| Hobbit feet reignite debate|
|The hobbit had much longer feet than modern humans, suggests a new paper, which has reignited debate on the origins of the tiny creature.|
A paper published tody in the journal Nature reports on the foot bones from the now famous LB1 specimen, known as Homo floresiensis, collected at Liang Bua cave on the Indonesian island of Flores in 2003.
"Here we show that LB1's foot is exceptionally long relative to the femur and tibia, proportions never before documented in hominins but seen in some African apes," write the researchers.
"The feet are almost the same length, as a proportion of the leg, as bonobos," says Australian archaeologist and contributing author, Professor Mike Morwood of the University of Wollongong.
He and colleagues also found that the hobbit feet had no arch and such a flat-footed creature would have made it hard for it to run.
For Morwood, this odd assortment of characteristics makes the hobbit an early human species that is more strange than anyone had realised.
"It's an interesting composite of very primitive and some more modern traits," he says.
Morwood says further analysis of hand bones may reveal the hobbit was "more arboreal" than modern humans.
The researchers suggest Homo floresiensis evolved from an ancestor other than Homo erectus.
"I think it's pre-Erectus and in some way more primitive than Homo habilis," says Morwood.
He says lead author US-based Professor William Jungers of Stonybrook University has referred to Homo floresiensis as the "black swan" of palaeoanthropology.
He says it challenges the generally accepted "Out of Africa" theory and suggests important human evolution may have happened in Asia.
A simpler explanation?
But others wonder if there's a simpler explanation.
According to biological anthropologist Professor Maciej Henneberg of the University of Adelaide, Morwood's conclusions are problematic.
First, he says the reconstructed foot may not even be representative of one particular individual.
He says foot bones were found scattered in Liang Bua cave along with bones from other individuals, therefore Morwood and colleagues can't be sure that they come from the same individual.
Henneberg says if the bones are a true reflection of the hobbit's feet, then this means it would had big floppy flat feet and walked like a duck - an analogy he says Jungers made when the findings were first delivered at a conference last year.
"These people would be very inefficient at walking at they would not be able to run," says Henneberg.
He says such attributes would be at odds with the claim that hobbits made complex stone tools and hunted stegadon.
Henneberg was co-author of a 2006 publication in Proceedings of the National Academy of Science that argued LB1 was actually a pygmy human with a developmental abnormality.
"To my mind a gross disorder is a simpler explanation," he says.
Other scientists have also published papers in the journal Science to support this hypothesis.
Morwood defends the integrity of the foot reconstruction.
"The major limb bones were photographed being articulated and almost certainly the feet bones were articulated as well. They were from one small part of the site," he says.
He agrees the hobbit would have had difficulty running, but thinks they could have still butchered and eaten that had already been killed by komodo dragons.
Case of dwarfism?
A related paper in the same issue of Nature reports another explanation for the hobbit's strange anatomy.
It argues the hobbit's tiny head, which some have put down to microcephaly, could have arisen because of a phenomenon known as "insular dwarfism" that occurs on islands.
Henneberg argues the paper relies on extrapolating from the dwarfing patterns of semi-aquatic herbivorous hippos, which can not be applied to omnivorous land-dwelling humans.
He also says, statistical uncertainties in the paper do not justify the conclusions reached.