Human diseases from Africa could have wiped out Neanderthals
DNA opens up new theory as to how disease spread from Africa to Europe and from Homo sapiens to Neanderthals.
Their ‘patients’ died about 50,000 years ago, but scientists from the University of Cambridge and Oxford Brookes University are discovering which diseases plagued Neanderthals during their lifetime. In a new study, the researchers used DNA to find out how diseases spread from Africa to Europe during the Stone Age and between Homo sapiens and Neanderthals.
What did they discover?
Researchers first analysed the genes of pathogens found in fossils, and then searched for traces of diseases in the DNA of Neanderthal and Homo sapiens remains.
They found that early humans originating from Africa carried genital herpes, tuberculosis, tapeworm and bacteria (like Helicobacter pylori, which causes stomach ulcers) with them when they moved to Europe and Asia.
It is likely that those diseases infected Neanderthals who lived in Europe when the two species came into contact and could have contributed to their extinction about 40,000 years ago.
“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,” explains Charlotte Houldcroft from the Division of Biological Anthropology at the University of Cambridge.
"However, it is unlikely to have been similar to Columbus bringing disease into America and decimating native populations. It's more likely that small bands of Neanderthals each had their own infection disasters, weakening the group and tipping the balance against survival."
Reversing scientific beliefs
It was long believed that many diseases spread from animals to humans in a process called zoonoses, when humans began to live from agriculture and were in closer contact with animals.
But the new study suggests that it happened the other way round: humans first transferred viruses and bacteria onto their animals, where the pathogens found the perfect living conditions to survive and then just jumped back into humans.
Who knows, with all the mysteries of our prehistoric ancestors being solved with DNA maybe we could be watching CSI: Stone Age on TV soon…