According to one study, the first farmers arose from the intermingling of two groups of hunter-gatherers brought together by dramatic climate change 12,900 years ago.
Researchers have unearthed a treasure trove of new genetic information extracted from bones of previously found ancient humans.
The results suggest that the world’s first farmers did not descend from a single group in Asia, as previously thought, before spreading westward into Europe.
In fact, the first farmers were the descendants of hunter-gatherers from Europe and the Middle East, the researchers claim.
European hunter-gatherers had moved east after the Last Glacial Maximum, a major climatic event that saw temperatures plummet 20,000 years ago.
When they reached the east, these European hunter-gatherers then breed with hunter-gatherers from the Middle East.
Eventually, their descendants (who later became the first farmers) moved west—essentially marking the spread of agriculture in Europe.
The first farmers were the descendants of hunter-gatherers from Europe and the Middle East. These hunter-gatherers from Europe migrated east because of the last glacial maximum and then breeded with Asian populations in Asia. Their descendants (the first farmers) moved west – marking the spread of agriculture across Europe
People transitioned from a hunter-gatherer lifestyle (consisting of killing animals and foraging on plants) to a farming lifestyle (where they grew crops and settled in a single location). Shown are some of the first European farmers
“We now find that the first farmers of Anatolia and Europe emerged from a population that mixed with hunter-gatherers from Europe and the Middle East,” said study author Nina Marchi from the University of Bern.
It is already known that the first agriculture took place in the so-called Fertile Crescent, a region in the Middle East, around 11,000 years ago.
This is when humans began to domesticate animals and plants in a settled place, rather than constantly roaming about in search of food.
Agriculture gradually spread westward from Asia through Europe, beginning in Greece about 9,000 years ago.
Areas further west, such as Britain, were unaffected for another 2,000 years, and Scandinavia later.
Genetic analyzes of prehistoric skeletons also suggest that Europe’s first farmers descended from hunter-gatherer populations in Anatolia, the great peninsula of western Asia.
That may well be the case, but this new study shows that the Neolithic genetic origins cannot be unequivocally pinned down to a single region.
Researchers analyze ancient human remains for paleogenetic research at Johannes Gutenberg University Mainz, Germany
Researchers have unearthed a treasure trove of new genetic information extracted from bones of previously found ancient humans. The picture shows the individual “Klein7” from the Kleinhadersdorf site in the Weinviertel region of Lower Austria, whose genome was analyzed in the work
For their study, the researchers analyzed bone genomes extracted from skeletons of ancient humans from a variety of locations, including Anatolia, Greece, Serbia, Austria and Germany.
The researchers used a technique called deep sequencing, which involved sequencing the genome of each ancient person multiple times.
This yielded higher data quality and much more information than traditional analyzes based on shallower or partial sequencing.
“We are getting much more detail about the demographic history of these populations, including population divergence, expansion and the derivation of admixture data, which was really impossible before,” said study author Laurent Excoffier of the University of Bern, Switzerland.
The model was then refined with additional geographic, cultural, archaeological and climatic data.
The results suggest that the first farmers represented a mix of Ice Age hunter-gatherer groups that stretched from the Middle East to south-eastern Europe.
Some of the first farmers emerged about 12,900 years ago from the mixing of hunter-gatherers from a western group and an already mixed group living in the east.
These farmers, who domesticated plants and animals, then migrated west, eventually bringing their culture to Central Europe.
Today many people from all over Europe are descended from them.
Locating archaeological sites with newly sequenced genomes and additional genomes used for modelling
There was also evidence that Western European hunter-gatherers experienced a period of extremely low population size during the maximum of the last ice age.
Descendants of European hunter-gatherers show lower diversity than early farmers because their ancestors went through a very severe population shortage during which they lost a lot of diversity.
Going forward, the team plans to further analyze ancient genomes from other geographic locations and times to understand cultures and populations that appeared at different stages of the Stone Age and possibly the Bronze Age.
“Although our study brought new insights into the story, I think what it really shows is that it pays to invest in high-quality genomic data,” Excoffier said.
“These ancient materials are limited and too precious to be analyzed less than optimally. We should extract as much information as possible that will become permanent resources that could be shared.’
The study was published today in the journal Cell.
