Jawbone fossil belongs to a Denisovan

In 1980, a Buddhist monk in Tibet entered a sacred cave to pray. On the floor, he found half of a human jawbone, studded with two teeth.

A team of scientists reported Wednesday that the fossil belonged to a 160,000-year-old Denisovan, a member of a lineage of mysterious, Neanderthal-like humans that disappeared about 50,000 years ago.

The fossil is the first evidence of this species found outside the Denisova Cave in Siberia, buttressing the theory that these relatives of modern humans once lived across much of central and eastern Asia.

“I’m very excited — we have a Denisovan that’s somewhere else than Denisova,” said Bence Viola, a paleoanthropologist at the University of Toronto who was not involved in the new study. “We’d known about Denisovans for 10 years and hadn’t found them anywhere else.”

The new fossil demonstrates that Denisovans were remarkably hardy, able to endure harsh conditions on the Tibetan plateau, at an elevation of 10,700 feet, with only simple stone tools.

The find also suggests that these Denisovans may have evolved genetic adaptations to high altitudes and that living Tibetans may have inherited those genes thanks to interbreeding

between Denisovans and modern humans in prehistoric times.

In the 1970s, Russian researchers began excavating Denisova Cave in Siberia. Over the years, they found a wealth of bones. A few looked like they might have come from humans or an extinct human relative.

Hoping for clues, the archaeologists sent some of the bones to the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, whose experts excel at retrieving DNA from fossils. Some of the bones contained Neanderthal DNA, it turned out. But in 2010, Max Planck researchers discovered that one finger

bone held different genes from an unknown human lineage.

Over the past decade, scientists have discovered more Denisovan teeth and bone fragments, including a chunk of a skull. Denisovans appeared to have lived in the cave, off and on, from 287,000 years ago to about 50,000 years ago.

Judging from their DNA, Denisovans shared a common ancestor with Neanderthals about 400,000 years ago. They interbred with Neanderthals and with our own species. Today, people in East Asia, Australia, the Pacific islands and the Americas all carry some Denisovan DNA.

DONGJU ZHANG — LANZHOU UNIVERSITY VIA THE NEW YORK TIMES An ancient mandible, found in a cave in the Jiangla Valley of Tibet. Scientists reported that it is the first evidence found outside Siberia of the Denisovans, a Neanderthal-like human that disappeared about 50,000years ago.