Canadians help use DNA to unlock secrets of Europe's first farmers
Canadian scientists are part of an international team that has used the genetics from bodies thousands of years old to reveal the secrets of how agriculture first came to Europe.
"This was the source from where most of the farming spread to western Europe and northern Europe," said Damian Labuda of the University of Montreal.
Labuda is one of the co-authors of a paper published Wednesday in Nature about using new analytical tools to peer into the genetic makeup of 225 people from the ancient past in what is now southeastern Europe. The human remains were anywhere from 2,500 to 14,000 years old.
Previously, scientists had to rely on artifacts such as tools or pottery shards found with bodies to guess at ancient movements of people. It wasn't the most reliable method, said Bence Viola of the University of Toronto, another co-author.
"You can learn how to make a certain kind of pot from your neighbour," he said. "Culture can spread independently from biology."
Current DNA techniques allow scientists to directly ask those ancient people from where they came.
Previous studies have shown that by 5,600 BC, farming was practised in Europe as far north as what is now Spain. But was it because the people who had always lived there learned something new? Or was it immigration?
"For the last hundred years, there's been this discussion, is this simply the spread of technology or is it actual migration of people?" said Viola. "It looks as if ... clearly there's new people coming in."
The scientists, led by Iain Mathieson at Harvard Medical School, found the 225 bodies they examined from the Balkan region were closely linked genetically to people from what is now central Turkey — an ancient culture highly correlated with farming. They concluded that's where Europe's first farmers came from.
They migrated into a continent that had been populated long before by a culture sustained by hunting and gathering. The two cultures lived apart, said Viola.
"It looks as if these two groups don't mix, kind of like parallel societies, who then start mixing. One of the interesting things is that in some regions, it's sex-biased — hunter-gatherer males who mated with farmer females.
"Can it be that some of these contacts were not necessarily peaceful?"
Those early farmers established Europe's first complex societies, with significant wealth inequality. One individual from that era was buried with more gold than is known from all other similarly aged burial sites combined.
The farmers, however, were not the last immigrants. By about 2,000 BC, a wave of mounted herdsmen swept in from the Eurasian steppes and adopted agricultural techniques.
That marks another shift in Europe.
"It's the first time we see things like ruling families, the use of metal, a much more stratified society with more specialization," said Viola. "Burial customs completely change all over Europe."
The next step, he said, is to link the genetic data with linguistic studies that trace the movement of languages.
"If we could show that the steppe migration is what brought Indo-European languages to Europe, that would be pretty cool. We're really at the beginning of this."
It's a tangled web, with influences running in every direction, said Labuda.
"All this is much more complicated than we thought. (This research) provides us with a tissue of how these three contributions mixed up."