Modern Europe`s Genetic History Starts in Stone Age
Baku, April 24 (AZERTAC). Europeans as a people are younger than we thought, a new study suggests, according to National Geographic News. DNA recovered from ancient skeletons reveals that the genetic makeup of modern Europe was established around 4,500 years ago in the mid-Neolithic, and not by the first farmers who arrived in the area around 7,500 years ago or by earlier hunter-gatherer groups. “The genetics show that something around that point caused the genetic signatures of previous populations to disappear,” said Alan Cooper, director of the Australian Centre for Ancient DNA at the University of Adelaide, where the research was performed.
“However, we don`t know what happened or why, and (the mid-Neolithic) has not been previously identified as (a time) of major change,” he said. Furthermore, the origins of the mid-Neolithic populations that did form the basis of modern Europe are also unknown. “This population moves in around 4,000 to 5,000 years ago, but where it came from remains a mystery, as we can`t see anything like it in the areas surrounding Europe,” Cooper said.
The surprising findings are part of a new study, published in this week`s issue of the journal Nature Communications, that provides the first detailed genetic history of modern Europe.
The study shows that “relatively recent migrations seem to have had a significant genetic impact on the population of Central Europe,” said study co-author Spencer Wells, who leads National Geographic`s Genographic Project. In the study, Cooper and his colleagues extracted mitochondrial DNA—which children inherit only from their mothers—from the teeth and bones of 39 skeletons found in central Germany. The skeletons ranged in age from about 7,500 to 2,500 years old. The team focused on a group of closely related mitochondrial lineages—mutations in mitochondrial DNA that are similar to one another—known as haplogroup H, which is carried by up to 45 percent of modern Europeans.
Cooper and his colleagues focused on haplogroup H because previous studies have indicated the mutations might have been present in Europeans` genetic makeup for several thousand years.
It`s unclear how this haplogroup became dominant in Europe. Some scientists have proposed that it spread across the continent following a population boom after the end of the last Ice Age about 12,000 years ago. But the new data paint a different picture of the genetic foundation of modern Europe: Rather than a single or a few migration events, Europe was occupied several times, in waves, by different groups, from different directions and at different times.
The first modern humans to reach Europe arrived from Africa 35,000 to 40,000 years ago. By about 30,000 years ago, they were widespread throughout the area while their close cousins, the Neanderthals, disappeared. Hardly any of these early hunter-gatherers carried the H haplogroup in their DNA.
About 7,500 years ago during the early Neolithic period, another wave of humans expanded into Europe, this time from the Middle East. They carried in their genes a variant of the H haplogroup, and in their minds knowledge of how to grow and raise crops.
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