National Geographic : 2005 Apr
(Continuedfrom page 7) from elsewhere in East Asia but of older, smaller erectus fossils. Viewed from above, the skull is pinched in at the temples, a feature also seen in the 1.77-million year-old Dmanisi people from Georgia, in west ern Asia. And in some respects, such as the shape of her lower jaw, the Liang Bua hominin harks back to even earlier fossils such as Lucy, the 3.2 million-year-old Australopithecusfrom Ethiopia. And yet-strangest of all-she lived practi cally yesterday. Radiocarbon dating of charcoal pieces found next to the skeleton, together with luminescence dating that indicated when the sur rounding sediments were last exposed to the sun, revealed her 18,000-year age. By mid-2004 our excavation at Liang Bua had yielded bones and teeth from at least six other individuals, from about 95,000 until as recently as 13,000 years ago. For a few skeptics, all this is too much to swal low. They argue that the one complete skull must have come from a modern human with a rare condition called microcephaly, in which the brain is shrunken and the body dwarfed. The other small bones, they say, might be the remains of children. But last year's discoveries include part of a second adult skull-a lower jaw-that is just as small as the first. It simply strains credibility to invoke a rare disease a second time. Instead, Hobbit is our first glimpse of an entirely new human species: Homoflores iensis. Her kind probably evolved from an earlier Homo erectus population, likely the makers of the tools Verhoeven found. Her ancestors may have stood several feet taller at first. But over hundreds of thousands of years of isolation on Flores, they dwindled in size. Such dwarfing is often the fate of large mam mals marooned on islands. There they generally face fewer predators-on Flores, Komodo drag ons were the only threat-which makes size and strength less important. And the scarce food resources on a small island turn a large, calorie hungry body into a liability. On mainland Asia, stegodonts sometimes grew bigger than African elephants; at Liang Bua they were only a bit bigger than present-day water buffalo. In the past some anthropologists have argued that even in prehistory humans could adapt to new environments by inventing new tools or behaviors rather than by physically evolving, like other creatures. The dwarfing seen on Flores is 12 NATIONAL GEOGRAPHIC * APRIL 2005 powerful evidence that humans aren't exempt from natural selection. The discovery of Hobbit is also a hint that still other human variants may once have inhabited remote corners of the world. In spite of their downsized brains, the little people apparently had sophisticated technology. The fireplaces, charred bones, and thousands of stone tools we found among their remains must have been their handiwork, for we found no sign of modern humans. Stone points, probably once hafted onto spears, turned up among stegodont bones, some of which bore cut marks. The little hominins were apparently hunting the biggest animals around. It was surely a group activity adult stegodonts, although dwarfed, still weighed more than 800 pounds, formidable prey for hunters the size of preschool children. The discovery underscores a puzzle going back to Theodor Verhoeven: How could ancient hom inins ever have reached Flores? Was Homo erec tus a better mariner than anyone suspected, able to build rafts and plan voyages? And it raises a new and haunting question. Modern humans colonized Australia from mainland Asia about 50,000 years ago, populating Indonesia on their way. Did they and the hobbits ever meet? There's no sign of modern humans at Liang Bua before 11,000 years ago, following a large volcanic eruption that would have wiped out any Homofloresiensisin the region. But other bands may have hung on elsewhere in Flores. Perhaps modern humans did meet their ancient neigh bors before something-maybe a changing environment, maybe competition or conflict with modern humans themselves-spelled the end for the little people. Further excavations on Flores, and on nearby islands that might have had their own hobbits, may settle the question. In the meantime a clue may come from local folktales about half-size, hairy people with flat foreheads-stories the islanders tell even today. It's breathtaking to think that modern humans may still have a folk memory of sharing the planet with another species of human, like us but unfathomably different. The Australian Research Council supportedthis work; your Society will help sponsorfuture study. O HOBBIT: A WHOLE NEW KIND OF HUMAN Share your thoughts in our forum and see how artists and scientists created athree-dimensional model of the Flores hominin-from bone to flesh-at nationalgeographic.com/magazine/0504.