'Red Deer Cave people' may be new species of human
The partial skulls and other bone fragments, which are from at least four individuals and are between 14,300 and 11,500 years old, have an extraordinary mix of primitive and modern anatomical features that stunned the researchers who found them.
Named the Red Deer Cave people, after their apparent penchant for home-cooked venison, they are the most recent human remains found anywhere in the world that do not closely resemble modern humans.
The individuals differ from modern humans in their jutting jaws, large molar teeth, prominent brows, thick skulls, flat faces and broad noses. Their brains were of average size by ice age standards.
"They could be a new evolutionary line or a previously unknown modern human population that arrived early from Africa and failed to contribute genetically to living east Asians," said Darren Curnoe, who led the research team at the University of New South Wales in Australia.
"While finely balanced, I think the evidence is slightly weighted towards the Red Deer Cave people representing a new evolutionary line. First, their skulls are anatomically unique. They look very different to all modern humans, whether alive today or in Africa 150,000 years ago," Curnoe told the Guardian.
"Second, the very fact they persisted until almost 11,000 years ago, when we know that very modern looking people lived at the same time immediately to the east and south, suggests they must have been isolated from them. We might infer from this isolation that they either didn't interbreed or did so in a limited way."
One partial skeleton, with much of the skull and teeth, and some rib and limb bones, was recovered from Longlin cave in Guangxi province. More than 30 bones, including at least three partial skulls, two lower jaws and some teeth, ribs and limb fragments, were unearthed at nearby Maludong, or Red Deer Cave, near the city of Mengzi in Yunnan province.
At Maludong, fossil hunters also found remnants of various mammals, all of them species still around today, except for giant red deer, the remains of which were found in abundance. "They clearly had a taste for venison, with evidence they cooked these large deer in the cave," Curnoe said.
The findings are reported in the journal PLoS ONE.
The stone age bones are particularly important because scientists have few human fossils from Asia that are well described and reliably dated, making the story of the peopling of Asia hopelessly vague. The latest findings point to a far more complex picture of human evolution than was previously thought.
"The discovery of the Red Deer Cave people shows just how complicated and interesting human evolutionary history was in Asia right at the end of the ice age. We had multiple populations living in the area, probably representing different evolutionary lines: the Red Deer Cave people on the East Asian continent, Homo floresiensis, or the 'Hobbit', on the island of Flores in Indonesia, and modern humans widely dispersed from northeast Asia to Australia. This paints an amazing picture of diversity, one we had no clue about until this last decade," Curnoe said.
Much of Asia was also occupied by Neanderthals and another group of archaic humans called the Denisovans. Scientists learned of the Denisovans after recovering a fossilised little finger from the Denisova cave in the Altai mountains of southern Siberia in 2010.
The fossils from Longlin cave were found in 1979 by a geologist prospecting in the area. At the time, researchers removed only the lower jaw and a few fragments of rib and limb bones from the cave wall. The rest of the skeleton was left encased in a block of rock, which sat in the basement of the Yunnan Institute of Cultural Relics and Archaeology in Kunming, Yunnan, for 30 years. The fossils were rediscovered in 2009 by Ji Xueping, a researcher at the institute, who teamed up with Curnoe to examine the remains.
"It was clear from what we could see that the remains were very primitive and likely to be scientifically important. We had a skilled technician remove the bones from the rock, and they were glued back together. Only then was it clear what we had found: a partial skeleton with a very unusual anatomy," Curnoe said.
The fossils at Maludong were found in 1989 but went unstudied until 2008.
Lumps of charcoal uncovered alongside the Longlin fossils were carbon dated to 11,500 years, a time when modern humans in southern China began to make pottery for food storage and to gather wild rice in some of the first steps towards full-scale farming.
Marta Mirazón Lahr, an evolutionary biologist at Cambridge University, is convinced the remains are from modern humans. The unusual features, she said, suggest the Red Deer Cave people are either "late descendants of an early population of modern humans in Asia" or a very small population that developed the traits through a process known as genetic drift.
Chris Stringer, head of human origins at the Natural History Museum, London, was similarly sceptical.
"The human remains from the Longlin Cave and Maludong are very important, particularly because we do not have much well-described and well-dated material from the late Pleistocene of China.
"The fossils are unlike recent populations of modern humans in several respects, and the mosaic of more archaic features could indicate the dispersal of a poorly known and more primitive form of modern human that left Africa before the main exodus at about 60,000 years. This dispersal could have reached as far as China, surviving there for many millennia, before disappearing in the last 12,000 years."
But he added: "There might be another possible explanation for the more archaic features. Could these alternatively be attributed to gene flow from a more archaic population that survived alongside modern humans? In the case of the Longlin Cave and Maludong fossils, the most likely candidate would be the enigmatic Denisovans who apparently interbred with the ancestors of modern Australasians somewhere in south east Asia. Could these Chinese fossils be further evidence of such hybridisation?"
Cave Fossil Find: New Human Species or "Nothing Extraordinary"?
Chinese fossils hint at "new evolutionary line"—depending who you ask.
The "mystery human fossils" might even represent an entirely new species that existed alongside our own as recently as 11,500 years ago, according to a team of Chinese and Australian researchers.
Or the fossils might represent an especially early migration of so-called modern humans out of Africa and into East Asia, the team suggests.
Or—as some critical scientists have said—the evidence may tell us something we already know: People come in all shapes and sizes.
(Related: "New Type of Ancient Human Found—Descendants Live Today?")
Primitive Humans Held On Past Heyday?
"We have discovered a new population of prehistoric humans whose skulls are an unusual mosaic of primitive features, like those seen in our ancestors hundreds of thousands of years ago," evolutionary biologist Darren Curnoe of the University of New South Wales, said via email.
"In short, they're anatomically unique among all members of the human evolutionary tree," added Curnoe, a co-author of the new study of the "Red Deer Cave people," published online today in the journal PLoS ONE.
The study was principally based on the remains of at least three individuals from Maludong (or Red Deer Cave) in Yunnan Province (map)—fossils that had been excavated in 1989 but hadn't been studied until now.
Among the human remains was an abundance of bones from an extinct species of giant deer—suggesting the cave people were hunters with a taste for venison.
Stone and antler tools were also found, some of which were likely used to prepare the deer for dinner, researchers say.
The team also analyzed a partial skeleton found in 1979 in neighboring Guangxi Province. That human specimen had been encased in stone until the study team removed and reconstructed it.
(Read "Malapa Fossils: Part Ape, Part Human" in National Geographic magazine.)
The Red Deer Cave Look
The Red Deer Cave dwellers' unusual features included a flat face, a broad nose, a jutting jaw that lacked a chin, large molar teeth, a rounded braincase with prominent brow ridges, and thick skull bones, the researchers say.
Their brains were "moderate in size," Curnoe added.
Despite this seemingly primitive human design, radiocarbon dating of charcoal from the fossil deposits suggests the Red Deer Cave people lived just 14,500 to 11,500 years ago, the team says—a time by which all other human species, such as Neanderthals, are thought to have died out.
That date would make the Red Deer humans even more recent than the famous Homo floresiensis from the Indonesian island of Flores—itself a disputed potential human species. Discovered in 2003, the Flores "hobbits" are dated to no later than 13,000 years ago.
(Read "The People Time Forgot: Flores Find" from National Geographic magazine.)
Potential New Human Species?
The study team is so far reluctant to call their find a new human species.
"One of the major ongoing questions for scientists studying human evolution is the lack of a satisfactory biological definition of our own species, Homo sapiens," Curnoe said.
"This is one of the main reasons why we have been cautious about classifying the Red Deer Cave people at this time," he said.
Even so, Curnoe thinks "the evidence is slightly weighted towards the Red Deer Cave people representing a new evolutionary line.
"Their skulls are anatomically unique. They look very different to all modern humans, whether alive today or in Africa 150,000 years ago," the anthropologist said.
"Second, the very fact they persisted until almost 11,000 years ago—when we know that very modern-looking people lived at the same time immediately to the east and south—suggests they must have been isolated from them," Curnoe added.
"We might infer from this isolation that they either didn't interbreed or did so in a limited way," which would have staved off their "absorption" into the mainstream human lineage.
Alternatively, if these people were members of the wider Stone Age population in East Asia, they may represent an early and unknown dispersal of modern humans from Africa, the study team argues.
(See "Oldest Modern Human Outside of Africa Found.")
"The Red Deer Cave people might then sample an early migration to East Asia: people who interacted in a limited way, perhaps didn't contribute at all, to the founding populations of living East Asians," Curnoe said. (Also see "New Type of Human Discovered via Single Pinky Finger.")
"Nothing Extraordinary" About Mystery Humans
The team's suggestion that the Red Deer Cave people are somehow evolutionarily unique is receiving a skeptical reception from other scientists.
Physical anthropologist Erik Trinkaus described the findings as "an unfortunate overinterpretation and misinterpretation of robust early modern humans, probably with affinities to modern Melanesians"—indigenous peoples of Pacific islands stretching from New Guinea to Fiji (map).
"There is nothing extraordinary" about the newly announced fossil human, added Trinkaus, of Washington University in St. Louis, via email.
Philipp Gunz, of Max Planck Institute for Evolutionary Anthropology in Germany, isn't convinced by the study team's interpretation either.
"I would be surprised if it really was a new human group that was previously undiscovered," said, Gunz, also a physical anthropologist.
Responding to the criticism, study co-author Curnoe said, "That's fine. I would expect a mixture of comments."
It Takes All Kinds
The odd appearance of the Red Deer Cave people probably "just tells us that modern humans are a very diverse species," Max Planck's Gunz suggested.
"Modern humans are exceptionally variable, especially if you compare modern humans to our closest fossil relatives, the Neanderthals," who seem to have had a comparatively narrow range of appearances, he said.
While unusual, the skull features detailed in the new study "plot very close, or even within, the modern human range of variation," Gunz added.
"I would say it's not completely unexpected for a modern human at that age, so my gut feeling is that this is not a new species."
Gunz does, however, think the Chinese fossils might be evidence of multiple migration waves out of Africa that involved different populations of modern humans.
(Related: "China's Earliest Modern Human Found.")
To make a convincing case for their new human, the study team will need genetic evidence, Gunz said.
"It should be fairly easy to extract DNA from these fossils, and then we will know for sure how related they are to us as a modern human species," he said.
Attempts to obtain DNA from the Red Deer Cave remains haven't been successful to date, however.
New attempts are under way, "involving three of the world's major ancient DNA laboratories and cutting-edge techniques," according to study co-author Curnoe.
"We'll just have to wait and see."
|Early humans in the BBC series Planet of the Apeman: The 'Red Deer' people could
have come from an early - and undocumented - migration of humans from Africa
Read more: http://www.dailymail.co.uk/sciencetech/article-2114867/Red-deer-people-Stone-Age-cavemen-entirely-new-species-discovered-China.html#ixzz1p8V6kBD1
There has been an observation on the books for some time that some of the early Chinese skulls resemble some of the early Auustralian ones very closely, and they are linked by the skull of "Wadjak Man" found on Java by Eugene DuBois, discoverer of "Java Man". There was a book on the subject printed by Franz Weidenrich.
Cast of Minatogowa 1 skull from Japan. This skull of a male was found in 1970. It shares more traits with the skull from Liujiang than is does with Neolithic and modern Asians. it is dated to 17,000 years old.
- Fran Dorey
- © Australian Museum
Best Wishes, Dale D.