Abstract
Over the last two decades, genome-wide data has challenged and expanded our understanding of the history of present-day and past populations. In particular, analysis of ancient human DNA - especially full genomes - has allowed researchers not only to elucidate the broad patterns of genetic variation across the world, but also to answer specific questions about past population dynamics. However, the distribution of both ancient and present-day genomes sampled across the world is, at present, quite fragmented, and Europe remains by far the most heavily sampled continent. In this context, Siberia and the Americas are two regions that have not been analysed with the same intensity as Western Eurasia. Several questions such as the early peopling of these regions and their migratory connection have been approached before using modern and ancient DNA. Siberia is a vast region in North Asia that has been occupied by modern humans from the Upper Paleolithic. Since then, there are evidences of a relative continuous occupation, unevenly distributed in time and space. Although several ancient and modern individuals have been analysed in the region using both, uniparental inherited markers and genome-wide data, the human population history of the region remains inextricable, with a complex history of migration and admixture. In this scenario recent events, not necessary involved in major cultural and population changes associated to the dispersion of new economies or technologies, have received less attention. In this work we focused on Siberia and analysed 150 ancient genomes belonging to 32 distinct groups widely distributed from the Urals to Northeastern Siberia and dated between the Iron Age to the early 20th century (Chapter 2). In combination with present-day data, we were able to identify finescale genetic variation between populations across Siberia. The use of haplotypebased methods reveals that the main three ancestries in Siberia (West Eurasia, East Asia and East Eurasia) can be subdivided into clusters that are heterogeneously distributed between populations. This suggests a significant variation between regions that may be associated to ...
The initial peopling of the Americas has been highly debated through genetic and archaeological data. Once again, the subsequent migrations and diversification along the continent have had less attention and are highly relevant to understand the genetic composition of present-day populations. From the southern end of South America, maritime hunter-gatherers differentiated from terrestrial hunters about 6,000 years ago. The harsh environment and continuous isolation trigger a rapid differentiation between sub-groups that remains until recent times (Chapter 3). The earliest individuals associated to these maritime traditions (Chapter 4) showed strong affinity with present-day populations and, unlike other modern and ancient individuals from South America, did not show evidence of a Mixe-related expansion, reflecting not only the isolation of these groups in the southern end, but also the Holocene genomic variation in South America.
The initial peopling of the Americas has been highly debated through genetic and archaeological data. Once again, the subsequent migrations and diversification along the continent have had less attention and are highly relevant to understand the genetic composition of present-day populations. From the southern end of South America, maritime hunter-gatherers differentiated from terrestrial hunters about 6,000 years ago. The harsh environment and continuous isolation trigger a rapid differentiation between sub-groups that remains until recent times (Chapter 3). The earliest individuals associated to these maritime traditions (Chapter 4) showed strong affinity with present-day populations and, unlike other modern and ancient individuals from South America, did not show evidence of a Mixe-related expansion, reflecting not only the isolation of these groups in the southern end, but also the Holocene genomic variation in South America.
| Originalsprog | Engelsk |
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| Forlag | Natural History Museum of Denmark, Faculty of Science, University of Copenhagen |
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| Status | Udgivet - 2018 |