Mysterious Lineage of Neanderthals in France Kept to Themselves For 50,000 Years

A Neanderthal dubbed Thorin just took a DNA test, and it turns out he represents a lineage of the ancient humans that is genetically separated from other groups by at least 50,000 years.

The roughly 45,000-year-old fossil Neanderthal, named Thorin by the researchers who recently analyzed his genome, was discovered in a French cave called Grotte Mandrin in 2015. Grotte Mandrin is a compelling site: Homo sapiens occupied the cave before Neanderthals, and in 2023 researchers published the earliest known evidence of bow and arrow use in Europe from the cave.

Since Thorin was found in 2015, the team has pored over the Neanderthal’s DNA. The team compared Thorin’s genome to that of other known late Neanderthals, revealing that the population Thorin belonged to didn’t exchange genes with other Neanderthal groups for tens of thousands of years. The team’s research is now published in Cell Genomics.

Neanderthals were a group of ancient humans that disappeared from the fossil record about 40,000 years ago. They had distinctive features that included barrel chests, pronounced brows, and tall noses. Despite being a different human species (Homo neanderthalensis), Neanderthals bred with Homo sapiens to the point that many people today carry bits of Neanderthal DNA. Thorin’s age makes him a late Neanderthal. By the time of Thorin’s existence, his particular population had not interacted with other Neanderthal groups for about 50,000 years.

Finding Thorin was “the kind of unique discovery that an archaeologist can only dream of finding in a well-lived life,” said Ludovic Slimak, a researcher at CNRS and the study’s lead author, in an email to Gizmodo. “But the study presented in Cell goes much further than just the remarkable anecdote of an exceptional discovery. We present the result of nearly 10 years of research, in the shadows, around this body and the genetics of this population.”

By comparing Thorin’s genome to that of other Neanderthals across Europe, the team found that Thorin’s genome resembled that of an individual found in Gibraltar. Slimak suggested in a Cell release that Thorin’s population may have migrated from Gibraltar to France.

In the same release, Slimak pointed out that a separate Neanderthal population lived “about ten days’ walk” from Thorin’s group, yet the two populations showed no genetic evidence of mixing. That indicates Neanderthals were more insular than Homo sapiens, though at least some Neanderthal groups interbred with our species. Slimak expanded on these ideas in his 2023 book, The Naked Neanderthal.

“The study of Slimak and collaborators presents very important evidence regarding small size, isolated Neanderthal populations,” said Marcelo Briones, a genome researcher at the Federal University of São Paulo in Brazil who is not affiliated with the recent paper, in an email to Gizmodo.

Earlier this year, a team led by Briones identified the herpes virus in Neanderthal remains, raising questions about how the lack of genetic diversity in our extinct cousins may have exposed them to environment threats like infectious diseases. “Probably a combination of population dynamics and structure combined with epidemic processes might have been important factors for Neanderthal extinction,” Briones added.

More Neanderthal DNA from other individuals across Europe would almost certainly improve our understanding of how the lost human species moved across the continent and interacted with other groups. For now, insights from Thorin’s DNA are revealing details of our ancient human that were previously unknowable.