Brain reconstruction hints at 'hobbit' intelligence

19:00 03 March 2005
NewScientist.com news service
Will Knight

A CT scan was used to create a virtual model, shown in red beneath a translucent image of the skull found in Flores (Image: Mallinckrodt Institute of Radiology, Washington University)Analysis of the diminutive cranium of Homo floresiensis - a tiny hobbit-like human that lived in Indonesia just 13,000 years ago - confirms it as a unique species and reveals remarkably advanced features for such a small brain.

The skull and other bones of one female and fragments from up to six other specimens were discovered in caves on the Indonesian island of Flores in 2003 and revealed to the world in October 2004. The remarkably petite human stood just a metre tall and had a brain about one-third the size of modern humans.

But Dean Falk, an expert on brain evolution at Florida State University, US, who has analysed the skull of H. floresiensis says it has some remarkably advanced morphological features, including ones associated with complex brain processes in living humans. "It has an extraordinary morphology unlike anything I've seen in 30 years," she told New Scientist.

This adds weight to the theory that H. floresiensis may have possessed an intelligence and tool-building ability traditionally associated with much larger-brained humans. The charred bones of animals were also found in the caves on Flores. "It may well be that the population was hunting, making tools and using fire," says Falk. "I'm conservative by nature but in light of these features we find nothing to contradict this speculation."

Surface features
Falk used data collected during CT scans performed shortly after the skull was discovered to build a 3D computer model of the cranial cavity. This mirrors the overall shape of the brain and can even reveal certain surface features. She compared the model to ones made from the skulls of other extinct pre-humans along with those of modern humans and living apes.

Falk found several advanced morphological features, including enlarged frontal and temporal lobes and an extended area at the back called the lunate sulcus. In modern humans the frontal lobes are associated with forward planning and problem solving and temporal lobes are thought to play a key role in memory. The extension of the lunate sulcus is typically associated with a more highly developed ability to analyse sensory information, says Falk.

Disregarding size, the brain of H. floresiensis most closely resembled that of Homo erectus, a human ancestor that disappeared around 70,000 years ago that was thought to have made relatively complex tools.

But Chris Stringer at the Natural History Museum in London, UK, says it may be rash to draw too many conclusions about the intelligence of H. floresiensis from the brain morphology alone. He notes that some features also seem to predate H. erectus. "I reserve judgement on what kind of intelligence and technology the animal might have had," he says.

Striking diversity
Stringer adds that the picture is far from simple as the brain has some features unlike anything seen before.

The discovery of H. floresiensis was hailed as the most important anthropological find for 50 years. It alters the picture of human evolution, showing that it have continued until very recently and was more diverse than previously thought.

But the find has stirred up heated debate among anthropologists, a small number of whom refuse to accept it is a unique new species at all. Bernard Wood, an anthropologist at George Washington University, US, says the model should at least dispel dissenting claims that the remains are not a unique species but simply a modern human with microcephaly, a rare condition that results in a reduced cranium size.

"Unequivocally, it is not what you would expect a miniaturised modern human brain to look like," Wood insists. "Nor is it like the brain of a human with a pathological microcephaly


http://www.newscientist.com/article.ns?id=dn7090

National Geographic will air a program on this discovery Mar 13th

http://www.nationalgeographic.com/channel/...ost_031305.html

Thanks for the post DWB04 -

I missed the National Geographic program, but I found another link that offers some more info and plenty of references:http://en.wikipedia.org/wiki/Homo_floresiensis

...The discovery is widely considered the most important of its kind in recent history, and came as a surprise to the anthropological community. The new species challenges many of the ideas of the discipline.

Homo floresiensis is so different in form from other members of genus Homo that it forces the recognition of a new, undreamt-of variability in that group, and reaffirms an intellectual trend away from the idea of linear evolution.

No doubt this discovery provides more fuel for the fire of the perennial debate over the out-of-Africa or multiregional models of the speciation of modern humans, despite H. floresiensis not itself being an ancestor of modern humans. Already, voices have been heard arguing it further on either side.

The discoverers of H. floresiensis fully expect to find the remains of other, equally divergent Homo species on other isolated islands of Southeast Asia, and do not think it impossible, if not quite "likely", that some lost Homo species could be found still living in some unexplored corner of jungle.

Henry Gee, a senior editor of the journal Nature, has agreed, saying, "Of course it could explain all kinds of legends of the little people. They are almost certainly extinct, but it is possible that there are creatures like this around today. Large mammals are still being found. I don't think the likelihood of finding a new species of human alive is any less than finding a new species of antelope, and that has happened" [1] (www.nature.com/news/2004/041025/pf/041025-2_pf.html).

Gee has also written that "The discovery that Homo floresiensis survived until so very recently, in geological terms, makes it more likely that stories of other mythical, human-like creatures such as Yetis are founded on grains of truth....Now, cryptozoology, the study of such fabulous creatures, can come in from the cold" [2] (www.lorencoleman.com/top_cryptozoology_2004.html).

Reaction
Professor Teuku Jacob, chief paleontologist of the Indonesian Gadjah Mada University and other scientists reportedly disagree with the placement of the new finds into a new species of Homo, stating instead "It is a sub-species of Homo sapiens classified under the Austrolomelanesid race". He contends that the find is from a 25–30 year-old omnivorous subspecies of H. sapiens, and not a 30-year-old female of a new species. He is convinced that the small skull is that of a mentally defective modern human, probably a pygmy, suffering from the genetic disorder microcephaly or nanocephaly. Some scientists reportedly believe the skeleton found may be of a male and not a female. When interviewed on the Australian television program Lateline, Professor Roberts reportedly conceded that the skeleton may be that of a male rather than a female but he strenuously maintained the fossil is of a new species. A paper published in Science disputes the microcephaly theory.

it's facinating to say the least! Anyway linear structures are too simplistic...but I guess that's all they could go on with what was originally known, so I won't fault their initial findings......it's all a process of discovery!!!

p.s. I saw the model and it doesn't seem to relate to a microcephalic or pygmie brain.....

Indeed. But even without religion people have liked to see themselves as the end of a line of progress with some vague idea of a goal towards us. Instead what you have is a branching bush, not a line. It's relentlessly naturalistic and moving without a goal.

Neandertals were first thought to be ancestors, but then they too were discovered to be a cousin instead and some think modern humans may have killed off the neandetals.