DNA from a 4,500-year-old Ethiopian skull sheds light on a West Eurasians migration to the Horn of Africa about 3,000 years ago that influenced the genetics of the people who still live there today.
The research marks the first ancient human genome from Africa to be sequenced, and the findings show a wave a migration back into Africa was twice as genetically significant as was previously believed, the University of Cambridge reported. The ancient DNA was taken from a the skull of a man buried face-down 4,500 years ago in a cave cool enough to preserve the genetic material in a way that has never been seen before for this region and time period.
The bones predate the "Eurasian backflow" event that from regions of Western Eurasia such as the Near East and Anatolia back to the Horn of Africa. The findings linked these Western Eurasians to the Early Neolithic farmers that are believed to have brought agriculture to Europe 4,000 years earlier. By comparing this ancient genome with those of modern Africans, the scientists were able to determine that modern East African populations have as much as 25 percent Eurasian ancestry from this massive migration. African populations from all over the continent were also found to share at least 5 percent of these genetics.
"Roughly speaking, the wave of West Eurasian migration back into the Horn of Africa could have been as much as 30 [percent] of the population that already lived there - and that, to me, is mind-blowing. The question is: what got them moving all of a sudden?" said Andrea Manica, senior author of the study from the University of Cambridge's Department of Zoology.
While the reason behind the migration remains a mystery, the researchers noticed it closely coincided with the arrival of Near Eastern crops into East Africa such as wheat and barley. This suggests the migrants helped revolutionize agriculture in the region.
"The sequencing of ancient genomes is still so new, and it's changing the way we reconstruct human origins," Manica said. "These new techniques will keep evolving, enabling us to gain an ever-clearer understanding of who our earliest ancestors were."