New study reveals third group of ancient ancestors of modern Europeans
It has long been thought that modern Europeans descended from both indigenous hunters and Middle Eastern farmers. However, a new study published in the journal Nature, shows that a third population came into the mix – Northern Eurasians. The research shows that interbreeding between the three groups within the last 7,000 years, accounts for the majority of the genetic landscape seen in Europe today. According to a report in the BBC, the study shifts scientists’ ideas of how groups of people migrated across the globe thousands of years ago.
“Prior to this paper, the models we had for European ancestry were two-way mixtures. We show that there are three groups,” said David Reich, professor of genetics at Harvard Medical School. “This also explains the recently discovered genetic connection between Europeans and Native Americans. The same Ancient North Eurasian group contributed to both of them,” he added.
Until now, assumptions about the origins of European people have been based on the genetic patterns of living people in Europe. However, with advances in the study of ancient DNA, the researchers were able to investigate these theories from another angle, which was through studying the genes of seven ancient hunter-gatherers from Scandinavia, a hunter found in a cave in Luxembourg, and an early farmer from Stuttgart, Germany. They then compared these genomes to those of the 2,345 people in their contemporary populations.
Scientists collected genetic data from nine ancient skeletons. Credit: National News and Pictures
The results showed that northern Europeans have more indigenous hunter DNA, while southern Europeans have more DNA from the Middle East. All Europeans were found to have DNA from Northern Eurasians. However, the research team did not find Northern Eurasian DNA in the ancient hunter-gatherers or the ancient farmers, suggesting that the north Eurasian line of ancestry was introduced into Europe after agriculture had been established, a scenario that most archaeologists had thought unlikely.
A map showing the proposed migration of people into Europe. Image source: BBC.
“Figuring out how these populations are related is extremely hard,” Professor Reich said. “There's a lot that happened in Europe in the last 8,000 years, and this history acts like a veil, making it difficult to discern what happened at the beginning of this period. We had to find statistics that were able to tell us what happened deep in the past without getting confused by 8,000 years of intervening history, when massive and important events occurred.”
The time of the ancient north Eurasians' arrival remains to be determined, but Professor Reich said their later-than-expected movement into Europe might help explain the complex mix of languages that exists there today.
Dr Carles Lalueza-Fox, from the Institute of Evolutionary Biology (CSIC - UPF) in Barcelona, Spain, who was not involved with the research commented: "The interesting point is the idea that we can dissect these components in any modern European and explain diversity in modern Europeans as different proportions of these three populations."
Featured image: This skull was unearthed from a lake bed in central Sweden near the town of Motala. It formed part of the analysis that linked Northern European to indigenous hunters as well as Ancient North Eurasians. Credit: National News and Pictures