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Background Ancient DNA studies suggest that Late Pleistocene climatic changes had a significant effect on population dynamics in Arctic species. The Eurasian collared lemming (Dicrostonyx torquatus) is a keystone species in the Arctic ecosystem. Earlier studies have indicated that past climatic fluctuations were important drivers of past population dynamics in this species. Results Here, we analysed 59 ancient and 54 modern mitogenomes from across Eurasia, along with one modern nuclear genome. Our results suggest population growth and genetic diversification during the early Late Pleistocene, implying that collared lemmings may have experienced a genetic bottleneck during the warm Eemian interglacial. Furthermore, we find multiple temporally structured mitogenome clades during the Late Pleistocene, consistent with earlier results suggesting a dynamic late glacial population history. Finally, we identify a population in northeastern Siberia that maintained genetic diversity and a constant population size at the end of the Pleistocene, suggesting suitable conditions for collared lemmings in this region during the increasing temperatures associated with the onset of the Holocene. Conclusions This study highlights an influence of past warming, in particular the Eemian interglacial, on the evolutionary history of the collared lemming, along with spatiotemporal population structuring throughout the Late Pleistocene.

International audience

Grey wolves (Canis lupus) are one of the few large terrestrial carnivores that maintained a wide geographic distribution across the Northern Hemisphere throughout the Pleistocene and Holocene. Recent genetic studies have suggested that, despite this continuous presence, major demographic changes occurred in wolf populations between the late Pleistocene and early Holocene, and that extant wolves trace their ancestry to a single late Pleistocene population. Both the geographic origin of this ancestral population and how it became widespread remain a mystery. Here we analyzed a large dataset of novel modern and ancient mitochondrial wolf genomes, spanning the last 50,000 years, using a spatially and temporally explicit modeling framework to show that contemporary wolf populations across the globe trace their ancestry to an expansion from Beringia at the end of the Last Glacial Maximum - a process most likely driven by the significant ecological changes that occurred across the Northern Hemisphere during this period. This study provides direct ancient genetic evidence that long-range migration has played an important role in the population history of a large carnivore and provides an insight into how wolves survived the wave of megafaunal extinctions at the end of the last glaciation. Moreover, because late Pleistocene grey wolves were the likely source from which all modern dogs trace their origins, the demographic history described in this study has fundamental implications for understanding the geographical origin of the dog.

Předmostí is one of the most famous Gravettian sites in Central Europe. Its fame is based on a unique human assemblage, sadly largely destroyed during the Second World War, a huge mammoth assemblage and a very rich large canid assemblage. It has been shown previously that mammoth played an important role in the subsistence practices of the Gravettian inhabitants of Předmostí. Detailed analyses of the large canid postcranial material were carried out to investigate whether these canid remains can be assigned to different size groups and whether these remains show evidence of being butchered and consumed by humans. Based on defleshing marks and impact traces on the long bones, it is proposed here that large canids were consumed by the Gravettian inhabitants of Předmostí, thus further elucidating the specific human-large canid relationships that existed during the Upper Palaeolithic.

International audience; Hunting seasonality and mobility patterns among late Neanderthals in Southwestern France. A cementochronological approach

Palaeoecological reconstructions are fundamental for the understanding of interactions between all the mammalian communities in a given environment and their choices in terms of habitat, diet and migrations. During the Late Pleistocene in north western Europe, hyenas and human groups shared essentially the same ecological niche. A comparison of their crossed relationships could therefore yield important data on the palaeoecological context. Unfortunately, numerous Palaeolithic sites in north western Europe were excavated well before modern archaeological techniques were devised. Thus the faunal assemblages collected during those early excavations do not have any stratigraphic context and the results extracted from these collections by classical approaches are therefore limited. However, in the karstic region of the Meuse Valley (southern Belgium), many sites have yielded massive amounts of archaeological and palaeontological material dated to the MIS 3. One of the challenges of this on-going doctoral research is to attempt to study this area by attempting an ecological reconstruction based on these old faunal collections in order to highlight settlements and dispersions of the MIS 3 key-species like ungulates, carnivores and humans.