for National Geographic News
An early modern human from China dated to about 40,000 years ago adds to evidence that the first Homo sapiens sapiens occasionally mated with older human species such as Neandertals.
The remains—which represent the oldest known example of modern humans found in China—share a few characteristics with older human species, according to a new study.
Other experts have argued that early modern humans and Neandertals were genetically distinct and therefore couldn't interbreed.
Such findings support the long-held theory that modern humans out-competed and eventually replaced other species as the modern humans spread out of Africa (explore an interactive map of human migration).
But the Chinese skeleton and similarly dated specimens from Europe and Asia have traits that had already been lost in the earliest modern humans found in Africa, said Erik Trinkaus, an anthropologist at Washington University in St. Louis, Missouri.
If the replacement theory is correct, the 40,000-year-old skeletons should look like modern human fossils from Africa or slightly more evolved, he explained.
"What we find is overwhelmingly they do," he said. "But these archaic characteristics that had been lost in African moderns keep popping up."
The remains of the newfound early modern human were discovered in Tianyuan Cave near Beijing in 2003.
Trinkaus and colleagues with the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences describe their findings in this week's issue of the Proceedings of the National Academy of Science.
Based on radiocarbon analysis, the team dated the skeleton to about 42,000 to 38,500 years ago.
The specimen is about the same age as an early modern human from Romania, which Trinkaus and colleagues described in a paper this past January, and another skeleton from a cave in Sarawak, Malaysia.
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