Scientists at the Max Planck Institute for the Science of Human History have uncovered DNA evidence in ancient bones of humans living in Europe across a 30,000-year timespan that reveal that there was a major population shift 14,500 years ago due to inconsistent climate characteristics.
"We uncovered a completely unknown chapter of human history: a major population turnover in Europe at the end of the last Ice Age," Johannes Krause, lead author, said in a press release.
The team reconstructed the mitochondrial genomes of 35 hunter-gatherers from Italy, Germany, Belgium, France, the Czech Republic and Romania from the time period of 35,000 to 7,000 years ago in order to shed light on the missing history.
"There has been a real lack of genetic data from this time period, so consequently we knew very little about the population structure or dynamics of the first modern humans in Europe," Krause said.
The study reveals that the mitochondrial DNA of three people who live in present-day Belgium and France before the coldest period of the last Ice Age represented the genetic group haplogroup M. This group is completely absent from modern European genetics despite being very common in current Asian, Australasian and Native American populations.
Krause and his team believe that their discovery of maternal lineage originating in Europe years ago points to non-African populations dispersing approximately 50,000 years ago. Years later, the M haplogroup completely disappeared from Europe.
"When the Last Glacial Maximum began around 25,000 years ago, hunter-gatherer populations retreated south to a number of putative refugia, and the consequent genetic bottleneck probably resulted in the loss of this haplogroup," said Cosimo Posth, first author of the study.
Another surprising finding was of the climate warming that stimulated a major turnover in Europe's population approximately 14,500 years ago.
"Our model suggests that during this period of climatic upheaval, the descendants of the hunter-gatherers who survived through the Last Glacial Maximum were largely replaced by a population from another source," said Adam Powell, another co-author on the study.
The findings are available in the Feb. 4 issue of Current Biology.