Svante Pääbo has struck again. A few days after the Nobel Prize for Medicine was awarded to this pioneer in the study of ancient DNA, he published in the journal Nature from October 20 “the first genomic portrait of a Neanderthal family”, in the words of paleogeneticist Lara Cassidy (Trinity College, Dublin), who was not involved in the work. The DNA analysis proposed by the Swedish researcher and the international team he led with his colleague Benjamin Peter indeed reveals kinship links between the fossils analyzed. And goes so far as to propose a hypothesis on a social organization where the woman circulated between Neanderthal communities to come and reside in the group of her husband – what is called “patrilocality”.
Recall that Svante Pääbo, head of the Max-Planck Institute for Evolutionary Anthropology in Leipzig, delivered in 2010 the first draft of the genome ofhomo neanderthalensis. Since then, there have been a total of 18 Neanderthal genomes, of varying quality. The last delivery in Nature suddenly brings 13 more genomes of our cousin who disappeared around 40,000 years ago, taken from two caves in Russian Altai. Not far from that of Denisova, where Pääbo and Russian colleagues had discovered in 2010 another humanity, the Denisovans, by analyzing a simple phalanx 41,000 years old.
Southern Siberia is definitely a formidable repository of ancient genomes. Eleven of the newcomers come from Chagyrskaya Cave, where 90,000 stone artifacts have already been found, and date back around 55,000 years. It was to be a “hunting lodge” offering temporary shelter to nomadic hunter-gatherers. The other two genomes are those of two 44,000-year-old individuals whose bones were found in another cave about a hundred kilometers away, Okladnikov.
Close relatives
The comparison of these genomes has enabled paleogeneticians not only to determine the sex of individuals, but also to discover close relationships between some of them. Chagyrskaya D, an adult male, was thus related to several other fossils. “We found a first-degree relationship between him and Chagyrskaya H, a teenager”, write the researchers, who were able to decide between three possibilities: son-mother, brother-sister or father-daughter. It was the third that they retained, insofar as the two individuals carried different mitochondrial DNA (mtDNA) sequences. Mitochondria, these energy factories cells, in fact contain a genome which is transmitted exclusively by the mother – those contained in the spermatozoa are destroyed during fertilization.
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