Invité par Eva-Maria Geigl et Thierry Grange, Diyendo Massilani va donner un séminaire IJM le mardi 18 avril 2023 sur le thème :
“Genomic analysis of a 34,000-year-old human individual from Mongolia”
We investigate the evolutionary history of modern and extinct human populations using ancient DNA. Our focus is to retrieve and sequence DNA from archaeological materials to study the peopling of the world, the history of human health and their adaptation to different environments and lifestyle conditions.
The early settlement of modern humans in East Asia remains uncertain due to a scarcity of fossil and genetic data. We have recently made a step forward in the understanding of early history of modern humans in that part of the world by dating and generating genome-wide data from a skullcap found in the Salkhit Valley in northeast Mongolia. This skullcap is the only known Pleistocene hominin fossil found in Mongolia to date. Our analysis revealed that this individual, who lived approximately 34,000 years ago, had recurrent gene flow from West Eurasia, likely due to contact with early Siberians. This suggests that modern human communities in East Asia were cosmopolitan even before 34,000 years ago, and that population structure, long-range migrations, and contacts between different populations were frequent throughout modern human history in Eurasia. Our study also identified, for the first time in ancient East Asian genomes, DNA that was introgressed from Denisovans, an elusive, extinct archaic group of humans who contributed ancestry to present-day people in East Asia and Oceania. We found that the Denisovan DNA fragments in these ancient East Asians overlap with Denisovan DNA fragments in the genomes of present-day populations in East Asia, but not with Denisovan DNA fragments in present-day Oceanians. This is consistent with a model of multiple independent admixture events between Denisovans and modern humans.