February 2, 2009

‘Hobbit’ Remains Spark Scientific Debate

A set of bones discovered in 2003 have sparked a five-year feud in the scientific world.

The bones, discovered inside Liang Bua cave on the Indonesian island of Flores, were believed to be the skeleton of an extinct human species called Homo floresiensis, or "Hobbits."

The first report on the discovery appeared in the Journal Nature in 2004.  In the report the authors wrote "here we report the discovery, from the Late Pleistocene of Flores, Indonesia, of an adult hominin," thus declaring a new human species.

These "hobbits" were believed to stand less than 40 inches tall and appeared to be buried with primitive tools.  

"The combination of primitive and derived (modern-looking) features assigns this hominin to a new species, Homo floresiensis. The most likely explanation for its existence on Flores is long-term isolation, with subsequent endemic dwarfing," said Peter Brown of Australia's University of New England.

Brown's declaration made the bones, dubbed LB1, the prototype for the new species,

Some scientists have disagreed with Brown's assessment.  Jochen Weber, of Leopoldina Hospital in Germany, believes the "hobbit" was not part of a new species but was a victim of microcephaly, a disorder causing a smaller than average circumference of the brain.  

In a 2007 Proceedings of the National Academies of Science paper, Dean Falk of Florida State University countered Weber's findings.

"Despite LB1's having brain shape features that sort it with normal humans rather than microencephalics, other shape features and its small brain size are consistent with its assignment to a separate species," wrote Falk, a neuroscientist.

The newest assessment of LB1 comes from Karen Baab, anatomical scientist at the Stony Brook University Medical Center.  In her report, which appears in the Journal of Human Evolution, Baab concludes that the hobbits "cranium is fairly asymmetrical, but within the range of asymmetry exhibited by modern humans and all extant African ape species."

Original critics of the new species theory previously pointed to microencephaly because of two lopsided halves on the skull.  Baab's report pointed out that the skull could be misshapen due to the fact that it was discovered under 10 feet of mud, a process called taphonomy by fossil researchers.

Peter Brown has argued that the microencephaly debate is nonsense.  The researcher and his team have discovered a dozen "hobbits" in the Liang Bua Cave, all with similar looks.  

Other researchers agree that a graveyard of microencephalics in one location is highly unlikely.

The "post-cranial" remains of LB1 were recently examined by William Jungers of Stony Brook University and his colleague Susan Larson.  In Larson's report she writes that the bones "present a unique mosaic of derived (human-like) and primitive morphologies, the combination of which is never found in either healthy or pathological modern humans."

The papers include a description of the Liang Bua cave, concluding that the hobbits fed on Stegodon pygmy elephants. They report that the remains of at least 47 Stegodon were found in the cave, and were likely wiped out along with the hobbits in a volcanic eruption.

The cave also lacked seashells, suggesting the hobbits did not venture to the coast.  

"Homo floresiensis probably descended from a very early Homo erectus, or from Homo habilis, both human species that are not known to have used marine resources. Homo floresiensis probably did not have the right behavior to exploit marine resources (perhaps fear of entering the water, just like for instance orangutans)," says Gert van den Bergh of Holland's Nationaal Natuurhistorisch Museum Naturalis.

He believes the hobbits may have been restricted to interior regions of Flores.

"You see, still many unanswered questions remain," he added.


Image Courtesy Of Wikipedia


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