Flores - A new study of ancient bones concludes that Palau‘s early inhabitants were simply small humans—not hobbit-like or dwarfs as suggested by earlier research.
The new findings may add to the continuing debate over remains found several years ago on the island of Flores, Indonesia, about 1,500 miles (2,300 kilometers) away. Scientists disagree about whether the tiny Flores "Hobbit" is its own species or a diseased human.
For the new study, scientists analyzed a nearly complete Palauan skeleton, several skulls, and bone fragments found at a burial site called Chelechol ra Orrak, on a small limestone island in the western Pacific island-nation.
The data suggest "that early Palauans were of normal size and that their physical characteristics are well within the variation seen in modern human populations," said lead author Scott Fitzpatrick of North Carolina State University.
The study was published in the open-access journal PLoS ONE.
Dwarfism?
The scientists say their research directly challenges some of the main findings of a study published earlier this year by Lee Berger, a paleoanthropologist at the University of Witwatersrand, in Johannesburg, South Africa.
(Berger and colleagues were funded by the National Geographic Society, which owns National Geographic News.)
Fitzpatrick‘s team measured ancient Palau individuals at more than 4.5 feet (1.5 meters) tall, whereas the earlier team described individuals as smaller—only 3 to 4 feet in height (94 to 120 centimeters)—based on less complete remains from two separate burial caves called Ucheliungs and Omedokel.
Berger‘s earlier study (see video) also said the bones showed traits that are unusual or archaic in the human lineage—including deep jaws, no chins, large teeth, and small eye sockets—and might indicate insular dwarfism, an evolutionary process that may occur when isolated, island-bound species shrink in size due to limited dietary resources.
Fitzpatrick countered that such traits were within normal human variation and that there is no reason to believe insular dwarfism occurred on Palau.
There is "plenty of evidence for people living a healthy lifestyle," he said. "They had a virtual cornucopia of food at their disposal.
"Palau could be seen as relatively isolated," he added, "but we have archaeological evidence of prehistoric interactions between Palau and other places."
Berger‘s team concluded last March that dwarfism on Palau would force a new interpretation of remains found in 2003 (also with National Geographic Society funding) on the Indonesian island of Flores. (Read about the Flores find in National Geographic magazine.)
With a full-grown individual of about three feet (a meter), the Flores skeleton, nicknamed the Hobbit, is even smaller than the Palau remains and considered by many to be a new species, Homo floresiensis.
But Berger and colleagues said dwarfism in the Palau remains could mean Hobbits on Flores were not so unique. Humans may have quickly shrunk in stature during evolution on several islands, and Flores Hobbits may simply have shrunk more, they suggested.
Fitzpatrick‘s team now says Berger misinterpreted fragmentary fossils.
Florida State University anthropologist Dean Falk called Fitzpatrick‘s new paper a "slam dunk."
Falk has conducted brain research on LB1—a Flores "hobbit" who lived 18,000 years ago—and concluded that it represents a new species.
"This is a rigorous, very thorough scientific analysis, and I find it totally convincing," Falk said of the work by Fitzpatrick‘s team.
"They [explore] the chronology, they ask about language, they ask about migrations, they look at the archaeological record, and most importantly they look at body size and the various hypotheses," she said.
Missing the Point?
Berger, who led the earlier Palau study, said the current research misinterprets his findings.
"Fitzpatrick et al say that their Palauan sample is pygmy sized, [that] pygmy sized is normal in the pacific islands, and therefore our sample is ‘normal in size‘ for islands—small bodied compared to all other humans.
"The point of our original paper, where body size was concerned, was quite simply to point out this very fact because of the euphoria around the small body size of Flores—it‘s actually quite normal, and you don‘t have to look very far around these islands to find it."
Berger added that his observations of facial morphology variation and frequent pathologies are supported by the same logic.
"If pathologies can take hold relatively easily in island populations, and thus appear in high[er] frequencies than in other contexts, then isn‘t the argument that this might be just the case in Flores worth pointing out?"
The Debate Continues
William Jungers, an anthropologist at Stony Brook University, is currently continuing excavations in Flores‘s "hobbit" cave.
He believes the "primitive" features of the Palauans suggested by Berger are nothing more than natural human variation.
"Fitzpatrick et al show in no uncertain terms that there is no need for the complex evolutionary scenario proposed by Berger et al because the prehistoric Palauans were not island ‘dwarfs‘ in any sense of the term, but rather of normal body size, well within the range of variation known for people from this region of the world," he said.
"As such, the Palauan fragments reported by Berger et al are simply irrelevant to discussions of Homo floresiensis."
Robert Eckhardt, a professor of developmental genetics and evolutionary morphology at Pennsylvania State University in University Park, disagrees.
He‘s published research suggesting that the Flores "Hobbits" are not a unique species but pygmy human ancestors.
Eckhardt believes that if the Palau specimens are human, it creates "huge problems" for classification of the Flores "Hobbits" as a new species.
And so the debate continues. Brian Handwerk
Source: http://news.nationalgeographic.com (August 27, 2008)
