European Neanderthals had their fate sealed once they went to bed with humans emigrating from Africa, with STDs parts of the suite of diseases that downed the species, according to new research.
Tapeworm, tuberculosis, stomach ulcers and types of herpes were the arsenal humans from Africa had, and European Neanderthals were the victims.
That’s according to researchers from Cambridge and Oxford Brookes, who suggest that interbreeding between humans and Neanderthals put in place an irreversible debilitating demise for the European hosts.
A reservoir of disease
Wonderfully calling humans who migrated out of Africa “a significant reservoir of tropical diseases”, Dr Charlotte Houldcroft, from Cambridge’s Division of Biological Anthropology, said that the chronic diseases listed above would have weakened hunter-gatherer Neanderthals, catalysing their extinction.
“For the Neanderthal population of Eurasia, adapted to that geographical infectious disease environment, exposure to new pathogens carried out of Africa may have been catastrophic,” she said.
This immediately screams ‘Columbus’, but the quick demise of Native Americans upon the introduction of European diseases ferried over with the 15th and 16th-century explorers was unlikely to have been a similar scenario.
“It’s more likely that small bands of Neanderthals each had their own infection disasters, weakening the group and tipping the balance against survival,” said Houldcroft.
A beastly thought
Houldcroft’s work, published in the American Journal of Physical Anthropology, overhauls previous understanding of infectious disease, which had always pointed to the agricultural age 8,000 years ago as a genesis point.
But rather than humans coexisting with livestock in dense environments, Houldcroft and her fellow researchers said the latest evidence suggests disease had a much longer “burn-in period”, dating far further back.
In fact, they claim that tuberculosis, originally thought to have come from animals to humans, was actually the other way around. “We are beginning to see evidence that environmental bacteria were the likely ancestors of many pathogens that caused disease during the advent of agriculture, and that they initially passed from humans into their animals,” said Houldcroft.
The evidence Houldcraft and her colleague Dr Simon Underdown rely on is circumstantial, using timelines and geography as guides.
*Update: This headline of this article was amended 11 April at 11.45
Neanderthal image via Shutterstock