The inhabitants of the Indonesian island of Flores used to tell stories of a separate race of little people called the ebu gogo, 3-ft.-tall, hairy human-like creatures that hid in the island's many limestone caves. Supposedly the ebu gogo the name roughly means "grandmother who eats everything" disappeared around the 16th century, when Dutch traders first came to this tropical island 350 miles east of Bali. It's a common myth with a convenient ending-as soon as witnesses who could have recorded the creature's existence come on the scene, the ebu gogo suddenly vanish. But then a team of researchers found the 18,000-year-old bones of 3.5-ft-tall people with grapefruit-sized brains and announced in Nature two years ago that they were the remains of a previously unknown, hobbit-like species of human: Homo floresiensis. The finding made the cover of National Geographic and threatened to upend the history of human evolution. It seemed for a moment as if any legend could be true.
Or perhaps too good to be true. Doubts were raised from the start about whether the findings really represented an unknown branch on the human family tree, but none of the opponents had a chance to base their critiques from first-hand examinations of the Flores bones. That changed in a paper published in the current issue of the prestigious Proceedings of the National Academy of Sciences (PNAS). A team of researchers from the U.S., Indonesia and Australia report on their own investigation of the Flores bones and conclude that the so-called hobbit isn't a separate species, but just an unfortunate pygmy with a form of microcephaly, a developmental disorder that shrinks the head and the brain. Or as the archaeologist Alan Thorne, one of the authors of the PNAS paper, says: "They are just like hobbits. They're the products of someone's imagination."
The PNAS team closely examined the one almost complete skull unearthed at Flores and say they found no evidence that it was belonged to anyone but a modern human. The skull was shaped asymmetrically, which the researchers argued was due to the effects of microcephaly. They also say that many of the features of the jaw and teeth cited as evidence that it belonged to a separate species-such as the lack of a chin-could be seen among modern Flores pygmies. It's that last part the fact that a population of pygmies can still be found living just a stone's throw away from the Liang Bua cave where the original bones were found that helped clinch the argument for Robert Eckhardt, a developmental geneticist at Penn State and another author of the PNAS paper. "If you look throughout the area, there are plenty of populations where the average male is under a meter and a half [4'11''] and females are shorter," he says. "If the people there are short now, so were the people who lived there 20,000 years ago."
The original authors of the Nature paper Peter Brown and Michael Morwood, both of the University of New England in Australia aren't about to surrender their belief in a new species. In an email, Brown says that the PNAS paper "provides absolutely no evidence that the unique combination of features found in Homo floresiensis are found in any modern human." Morwood points out that supporting papers have previously been published in elite journals like Science and Nature, while Brown argues that the asymmetry in the skull was due to the fact that the original skeleton was buried in 30 ft. of sediment, which deformed the fossil. (Thorne insists the deformity must have happened before death). Colin Groves, an Australian biological anthropologist who is an author on an upcoming paper in the Journal of Human Evolution that discounts the microcephaly hypothesis, says the PNAS team subtly shaped the evidence to fit their conclusion: that the hobbit was just a developmentally stunted human. "They have a scattergun approach," he writes in an email. "They are convinced from the very start that it is pathological, so they find anything that remotely resembles pathology and apply it to the poor hobbit." Henry Gee, a senior editor at Nature who was responsible for overseeing the publication of the original Flores paper, concedes that the PNAS paper is "very interesting" but says the authors "cherry-pick the evidence [they] like." Ultimately, he says, "I do not think that the new work dents the contention that Homo floresiensis is a new species of human."
If this sounds like he-said, she-said for the paleoanthropological crowd, you're not far off. The two sides quickly descend from debating the finer points of human fossils to slagging off on each other's ethics. Brown has accused Teuku Jacob the lead author of the PNAS paper and one of Indonesia's most venerable anthropologists of removing the fossils from their legal depository and damaging them while attempting to make a copy. Jacob has denied the charges in the past, and Thorne takes umbrage at the accusations. "This is a very senior academic," he says of Jacob. "This is not some guy off the street stealing bones." (Jacob could not be reached for comment.)
Such sharp animosity isn't unusual in the disputatious field of human evolution studies, where as Thorne points out, "There are more human evolutionists than there are fossils to go along with them." But the Flores debate seems to bring out the inner fifth-grader in grownups with PhDs. After Brown was quoted in Discover magazine this past January saying that Eckhardt was "thick as a plank" for trying to refute Homo floresiensis, Eckhardt attended a scientific meeting where he took off his shirt and had his wife measure his chest. "We were able to establish to the satisfaction of the audience of 300 people that I was in fact thicker than two short planks," he says.
If only the Flores debate could be so clearly decided. The one definitive piece of evidence could be DNA tests of the original skeleton that might prove for sure whether the hobbit belonged to Homo sapiens or something else, but such samples will be difficult to recover, because DNA doesn't keep long in a tropical environment. What's certain is that the scientific stakes are extremely high: if the Flores find is really a separate species, then the history of human evolution will have to be rewritten. Instead of automatically evolving toward bigger brains, at least one branch of humanity would seem to have evolved in reverse. Though each side is utterly convinced as Eckhardt puts it: "We will be substantially right, and they will be substantially wrong," the issue will probably be fought in open scientific combat for some time. And one gets the sense that it's exactly how these intellectual gladiators like it.