A new paper has detailed how scientists sequenced five new Neanderthal genomes from specimens that lived about 39,000 to 47,000 years ago. These new findings, according to reports, could offer more insight into the final years of this early human species and their genetic connection with modern humans.
In a study published Wednesday in the journal Nature, a team of researchers led by Max Planck Institute for Evolutionary Anthropology biologist Mateja Hajdinjak analyzed the teeth and bones of Neanderthal specimens from Belgium, Croatia, France, and the Russian Caucasus, and compared them against another Neanderthal genome from the Caucasus region. The analysis, according to The Scientist, revealed that extreme cold weather might have wiped out Neanderthal populations in the Caucasus around 38,000 years ago, with a separate group of Neanderthals recolonizing the area.
Separately, Ars Technica wrote that the population turnover might have manifested in the opposite way, as it’s possible that Western European Neanderthals from Belgium, France, Croatia, and other countries were descended from populations that hailed from the Caucasus.
Interestingly, the researchers were not able to find any modern human DNA in the Neanderthal genomes they sequenced. This was despite four of the specimens existing around the same time that modern humans had a presence in Europe. According to Ars Technica, the research also revealed that humans might have already had Neanderthal genes in them between 70,000 to 150,000 years ago, well before the heyday of the five individuals whose genomes were sequenced.
The above findings, said Max Planck Institute for Evolutionary Anthropology director Svante Paabo, could be a sign of mostly “unidirectional” gene flow from Neanderthals to modern humans, but not the opposite.
Genome Sequencing Adds 5 New Neanderthals to the Human Family Tree - Inverse https://t.co/hi8Kz7E1c1— Otis Odell (@OtisOdell) March 23, 2018
Commenting on her team’s study, Hajdinjak said in a statement published on the Max Planck Society website that the similarities shown by the Neanderthal genome analysis are “well-correlated” with the geographical location of separate populations.
“By comparing these genomes to the genome of an older Neanderthal from the Caucasus we show that Neanderthal populations seem to have moved and replaced each other towards the end of their history,” she added.
In an interview with a Danish publication quoted and translated by The Scientist, University of Copenhagen researcher Morten Allentoft, who was not involved in the new paper, said that the research allows scientists to “get a real picture” of the genetic diversity of the Neanderthal species.
“The study clearly shows that there was a geographical population structure (different characteristics of people in different geographic areas) in Neanderthals, just as we see it at Homo sapiens.”
As noted by Inverse, the new study added to the number of Neanderthal genomes sequenced since 2010, with the five genomes from more recent Neanderthal specimens, making it a total of nine whole-genome sequences generated in the past eight years. Speaking to the publication, senior author Janet Kelso, a professor at the Max Planck Institute, said that the findings could lead to a greater percentage of Neanderthal DNA being revealed as present in today’s humans. She added, however, that several questions remain unanswered, such as whether the gene flow came from males or females of the species.