Earlier this year, researchers from Oxford University published a study showing how the slave trade and colonization shaped the genetics of North and South America....

In a paper published today in the journal Current Biology, the same  team moved its analysis to the other side of the ocean and tweaked the order. This time, they used genetic data to create a historical record as well as confirm it, discovering evidence for previously unknown patterns of movement across Asia and Europe over the past 1,500 years.

Using around 2,000 DNA samples—slightly more than half from 63 locations in Europe and the Middle East, and the rest taken from another 87 locations elsewhere in the world—the researchers looked at where certain shared genetic markers fell on the chromosome to determine the date of admixing, the term for when two previously separate groups begin to merge.