Jawbone from Tibet identified as Denisovan

Denisovans are an extinct human group similar to Neanderthals. Traces of both can be found in modern human genes, so interbreeding took place.

ABC (2016): Aboriginal Australians, Pacific Islanders carry DNA of unknown human species, research analysis suggests

They found Europeans and Chinese people carry about 2.8 per cent of Neanderthal DNA.

But Europeans have no Denisovan ancestry, and Chinese people only have 0.1 per cent.

Modern populations from South Pacific regions including Vanuatu, the Solomon Islands, Fiji, Papua New Guinea, New Caledonia, West Papua, and the Maluku Islands have 2.74 per cent of their DNA as coming from Neanderthals.

Mr Bohlender estimates the amount of Denisovan DNA in these people is as low as about 1.11 per cent, not the 3 to 6 per cent estimated by other researchers.

Therefore, Mr Bohlender and his colleagues came to the conclusion that a third group of hominids may have bred with the ancestors of Melanesians.

“The sequencing of complete Neanderthal and Denisovan genomes has provided several insights into human history. One important insight stems from the observation that modern non-Africans and archaic populations share more derived alleles than they should if there was no admixture between them. We now know that the ancestors of modern non-Africans met, and introgressed with, Neanderthals and Denisovans.”

Until recently the only identified Denisovan remains had been found in Siberia.

The Denisovans or Denisova hominins are an extinct species or subspecies of archaic humans in the genus Homo. Pending its taxonomic status, it currently carries temporary species or subspecies names Homo denisova,[1] Homo altaiensis, Homo sapiens denisova, or Homo sp. Altai. In 2010, scientists announced the discovery of an undated finger bone fragment of a juvenile female found in the Denisova Cave in the Altai Mountains in Siberia, a cave that has also been inhabited by Neanderthals and modern humans.

The lineage that developed into Denisovans and Neanderthals is estimated to have separated from the lineage that developed into “anatomically modern” Homo sapiens approximately 600,000 to 744,000 years ago. Denisovans and Neanderthals then significantly diverged from each other genetically a mere 300 generations after that. Several types of humans, including Denisovans, Neanderthals and related hybrids, may have each dwelt in the Denisova Cave in Siberia over thousands of years, but it is unclear whether they ever co-habitated in the cave. Denisovans may have interbred with modern humans in New Guinea as recently as 15,000 years ago.

https://en.wikipedia.org/wiki/Denisovan

Now what is believed to be a jawbone, found  found in a cave in Tibet in 1980, has been identified as Denisovan.

Stuff:  Ancient humans were more resourceful than we give them credit for

Scientists are being urged to step up the search for ancient human remains in Oceania and Asia, after researchers revealed a 160,000-year-old jawbone found in Tibet is from the archaic human Denisovan group.

Previously Denisovans – an extinct sister group of Neanderthals – were only known from a small collection of fossil fragments found in 2010 at Denisova Cave in Siberia.

Researchers have now identified the lower jawbone – found on the Tibetan Plateau in Baishiya Karst Cave in Xiahe, China in 1980 by a local monk – as being from a population closely related to the Siberian Denisovans.

“The Xiahe mandible likely represents the earliest hominin fossil on the Tibetan Plateau,” researcher Fahu Chen, director of the Institute of Tibetan Research, Chinese Academy of Sciences, said.

These people had already adapted to living in this high-altitude low-oxygen environment long before Homo sapiens even arrived in the region.”

Unless they find other remains that show otherwise.

Murray Cox, associate professor of computational biology at Massey University, said it used to be thought only modern humans could live on the Tibetan Plateau, and only from about 30,000 years ago.

“There’s a strong bias in much of our thinking – we tend to believe that only modern humans are clever enough to go to certain places or live in certain ways. It’s now clear we’ve overestimated our uniqueness. Archaic humans like Denisovans were much more resourceful and adaptable than we have given them credit for,” Cox said.

Perhaps most important was the finding that human remains misclassified in the 1980s were now being recognised as Denisovan

“This suggests that other Denisovan bones and remains are hiding in plain sight – sitting in museums and university collections around the world  – and we just need to put the correct label on them to get a better idea of what Denisovans looked like. This study is the first, probably of many, that I expect will find them,” Cox said.

Otago Palaeogenetics Laboratory director Nic Rawlence said Denisovans had left a genetic legacy within the genomes of east Asian, Aboriginal Australians and Melanesians through interbreeding.

“The genes that allow modern day Tibetans to survive at high altitudes can be traced back to interbreeding between Denisovans and the ancestors of Tibetans,” Rawlence, a senior lecturer in ancient DNA at the University of Otago, said.

“Until now this has always intrigued scientists as there was no evidence of Denisovans in central east Asia, and modern humans only arrived on the scene around 30,000-40,000 years ago.

“The 160,000-year-old Tibetan Denisovan goes someway to potentially explaining where and when this interbreeding occurred.” But the jury was still out on whether Denisovans were adapted to living at high altitudes. It may be that the genes involved were initially used for something else, then repurposed for surviving at high altitudes.

Research on this is obviously ongoing.

 

Neanderthal art pre-dates humans in Europe

Scientific analysis of cave paintings in Spain suggests that the artists must have been Neanderthals as they are dated prior to when ‘modern humans’ are thought to have arrived in Europe.

The researchers said their work suggested that Neanderthals were“cognitively indistinguishable” from early modern humans.

Reuters – Primitive art: Neanderthals were Europe’s first painters

A high-tech analysis of cave art at three Spanish sites, published on Thursday, dates the paintings to at least 64,800 years ago, or 20,000 years before modern humans arrived in Europe from Africa.

That makes the cave art much older than previously thought and provides the strongest evidence yet that Neanderthals had the cognitive capacity to understand symbolic representation, a central pillar of human culture.

“What we’ve got here is a smoking gun that really overturns the notion that Neanderthals were knuckle-dragging cavemen,” said Alistair Pike, professor of archaeological sciences at the University of Southampton, who co-led the study.

“Painting is something that has always been seen as a very human activity, so if Neanderthals are doing it they are being just like us,” he told Reuters.

While some archaeologists already viewed Neanderthals as more sophisticated than their commonplace caricature, the evidence until now has been inconclusive. With the data from the three Spanish cave sites described in the journal Science, Pike and colleagues believe they finally have rock-solid proof.

The early cave art at La Pasiega, Maltravieso and Ardales includes lines, dots, discs and hand stencils – and creating them would have involved specific skills, such as mixing pigments and selecting appropriate display locations.

Cave painting from Pasiega, Spain

My Neanderthal artist genes must not be dominant.

Scientists used a precise dating system based on the radioactive decay of uranium isotopes into thorium to assess the age of the paintings. This involved scraping a few milligrams of calcium carbonate deposit from the paintings for analysis.

A second related study published in Science Advances found that dyed and decorated marine shells from a different Spanish cave also dated back to pre-human times.

Joao Zilhao of the University of Barcelona said the new findings meant the search for the origins of human cognition needed to go back to the common ancestor of both Neanderthals and modern humans more than 500,000 years ago.

Neanderthals died out about 40,000 years ago, soon after direct ancestors arrived in Europe. It is unclear what killed them off, although theories include an inability to adapt to climate change and increased competition from modern humans.

According to the dates given here:

  • Paintings dated to at least 64,800 years ago
  • ‘Modern humans’ arrived in Europe about 20,000 years later ie about 45,000 years ago
  • Neanderthals ‘died out’ about 40,000 years ago

The genome connection between Neanderthals and modern humans was proved in 2013: The Mating Habits of Early Hominins

A high-quality genome sequence obtained from a female Neanderthal toe bone reveals that the individual’s parents were close relatives and that such inbreeding was prevalent among her recent ancestors, according to a paper published today (December 18) in Nature. But the sequence also reveals that interbreeding occurred between Neanderthals and other hominin groups, including early modern humans.

Despite the high degree of inbreeding that took place in the family of this particular Neanderthal—named the Altai Neanderthal—there was also evidence that Neanderthals in general interbred with other hominin groups. The team compared the genomes of the Altai Neanderthal, a Denisovan, a number of modern humans, and Neanderthals from Croatia and the Caucasus mountains, and confirmed earlier indications that modern humans contain both Neanderthal and Denisovan DNA.

They also showed that Denisovans contained both Neanderthal DNA sequences—most similar to that from the Altai Neanderthal—and sequences absent from Neanderthals and modern humans, which thus appear to have come from an unknown archaic hominin group.

This is very interesting, but there is something that puzzles me – humans are thought to have only arrived in Europe about 45,000 years ago, and interbred with Neanderthals, but:

In a 2011 genetic study by Ramussen et al., researchers took a DNA sample from an early 20th century lock of an Aboriginal person’s hair with low European admixture. They found that the ancestors of the Aboriginal population split off from the Eurasian population between 62,000 and 75,000 BP, whereas the European and Asian populations split only 25,000 to 38,000 years BP, indicating an extended period of Aboriginal genetic isolation.

The same genetic study of 2011 found evidence that Aboriginal peoples carry some of the genes associated with the Denisovan (a species of human related to but distinct from Neanderthals) peoples of Asia; the study suggests that there is an increase in allele sharing between the Denisovans and the Aboriginal Australians genome compared to other Eurasians and Africans.

The data suggest that modern and archaic humans interbred in Asia before the migration to Australia.

https://en.wikipedia.org/wiki/Aboriginal_Australians

Before humans moved into Europe and interbred with Neanderthals.

Dating Aborigine art is difficult but:

“We don’t have the [dated] art itself, but we’ve found the tools that were used to make the art. For that reason, we rightfully assume that Australia has pigment art going back to when people first came here which is close to 50,000 years ago.”

http://www.abc.net.au/science/articles/2014/10/09/4102916.htm

That is before modern humans are thought to have arrived in Europe, which is much closer to Africa than Australia.