Past climate changes, population dynamics and the origin of Bison in Europe

International audienceBackground: Climatic and environmental fluctuations as well as anthropogenic pressure have led to theextinction of much of Europe’s megafauna. The European bison or wisent (Bison bonasus), one of the last wildEuropean large mammals, narrowly escaped extinction at the onset of the 20th century owing to hunting andhabitat fragmentation. Little is known, however, about its origin, evolutionary history and population dynamicsduring the Pleistocene.Results: Through ancient DNA analysis we show that the emblematic European bison has experienced severalwaves of population expansion, contraction, and extinction during the last 50,000 years in Europe, culminatingin a major reduction of genetic diversity during the Holocene. Fifty-seven complete and partial ancient mitogenomesfrom throughout Europe, the Caucasus, and Siberia reveal that three populations of wisent (Bison bonasus) andsteppe bison (B. priscus) alternately occupied Western Europe, correlating with climate-induced environmentalchanges. The Late Pleistocene European steppe bison originated from northern Eurasia, whereas the modernwisent population emerged from a refuge in the southern Caucasus after the last glacial maximum. A populationoverlap during a transition period is reflected in ca. 36,000-year-old paintings in the French Chauvet cave. Bayesiananalyses of these complete ancient mitogenomes yielded new dates of the various branching events during theevolution of Bison and its radiation with Bos, which lead us to propose that the genetic affiliation betweenthe wisent and cattle mitogenomes result from incomplete lineage sorting rather than post-speciation gene flow.Conclusion: The paleogenetic analysis of bison remains from the last 50,000 years reveals the influence ofclimate changes on the dynamics of the various bison populations in Europe, only one of which survived intothe Holocene, where it experienced severe reductions in its genetic diversity. The time depth and geographicalscope of this study enables us to propose temperate Western Europe as a suitable biotope for the wisentcompatible with its reintroduction

Old World camels in a modern world - a balancing act between conservation and genetic improvement

International audienceOld World camels have served humans in cross-continental caravans, transporting people and goods, connecting different cultures and providing milk, meat, wool and draught since their domestication around 3000-6000 years ago. In a world of modern transport and fast connectivity, these beasts of burden seem to be out-dated. However, a growing demand for sustainable milk and meat production, especially in countries affected by climate change and increasing desertification, brings dromedaries (Camelus dromedarius) and Bactrian camels (Camelus bactrianus) back onstage and into the focus of animal breeders and scientists. In this review on the molecular genetics of these economically important species we give an overview about the evolutionary history, domestication and dispersal of Old World camels, whereas highlighting the need for conservation of wild two-humped camels (Camelus ferus) as an evolutionarily unique and highly endangered species. We provide cutting-edge information on the current molecular resources and on-going sequencing projects. We cannot emphasise enough the importance of balancing the need for improving camel production traits with maintaining the genetic diversity in two domestic species with specific physiological adaptation to a desert environment