A WORLD THAT WAS A LOT LIKE MIDDLE EARTH: In a Tooth, DNA From Some Very Old Cousins, the Denisovans. “Some of the DNA in the Denisova 8 tooth hints at an even older interbreeding. While most of the genetic material in the tooth bears a close kinship with Neanderthals, some of it seems only distantly related to Neanderthal or human DNA. One possible explanation, Dr. Paabo said in an interview, is that Denisovans interbred with another hominin species that lived somewhere in Asia. It is conceivable that this hominin was a species already known from fossil discoveries, such as Homo erectus. But it could also be a distantly related species whose bones have never been found.”