Migration as a drive for Western sheep evolution: using ancient DNA to track secondary expansions of sheep into Western Asia and Europe

Since sheep were domesticated 12.500-years ago in the Fertile Crescent, they have been one of the most popular species for human exploitation. As Neolithic farmers expanded from this region, sheep played an important role as a source of meat and skin.

This expansion has been traced both at the continental and local scale in Europe, but later migrations involving sheep have not been properly studied.

Several studies have suggested at least one major migration, associated with the expansion of wool into Europe from a source in Central Asia, but the origin, timing and how it relates to human population movements is not well understood.

To describe this and other migrations that may have shaped Western sheep, we aim at sequencing ancient sheep genomic data from bones and sediments from the Levant, an important region for sheep since their domestication.

The site, Pella, has been continuously occupied since the Neolithic, and for thousands of years was a trade center that connected thriving civilizations, so it is the perfect place for a time-series study tracking demographic changes and ancestries moving through this region.

Lastly, this project aims at using state-of-the-art statistical methods to analyze what traits were associated with these population movements and what kinds of pathogens these new sheep were bringing with them.

These results will help us properly understand the role of human-mediated migration in sheep evolution and how modern sheep diversity was formed.