Read the whole article.
A Tiny Hominid With No Place on the Family Tree STONY BROOK, N.Y. — Six years after their discovery, the extinct little people nicknamed hobbits who once occupied the Indonesian island of Flores remain mystifying anomalies in human evolution, out of place in time and geography, their ancestry unknown. Recent research has only widened their challenge to conventional thinking about the origins, transformations and migrations of the early human family.
Indeed, the more scientists study the specimens and their implications, the more they are drawn to heretical speculation.
*Were these primitive survivors of even earlier hominid migrations out of Africa, before Homo erectus migrated about 1.8 million years ago? Could some of the earliest African toolmakers, around 2.5 million years ago, have made their way across Asia?
*Did some of these migrants evolve into new species in Asia, which moved back to Africa? Two-way traffic is not unheard of in other mammals.
*Or could the hobbits be an example of reverse evolution? That would seem even more bizarre; there are no known cases in primate evolution of a wholesale reversion to some ancestor in its lineage.
The possibilities get curiouser and curiouser, said William L. Jungers of Stony Brook University, making hobbits “the black swan of paleontology — totally unpredicted and inexplicable.”
Everything about them seems incredible. They were very small, not much more than three feet tall, yet do not resemble any modern pygmies. They walked upright on short legs, but might have had a peculiar gait obviating long-distance running. The single skull that has been found is no bigger than a grapefruit, suggesting a brain less than one-third the size of a human’s, yet they made stone tools similar to those produced by other hominids with larger brains. They appeared to live isolated on an island as recently as 17,000 years ago, well after humans had made it to Australia.
Although the immediate ancestor of modern humans, Homo erectus, lived in Asia and the islands for hundreds of thousands of years, the hobbits were not simply scaled-down erectus. In fact, erectus and Homo sapiens appear to be more closely related to each other than either is to the hobbit, scientists have determined.
It is no wonder, then, that the announcement describing the skull and the several skeletons as remains of a previously unknown hominid species, Homo floresiensis, prompted heated debate. Critics contended that these were merely modern human dwarfs afflicted with genetic or pathological disorders.
Scientists who reviewed hobbit research at a symposium here last week said that a consensus had emerged among experts in support of the initial interpretation that H. floresiensis is a distinct hominid species much more primitive than H. sapiens. On display for the first time at the meeting was a cast of the skull and bones of a H. floresiensis, probably an adult female.
Several researchers showed images of hobbit brain casts in comparison with those of deformed human brains. They said this refuted what they called the “sick hobbit hypothesis.” They also reported telling shoulder and wrist differences between humans and the island inhabitants.
Even so, skeptics have not capitulated. They note that most of the participants at the symposium had worked closely with the Australian and Indonesian scientists who made the discovery in 2003 and complain that their objections have been largely ignored by the news media and organizations financing research on the hobbits.
Some prominent paleoanthropologists are reserving judgment, among them Richard Leakey, the noted hominid fossil hunter who is chairman of the Turkana Basin Institute at Stony Brook University. Like other undecided scientists, he cited the need to find more skeletons at other sites, especially a few more skulls.
Mr. Leakey conceded, however, that the recent research “greatly strengthened the possibility” that the Flores specimens represented a new species.
At the symposium, Michael J. Morwood, an archaeologist at the University of Wollongong in Australia who was one of the discoverers, said that further investigations of stone tools had determined that hominids arrived at Flores as early as 880,000 years ago and “it is reasonable to assume that those were ancestors of the hobbits.” But none of their bones have been uncovered, so they remain unidentified, and no modern human remains have been found there earlier than 11,000 years ago.
Excavations are continuing at Liang Bua, a wide-mouth cave in a hillside where the hobbit bones were found in deep sediments, but no more skulls or skeletons have turned up. Dr. Morwood said the search would be extended to other Flores sites and nearby islands.
Peter Brown, a paleontologist at the University of New England in Australia, said that his examination of the premolars and lower jaws of the specimens made it almost immediately “very, very clear that this was a hominid in the wrong place at the wrong time.” The first premolars in particular, he said, were larger than a human’s and had a crown and roots unlike those of H. sapiens or H. erectus.
Dr. Brown, a co-author of the original discovery report, said that no known disease or abnormality in humans could have “replicated this condition.”
At first, Dr. Brown and colleagues hypothesized that the hobbits were descendants of H. erectus that populated the region and had evolved their small stature because they lived in isolation on an island. Island dwarfing is a recognized phenomenon in which larger species diminish in size over time in response to limited resources.
The scientists soon backed off from that hypothesis. For one thing, dwarfing reduces stature, but not brain size. Moreover, researchers said, the hobbit bore little resemblance to an erectus.
In an analysis of the hobbit’s wrist bones, Matthew W. Tocheri of the Smithsonian Institution found that certain bones were wedge-shaped, similar to those in apes, and not squared-off, as in humans and Neanderthals. This suggested that its species diverged from the human lineage at least one million to two million years ago.
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Saturday, May 02, 2009
NYT - A Tiny Hominid With No Place on the Family Tree
I just watched a show on the History Channel about this fossil discovery - so this article was a welcome addition to what we think we know about the strangest set of human fossils so far discovered.
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