(p. A17) A tooth fossil discovered in a Siberian cave has yielded DNA from a vanished branch of the human tree, mysterious cousins called the Denisovans, scientists said Monday [November 16, 2015].
Their analysis pushes back the oldest known evidence for Denisovans by 60,000 years, suggesting that the species was able to thrive in harsh climates for thousands of generations. The results also suggest that the Denisovans may have bred with other ancient hominins, relatives of modern humans whom science has yet to discover.
Todd Disotell, a molecular anthropologist at New York University who was not involved in the new study, said the report added to growing evidence that our species kept company with many near relatives over the past million years.
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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 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 related species.
“If you would have told me five years ago I would be talking about species we don’t have any fossils for, I would have thought you were crazy,” Dr. Disotell said.
For the full story, see:
CARL ZIMMER. “Tooth in Cave Adds Earlier Evidence of Some Very Old Cousins, the Denisovans.” The New York Times (Tues., NOV. 17, 2015): A6.
(Note: ellipsis, and bracketed date, added.)
(Note: the online version of the story has the date NOV. 16, 2015, and has the title “In a Tooth, DNA From Some Very Old Cousins, the Denisovans.”)