A fossilised finger found in a Siberian cave contains mitochondrial DNA that may come from a previously unknown human ancestor.
Research published online today describes mapping the DNA from what appears to be a youngsters little finger. Either that or the middle finger of a Hobbit. The digit was found in 2008 in Denisova Cave in the Altai Mountains of southern Siberia.
The sample was compared to the DNA of 54 modern humans and six Neanderthals - none matched. The boffins think the Siberian shared a common ancestor with modern humans - and Neanderthals - until about a million years ago.
The research, published by the journal Nature, was reported by Johannes Krause and Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, amongst others.
"We are not saying this is a new species," Paabo said, although they certainly think it is.
It is not unlikely that other species of Homo have lived around or alongside homo sapiens sapiens over the past million years or so. The last known example is the neanderthals who disappeared from the record around 40,000 years ago.
Whether we killed the other species or they faded out is a matter of conjecture. Since the past 2000 years show that we're quite happy to kill each other, chances are we'd have had no compunction about annihilating any competitors.