<tr><td align="center">Image:Cover of Nature October 2004-Homo floresiensis.jpg
Homo floresiensis cranium.
On the cover of Nature. <tr><th bgcolor=pink>Scientific classification <tr><td>

Homo floresiensis

Homo floresiensis


Conservation status: Prehistoric

<tr><td>Kingdom:<td>Animalia <tr><td>Phylum:<td>Chordata <tr><td>Subphylum:<td>Vertebrata <tr><td>Class:<td>Mammalia <tr><td>Order:<td>Primates <tr><td>Family:<td>Hominidae <tr><td>Genus:<td>Homo <tr><td>Species:<td>H. floresiensis </table> <tr><th bgcolor=pink>Binomial name <tr><td align="center">Homo floresiensis
P. Brown et al., 2004 </table> Homo floresiensis ("Man of Flores") is a newly described species in the genus Homo, remarkable for its small body, small brain, and recent survival, thought to have been contemporaneous with modern humans (Homo sapiens) on the remote Indonesian island of Flores. Seven skeletons and associated stone tools were discovered on Flores in 2003. Flores has been described (in the journal Nature) as "a kind of Lost World", where archaic animals, elsewhere long extinct, had evolved into giant and dwarf forms through allopatric speciation. The island had dwarf elephants (a species of Stegodon) and giant lizards akin to the Komodo dragon, as well as Homo floresiensis, which can be considered a species of dwarf human. The discoverers have nicknamed the diminutive species hobbits, after J.R.R. Tolkien's fictional race of roughly the same height.
Contents
1 Discovery
2 Small bodies
3 Small brains
4 Recent Survival
5 Significance
6 Reaction
7 References
8 External links

Discovery

The first (and so far only) specimens were discovered by a joint Australian-Indonesian team of paleoanthropologists and archaeologists looking on Flores for evidence of the original human migration of Homo sapiens from Asia into Australia. They were not expecting to find a new species, and were quite surprised at the recovery of the remains of at least seven individuals, from 95,000 to 12,000 years old, from the Liang Bua limestone cave on Flores.

The specimens are not fossilized, but were described as being "the consistency of wet blotting paper" (Nature News article (http://www.nature.com/news/2004/041025/full/4311029a.html)). Researchers hope to find preserved mitochondrial DNA to compare with samples from similarly unfossilised specimens of H. neanderthalensis and H. sapiens. The likelihood of there being preserved DNA is, however, low, as it degrades more rapidly in warm tropical environments; in such conditions it is known to degrade in as little as a few dozen years. Contamination from the surrounding environment seems highly possible given the moist environment in which the specimens were found.

Small bodies

Homo erectus, thought by the discoverers to be the immediate ancestor of Homo floresiensis, was approximately the same size as another descendant species, modern humans. In the limited food environment on Flores, however, Homo erectus is thought to have undergone strong island dwarfing, a form of allopatric speciation also seen on Flores in a dwarf species of Stegodon (an extinct genus of elephant) and other species as well as on other small islands.

Despite the size difference, the specimens seem otherwise to resemble in their features H. erectus, known to be living in Southeast Asia at times coinciding with earlier finds of H. floresiensis. These observed similarities form the basis for the establishment of the suggested phylogenetic relationship. Despite a controversial reported finding by the same team of alleged material evidence of a H. erectus occupation 840,000 years ago, actual remains of H. erectus itself have not been found on Flores, much less transitional forms.

The type specimen for the species is a fairly complete skeleton and near-complete skull of a 30-year-old female about 1 metre (3 feet 3 inches) in height. Not only is this a drastic reduction compared to H. erectus, it is even somewhat smaller than the three million years more ancient ancestor Australopithecines, not previously thought to have expanded beyond Africa. This tends to qualify H. floresiensis as the most "extreme" member of the extended human family. They are certainly the shortest and smallest.

H. floresiensis is also rather tiny compared to the modern human height and size of all peoples today. The estimated height of adult H. floresiensis is considerably shorter than the average adult height of even the physically smallest populations of modern humans, such as the African Pygmies (< 1.5 m, or 4 ft. 11 in.), Twa, Semang (1.37 m, or 4 ft. 6 in. for adult women), or Andamanese (1.37 m, or 4 ft. 6 in. for adult women). Mass is generally considered more biophysically significant than a one-dimensional measure of length, and by that measure, due to effects of scaling, differences are even greater. The type specimen of H. floresiensis has been estimated as perhaps about 25 kg (55 lb).

H. floresiensis had relatively long arms, perhaps allowing this small creature to climb to safety in the trees when needed.

Inevitable comparisons with modern human achondroplasiacs (about 1.2 m, or 3 ft. 11 in.) or other dwarfs, are flawed, as these people are not generally proportionally smaller than other humans, only short-limbed.

Small brains

In addition to a small body size, H. floresiensis had a remarkably small brain. The type specimen, at 380 cm³(23 in³), stands on the lower range of the ancient Australopithecines, or chimpanzees. The brain is reduced even more than body size relative to this species' presumed immediate ancestor H. erectus, which at 980 cm³ (60 in³) had more than double the brain volume of its descendant species. Despite this, the discoverers have associated the species with some advanced behaviors. There is evidence of the use of fire for cooking. More incredibly, the species has been associated with stone tools of the sophisticated Upper Paleolithic tradition typically associated with modern humans, who at 1310-1475 cm³ (80-90 in³) nearly quadruple the brain volume of H. floresiensis. Some of these tools were apparently used in the necessarily cooperative hunting of local dwarf Stegodon by this small human species.

Flores, because of a deep neighboring strait, remained isolated during the most recent ice age despite the low sea levels that united much of the rest of Sundaland. This has led the discoverers of H. floresiensis to conclude that the species or its ancestors could only have reached the isolated island by water transport, perhaps arriving in bamboo rafts around 100,000 years ago. This perceived evidence of advanced technology and cooperation on a modern human level has prompted the discoverers to hypothesize that H. floresiensis almost certainly had language. These suggestions have proved the most controversial of the discoverers' findings.

Recent Survival

The other remarkable aspect of the find is that this species is thought to have survived on Flores until at least as recently as 12,000 years ago. This makes it the longest-lasting non-modern human, long outsurviving the Neanderthals (Homo neanderthalensis) who went extinct about 30,000 years ago. H. floresiensis certainly coexisted with modern humans, who arrived in the region 35,000-55,000 years ago, for a long time, but it is unknown how they may have interacted.

Local geology suggests that a volcanic eruption on Flores was responsible for the demise of H. floresiensis in the part of the island under study at approximately 12,000 years ago, along with other local fauna, including the dwarf Stegodon.

The discoverers suspect, however, that this species may have survived longer in other parts of Flores to become the source of the Ebu Gogo stories told among the local people. The Ebu Gogo are said to have been small, hairy, language-poor cave-dwellers on the scale of H. floresiensis. Widely believed to be present at the time of the Dutch arrival five hundred years ago, these strange creatures are said to have last been spotted just a century ago.

Significance

The discovery is widely considered the most important of its kind in recent history, and came as a surprise to the anthropological community. The new species challenges many of the ideas of the discipline.

H. floresiensis is so different in form from other members of genus Homo that it forces the recognition of a new, undreamt-of variability in that group, and reaffirms an intellectual trend away from the idea of linear evolution.

No doubt this discovery provides more fuel for the fire of the perennial debate over the Out-of-Africa or Multiregional models of the speciation of modern humans, despite H. floresiensis not itself being an ancestor of modern humans. Already, voices have been heard arguing it furthers either side.

If it is confirmed that a creature with such a small brain was capable of such advanced behavior and even language, then many theories about the evolution of intelligence will need to be rethought.

The discovers of H. floresiensis fully expect to find the remains of other, equally divergent Homo species on other isolated islands of Southeast Asia, and do not think it impossible, if not quite "likely", that some lost Homo species could be found still living in some unexplored corner of jungle.

Henry Gee, a senior editor of the journal Nature, has agreed, saying, "Of course it could explain all kinds of legends of the little people—They are almost certainly extinct, but it is possible that there are creatures like this around today. Large mammals are still being found. I don't think the likelihood of finding a new species of human alive is any less than finding a new species of antelope, and that has happened."

Reaction

Professor Teuku Jacob, chief paleontologist of the Indonesian Gajah Mada University, disagrees with the placement of the new finds into a new species of Homo. "It is a sub-species of homo sapiens classified under the Austrolomelanesid race," he said. He will attempt to prove that the find is from a 25-30 year-old omnivorous subspecies of Homo sapiens, and not a 30-year-old female of a new species. He is convinced that the small skull is that of a mentally defective human.

References

H. floresiensis was first described in two papers which appeared in the journal Nature, a year after the discovery:

External links


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