Tooth found in Laos sheds light on Denisovan’s enigmatic group of extinct humans

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A young girl’s tooth excavated from a cave wall in northeastern Laos provides new insight into the mysterious extinct human species called Denisovans and reveals their ingenuity in adapting to both tropical and cold climates.

The tooth is one of the few physical remains known from Denisovans, a sister lineage of Neanderthals known until now only from neglected tooth and bone fossils from a single location in Siberia and one in the Himalayas.

The molar, between 164,000 and 131,000 years old, belonged to a girl about 4 to 6 years old and had not yet erupted.

Due to the humid Laotian conditions, ancient DNA was not preserved in the molar, unlike other remains from Denisovan. The researchers determined it was Denisovan based on its shape — short and heavily wrinkled — and enamel features. Ancient proteins indicated that the molar came from a girl.

It was excavated in a limestone cave called Tam Ngu Hao 2, known to the locals as Cobra Cave, in the Annamite Mountains.

“This is the first time a Denisovan has been found in a warm region,” said paleoanthropologist Fabrice Demeter of the Lundbeck Foundation GeoGenetics Center at the University of Copenhagen, lead author of the study published last week in the journal Nature Communications.

“It means they adapted to opposite environments, from cold and high altitude to warm and low-lying areas. In this respect they were like us, modern humans,” Demeter said.

The existence of Denisovans was unknown until in 2010 the tip of a finger bone about 40,000 years old was found in a cave in the Altai Mountains of Siberia. Three molars were also found at that location. A partial Denisovan jawbone from about 160,000 years ago was later discovered in a Tibetan cave.

“We would like to know a lot more about Denisovans. But I think it’s important to know that just as the Neanderthals were known from Western Europe and the Near East, the Denisovans were a similar and closely related species found across much of Asia,” the paleoanthropologist of the University of Illinois and fellow student. author Laura Shackelford said.

The Laotian Cave is about 2400 miles from the Siberian Cave.

“Unfortunately, we know very little about what they looked like because so few fossils are available,” Shackelford said.

Neanderthals had strong double-curved browbones, relatively large noses and relatively large front teeth.

Genome studies have shown that our species, Homo sapiens, crossed with Denisovans only 30,000 years ago. As a result, some modern humans share about 5 percent of their DNA with Denisovans, including native populations in Papua New Guinea, Australia and the Philippines, with smaller DNA percentages among the broader Southeast Asian populations.

“This Discovery” [of the molar] is particularly important because it is the first direct evidence of the presence of Denisovans in Southeast Asia,” said Eske Willerslev, director of the Lundbeck Foundation GeoGenetics Center and co-author of the study.

A common ancestor of Denisovans, Neanderthals and Homo sapiens is said to have lived in Africa 700,000 to 500,000 years ago, with a branch that led to Denisovans and Neanderthals splitting off 470,000 to 380,000 years ago. Homo sapiens originated in Africa about 300,000 years ago and then spread around the world.

By 200,000 years ago, four different archaic human species inhabited Asia, including the Denisovans, Homo erectus, and small islanders called Homo floresiensis and Homo luzonensis† Our species then joined the fray.

Scientists have been searching for prehistoric human remains in northeastern Laos for decades. The cave with the tooth was located near another where 70,000-year-old Homo sapiens remains were found.

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