November 2, 2011

Modern Man Arrived in Europe Earlier than Previously Thought

By taking a second look at seemingly insignificant fossils, two international teams of researchers have discovered that modern humans arrived in Europe earlier than scientists had originally believed, various media outlets reported on Wednesday.

According to AP Science Writer Alicia Chang, the fossils at the center of the discovery were a piece of jawbone with three teeth from England, and a pair of infant teeth from the southern part of Italy. Using what Chang refers to as "refined techniques," the experts discovered that the age of one specimen had been "significantly underestimated" and that the other had been "misinterpreted."

The baby teeth, which were discovered by a group of experts led by officials at the University of Vienna's Department of Anthropology, were tested at the Oxford Radiocarbon Accelerator Unit in England, John Noble Wilford of the New York Times said. The fossils, which had been discovered at a prehistoric cave known as the Grotta del Cavallo, were dated at between 43,000 and 45,000 years old.

The results of the study, which have been published in the journal Nature, prove that the remains are older than any previously discovered European homo sapiens fossils, the university said in a November 2 press release.

"We worked with two independent methods: for the one, we measured the thickness of the tooth enamel, and for the other, the general outline of the crown," Stefano Benazzi, a post-doctoral student at the University of Vienna, said in a statement. "By means of micro-computed tomography it was possible to compare the internal and external features of the dental crown. The results clearly show that the specimens from Grotta del Cavallo were modern humans, not Neanderthals as originally thought."

"What the new dates mean“¦ is that these two teeth from Grotta del Cavallo represent the oldest European modern human fossils currently known," he added. "This find confirms that the arrival of our species on the continent -- and thus the period of coexistence with Neanderthals -- was several thousand years longer than previously thought. Based on this fossil evidence, we have confirmed that modern humans and not Neanderthals are the makers of the Uluzzian culture."

In a second, similar study, also conducted Oxford University's Radiocarbon Accelerator Unit (ORAU) and scheduled for publication in Nature, a jawbone that had been recovered from a prehistoric cave at Kent's Cavern in southwestern England -- originally dated at approximately 35,000 years old -- has now been confirmed to be between 41,000 and 44,000 years old.

"Radiocarbon dating of ancient bones is very difficult to do," Tom Higham, Deputy Director of the ORAU and the head of the research team, said in a Wednesday press release. "Because the initial date from this fragment of jawbone was affected by traces of modern glue, the initial measurement made in 1989 was too young. The new dating evidence we have obtained allows us, for the first time, to pinpoint the real age of this key specimen. We believe this piece of jawbone is the earliest direct evidence we have of modern humans in northwestern Europe."

"What's significant about this work is that it increases the overlap and contemporaneity with Neanderthals," he added in a separate interview with BBC News Science Correspondent Jonathan Amos. "We estimate that probably three to five thousand years of time is the amount of the overlap between moderns and Neanderthals in this part of the world."


Image Caption: Mesial view of the specimen Cavallo-B (deciduous left upper first molar), the first European anatomically modern human. The white bar in the figure is equivalent to 1 cm. Credit: Stefano Benazzi


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