Hobbit revisited


September 24, 2007

In a paper appearing on September 20 in Science, analysis of the wrist bones of Homo floresiensis demonstrates this skeleton could not be a dwarf human, as has been argued. The paper also adds to the accumulating evidence the specimen is a strange mix of nearly modern and very primitive characteristics.

In a cave called Ling Bua on the small island of Flores east of Bale, Australian and Indonesian scientists in 2004 found the fossilized skeleton, no more than three feet high, of an individual looking remarkably human like and dated to about 18,000 years ago. Immediately there arose two contending theories: she (the remains are most likely female) was either a modern human from the late Stone Age whose anatomy had been determined by "island dwarfism" - the tendency of animals in shrinking habitats, such as this island is, to reduce their size over many generations in order to reduce their food needs - or an example of Homo erectus, known to have arrived in Asia about one million years ago, and the group of which this specimen was a member survived until very recent times.

The authors of the paper entitled "The Primitive Wrist of Homo floresiensis and Its Implications for Hominin Evolution" (link below) argue the wrist bones are closer to the Australopithecines than modern humans, They say "Analysis of three wrist bones from the holotype specimen (LB1) shows that it retains wrist morphology that is primitive for the African ape-human clade." And add "This evidence indicates that LB1 is not a modern human with an undiagnosed pathology or growth defect; rather, it represents a species descended from a hominin ancestor that branched off before the origin of the clade that includes modern humans, Neanderthals, and their last common ancestor."

The more modern, more flexible wrist appeared in Homo erectus about 800,000 years , according to the authors. Three years ago, noted paleontologist Chris Stringer, writing in Nature (link below) three years ago noted this mixture of primitive and derived (more modern) characteristics and said "... The small brain size and the hip-bone shape might favor classification as an australopithecine, whereas the size and shape of the skull might suggest a primitive form of H. erectus."

The recent Science paper should close the door on the argument favoring floresiensis as a dwarf but essentially modern human, while leaving unresolved the mystery of the combination of Australopithecus and Homo in this diminutive creature.

Additional information: