Rose-Marie Arbogast | Search bioRxiv

bioRxiv2016

Ancient European dog genomes reveal continuity since the early Neolithic

Europe has played a major role in dog evolution, harbouring the oldest uncontested Paleolithic remains and having been the centre of modern dog breed creation. We sequenced the whole genomes of an Early and End Neolithic dog from Germany, including a sample associated with one of Europes earliest farming communities. Both dogs demonstrate continuity with each other and predominantly share ancestry with modern European dogs, contradicting a previously suggested Late Neolithic population replacement. Furthermore, we find no genetic evidence to support the recent hypothesis proposing dual origins of dog domestication. By calibrating the mutation rate using our oldest dog, we narrow the timing of dog domestication to 20,000-40,000 years ago. Interestingly, we do not observe the extreme copy number expansion of the AMY2B gene that is characteristic of modern dogs and has previously been proposed as an adaptation to a starch-rich diet driven by the widespread adoption of agriculture in the Neolithic.

Genomics↗

bioRxiv2016

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

Climatic and environmental fluctuations as well as anthropogenic pressure have led to the extinction of much of Europes megafauna. Here we show that the emblematic European bison has experienced several waves of population expansion, contraction and extinction during the last 50,000 years in Europe, culminating in a major reduction of genetic diversity during the Holocene. Fifty-seven complete and partial ancient mitogenomes from throughout Europe, the Caucausus and Siberia reveal that three populations of wisent (Bison bonasus) and steppe bison (B. priscus) alternated in Western Europe correlating with climate-induced environmental changes. The Late Pleistocene European steppe bison originated from northern Eurasia whereas the modern wisent population emerged from a refuge in the southern Caucasus after the last glacial maximum. A population overlap in a transition period is reflected in ca. 36,000 year-old paintings in the French Chauvet cave. Bayesian analyses of these complete ancient mitogenomes yielded new dates of the various branching events during the evolution of Bison and its radiation with Bos that lead us to propose that the genetic affiliation between the wisent and cattle mitogenomes result from incomplete lineage sorting rather than post-speciation gene flow.\n\nSignificanceClimatic fluctuations during the Pleistocene had a major impact on the environment and led to multiple megafaunal extinctions. Through ancient DNA analyses we decipher these processes for one of the largest megafauna of Eurasia, the bison. We show that Western Europe was successively populated during the Late Pleistocene by three different bison clades or species originating from the Caucasus and North-Eastern Europe that can be correlated to major climatic fluctuations and environmental changes. Aurignacian cave artists were witnesses to the first replacement of bison species ~35,000 years ago. All of these populations went extinct except for one that survived into the Holocene where it experienced severe reductions of its genetic diversity due to anthropogenic pressure.

Evolutionary Biology↗