The cave bear spread from Western Europe to the Near East during the Riss glaciation (250 KYA) before becoming extinct approximately 12 KYA. During that period, the climatic conditions were highly dynamic, oscillating between glacial and temperate episodes. Such events have constrained the geographic repartition of species, the movements of populations and shaped their genetic diversity. We retrieved and analyzed ancient DNA from 21 samples from five European caves ranging from 40 to 130 KYA. Combined with available data, our data set accounts for a total of 41 sequences of cave bear, coming from 18 European caves. We distinguish four haplogroups at the level of the mitochondrial DNA control region. The large population size of cave bear could account for the maintenance of such polymorphism. Extensive gene flow seems to have connected European populations because two haplogroups cover wide geographic areas. Furthermore, the extensive sampling of the deposits of the Scladina cave located in Belgium allowed us to correlate changes in climatic conditions with the intrapopulational genetic diversity over 90 KY.

The current phylogeographic pattern of European brown bears (Ursus arctos) has commonly been explained by postglacial recolonization out of geographically distinct refugia in southern Europe, a pattern well in accordance with the expansion/contraction model. Studies of ancient DNA from brown bear remains have questioned this pattern, but have failed to explain the glacial distribution of mitochondrial brown bear clades and their subsequent expansion across the European continent. We here present 136 new mitochondrial sequences generated from 346 remains from Europe, ranging in age between the Late Pleistocene and historical times. The genetic data show a high Late Pleistocene diversity across the continent and challenge the strict confinement of bears to traditional southern refugia during the last glacial maximum (LGM). The mitochondrial data further suggest a genetic turnover just before this time, as well as a steep demographic decline starting in the mid‐Holocene. Levels of stable nitrogen isotopes from the remains confirm a previously proposed shift toward increasing herbivory around the LGM in Europe. Overall, these results suggest that in addition to climate, anthropogenic impact and inter‐specific competition may have had more important effects on the brown bear's ecology, demography, and genetic structure than previously thought.

A very rich assemblage of ancient brown bears (Ursus arctos arctos Linnaeus, 1758) from Mont Ventoux caves (France) has been investigated using carbon and nitrogen isotopic composition of bone collagen. The isotopic data showed that these bears were feeding in an open environment and consumed mainly plant food items. The access to livestock meat appeared to have been much more limited for these ancient brown bears than for 20th-century Pyrenean bears, suggesting that husbandry patterns had kept bears away from domestic herds. The isotopic variations observed are large according to the ontogenic stage of the bears when they died, which could be accounted for by the isotopic changes that occur during hibernation of the lactating female bear and by different time periods averaged in bone collagen, and without the need to involve different food resources for cubs relative to adult bears.Résumé : Un très riche assemblage d'ours bruns (Ursus arctos arctos Linnaeus, 1758) anciens de grottes du Mont Ventoux (France) a été étudié en utilisant les compositions isotopiques du carbone et de l'azote du collagène osseux. Les données isotopiques montrent que ces ours se nourrissaient dans un environnement ouvert et qu'ils consommaient une majorité de nourriture végétale. L'accès au bétail domestique semble avoir été beaucoup plus limité pour les ours anciens que pour des ours pyrénéens du 20 ième siècle, ce qui suggère que les modes d'élevages maintenaient les ours éloignés des troupeaux. Les variations isotopiques observées selon le stade ontogénique au décès des ours sont importantes. Elles peuvent être liées aux changements isotopiques qui se produisent pendant l'hibernation de l'ourse allaitante et aux différentes périodes moyennées dans le collagène osseux, sans qu'il ne soit nécessaire de faire intervenir des sources alimentaires différentes pour les oursons et pour les ours adultes. Bocherens et al. 586

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