An amazing find was just published last week in Nature magazine. Based on the DNA in a small hominin bone from about 90,000 years ago, scientists at the Max Planck Institute for Evolutionary Anthropology were stunned to discover that it came from the teenage daughter of a Denisovan father and a Neanderthal mother. This is like finding the proverbial needle in a haystack. The researchers involved couldn’t believe it and had to check and recheck their results.
Here’s a summary of the findings:
Anthropological geneticists already knew that Denisovans and Neanderthals had interbred, despite being separate species (or sub-species, depending on which scientist you’re talking to). But this was the first time that a specific individual was discovered whose DNA was split 50-50 between the Neanderthal genome and Denisovan genome, and who must be, therefore, the direct offspring of that union. She is, in other words, a first-generation hybrid.
Neanderthals have been known for a century and a half, while the Denisovan species was discovered only 8 years ago. Neanderthal fossils have been found in numerous locations throughout Europe, the Levant, and Western Asia. Denisovan fossils have only been found in one location, the Denisova Cave in Siberia. Although the dating on these things is still very tricky, it can be said in a nutshell that our ancestors split from the ancestors of the Neanderthals & Denisovans approximately 600,000 years ago and that Neanderthals and Denisovans split from each other maybe 400,000 years ago. In other words, Neanderthals and Denisovans are more closely related to each other than either is to Homo sapiens.
The current state of DNA research suggests that all non-Africans today possess a small amount of Neanderthal genetic heritage (1-3%) based upon one or more interbreeding events – probably more than one. Denisovan DNA, on the other hand, has only been found in human populations in East Asia, South Asia, and Oceania. The Denisovan contribution, for example, to Aborigines in Australia and Papua New Guinea is substantial (4-6%). The number of Denisovan DNA samples available is still very small, however, so much of what we know may change as other samples are found and analyzed.
Here is a longer explanation of the discovery in Nature magazine: