Just an interesting article. A couple of excerpts below …
Researchers already knew that living people from a vast area spanning the Philippines and New Guinea to China and Tibet have inherited 3% to 5% of their DNA from Denisovans. The leading scenario had suggested that as modern humans swept out of Africa, they first encountered Neanderthals and mated with them; hence, all people in Europe and Asia now have 1% to 3% of their DNA from Neanderthals. The ancestors of Asians then encountered Denisovans 50,000 years ago or so and acquired 3% to 5% of their DNA from them.
“Papuans carry DNA from at least two [other] Denisovan populations, called D1 and D2,” Cox said in his talk, which was filmed in advance and played at the meeting. When the team members analyzed the DNA with three statistical methods, they found that the two additional sources of Denisovan DNA came from populations so distantly related that they had diverged more than 283,000 years ago. And the D2 population is most distant from the Siberian Denisovans, splitting off roughly 363,000 years ago. That makes those two populations almost as distantly related to each other as they are to Neanderthals, Cox says. “We used to think of Denisovans as a single group,” notes Cox, who suggests as an aside that the D2 group might even need a new name.
The D1 DNA isn’t found in people outside New Guinea, and it’s found on large chunks of chromosome that haven’t been mixed over time, suggesting it entered the modern human genome from 15,000 to 30,000 years ago.