas and close to the place of discovery. All this on the whole suggests that the migrations of Neanderthals through Eurasia occurred well before their disappearance, starting 120 thousand years ago .
Despite the frequent finding of crosses between archaic populations, which is recognized even today (we know for example that we are all a little bit Neanderthal, with the exception of the African populations, and that some of the DNA of the Denisova it survives in modern Asian populations and Oceania ), Neanderthal and Denisova they remained distinct genetic populations.
Perhaps because, the authors speculate, they mostly continued to live in separate areas , one to the west and the other to the east, respectively, or perhaps because their offspring were less suited to survive, reproduce, thrive.