Diseased human or whole new species? The saga continues.

Credit: Kevin Stead

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SYDNEY, 22 August 2006: The hobbit of the Indonesian island of Flores is not a new species in the human branch of the family tree, but an ordinary human with a neurological disorder, according to a paper published by the Proceedings of the National Academy of Sciences today. But these claims have been slammed by two Australian researchers.

Peter Brown and Mike Morwood from the University of New England, were part of the team that discovered nine skeletons on Flores in 2003. They believe that the tiny skeletal remains represent a new species of human they called Homo floresiensis. The media wasted no time in dubbing the creature a ‘hobbit' after the pint-size people in JRR Tolkein's Lord of the Rings books.

The paper's conclusions are "unsupported by any published evidence," Brown said, describing its claims as "complete nonsense".

The paper's authors, led by Teuku Jacob from Gadja Mada University, Indonesia, argue that the hobbit's diminutive size and apparently small brain are actually indicative of microcephaly, a disorder in which the circumference of a person's head is smaller than average for his or her age and gender, and in which the entire body is often underweight and dwarfed.

The assertion was raised in June, however this is the first time it has been published in a scientific journal. An important step in giving credence to rival claims.

But even if microcephaly is not present, the authors say, a reduction in body size, over generations, is unsurprising in an ecosystem such as that on Flores, with its humid climate and hilly topography, and does not necessarily point to a separate species.

"Maintenance of body temperature alone can be a sufficient selective factor for small body size in such surroundings," the authors claim. "Size fluctuations occur repeatedly in mammalian, including human, lineages."

Furthermore, the authors say that out of the 94 descriptive features of the hobbit's cranium, not one lies outside the range of modern humans, aside from the abnormalities that indicate microcephaly.

If the hobbit's brain, which was smaller than a chimpanzee's, was normal for the new species, they argue, then how were these hominins able to manufacture stone tools (like the ones found with the hobbit) only previously known to be crafted by humans with brains three times larger?

Brown, however, refutes these claims.

Some stone tools found on Flores, he said, pre-date human existence.

"We now know you don't have to be a modern day human to make these kinds of tools," he said.

Brown also pointed out that a person with microcephaly exhibits a whole range of abnormalities, which the hobbit does not - apart from the smallish brain, and that climate alone could not account for the hobbit's diminutive size.

"These people were only a metre tall," he said. "A very short modern-day human is 1.4 metres at least."

He said that sceptics had been unable to produce a modern skeleton with microcephaly, or otherwise, that resembled the remains of the hobbit.

"It's a different species," he concluded adamantly.

Mike Morwood told the tale of the hobbit discovery in Cosmos, Issue 3 p10.