(p. A14) Scientists have reconstructed the genome of a man who lived 45,000 years ago, by far the oldest genetic record ever obtained from modern humans. The research, published on Wednesday [October 22, 2014] in the journal Nature, provided new clues to the expansion of modern humans from Africa about 60,000 years ago, when they moved into Europe and Asia.
And the genome, extracted from a fossil thighbone found in Siberia, added strong support to a provocative hypothesis: Early humans interbred with Neanderthals.
“It’s irreplaceable evidence of what once existed that we can’t reconstruct from what people are now,” said John Hawks, a paleoanthropologist at the University of Wisconsin who was not involved in the study. “It speaks to us with information about a time that’s lost to us.”
. . .
By comparing the Ust’-Ishim man’s long stretches of Neanderthal DNA with shorter stretches in living humans, Dr. Paabo and his colleagues estimated the rate at which they had fragmented. They used that information to determine how long ago Neanderthals and humans interbred.
Previous studies, based only on living humans, had yielded an estimate of 37,000 to 86,000 years. Dr. Paabo and his colleagues have now narrowed down that estimate drastically: Humans and Neanderthals interbred 50,000 to 60,000 years ago, according to the new data.
For the full story, see:
Carl Zimmer. “Man’s Genome From 45,000 Years Ago Is Reconstructed.” The New York Times (Thurs., OCT. 23, 2014): A14.
(Note: ellipsis, and bracketed date, added.)
(Note: the online version of the story has the date OCT. 22, 2014.)