Human Teeth
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A trove of 47 fossil human teeth unearthed from a cave in southern China may change the human migration history to prove that Homo sapiens may have arrived in Asia much before they did in Europe. The teeth are reportedly close to 80,000 years old, whereas most researchers until now have believed humans only left Africa for the first time around 60,000 years ago that too towards Europe.

According to findings published in the journal Nature, the discovery seeks to challenge the widely accepted theory of modern human migration, known as "Out of Africa," which indicates that modern humans originated in Africa and made their first successful migration across the continent between 50,000 and 70,000 years ago. The finding now puts the migration of modern human species northward earlier by at least 20,000 years.

"It was very clear to us that these teeth belonged to modern humans [from their morphology]. What was a big surprise was the date," said Maria Martinon-Torres from University College London, co-author of the study published in Nature.

The teeth found in the Fuyan Cave in the Daoxian region of Hunan province are in fact so ancient that they could not be tested using carbon dating and thus scientists had to date the surrounding calcite deposits. Luckily for them, a layer of flowstone had grown over the layer that held the human teeth, sealing them in and preventing them from being disturbed. Over the flowstone grew a stalagmite, which was dated to at least 80,100 years old — which means all the material below it, teeth included, must be older.

The finding may also help explain why it took Homo sapiens so long to move into Europe which was already inhabited by the Neanderthals -- a species in the genus homo that became extinct between 41,000 and 39,000 years ago. Previously, research on the Neanderthals has vaguely suggested that they prevented the migration of modern humans to Europe. But the present research says the Neanderthals may have been much more formidable opponents than we once gave them credit for.

Challenges ahead

While researchers find the discovery and the study compelling, most say it is not definitive. More parts of the human anatomy have to be linked to these teeth to come to a full-proof conclusion. Moreover, the study suggests that no tools were found in the cave area which indicates that it was impossible for these humans to live there and only a predator or likewise could have dragged them there.

"What is the origin of this population? And what was their fate? People really now have to reconsider models. Maybe there's not only one 'out of Africa' theory but several," said Torres as the research group will now extract DNA from the teeth samples to shed more light on the origins.