Human fossil discovery complicates evolution research

Scientists have found fossilized remains of a stone age people that show a unique mix of primitive and modern anatomical features, puzzling researchers of human evolution.

Although the Red Deer Cave People have not been proved to be a new species, the discovery reminds scientists of the complexity of human evolution in East Asia given the diversity of neolithic populations here.

Past research about the modern human evolution has focused on the fossil records of Europe and Africa as well as the Levantine corridor connecting them. The role of the vast Asian continent in his evolutionary episode remains largely unknown, said a paper of the findings recently published by Chinese and Australian scientists on Public Library of Science journal.

"It is far too early to conclude on the theory that modern human originated from Africa or any other region. The evolution proves to be more complicated than what we know," said Ji Xueping, a researcher with Yunnan Institute of Cultural Relics and Archaeology, who led the four-year research with Darren Curnoe of the University of New South Wales in Australia.

The Red Deer Cave People lived around 14,500 to 11,500 years ago in areas that are today's southwest China, Ji said. They had jutting jaws, prominent brows, thick skulls, flat faces -- features resembling archaic humans that existed at an earlier time, or 250,000 to 40,000 years ago.

The latest finding marks the most recent human remains found so far in the world that retained archaic human features, scientists said.

"It may represent a late-surviving archaic population, perhaps paralleling the situation seen in North Africa," the paper said. "Alternatively, East Asia may have been colonized during multiple waves during the Pleistocene period... The people may reflect a deep population substructure in Africa prior to modern humans dispersing into Eurasia."

As early as 1989, Chinese scientists found the fossils of a relatively complete skull, with the lower jaw and some teeth, and other bones of the rare people in a cave in the southwest province of Yunnan. But study of the fossils only went into full swing after Australian scientists joined in 2008.

Scientists also found large number of mammal remains -- a type of ancient red deer -- in the cave along with primitive cooking tools made of deer bones, indicating the neolithic people lived on hunting and had a penchant for home-cooked venison.

"That is why we named it Maludong Ren, or Red Deer Cave People," Ji said.

In an interview with the Guardian this month, Curnoe said multiple populations lived at the end of the ice age in Asia, probably representing different evolutionary lines: the Red Deer Cave People in East Asia, 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," he was quoted by the paper as saying.

Huang Weiwen, a researcher with Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, said the distinct features of the Red Deer Cave People from other populations indicate that modern humans might have evolved from more than one origin.

He said the latest discovery is "very significant" and may provide additional clues to the cross-continental migration and interbreeding of the archaic humans at the end of the fourth ice age.