160,000 year-old remains of human relative found in Tibet

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This combination of images provided by the Max Planck Institute for Evolutionary Anthropology, Leipzig shows two views of a virtual reconstruction of the Xiahe mandible. (Jean-Jacques Hublin, MPI-EVA, Leipzig)
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A handout photo made available by the Max Planck Institute for Evolutionary Anthropology on April 29, 2019 shows the Xiahe mandible, only represented by its right half, was found in 1980 in Baishiya Karst Cave. (AFP)
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This undated photo made available by Dr. Dongju Zhang of Lanzhou University in April 2019 shows Jiangla Valley in the Gansu province of China. (AP)
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This undated photo made available by Dr. Dongju Zhang of Lanzhou University in April 2019 shows the Baishiya Karst Cave above the Jiangla riverbed in the Gansu province of China. (AP)
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The opening of the Baishiya Karst cave, where a fossil jawbone of an extinct member of the human family tree called a Denisovan was discovered, in Xiahe County, Gansu Province, China, is seen in this picture released from Lanzhou University on May 1, 2019. (REUTERS)
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A handout photo made available by the Max Planck Institute for Evolutionary Anthropology on May 1, 2019 shows a view of the virtual reconstruction of the Xiahe mandible after digital removal of the adhering carbonate crust, which was found in 1980 in Baishiya Karst Cave. (AFP)
Updated 02 May 2019
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160,000 year-old remains of human relative found in Tibet

  • The right half of a jawbone with teeth is at least 160,000 years old, scientists reported Wednesday in the journal Nature

NEW YORK: Nearly 40 years after it was found by a monk in a Chinese cave, a fossilized chunk of jawbone has been revealed as coming from a mysterious relative of the Neanderthals.
Until now, the only known remains of these Denisovans were a few scraps of bone and teeth recovered in a Siberian cave. DNA from those Siberian fossils showed kinship with Neanderthals. But the remains disclosed little else.
The new discovery was made roughly 1,400 miles (2,300 kilometers) to the southeast in Gansu province of China. The right half of a jawbone with teeth is at least 160,000 years old, scientists reported Wednesday in the journal Nature. No DNA could be found, but scientists recovered protein fragments that they compared to the Siberian DNA. That showed the fossil came from a Denisovan.
The find addresses several mysteries. One was why the Siberian DNA indicated Denisovans were adapted to living at high altitudes when the Siberian cave is relatively close to sea level. The Chinese cave, by contrast, is on the high-altitude Tibetan Plateau, about 10,800 feet (3,280 meters) high.
“Now we have an explanation,” said Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, one of the paper’s authors.
In fact, “it’s a big surprise” that any human relative could live in the cold climate and thin air of the plateau at that time, more than 100,000 years before our own species showed up there, he told reporters.
Previous research had indicated that Denisovans must have lived somewhere other than Siberia, because traces of their DNA can be found in several present-day populations of Asia and Australia whose ancestors probably didn’t pass through that region. The new finding expands their known range, although Hublin said it’s still not clear where Denisovans first appeared. They are named for Siberia’s Denisova cave, where the remains were found.
The new work was a long time in coming. The monk who found the fossil in 1980 gave it to a Buddhist leader, who passed it along to Lanzhou University in China. Study of it began in 2010.
The discovery also provides new anatomical details that can be compared to other fossils from China, some of which are “good candidates for being Chinese Denisovans,” Hublin said.
Experts unconnected to the research agreed the fossil could help identify other remains as Denisovan.
“We always assumed ... that Denisovans were distributed all across Asia,” said Bence Viola of the University of Toronto.
The Nature paper points out similarities to a fossil jaw reported in 2015 that had been dredged by a fishing net off the coast of Taiwan. So maybe the Denisovan range can be extended that far south, he said.
Such linking of fossils might eventually reveal Denisovan body shape and size, he said. From the scant known remains “I assume they were large guys, but it’s kind of hard to prove,” Viola said.
In addition to the anatomy, the study’s approach of using protein from the bone or teeth could also be used on fossils to look for evidence of Denisovan identity, said Eric Delson of Lehman College in New York. Even if a fossil is found not to be Denisovan, the analysis could reveal details of how it fits on the evolutionary tree, he said.
“The method potentially tells us a whole new way of looking at fossils,” he said.
Katerina Harvati of the University of Tuebingen in Germany said the ability of Denisovans to adapt to the inhospitable climate of the Tibetan Plateau is remarkable. It adds to growing evidence that our ancient relatives were more capable than scientists had thought, she said.


Man’s best friend: The dogs who sniff out explosives in Kabul

In this photo taken on April 7, 2019, Afghan dog handlers walk along with explosive detection dogs on leash during a practice session at the Mine Detection Centre (MDC) in Kabul. (AFP)
Updated 16 July 2019
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Man’s best friend: The dogs who sniff out explosives in Kabul

  • The canines’ initial mission was to hunt for land mines, a vital task in a country left strewn with the devastating weapons during the war with the Soviet Union in the 1980s

KABUL: Naya, a three-year-old Belgian Malinois, focuses intently as she leaps over hurdles and zooms through tunnels on an obstacle course at a training center on a hill overlooking Kabul.
She seems to be having fun, but is in fact being trained for a life-or-death mission: finding explosives in a country where hidden mines, bombs and weapons routinely kill.
Naya is one of about 200 dogs at the Afghan capital’s Mine Detection Center (MDC), a non-governmental group raising the animals from rambunctious pups into a disciplined force, and teaching handlers how to work with the canines.
A common sight around the Afghan capital, explosives-sniffing dogs are deployed at checkpoints and government facilities, where they are an important tool in combatting the flow of homemade bombs being smuggled into Kabul.
“The dogs are very useful — they are very fast, they do their jobs with great speed,” Taj Mohammad, a long-time trainer at the center, told AFP on a recent visit.
Handlers demonstrated how they train dogs to hone in on particular scents — explosives mainly, but also narcotics — by using a special carousel of identical metal cannisters that conceal different smells.
Each time a dog correctly identifies a target smell, the handler gives it a rubber chewy ball to chomp on as a reward.
“The relationship with the handler must be perfect. If it does not work, there will be casualties,” Mohammad said.
It takes about two years to train an explosives dog, and the process is intense for both the handler and the canine. The animals at the MDC are all German Shepherds or Belgian Malinois.
“It’s as if you are building a house or bringing up a child,” Mohammad said.
Handlers get about $500 a month for their dangerous work — not a bad wage in Afghanistan — as well as life insurance and retirement benefits.
Explosives are “a hidden enemy, so all the time I have a little fear in my heart,” dog handler Zabihullah Amin said.

After the MDC was established in 1989, the dogs mainly came from the Netherlands, but now most are local after breeding started here in 1994. More than 1,100 dogs have completed the training.
The canines’ initial mission was to hunt for land mines, a vital task in a country left strewn with the devastating weapons during the war with the Soviet Union in the 1980s.
But the dogs’ use tapered off in recent years following a series of incidents where they missed explosives, sometimes causing casualties as people returned to areas thought to be cleared.
According to Abdul Qudos Ziaee, head of operations at Afghanistan’s Directorate of Mine Action Coordination, dogs can be a useful mine-detection tool if properly managed.
But in several areas contaminated with anti-vehicle mines, some agencies failed to use the canines correctly or handlers were improperly trained, leading to sloppy practice and areas of terrain left dangerous.
“Whether it was fault of the dog handler or the dog was not properly trained ... the mine will be missed and the negative consequence will be borne by civilians,” Qudos Ziaee told AFP.
Dogs can still be used to sweep large areas deemed “low threat,” he said, noting that procedures are currently being revised and new standards will be introduced in about a year.
At the MDC, handlers insist dogs are a better tool for finding mines than mechanical detectors, as they can sniff the explosives in non-metallic devices.
According to Ziaee, at least 1,432 people were killed or wounded in Afghanistan by mines and so-called explosive remnants of war in 2018.
Mohammad Wirwais, who works at the Mine Detection Center, was blinded by a mine while clearing terrain in 2008.
“I am fortunate and lucky, I have friends ... who lost their lives to mine explosions,” he said.
“I am good, thank God, I can solve my problems on my own, and I can work here too.”