News from the “hobbit conference” in New York

April 28, 2009 • 5:56 am

The hobbit continues to be a mystery: perhaps the deepest mystery about human evolution. Today’s New York Times has a longish and interesting report on the status of the “hobbit,” Homo floresiensis, that I’ve posted about several times.  This is a diminutive (3-foot-tall) human skeleton found on the island of Flores, in Indonesia, that has a brain case not much larger than those of modern chimps.  It is, however, modern in time, going back only about 18,000 years ago (see chapter 8 of WEIT).  Based on its wrist bones and other skeletal characteristics, scientists are now beginning to think it was not an aberrant or diseased individual, but a representative of a distinct species, perhaps an earlier species of hominin that became isolated on Flores hundreds of thousands or even millions of years ago:

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. . . . .

. . . 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.

It’s possible that hobbits represented a much earlier migration out of Africa than previously thought, earlier than the migration that gave rise to the widespread Homo erectus.  It could even represent a migration of the very early australopithecines!   As John Noble Wilford, the writer, says, lots of puzzles remain:

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.

Stay tuned; I’ll provide further information on this strange branch of our family tree as more research is published.  Be sure to listen to the 20-minute podcast on the Times website.  Meanwhile, courtesy of the NYT, here is the hobbit’s tiny foot (notice that the ruler is 5 cm long: about 2 in., which makes the foot about 6 inches long).

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Is “The Hobbit” a fraud?

February 1, 2009 • 10:50 am

As recounted in WEIT, one of the most remarkable hominin fossils is that of Homo floresiensis, discovered on the island of Flores in Indonesia in 2003. This creature was remarkable in that although it lived only 18,000 years ago, when modern H. sapiens had already evolved, it was only a meter tall, weighed 50 pounds, and had a brain of less than 500 cc.–similar in size to of our distant cousin Australopithecus afarensis (“Lucy”). It seemed that some relict populations of Homo had survived on this Indonesian island, bypassed by modern humans.

Ever since H. floresiensis (dubbed “The Hobbit”) was found, it has been the center of heated controversy. Some have said that rather than being a long-surviving ancient hominin, for example, the one good specimen found is simply that of a modern human afflicted with a growth disease (such as goiterious cretinism) that produced a small skull. Others counter-claim that the wrist bones of the hobbit are clearly not that of a modern human, but of an earlier relative.

Now another criticism has surfaced–the claim that the hobbit’s teeth show dental work! In particular, an anthropologist at the University of Adelaide in Australia, Maciej Henneberg, claims that a lower molar of H. floresiensis shows a filling (and possibly a root canal) of the type performed in Indonesia in the 1930s. (See the articles about this claim here and here.) Could the hobbit be another Piltdown Man, a fraud foisted on a credulous scientific community?

Well, probably not. In a careful analysis of the dentition of H. floresiensis and a comparison with other ancient skulls, Peter Brown, one of the hobbit’s discoverers, debunks Henneberg’s claims. X rays and careful analysis (see the pictures on Brown’s page) show absolutely no evidence of dental work. Thus this claim, at least, has been debunked.

It is starting to look as if H. floresiensis really was a genuine species, but an anomalous one: a small population of tiny humans who hunted dwarf elephants with miniature spears. There will undoubtedly be more argument before this is settled.

flores_sapiens

H. floresiensis (l.), H. sapiens (r.). Photograph courtesy of National Geographic news.