Evolutionary Genetics, Max Planck Institut für evolutionäre Anthropologie
April 14, 2016 1:00, Imperial Ballroom B
The study of the genomes of our closest extinct relatives allows for insights into the recent evolutionary history of anatomically fully modern humans. Recovery of ancient samples with extraordinary preservation from a cave in the Altai mountains allowed us to sequence high coverage genomes for a Neandertal and Denisovan individual. The analysis of the genomes of these two archaic humans revealed that that they are more closely related to one another than they are to modern humans. Furthermore, at least two events of gene flow from these groups into modern humans have been found; Neandertal admixture has been detected in all out-of-Africa populations while Denisovan gene flow likely occurred to the common ancestors of Australians and New Guineans.
The high quality sequences of a Denisovan and a Neandertal individuals also allows for analyses of gene flow into the archaic lineages. We found evidence for two gene flow events into Denisovans: Gene flow from Neandertals and gene flow from am unknown hominin with a deeply divergent lineage. Taken together, these results show that gene-flow was more common among human groups in the Pleistocene than previously thought.
Apart from demographic inferences, the high-coverage Denisovan and Neandertal genomes allow us to scan for regions in the human genome that carry the signatures of recent positive selection. Using a hidden-Markov model approach, we identify such regions and discuss the resulting candidates that may underly modern human specific traits.