Scientists have discovered a new Neanderthal lineage that appears to have had little interaction with other humans of its kind, using DNA extracted from a roughly 45,000-year-old bone belonging to a man archaeologists have named “Tholin.” Thorin Oakenshield is a dwarf who appears in the novels of J. R. R. Tolkien. The Hobbit. This Neanderthal, Thorin, lived in a small community in what is now the Rhône Valley in France.
The new genetic analysis reveals that the Thorin community was isolated from other groups and diverged from the better-studied Neanderthals about 100,000 years ago. The study was published in Cell Press on September 11th. Cell Genomics This may shed light on the cause of this species’ extinction.
[Related: Neanderthals may have been early risers.]
“Previously it was thought that there was just one genetically homogeneous population of Neanderthals at the time of the extinction, but we now know that there were at least two populations at the time,” said study co-author Tarshika Vimala, a population geneticist at the University of Copenhagen. It said in a statement.
Archaeologists first discovered Thorin’s fossils in 2015. Grotte Mandolinis a well-studied cave system. Several ancient tools and remains have been found here, and the area is still being excavated. Mandolin Cave contains early Homo sapiensHowever, not necessarily from the same period as the Neanderthals.
“Thorin’s group went 50,000 years without exchanging genes with other Neanderthal groups,” says study co-author Ludovic Slimac, an archaeologist at France’s Toulouse-Paul Sabatier University, who first discovered Thorin. It said in a statement“Thus, for 50,000 years, two groups of Neanderthals coexisted within a 10-day walking distance of each other, completely ignoring each other. Sapiens And it makes clear that Neanderthals must have imagined a world quite different from ours, biologically speaking. Sapiens.”
Based on Thorin’s location in the cave deposits, archaeologists on the team believe he It lived between 40,000 and 45,000 years ago.This makes him a late Neanderthal, or They lived during the last Ice Age, between 39,000 and 47,000 years ago..
The team’s genomicists then extracted DNA from Thorin’s teeth and jaw and compared its entire genome sequence to previously sequenced Neanderthal genomes, revealing Thorin’s age and genetic relationships to other Neanderthals whose genes have been previously discovered.
To my surprise, Genomic analysis was proposed Thorin was actually much older than archaeologists estimated, and his genome, unlike other late Neanderthals, resembled that of Neanderthals who lived more than 100,000 years ago.
“We spent seven years working to determine whether the archaeologists or the genomics scientists were wrong,” Slimak said.
To resolve this archaeological controversy, the team Isotopic analysis of Thorin’s bones and teeth “The isotope analysis shows that Thorin lived in a very cold climate, so he is likely a late Neanderthal.”
“This genome is a relic from part of the earliest known Neanderthal population in Europe,” study co-author Martin Sikora, a population geneticist at the University of Copenhagen, said in a statement. “The lineage leading to Thorin would have split off from the lineage leading to other late Neanderthals around 105,000 years ago.”
Compared to other Neanderthal genomes sequenced so far, Thorin’s genome was most similar to an individual unearthed about 1,000 miles northeast of Gibraltar. Slimak said Thorin’s population They likely migrated south from Gibraltar to France..
[Related: Neanderthal genomes reveal family bonds from 54,000 years ago.]
“This means that a previously unknown population of Neanderthals existed in the Mediterranean region, stretching from the westernmost tip of Europe all the way to the Rhône Valley in France,” Slimak said.
Understanding how potentially small and isolated Neanderthal communities were may be important in understanding their extinction: genetic isolation is generally thought to be detrimental to the population fitness of a gene pool.
“It’s always a good thing for populations to come into contact with other populations,” Vimala says. “Prolonged isolation limits genetic diversity and reduces the ability to adapt to changes in climate and pathogens. It’s also socially limiting, as you don’t share knowledge or evolve as a population.”
To truly understand how Neanderthal populations were structured and why they ultimately went extinct, scientists need to sequence many more Neanderthal genomes. Climate ChangeIncreased competition and reproduction with humans, and perhaps this isolation and lack of connections with conspecifics, may have contributed to the Neanderthals’ eventual extinction around 40,000 years ago.
“Although this is a more speculative conclusion, the mere concept of being able to increase communication and exchange knowledge is something that humans can do that may not have been possible to some extent with Neanderthals, who lived in small, isolated groups,” the study said. Vimala said:“And that’s an important skill. There is evidence that early modern humans in Siberia, living in small communities, formed so-called mating networks to avoid problems with inbreeding, something that wasn’t seen in Neanderthals.”
