Rowan et al. generated a dataset of over 17,000 meiotic crossovers (COs) from over 2000 F2 individuals from a single Arabidopsis thaliana cross. The unprecedented density of COs and the high-quality reference genomes of the two...

Advances in the isolation and sequencing of ancient DNA have begun to reveal the population histories of both people and dogs. Over the last 10,000 y, the genetic signatures of ancient dog remains have been linked with known human dispersals in regions such as the Arctic and the remote Pacific. It is suspected, however, that this relationship has a much deeper antiquity, and that the tandem movement of people and dogs may have begun soon after the domestication of the dog from a gray wolf ancestor in the late Pleistocene. Here, by comparing population genetic results of humans and dogs from Siberia, Beringia, and North America, we show that there is a close correlation in the movement and divergences of their respective lineages. This evidence places constraints on when and where dog domestication took place. Most significantly, it suggests that dogs were domesticated in Siberia by ∼23,000 y ago, possibly while both people and wolves were isolated during the harsh climate of the Last Glacial Maximum. Dogs then accompanied the first people into the Americas and traveled with them as humans rapidly dispersed into the continent beginning ∼15,000 y ago.

The grey wolf (Canis lupus) was the first species to give rise to a domestic population, and they remained widespread throughout the last Ice Age when many other large mammal species went extinct. Little is known, however, about the history and possible extinction of past wolf populations or when and where the wolf progenitors of the present-day dog lineage (Canis familiaris) lived1–8. Here we analysed 72 ancient wolf genomes spanning the last 100,000 years from Europe, Siberia and North America. We found that wolf populations were highly connected throughout the Late Pleistocene, with levels of differentiation an order of magnitude lower than they are today. This population connectivity allowed us to detect natural selection across the time series, including rapid fixation of mutations in the gene IFT88 40,000–30,000 years ago. We show that dogs are overall more closely related to ancient wolves from eastern Eurasia than to those from western Eurasia, suggesting a domestication process in the east. However, we also found that dogs in the Near East and Africa derive up to half of their ancestry from a distinct population related to modern southwest Eurasian wolves, reflecting either an independent domestication process or admixture from local wolves. None of the analysed ancient wolf genomes is a direct match for either of these dog ancestries, meaning that the exact progenitor populations remain to be located.