(CNN)A mystery surrounding human fossils found in a cave in China has been solved by DNA sequencing, according to a new study, and it sheds light on the ancestry of the very first Americans.
Identity of mystery fossils found in Chinese cave revealed by DNA analysis
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In 1989, a thigh bone and part of a skull were found in a cave in the Chinese province of Yunnan in the southwest area of the country.
Radiocarbon dating conducted in 2008 on the sediments where the fossils were found indicated they were around 14,000 years old -- which would mean they were from a period of time when Homo sapiens (modern humans) had migrated to many parts of the world.
However, primitive features of the bones niggled scientists, who questioned what species of human the fossils belonged to.
The shape of the skull resembled that of Neanderthals -- an archaic human population that disappeared about 40,000 years ago -- and it seemed the brain would have been smaller than that of modern humans.
As a result, some experts in human evolution thought the skull probably belonged to a hybrid population of archaic and modern humans or perhaps a previously unknown human species that existed alongside our own. Researchers gave the group the name Red Deer People after the name of the cave in which the remains were found.
Now, Chinese scientists have extracted genetic material from the skull cap and sequenced the DNA. They found that the skull belonged to a female individual, who was most likely a direct human ancestor -- a member of Homo sapiens -- not a previously unknown type of human.
"Ancient DNA technique is a really powerful tool," said Bing Su, a professor at the Kunming Institute of Zoology at the Chinese Academy of Sciences in Yunnan who was involved in the research, in a news release. "It tells us quite definitively that the Red Deer Cave people were modern humans instead of an archaic species, such as Neanderthals or Denisovans, despite their unusual morphological features."
Su and his colleagues have shared their findings in a study that published Thursday in the journal Current Biology. Their analysis of the genome revealed the individual the bones belonged to had levels of Neanderthal and Denisovan ancestry that were similar to those found in modern humans -- suggesting that they weren't part of a hybrid population that interbred with one another.
DNA from Denisovans, a little understood group of archaic humans, and Neanderthals lives on in some humans today. That's because long ago our Homo sapiens ancestors encountered these groups as they spread around the world and reproduced with them.