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morfrain_encilgar
Monday, May 30th, 2005, 07:30 PM
Bones of Contention : Is a small, 18,000-year-old skeleton the older cousin of modern-day Pygmies - or a new human species?

(Simon Elegant)

"In those days we ate our meat raw, like animals." The speaker is Viktor Jurubu, an Indonesian farmer in his 60s, who, in his T shirt and sarong, looks little like the cavemen he's describing. Except for his height, which is about 140 cm. In the world of anthropology, Jurubu's small size is big news because he and his 246 fellow villagers of Rampasasa on the remote island of Flores say they are descended from a tribe of tiny, hairy folk whom they call "the short people." "We didn't have knives but used rocks," he explains. "We didn't even know how to make fire." Jurubu, a soft-spoken man with close-cropped gray hair, high cheekbones and deeply inset eyes, looks to the 30 or so villagers sitting in a circle around him for confirmation. They nod and grunt assent, and he proceeds to talk about the time their shy ancestors hid themselves from the outside world in Liang Bua, a high-ceilinged cavern scooped out of a limestone hill about a kilometer away. Again a chorus of agreement. "Tell how Paju left the cave and married one of the normal humans," calls out a voice from the crowd, "[and] how we came to live here in Rampasasa." Jurubu hesitates. After a pause, he opens his mouth to speak, but his words are drowned out by an impatient babble of voices competing to tell the story.

The inhabitants of Rampasasa insist their claimed genealogy is no tall tale. Indeed, among the rattan-and-thatch shacks of what otherwise seems an ordinary if very poor Flores village, it's hard not to notice the large number of very short people, particularly among the older folk, some of whom are the same height as a typical 10-year-old. Some six generations of intermarriage with outsiders, says Rampasasa's headman Alfredus Ontas, have left few truly tiny individuals. But to prove their antecedents, he and other locals eagerly display photos of recently deceased relatives whom they say were of purer "short people" stock. "The brothers in this photograph were only 110 cm," Ontas says proudly, his broad smile revealing jagged teeth stained ox-blood red by betel nut. Another elder is introduced, who, as well as measuring only 135 cm tall, has a pelt of hair covering his arms and legs. "It was because we were so hairy that our ancestors hid in Liang Bua," says Jurubu. "They were embarrassed."

Today, it's the villagers of Rampasasa who are causing others to be, if not embarrassed, then at least flustered. Liang Bua is where a team of Australian and Indonesian scientists reported in Nature magazine last October that they had discovered the bones of seven individuals ranging in age from 13,000 to 95,000 years old. (Another set was found later.) Among the findings: a nearly intact skeleton that the anthropologists said belonged to an adult female who lived as recently as 18,000 years ago yet was only the size of a modern-day 6-year-old. Because the female skeleton looked humanoid rather than human and the brain size was small, the researchers concluded she was not a Pygmy—a short but otherwise normal version of Homo sapiens you still find in equatorial Africa and pockets of Southeast Asia—but a member of an entirely new species whom its discoverers named Homo floresiensis. This species, say the scientists, probably branched off from Homo erectus, the commonly accepted ancestor of Homo sapiens. The news meant that the two different human species H. sapiens and H. floresiensis had been living parallel lives on earth at the same time. (The existence of H. sapiens dates back 250,000 years.) The story made headlines worldwide—TIME covered it last November, and National Geographic ran a lengthy feature in its April 2005 edition.

Now, however, the presence of small people living within strolling distance of Liang Bua has cast doubt over the separate-species theory, and sparked a bitter split in scientific circles over its validity. Battle lines have been drawn, with each side vigorously trying to discredit the other. Rampasasa "makes the short-stature argument completely irrelevant," says skeptic Alan Thorne, an anthropologist at the Australian National University. "There are plenty of Pygmies in that area. In the case of these bones, it was probably a diseased Pygmy." Counters Peter Brown, the University of New England paleoanthropologist who co-wrote the Nature report with a colleague, archaeologist Michael Morwood: "Of course, there are small-bodied people on Flores, but they don't have brains one-third the size of ours, or unusually shaped pelvises or very long arms like H. floresiensis. They are just small modern humans."

For Henry Gee, an editor at venerable Nature who was responsible for overseeing publication of the original H. floresiensis article, such squabbling is par for the course. "Science is a disputatious business, and human evolution is notorious for being even more disputatious. historically, whenever anyone discovers a new hominid, a lot of people come along and say it's an ape or a diseased human." Gee, who says the critics haven't shaken his belief that a new species has been found, cites the example of another hotly debated discovery, that of Australopithecus africanus in 1924, the so-called "missing link" between apes and human ancestors. "Nature published that paper too and all the great and good in the scientific establishment refused to believe it." It took 25 years, but eventually the discovery was accepted, Gee says, noting that it will be a while before H. floresiensis achieves complete acceptance as well. "They're going to have to discover some more bones that prove this, but we have history on our side."

Critics of the H. floresiensis hypothesis, meanwhile, are working overtime to disprove it. Thorne and a colleague spent three days in February examining the Liang Bua bones in Jakarta on the invitation of Teuku Jacob, Indonesia's most senior anthropologist, who gained possession of the bones for a brief period before handing them back to the Australian-Indonesian team that made the discovery. Thorne and another Australian scientist subsequently wrote a paper flatly rejecting the idea that a new species had been discovered. Jacob, who is among the fiercest critics of the H. floresiensis theory and has been accused by Brown of damaging the bones while they were in his possession (a charge he denies), led an expedition to Rampasasa in April to determine if its residents could indeed be classified as Pygmies (the height threshold is 150 cm or shorter). Jacob measured more than 70 villagers and says 80% of them qualified. The theory that Thorne, Jacob and other like-minded anthropologists are propagating is that the Liang Bua female was an ancestor of a Rampasasa villager and a Pygmy, but that she suffered from microcephaly, a condition that causes abnormally slow skull growth. Says Jacob: "They say they have eight specimens. But there is only one skull and that could be microcephalic. The rest could just be Pygmies and that is even more likely now that we know people in the area around the cave are also Pygmies." Brown's response to Jacob's assertion: "Complete rubbish" and "sour grapes."

The virulence of the invective isn't surprising given what's at stake. If proved correct, the existence of H. floresiensis would be nothing less than a revolution in the understanding of human evolution. It's not just that a new species has been claimed to be found, itself an event of seismic proportions. Conventional anthropological wisdom holds that animals, in the absence of big predators, shrink to adapt to life on small, closed habitats like Flores, a phenomenon known as island dwarfism. Humans, however, are thought to have evolved linearly, developing bigger bodies and brains. H. floresiensis, relatively modern yet small—but not a Pygmy, according to its supporters—explodes that theory. "[It'd] go completely against the flow of human evolution," says Thorne. "This would undo everything that we are." Even if the island-dwarfing process did indeed shrink H. floresiensis, says Robert Martin, curator at the Field Museum in Chicago and author of a widely cited textbook on human evolution, the grapefruit size of the brain is too small. "Brains do not shrink proportionally to bodies in a species but remain relatively large," says Martin. "That's why the heads of small dogs, for example, are proportionally large for their bodies compared with larger dogs. To get a brain this size, H. erectus would have to have shrunk to about 3% of its previous 60-kg size. That's about the size of a house cat's." Martin says one thing would persuade him—more physical evidence: "Show me eight more similar skulls from the site and I'll shut up."

The argument should have been at least partly settled by a study conducted by a group of Australian, U.S. and Indonesian scientists (including Brown and Morwood) earlier this year that used computer tomography and 3-D reconstruction techniques to model the brain of H. floresiensis. The resulting paper, published in the journal Science in March, contended that the findings supported the theory of a new species and strongly downplayed the possibility of a disease like microcephaly playing a role. But critics remained unconvinced, citing flaws in the study, such as the suitability of skulls used for comparison. Even one of the paper's authors, Washington University radiologist Charles Hildebolt, conceded that secondary microcephaly (the type not inherited but acquired during life) could not be ruled out.

Controversy over the existence of Pygmies in Indonesia's numberless islands is centuries-old. Writing in the 14th century, Marco Polo described how natives of Sumatra would try to sell the mummified bodies of Pygmies to visitors. But, wrote Polo, "'tis all a lie and cheat. Those ... little men ... are manufactured on the island. There is a kind of monkey on the island which is very small and has a face just like a man's. They take these and pluck out all the hairs except on the beard and chest and then they dry them and stuff them and daub them with saffron until they look like men."

In the village of Rampasasa, Viktor Jurubu harbors no such doubts. He has the floor again and is recounting the story of how Paju, a famous warrior, ran into one of the "normal" people in the woods one day while out hunting. "This beautiful lady lit a fire and cooked the wild boar Paju had killed," Jurubu says. "She wanted to marry him and knew she could tempt him with the taste of cooked meat. He did like the taste, so he agreed to marry her and come out of Liang Bua with the rest of the tribe, founding a new village."

And the bones in the cave? "Of course, they were our ancestors," says Jurubu, with a touch of rheumy indignation. "They must have retreated into the cave after a hunt and got caught there when the river rose. Who else could it be?" That's proving to be a question for the ages.

Dr. Solar Wolff
Wednesday, June 8th, 2005, 02:28 AM
It is time for genetic testing on these people. These people could prove multi-regionalism was a factor in human evolution once and for all.