Svante Paabo
Director
Max Planck Institute for Evolutionary Anthropology

Abstract:
Over the past 25 years, our laboratory has developed of techniques for extracting and analyzing DNA from Pleistocene fossil remains. We recently produced a draft genome sequence from Neandertals, who lived in western Eurasia until becoming extinct around 30,000 years ago. We find that about 2.5% of the genomes of people living outside Africa derive from Neandertals, implying that interbreeding occurred between Neandertals and the ancestors of all present-day people living outside Africa.

We have also sequenced the genome of an ancient finger bone from Denisova Cave in southern Siberia. The analysis of the sequence reveals that it drives from a hitherto unknown group of hominins, which we call Denisovans. Approximately 4.8% of the genomes of people now living in Papua New Guinea and other parts of Melanesia derive from Denisovans, suggesting interbreeding in eastern Eurasia between Denisovans and ancestors of some present-day human groups.

Together, these finding suggest a ‘leaky replacement’ scenario of human origins in which anatomically modern humans emerged out of Africa and received some degree of gene flow from the anatomically archaic human populations in Eurasia that they ultimately replaced. The Neandertal and Denisova genomes also allow novel genomic features that appeared in present-day humans since their divergence from common ancestors with these archaic humans to be identified.