The Neanderthals may have died out because they were not adventurous enough and had a poor social network, according to a new study that challenges traditional theories of climate change or violence from our ancestors.
The Isolated Neanderthals
Published yesterday in the journal Cell Genomics, the study focused on a Neanderthal whose remains were found in France’s Rhone Valley. The Homme de Spy ‘Thorin’ belonged to a small, isolated and previously unknown contemporary Neanderthal group that derived from some of the first Neanderthals spread across Europe.
Researchers think that Thorin’s lineage broke with other late Neanderthals long before they ever mixed because, although they were only a two-week walk away from their ‘classic’ European cousins, the lineage spent almost 50,000 years without any genetic exchange. Homo sapiens, on the other hand, have dispersed across most of the planet, with far larger social networks than their currently existing hominids.
The Dangers of Inbreeding
The researchers argue that the Neanderthals of Europe were socially insular, living in small groups and staying close to home, so there were probably few other partners available outside their own family. Such mating between close kin can ultimately decrease genetic variation and be harmful for the species.
Tharsika Vimala, a co-author of the study and population geneticist at the University of Copenhagen says that this depletion in genetic diversity may have left Neanderthals more susceptible to new environments or pathogens. This, of course, put them at a disadvantage on the social adaptation front—because here they were not communally learning and evolving as a population.
Conclusion
So this study gives an astonishing new look at what might have been the fall of the Neanderthals. The researchers proposed that their timidity and tendency to stick together might have made them easier targets for extinction — an assertion that runs counter to conventional narratives of how Homo sapiens snuffed out the competition, through climate change or a more direct brand of violence. These findings bring to light questions regarding the role of social versus genetic diversity in human survival, and underscore the importance of more fine-grained investigation into this murky period of our collective evolutionary past.
