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.
Analyzing more than 4,000 DNA samples from across both continents, as well as Europe and Africa, they were able to detect patterns in line with what historians knew about migrations across the Atlantic.
Many people in Colombia and Puerto Rico had Sicilian ancestry, for example, on account of the wave of Italian immigrants to those areas in the 1800s and early 1900s. Most African Americans shared a genetic ancestor with the Yoruba of West Africa, which supplied around one-third of the slaves sent to the Americas in the 1600s.
“We can see the huge genetic impact that the slave trade had on American populations, and our data match historical records,” Cristian Capelli, the lead study author and a professor of zoology at Oxford, said in a statement at the time.
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.