“Denisovans could have interbred with the ancestors of modern humans.”
No the Denisovans did interbreed with modern humans, they were a subspecies, sort of like the Key Deer from Florida are just a small, garden variety version of the white-tailed deer.
Look up Melanesia + blue eyes. The blue eyes came from Denisovans. It’s kinda interesting the results, you’ll see blond haired people in Africa, blue eyed people in Africa, white kids with curly, African hair in the Pacific Islands.
Humans in general are not “racially pure”. That does not exist except in some ancient peoples of Africa.
Europeans for instance interbred with dark-skinned peoples who somehow endured the ice age. And they and Asians interbred with Neanderthals.
Ethiopians have a mix of African, European and Asian genes.
Source? A lot of assertions here.
The 'could' in that sentence refers to where the interbreeding might have taken place (at least some of it) not that the interbreeding itself is in question.
They are making an assumption that the cave was an attractive den of iniquity to them. Maybe they found a lava lamp in there too.
It was late and I was tired. Just look up Melanesia + Denisovan on a search engine. It will come up.