According to new research, we didn't drive Neanderthals to extinction by fighting or even outcompeting for resources. Instead, we mated until their unique lineage fizzled out and assimilated into the Homo sapien gene pool – bringing a whole new meaning to the phrase "make love, not war".
The prevailing theory is that Neanderthals diverged from a common ancestor some 500,000 or more years ago. While our ancestors were evolving in Africa, the Neanderthals spread across the Eurasian continent, making their home from Wales in the west to Siberia in the east and surviving on their own until modern humans came along approximately 60,000 years ago. We know that the two species met and that they mated, and that after thousands of years of co-existing the Neanderthals appear to have vanished.
Now, researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have completed a genetic analysis of the fossilized remains of Neanderthals, early humans, and modern humans. The results suggest the Neanderthals lost their identity as their genes became more and more diluted – an argument supported by the presence of Neanderthal DNA in people alive today.
"It means they were incorporated, which is why we see so many of their genes living on in modern Europeans," Svante Paabo, a professor of evolutionary genetics at the Max Planck Institute for Evolutionary Anthropology, told The Times.
It was Paabo's team who, in 2010, found that 2 to 3 percent of the DNA in modern Europeans came from Neanderthals. It sounds like a tiny amount and it is because of this that scientists initially thought interbreeding between the two species was a very rare occurrence. However, new evidence reveals that many more Neanderthal genes survived than we originally thought. In fact, as much as half of their genome can be found in people today.
“If we look at a few thousand genomes we can pick out 15,000 Neanderthal genes – so at least half their genome is walking around in people today,” Paabo added.
You can blame our Neanderthal ancestors and their genes (at least in part) for seasonal allergies, depression. obesity, HPV, and your smoking habit. But it's not all bad. Neanderthal genes are also (again, in part) responsible for different skin and hair tones (plus freckling) and protection against certain pathogens – traits that helped our ancestors to (relatively) quickly adapt to conditions outside of Africa.
This is not the first time scientists have pinned the Neanderthal's downfall on their dalliances with Homo sapiens, nor does it completely contradict other hypotheses contemplating the cause of their demise, whether that is climate change, disease, or modern humans' cultural and intellectual superiority. Though new research shows Neanderthals were probably not the inferior beings of popular imagination.
Maybe it was an amalgamation of all these factors – or maybe they were doomed all along.
[H/T: The Times]