Scientific evidence does not support the widely held belief that Neanderthals were dim-witted and that inferior intelligence led to their extinction as the smarter ancestors of modern humans survived, according to a new study published Wednesday in the scientific journal PLOS ONE.
Instead, there is evidence that Neanderthals worked together to hunt and may have participated in cultural rituals, becoming extinct as the result of a gene that made them less fertile than human ancestors.
“The evidence for cognitive inferiority is simply not there,” said Paola Villa, who is one of the authors of the report and a curator at the University of Colorado Museum of Natural History. “What we are saying is that the conventional view of Neanderthals is not true.”
Neanderthals thrived across Europe and Asia between 350,000 and 400,000 years ago, and disappeared after Homo sapiens — or anatomically modern humans — crossed into Europe from Africa.
The Neanderthals’ extinction, like those of other archaic populations, is routinely explained by the supposed intellectual superiority of modern humans. Past theories have suggested that Neanderthals did not have the skills that our ancestors had — the ability to hunt, communicate, innovate and adapt to different environments.
Other explanations have posited that Neanderthals did not use complex, symbolic communication, that they were less efficient hunters with inferior weapons, and that they had a narrow diet, putting them at a disadvantage.
But in the new report, scientists at the University of Colorado Boulder say the available evidence does not suggest that Neanderthals were any less advanced than anatomically modern humans. Some evidence even counters such hypotheses.
Evidence from several European archaeological sites shows that Neanderthals used the landscape to their advantage, the report said. It said they likely led groups of bison, mammoths and woolly rhinoceroses to their deaths by steering them into sinkholes and ravines. Researchers said this implies that Neanderthals could plan ahead and communicate as a group.
Archaeological evidence also shows that the Neanderthal diet may have been much more diverse than previously thought — including wild peas, acorns, pistachios, grass seeds, wild olives, pine nuts and dates.
Ocher, a red-colored pigment used for painting, was found along with ornaments at sites inhabited by Neanderthals, suggesting they had culture, rituals and symbolic communication, the study said. Archaeological evidence from a Neanderthal burial ground in France implied that they cared for their elders and buried their dead.
Instead of anatomically modern humans wiping out Neanderthals based on differences in intelligence, the report said it is more likely that the two groups interbred. Genomic studies have shown that the male offspring from that interbreeding had reduced fertility, and researchers say that factor — combined with Neanderthals' apparent tendency to live in relatively small groups — could have led to their decline.
Further bolstering the interbreeding theory, studies released in January confirmed that traces of Neanderthal DNA affect the skin and hair of modern humans. The research confirmed that the DNA was not found in genes that influence testicles or the X chromosome, which implies that when the two groups interbred, Neanderthal DNA may have reduced male fertility in early humans. In that way, evolution would have wiped out Neanderthals by negatively affecting chances of producing offspring.
“Researchers were comparing Neanderthals not to their contemporaries on other continents but to their successors,” Villa said. “It would be like comparing the performance of Model T Fords, widely used in America and Europe in the early part of the last century, to the performance of a modern-day Ferrari and [concluding] that Henry Ford was cognitively inferior to Enzo Ferrari.”