Excavations from a German cave suggest ancient hunters and European farmers lived together 7,500 years ago but didn't interbreed much.
A discovery that sheds light on how ancient hunters and European farmers coexisted was made from the largest ancient DNA set ever compiled, gathered from the remains of 364 people at 25 sites in the Blätterhöhle cave near Hagen in North Rhine-Westphalia.
Researchers were able to determine from the skeletons that ancient hunters and European farmers coexisted for more than 2,000 years about 7,500 years ago. Though they lived side by side and mingled with each, researchers were surprised to find that they didn't interbreed.
The findings prove that the hunter-gatherer lifestyle died out much later than previously thought, contrary to previous archaeological records that suggest the hunter-gatherers died out or were absorbed into the farming populations.
"It is commonly assumed that the Central European hunter-gatherers disappeared soon after the arrival of farmers," Dr. Ruth Bollongino, lead author of the study, said in a statement. "But our study shows that the descendants of Mesolithic Europeans maintained their hunter-gatherer way of life and lived in parallel with the immigrant farmers, for at least 2,000 years."
Up until now, not many studies have been conducted on the relationship between immigrant agriculturalists and local hunter-gatherers. Researchers found that many hunter-gatherer women married into the farming communities, but no genetic lines of farmer women have been found in hunter-gatherers. The two groups rarely interbred.
At first, researchers were unable to make sense of the discovery. Only after the isotope content mitochondrial DNA results taken from 25 skeletons were analyzed did researchers discover that the two societies maintained their lifestyles and rarely mingled. The isotopes also reveal that the hunter-gatherers sustained a diet of fish while farmers relied on domesticated animals, Bollongino said.
"It wasn't until we saw the isotopes that we realized we were going to have to rewrite the paper completely," Bollongino told the Washington Post. "They shared the same burial place for something between 400 and 600 years, so it would be very hard to explain that they did not know each other. We believe that they were close neighbors and had contact with each other and traded with each other. But still they didn't mix."
Findings of the study led researchers to conclude that neither farmers nor hunter-gatherers can be deemed the sole ancestors of modern-day Central Europeans. European ancestry reflects a mixture of both populations.
