Continued study of an approximately 40,000 year old finger bone from Siberia has identified a previously unknown type of human — one that may have interbred with the ancestors of modern-day Melanesian people.
The fossil scrap — just the tip of a juvenile female’s finger — was discovered in 2008 during excavations of Denisova cave in Siberia’s Altai Mountains. Anatomically, it looks like it could have belonged to a Neanderthal or a modern human.
But, in an initial announcement published in April in Nature, a team of scientists led by geneticist Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology concluded the bone belonged to a distinct population of humans that last shared a common ancestor with Neanderthals and our species about a million years ago.
The new study, published by Pääbo and colleagues Dec. 22 in Nature, provides further evidence that Denisova cave was home to unique humans. The researchers analyzed genetic sequences recovered from the nuclei of cells, which offer better resolution of relationships than the mitochondrial samples used in the previous research
. The Denisova DNA sequences were closest to the Neanderthals, indicating they shared a more recent common ancestor with Neanderthals than with us.