Data Bolster Claim of a ‘Hobbit’ Human Species

New skull measurements from a set of “hobbit”-sized human skeletons discovered last year in Indonesia bolster the controversial claim that the fossils belong to a new human species, scientists said Thursday.

A computer reconstruction of the creature’s brain showed it was unlike any other and could have been capable of advanced thought, an international team of researchers led by anthropologist Dean Falk at Florida State University reported.

Last year, scientists trumpeted the discovery of the bones on the isolated island of Flores, east of Java, and identified them as the remains of a previously unknown species marooned there between 95,000 and 12,000 years ago, a time when modern Homo sapiens was thought to be Earth’s sole human inhabitant.

So far, archeologists have found bones from eight of the humans.

In the months since, some skeptical scholars have contended that the researchers had merely unearthed evidence of a human deformity.

The search for the creature’s proper place in natural history centers on its pint-size brain, which is about one-third the size of the modern human brain. At a mere 25 cubic inches, the brain is more in keeping with those of pre-human primates that lived more than 3 million years ago.

So small a brain should be incapable of sophisticated thought, experts said, yet evidence suggests that the creatures made stone tools, tended fires and organized hunts for pygmy elephants that once roamed the region.

If that is true, it would overturn scientific axioms about the relationship of brain size to intelligence.

But several anthropologists believe the creature’s skull was a sign of a neurological disease called microcephaly that causes a small head, large face, sloping forehead and, on occasion, a dwarfed body.

“I am very worried about that brain size,” said anthropologist Robert Martin, provost of the Field Museum in Chicago, who challenged the claim for a new species. “It is unusually small, especially for something that is only 18,000 years old.” To dispel such doubts, researchers Thursday presented indirect evidence that the creature’s brain was quite advanced despite its size. They used medical diagnostic software to create a three-dimensional reconstruction of the organ.

“Pulsating brains leave impressions inside the brain case, much as a hand shapes a tightly fitting glove,” Falk said.

They compared the reconstruction with those of brains taken from across the palette of human evolution, including that of an ape and three extinct pre-human species: Homo erectus, Australopithecus africanus and Paranthropus aethiopicus. They also compared it with a modern human brain, a modern human pygmy brain and the brain of a modern human with a microcephalic disorder.

Their work was funded by the National Geographic Society and published online Thursday in Science Express, an electronic adjunct of the journal Science.

“We found that the general overall shape of the hobbit’s brain was unique,” Falk said. The creatures were nicknamed for the characters in J.R.R. Tolkien’s novels.

The brain combined both primitive and relatively modern features in a way that set it apart from other species, Falk said. There was no resemblance to the modern microcephalic brain.

In particular, the brain reconstruction revealed large temporal lobes, which are associated with speech, and the anatomical signature of structures in the prefrontal cortex that are associated with higher cognition in modern humans.

“I am bowled over,” Falk said. “I never thought I would see this in a brain this small.”

While researchers investigated the creature’s brain structure, anthropologists in Indonesia were locked in a months-long squabble over custody of the bones. They were returned to their rightful repository at the Center for Archeology in Jakarta only last week, archeologist Michael Morwood, who led the team that made the discovery, said Thursday.

“Some of the most important material has been damaged,” said Morwood, a professor at the University of New England in New South Wales, Australia. “This is not the activity of responsible scientists. This is appalling, irresponsible behavior.”