Ancient DNA is revealing the hidden history of human adaptation. 

Samples of human remains around 45,000 years old have shed light on a previously unknown aspect of human evolution.

“It was widely believed the genetics of our human ancestors didn’t change due to environmental pressures as much as other animals, due to our enhanced communication skills and ability to make and use tools,” says Dr Yassine Souilmi from the University of Adelaide’s Australian Centre for Ancient DNA. 

“However, by comparing modern genomes with ancient DNA, we discovered more than 50 cases of an initially rare beneficial genetic variant becoming prevalent across all members of ancient human groups.

“In contrast to many other species, evidence for this type of adaptive genetic change has been inconsistent in humans. This discovery consequently challenges the prevailing view of human adaptation, and gives us a new and exciting insight into how humans have adapted to the novel environmental pressures they encountered as we spread across the planet.”

The experts say examining ancient DNA has been critical in unlocking the secrets of human evolution.

“We believed historical mixing events between human groups might have hidden signs of genetic changes in modern human genomes,” says co-lead author Dr Ray Tobler. 

“We examined DNA from more than 1,000 ancient genomes, the oldest which was around 45,000 years old, to see if certain types of genetic adaptation had been more common in our history than studies of modern genomes had suggested.”

Professor Christian Huber, a senior author of the research paper, says “the use of ancient genomes was crucial because they preceded major historical mixing events that have radically reshaped modern European genetic ancestry”.

“This allowed the recovery of historical signs of adaptation that are invisible to standard analysis of modern genomes,” he said. 

The full study is accessible here.