From the New York Times:
By JOHN NOBLE WILFORD
The dispute over the “little people” of Flores continues, unabated.
The bones and a single skull of these “little people” are believed to be remains of a separate species of the human family that lived about 18,000 years ago on an island in Indonesia, as the scientists who made the sensational discovery concluded in 2004.
But persistent skeptics have contended in a recent flurry of scientific reports that they were nothing more than modern humans with unusually small bodies possibly malformed by genetic or pathological disorders.
Neither side is backing off in this sometimes bitter row, which intensified last week with the announcement of the discovery that in Palau, in the Western Caroline Islands of Micronesia, other abnormally small-bodied people had lived long ago. Their bones were found in two caves and described in the online journal PloS One.
Lee Berger, a paleoanthropologist at the University of Witwatersrand in Johannesburg and his colleagues said the Palauan bones, representing at least 25 individuals, were from modern humans about four feet tall, close in size to some pygmies living in this region of the Pacific. Populations on isolated islands with limited resources often evolve short statures.
The Palauan specimens shared facial, chin and dental traits with the Flores people, the scientists said, but had larger braincases “possibly at the very low end or below that typically observed in modern, small-bodied humans.”
For these and other reasons, the scientists say, these Palauan people, who lived from 1,400 to 3,000 years ago, suggest the possibility that the Flores people were not a distinct species, designated Homo floresiensis, but “simply an island adapted population of Homo sapiens, perhaps with some individuals expressing congenital abnormalities.”
In previous reports and interviews, other skeptical scientists have contended that the extremely small brain size of the Flores people, close to that of a chimpanzee, was more likely a consequence of any number of growth disorders. Teuku Jacob, an Indonesian paleoanthropologist who was one of the first to examine the Flores bones, immediately suspected microcephaly, a genetic condition causing a small head.
This hypothesis has been argued back and forth, and last month an Australian scientist offered another possible explanation. The scientist, Peter Obendorf of RMIT University in Melbourne, reported that an image of the base of the Flores skull showed evidence of an enlarged pituitary gland, suggesting the individual may have suffered from cretinism, which can cause stunted growth and a small brain.
The two principal scientists who advanced the separate-species thesis — Peter Brown, a paleoanthropologist, and Michael Morwood, an archaeologist, of the University of New England in Armidale, Australia — have said they are unmoved by the criticism. And prominent experts on early humans have endorsed the new-species interpretation, including Tim D. White of the University of California, Berkeley, and Chris Stringer of the Natural History Museum in London.
After the publication of Dr. Berger’s findings, Bernard Wood, a paleoanthropologist at George Washington University, said, “Obviously the Flores material came as a bit of a surprise to many of us, but it was not a surprise that might not have been anticipated.”
Dr. Wood, who was not involved in the original research, said the one fairly complete Flores skeleton and other fragments have got “all sorts of intriguing morphology” that distinguishes the individuals from modern humans. He and a group of other scientists have prepared their own assessment in a report to be published in The Proceedings of the National Academy of Sciences.
“All of these exotic explanations being proposed require the suspension of any fragment of common sense,” Dr. Wood said. “They are seeking a much more exotic explanation than the one for a distinct species that looks like an earlier Homo.”
Dean Falk, an anthropologist at Florida State University who has examined casts of the Flores braincase, disputed the microcephaly argument and the Berger paper.
In a study comparing the Flores specimen with known microcephalics, Dr. Falk and researchers at the Mallinckrodt Institute of Radiology at Washington University concluded three years ago that the ancient individual did not suffer such a disorder. Its wide brain and frontal lobes, she said, were not like the brains of microcephalics.
“Suites of features from head to feet set the Flores individuals apart from Homo sapiens, which is why this is a new species,” she said in an interview.
William L. Jungers, a paleoanthropologist at the State University of New York at Stony Brook who has worked closely with the Flores researchers, said in an e-mail message that the Berger paper “is really much ado about nothing,” adding that modern human pygmies of the size reported on Palau “are old news in this part of the world.”
Dr. Jungers said that none of these small-bodied humans “are as short as the various individuals of Homo floresiensis” or have similar limb proportions, cranial capacity, jaw anatomy, wrist bones and other characteristics.
The new-species proponents concede that they would have a stronger case if it rested on more than a single skeleton with a skull and assorted bones of about 12 other individuals.
Dr. Berger, whose research at Palau was supported by the National Geographic Society, emphasized in an interview, “I’m not on either side of this debate.” But he defended his report, which he said was preliminary yet based on substantial fieldwork and analysis, as a contribution to “the discussion of modern human variations that has been missing in the Flores debate.” These variations, he added, “occur with high frequency or we would not have found them so readily.”