The proportion of Neanderthal-derived toll-like receptors in populations, with Neanderthal alleles in orange and green and non-archaic alleles in blue.DANNEMANN ET AL./AJHG Modern humans adopted innate immune genes responsible for recognizing invading microbes from Neanderthals and Denisovans, according to two studies published today (January 7) in The American Journal of Human Genetics. The two teams, based in France and Germany, independently concluded that humans picked up some versions of a cluster of toll-like receptors by interbreeding with archaic hominin relatives.
“Once humans came out of Africa and then encountered archaic species, they might also have encountered their pathogens,” said Rasmus Nielsen, an evolutionary biologist at the University of California, Berkeley, who was not involved in the studies. “There might have been pathogens that could affect Neanderthals and Denisovans that also could jump into modern humans.”
“At least partially, Neanderthals may have harbored already adaptive mutations, mutations that rendered them more resistant to infections,” said Lluis Quintana-Murci, an evolutionary geneticist at the Pasteur Institute in Paris and a coauthor of one of the new papers.
Previous studies have shown that modern humans interbred with Neanderthals and Denisovans. For instance, Nielsen and his colleagues showed that humans who migrated to Tibet likely picked up an allele controlling ...