A recent bottleneck of Y chromosome diversity coincides with a global change in culture

Contains fulltext : 153022.pdf (publisher's version ) (Open Access)It is commonly thought that human genetic diversity in non-African populations was shaped primarily by an out-of-Africa dispersal 50-100 thousand yr ago (kya). Here, we present a study of 456 geographically diverse high-coverage Y chromosome sequences, including 299 newly reported samples. Applying ancient DNA calibration, we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192-307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47-52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males

Combat : hebdomadaire du Mouvement de libération française

16 février 19431943/02/16 (N92)-1943/02/16

A recent bottleneck of Y chromosome diversity coincides with a global change in culture

© 2015 Karmin et al. It is commonly thought that human genetic diversity in non-African populations was shaped primarily by an out-of-Africa dispersal 50-100 thousand yr ago (kya). Here, we present a study of 456 geographically diverse high-coverage Y chromosome sequences, including 299 newly reported samples. Applying ancient DNA calibration, we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192-307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47-52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males

A recent bottleneck of Y chromosome diversity coincides with a global change in culture

© 2015 Karmin et al. It is commonly thought that human genetic diversity in non-African populations was shaped primarily by an out-of-Africa dispersal 50-100 thousand yr ago (kya). Here, we present a study of 456 geographically diverse high-coverage Y chromosome sequences, including 299 newly reported samples. Applying ancient DNA calibration, we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192-307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47-52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males

Cretaceous Continental Bridges, Insularity, and Vicariance in the Southern Hemisphere: Which Route Did Dinosaurs Take?

The history of biota distribution in the southern hemisphere represents a fascinating and strongly debated argument. The sequential break-up of Gondwana was indeed responsible for physical barriers that precluded dispersal event, and therefore phylogenies? Did different organism had the opportunity for dispersal episodes through recently claimed continental bridges? When geographic and environmental conditions were suitable for active diffusion during the Mesozoic? Among the most relevant taxa that inhabitant the southern landmasses in the Cretaceous period are dinosaurs. Their vast stratigraphic and geographic occurrence is intimately linked to the evolution of Gondwana and recent discoveries from all southern landmasses greatly challenged several vicariant models. In this study are summarised the most significant geological, palaeogeographic, palaeontological and phylogenetic data on Cretaceous Gondwanan dinosaur evolution, with particular emphasis on the ephemeral land bridges that constitute the bulk of the recently developed biogeographic models. A comparison between different datasets suggest that a complex and sequential mix of vicariance and dispersal patterns characterized the distribution of dinosaurian faunas in the Cretaceous. In particular, this study dispute the role of ephemeral intercontinental connections for biota dispersal in the Late Cretaceous and support an earlier peak in dinosaur distribution