Ancient genome mapping shows link between humans and Neanderthals

Avatar By Joseph Scalise | 3 years ago

New genetic testing shows that Europeans and Asians both have approximately 2 percent Neanderthal DNA, and that such a proportion could steadily increase over time.  

DNA testing — both official and at home — is supposed to give people insight into their ancestry. While it largely achieves that goal, it also helps scientists better understand what percent of our DNA is not human.  

In the new study, a group of researchers from the Max Planck Institute sequenced the genomes of five Neanderthal specimens that lived between 39,000 and 47,000 years ago.

All of the specimens are significant in that they are more closely related to Neanderthals that can be traced in modern human DNA than they are to older species who already had their genomes sequenced. Since 2010, researchers have generated four whole-genome sequences from Neanderthal specimens. The recent research adds five more from a much later time period.  

“It is the case that having the genomes of these younger Neanderthals increases the amount of Neanderthal DNA that can be identified in present-day people,” explains senior author Janet Kelso, a professor at the Max Planck Institute, according to Inverse.

The new genomes are important because they allow scientists to identify 10 to 20 percent more Neanderthal DNA in people alive today than they would if they only used past genomes.

While researchers know that Neanderthals and modern humans mated, they understand very little about Neanderthal genetic diversity. The team in the new study shed on that by using a process that carefully removed contaminated DNA from microbes. That then allowed them to use powdered bones and teeth to create the genomes of five Neanderthals sourced from Belgium, France, Croatia, and Russia.

The study showed that, while the Neanderthals lived at the same time as early modern humans, they did not have any human DNA. As a result, the gene flow between populations likely only went from Neanderthals to humans, not the other way around.

While the study did not enable scientists to figure out if the gene flow came from males or females, there is no doubt the study shed new light on ancient populations. It also gave researchers a better way to reconstruct ancient populations.

The study revealed that population turnover occurred among Neanderthals towards the end of their species, as groups throughout Eurasia steadily replaced each other. All of the above information is key to understanding, not just how the ancient species lived, but how we relate to them.

“It’s an amazing paper,” Anders Eriksson, a researcher from King’s College London who was not involved in the study, told Ars Technica. “This really opens up the possibility of starting to do proper population genetics on Neanderthals.”

The new findings are outlined in the journal Nature