Genome analysis can tell us a lot about not only eye and skin color, but also lifestyle. Scientists have studied the DNA of late Neanderthals from across Europe, building up a picture of them as a single metapopulation. The discovery of the Thorin skeleton has shaken these ideas. We have a representative of a small group that lived close to relatives but did not come into contact with them.
Neanderthals lived in Eurasia at the same time as sapiens and became extinct around 40,000 years ago. Scientists have proposed various theories for their disappearance, mostly related to external factors, from climate change to volcanic eruptions to reversals in the planet’s magnetic field. The internal causes of the extinction have been little studied, although paleogenetics and osteology provide some clues.
Siberian and late European Neanderthals appeared to form small groups that interacted poorly with each other. They are characterized by a minimum effective population size that indicates an average number of individuals that provided development and traces of inbreeding, i.e. closely related interbreeding. It remains unclear to what extent this is a general feature of appearance.
Until now, the largest differences between Neanderthal genomes were found between Altai people living in Denisova Cave 120,000 years ago and Europeans from Vindia Cave in Croatia, 40,000 years ago. Recent scientific studies have shown that the population increased 105,000 years ago and three Neanderthal lineages emerged: in Siberia, the Caucasus and Europe. However, scientists have not seen any signs of separate populations.
In 2015, parts of the best-preserved Neanderthal skeleton were discovered in the Mandrin rock shelter in southern France. It was named “Thorin” after the hero of John R. Tolkien’s epic.
The cave is notable because the upper sediment layers contain evidence of the presence of the last Neanderthals and modern humans, between 65 and 41 thousand years ago. Scientists have excavated more than 60,000 stones and more than 70,000 bone fragments belonging to fauna. All layers contain traces of hearths and hominid remains.
For almost 10 years, several parts of the “Torin” skeleton have been removed, excavations are gradually continuing. The important thing is that the jaws and teeth are partially preserved. The researchers determined that this is a typical adult Neanderthal, but with an unusual dental anomaly: two fourth molars. This has never been seen in Pleistocene people. Such an anomaly is quite rare among modern inhabitants.
A number of methods were used to determine the age, including uranium-lead. The most reliable estimates are 52-42 thousand years ago.
Genetic analysis showed that Thorin’s lineage split from the Neanderthal ancestral population 105,000 years ago. Testing for gene transfer between the main population and modern humans revealed that the Thorin population had been isolated for 50,000 years. They were some of the last Neanderthals in this part of Europe.
“So we have two Neanderthal populations that completely ignored each other, 10 days apart. “It’s hard to imagine this for Sapiens, Neanderthals were different in this respect,” explained Ludovic Slimak, a paleoanthropologist at the University Paul Sabatier (France), who discovered “Torina”. His paper, of which he is the first author, was published in a journal Cell Genomics.
This discovery raises new questions about the causes of the Neanderthal extinction. It is known that isolation was not beneficial for the development of the species. It is not clear how local this population was, what were the roots of its material culture (the authors of the study called it Post-Neronian II).
The closest genetically to “Torin” is a Neanderthal from Gibraltar. Whether they are a single branch or not is questionable. “This means that there was a hitherto unknown Mediterranean Neanderthal population living in the area from the western tip of Europe to the Rhone Valley in France,” Slymak said.
Coincidentally, the researchers made another discovery: in addition to “Torin,” they also discovered another Neanderthal lineage originating from Le Cote in southwestern France. This means that Europe was home to at least two, perhaps even three, populations of the last Neanderthals.
Source: Port Altele
