Genetic analysis of a 90,000-year-old bone fragment found in a Siberian cave showed that it came from a female whose father was a Denisovan and whose mother was a Neanderthal.
The discovery of the first-known offspring of parents from two different hominin species took scientists by surprise. While evidence has been pointing to interbreeding among the ancestor species of modern humans, the direct link is being hailed as a significant finding.
Hominin refers to a taxonomic tribe of extinct members of human lineage, including Neanderthals and Denisovans. In 2010, researchers in the same Siberian cave where the hybrid bone was found discovered the first bones of a previously undiscovered species, named Denisovans, that was a distant cousin of Neanderthals and humans.
“The father, whose genome bears traces of Neanderthal ancestry, came from a population related to a later Denisovan found in the cave,” researchers said in a paper published in the journal Nature. “The mother came from a population more closely related to Neanderthals who lived later in Europe.”
The inbreeding of Neanderthals and Denisovans suggests migrations of Neanderthals between eastern and western Eurasia occurred sometime after 120,000 years ago.
“The cool thing about this is, this is extremely direct evidence,” said Svante Pääbo, a molecular geneticist who led the new research, told the Washington Post. “We’ve almost caught them in the act, so to speak.”
The discovery adds to a growing body of evidence that hybrids between different groups of hominins was more common around 100,000 years ago than previously thought.
“The finding of a first-generation Neanderthal–Denisovan offspring among the small number of archaic specimens sequenced to date suggests that mixing between Late Pleistocene hominin groups was common when they met,” the Nature paper said.