In a pair of new studies, scientists examine DNA from European hunter-gatherers during the last ice age, painting the most detailed picture of these people to date. They trace the movement of different populations across the continent between 5,000 and 35,000 years ago, revealing how some survived the period when glaciers covered much of the land.
“We are finally understanding the dynamics of European hunter-gatherers,” Vanessa Villalba-Mouco, a co-author of both studies and a paleogeneticist at the Max Planck Institute for Evolutionary Anthropology in Germany, tells the New York Times’ Carl Zimmer.
In one of the studies, published last week in the journal Nature, the researchers analyzed the DNA of 356 hunter-gatherers, including new data for 116 individuals from 14 countries in western and central Eurasia.
This was the first ancient DNA study to include people from the Gravettian culture, a group of mammoth hunters that lived in caves or shelters made from the large mammals’ bones, even carving sculptures from their tusks, according to Science’s Andrew Curry. The researchers discovered that two Gravettian populations, one in western Europe and the other in southern Europe, were genetically distinct, despite being associated with the same culture.
“What we previously thought was one genetic ancestry in Europe turned out to be two,” Mateja Hajdinjak, a paleogeneticist also at the Max Planck Institute for Evolutionary Anthropology but who did not contribute to the research, tells Science News’ Bruce Bower.
“This result is, in my opinion, groundbreaking,” Anaïs Luiza Vignoles, an archaeologist at the University of Paris who did not contribute to the research, tells the Times. The findings help explain why archaeologists had observed slight cultural differences between Gravettian populations in different regions, writes Science.
The researchers found that the western Gravettians managed to survive the Last Glacial Maximum (LGM)—when glaciers covered 25 percent of Earth’s land area and much of Europe between 19,000 and 25,000 years ago—by taking refuge in the Iberian Peninsula in the southwest, according to Nature News’ Ewen Callaway. After that, they migrated to the northeast across the continent.
This idea got extra support from the second study, also published last week in Nature. By examining 23,000-year-old fossilized teeth, the researchers found that a person affiliated with a different southwestern European culture had genetic similarities to the western Gravettians, per Science News.
Meanwhile, the southern population of Gravettians disappeared after the LGM and were replaced by a population from the Balkans. This new group, called the Villabruna, then spread from the south across the rest of Europe around 14,000 years ago, mixing with the population that had spread across the continent from Iberia.
At around that time, forests grew across Europe as the climate warmed, and a new, hybrid population became the dominant one, perhaps because these people were better at hunting in forests, Cosimo Posth, a co-author of both papers and a paleogeneticist at the University of Tübingen in Germany, says to the Times.
The new findings help deepen researchers’ understanding of the complex groups that resided in Europe. “This genetic data shows we’ve oversimplified what was going on in terms of population interaction,” Jennifer French, an archaeologist at the University of Liverpool in England who did not contribute to the research, tells Science. “It provides a lot more nuance than we’ve been able to with archaeological data alone.”