A sliver of bone from a cave in Russia is at the centre of what may be the biggest archaeological story of the year.
By Michael Marshall, New Scientist
A sliver of bone from a cave in Russia is at the centre of what may be the biggest archaeological story of the year. The bone belonged to an ancient human who had a Neanderthal mother and a Denisovan father. “Denny” is the only first-generation hybrid hominin ever found.
“My first reaction was disbelief,” says Viviane Slon of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
The find is either a stunning stroke of luck or a hint that hominins interbred more often than we thought. It may even suggest that extinct groups like Neanderthals did not die out, but were absorbed by our species.
In prehistory, members of our species interbred with at least two other ancient humans: the Neanderthals and the mysterious Denisovans, who are known only from fragments of bone and teeth discovered in Denisova cave, Russia. Neanderthals and Denisovans interbred too, and Denisovans carried genes from unidentified hominins.
These interbreeding events were thought to be rare. “The likelihood of actually finding a [first-generation] hybrid has always been considered infinitesimally low,” says Katerina Harvati-Papatheodorou at the University of Tübingen, Germany.
A sliver of bone
A few years ago, archaeologists found a 90,000-year-old bone fragment in Denisova cave. Samantha Brown, then at the University of Oxford, discovered that it came from a hominin by examining the proteins preserved inside it. Her team nicknamed the hominin “Denny”. Based on the structure of the bone, Denny died at about 13 years of age.
Slon and her colleagues have now examined Denny’s DNA, discovering that Denny was female – and that she had astonishing parentage. Her DNA was almost 50:50 Neanderthal and Denisovan, arranged in a tell‑tale way. Our DNA comes in paired strands called chromosomes, one from each parent. In Denny’s case, each pair had one Neanderthal and one Denisovan chromosome, with very little mixing. She was the daughter of parents from different species.
Denny’s mitochondrial DNA, which is inherited only from mothers, is Neanderthal. Therefore, her mother was Neanderthal and her father Denisovan.
Experts contacted by New Scientist all accept the finding. “They nail it,” says Pontus Skoglund of the Francis Crick Institute in London, UK. “There seems to be no uncertainty at all.”
Denny is an enigma, says Harvati-Papatheodorou. “Since her known remains consist of an unidentifiable bone fragment, it is very difficult to say anything about her daily life, activities, health or subsistence.”