Human immigration may have doomed Neanderthals,
NEW YORK—What killed off the Neanderthals? It’s a big debate, and now a study says that no matter what the answer, they were doomed anyway.
Our close evolutionary cousins enjoyed a long run in Europe and Asia, but they disappeared about 40,000 years ago after modern humans showed up from Africa.
The search for an explanation has produced many theories including climate change, epidemics, or inability to compete with the modern humans, who may have had some mental or cultural edge.
The new study isn’t intended to argue against those factors, but just to show that they’re not needed to explain the extinction, says Oren Kolodny of Stanford University.
He and colleague Marcus Feldman present their approach in a paper released recently by the journal Nature Communications.
They based their conclusion on a computer simulation that represented small bands of Neanderthals and modern humans in Europe and Asia. These local populations were randomly chosen to go extinct, and then be replaced by another randomly chosen population, with no regard for whether it represented the same species.
Neither species was assumed to have any inherent advantage, but there was one crucial difference: Unlike the Neanderthals, the modern humans were supplemented by reinforcements coming in from Africa. It wasn’t a huge wave, but rather “a tiny, tiny trickle of small bands,” Kolodny said.
Still, that was enough to tip the balance against the Neanderthals. They generally went extinct when the simulation was run more than a million times under a variety of assumptions.
If survival was a game of chance, “it was rigged by the fact that there’s recurring migration,” Kolodny said. “The game was doomed to end with the Neanderthals losing.”
Katerina Harvati of the University of Tuebingen in Germany said the new work doesn’t address the question of why modern humans dispersed from Africa into Europe and Asia.