Archive for August 25th, 2006

How Modern were European Neanderthals?

Church of Darwin, Science, Sophistication of Ancestors, Uncategorized | Posted by Chris Parker
Aug 25 2006

 Eurekalert

Neandertals were much more like modern humans than had been previously thought, according to a re-examination of finds from one of the most famous palaeolithic sites in Europe by Bristol University archaeologist, Professor Joao Zilhao, and his French colleagues.

Professor Zilhao has been able to show that sophisticated artefacts such as decorated bone points and personal ornaments found in the Châtelperronian culture of France and Spain were genuinely associated with Neandertals around 44,000 years ago, rather than acquired from modern humans who might have been living nearby. His findings are published in the Proceedings of the National Academy of Sciences (PNAS) USA.

The site from which this Neandertal culture derives its name is the Grotte de Fées at Châtelperron in Central France, first excavated in the 1840s. It has been one of the most important and controversial places to understand how modern humans that had previously moved out of Africa replaced the Neandertals, often portrayed as more ‘primitive’.

In the conventional interpretation of the rock strata of the site, the cave was thought to have evidence of both modern human and Neandertal occupation in interleaved layers.

The fact that Neandertals came back to the site after modern humans had lived in it for quite some time would prove the long-term contemporaneity of the two groups, and validate the notion that the cultural novelties seen among the latest Neandertals represented immitation or borrowing, not innovation.

Now archaeologists can show that the Grotte des Fées stratigraphic pattern is illusory because the supposedly Neandertal levels overlying those belonging to the modern human Aurignacian culture are in fact backdirt from nineteenth-century fossil hunting.

According to Professor Zilhao and his team, this adds to the evidence from other sites in the region that the Neandertals already had the capacity for symbolic thinking before the arrival of the modern humans into western Europe, which has been radiocarbon dated to around 40,000 years ago.

Professor Zilhao said: “This discovery, along with research on the rock strata at other cave sites, has huge implications for how we view the European Neandertals and, more widely, human evolution. The differences between Neandertals and modern humans may be much less than had been previously thought, suggesting that human cognition and symbolic thinking may date back to before the two sub-species split around 400,000 years ago.”

 

Pruning the Human Family Tree
New doubts are cast on the existence of a “hobbit” species.

Church of Darwin, Science, Uncategorized | Posted by Chris Parker
Aug 25 2006

August 24, 2006

To illustrate the deformities in the “hobbit” skull, David Frayer at the University of Kansas took an image of one half of the skull, created a mirror image of it and spliced them together to show how different the skull would look if it were symmetrical. The photo on the left shows the actual “Hobbit” skull. The photo in the center shows the right half of the skull spliced together with its mirror image, and the photo on the right shows the left half of the skull with its mirror image. (Courtesy of David Frayer, Etty Indriati, and PNAS)

A discovery that has been hailed as the most important development in human evolution in the last 50 years has formally come under scientific attack this week, as a draft of a study to be published in the Proceedings of the National Academy of Sciences (PNAS) has begun circulating among scientists and journalists. The study provides scientific evidence that the so-called “hobbit” bones found in 2003 on the Indonesian island of Flores belonged to a pygmy with a skull-deforming condition called microcephaly, not a member of a previously unknown species of human being  

The controversial bones were excavated by a joint Australian and Indonesian research team led by Mike Morwood, an archaeologist at Australia’s University of New England. The excavations uncovered the remains of up to seven individuals, but only one skull with a receding chin, strangely shaped premolar teeth, and a brain size measured at 380 ccs–less than a third the size of a modern human brain. Some of the 18,000-year-old skull’s other traits seemed to resemble Australopithecus or Homo erectus. The researchers claimed it was a new species, which they named Homo floresiensis (see Indonesia’s Lost World: Shaking Up the Family Tree). 

Soon after Morwood’s team published their results in the October 28, 2004, edition of Nature, the bones were–depending on whom you ask–either appropriated by or loaned to Teuku Jacob, a senior paleoanthropologist at Indonesia’s Gadjah Mada University. Jacob, who has always maintained that the bones were from a very small Homo sapiens (modern human) suffering from microcephaly, is one of the authors of the new study in PNAS. His main arguments against calling the “hobbit” a new species are summarized below. 

*        Pygmies living in a village near Liang Bua cave where the bones were found display many of the distinctive dental traits used to define the new species. 

*        The hobbit’s leg bones are abnormally thick and round, and have very weak muscle attachments, probably indicating some kind of growth disorder. 

*        The “hobbit’s” skull is deformed in a way that makes it less symmetrical than a healthy human skull, a strong indicator that the individual suffered from a pathological condition like microcephaly. 

*        The lack of a chin was also used a defining characteristic for Homo floresiensis, but some of the local pygmies also lack chins. 

“From the very beginning the scientific case for Homo floresiensis being a new species was very weak on the evidence and very implausible on the science,” said Robert Eckhart a paleoanthropologist at Penn State University, one of the study’s authors. Jacob’s group plans to follow this study with a series of articles presenting additional evidence to support their case. 

Zach Zorich is is an associate editor at ARCHAEOLOGY.
© 2006 by the Archaeological Institute of America
www.archaeology.org/online/features/flores/hobbit.html