As scientists are acquiring more sequenced genomes that belonged to Neanderthals, they are getting more details about the dangers ancient humans experienced. The new data originates from between 39,000 and 47,000 years ago. The new genomes help scientists determine how individual population groups of Neanderthals moved through Europe, and when and if they were interbreeding with humans.
Mateja Hajdinjak at the Max Planck Institute for Evolutionary Anthropology and her team conducted the study published in the journal Nature in which they extracted tiny amounts of bone and tooth powder. With the help of chemical processes, they removed genetic contamination, while also looking for signs of degradation in ancient DNA.
After they extracted the new sequenced genomes, they compared it to the previously published data that was collected from a range of Neanderthals and a Denisovan. After taking a look at the data from Mezmaiskaya 1 and Mezmaiskaya 2, which originally were thought to be closely related to each other and also distantly related to others in caves where the Western European Neanderthals resided, they found that the data from Mezmaiskaya 2 seemed more related to the Western European caves group, unlike the Mezmaiskaya 1 cave that is not as related to the western cave group.
The authors of the study wrote that “extreme cold periods in northern Europe may have triggered the local extinction of Neanderthal populations.” After those Neanderthal individuals went extinct, the area may have been populated by Neanderthals that arrived from other locations.
The study also suggests that Neanderthals were interbreeding with other early human species, although when humans moved to Europe there were “no indications of recent gene flow from early modern humans to late Neanderthals,” the authors wrote in the study. According to the data, the Neanderthal gene flows into the human genes before the time the five individuals found in different caves were alive, at between 70,000 and 150,000 years ago.
“It’s an amazing paper,” Anders Eriksson, who studies ancient genomes and wasn’t involved with the study, told Ars Technica. “This really opens up the possibility of starting to do proper population genetics on Neanderthals.”
According to Eriksson, the new sequenced genomes of Neanderthals tells a lot about when they mixed with modern humans. Also, such information fits into the puzzle scientists are trying to solve about the connection of ancient humans and Neanderthals. The data “fills in a lot of detail where we only really had a couple of data points.” He also added that they can continue comparing genomes, pointing out that they can start filling in the complete picture of Neanderthal history “so you can really start putting together a picture of the population that you had in Europe.”