|23 November 2009
Early humans may have been 'hobbits', scientists say
Since its 2003 discovery on the Indonesian island of Flores, the Homo floresiensis (nicknamed 'hobbit' because it only grew to be about three feet tall) has caused scientists across the world to debate whether the find is a new species or simply a variation of the modern human. The difference could signal a major paradigm shift in the study of primitive humans.
The earliest known hobbit lived approximately 18,000 years ago, although archaeological records of ancient tools suggest that hobbits may have been alive as early as 12,000 years ago. Until the discovery of H. floresiensis, scientists had widely believed that the last non-modern humans were the Neanderthals, which became extinct around 24,000 years ago. If hobbits are indeed a new species, they will replace Neanderthals as the most recent non-modern humans.
Aside from its unusually short height, H. floresiensis was believed to have a very small brain. For many scientists, the brain size has become a focal point. Opponents of hobbits as a new species contend that H. floresiensis is simply modern human with a smaller stature and brain due to some pathological abnormality. Among the disorders proposed are Laron Syndrome (insensitivity to growth hormones), cretinism (stunted growth due to thyroid problems), and microcephaly (abnormal brain growth that results in a small head).
Prof. Dean Falk, anthropology at Florida State University and one of the main proponents of H. floresiensis' identity as a new species, was at Cornell to explain her position and place hobbits - which she referred to as 'lightning rods for controversy' - in the history of other paleontology discoveries. "I view 1925 as the beginning of the modern era of anthropology," she said, referring to the year that Raymond Dart discovered his famous Taung baby. The Taung baby, estimated to be 2.5 million years old, is today seen as one of the critical factors in developing the theory that humans evolved out of Africa. At the time of its discovery, however, the specimen was rejected because it contradicted an earlier specimen called the 'Piltdown Man.' It took until 1953 for the scientific community as a whole to realize that the Piltdown Man was a hoax, composed of a modern human skull with an orangutan jawbone attached to it.
In Falk's view, the current situation with H. floresiensis is analogous to the situation faced by Dart's Taung baby. She and her colleagues have spent much of their time since descriptions of the remains of a specimen called LB1 (the first to be discovered) were published in 2004 doing research that has led them to reject various 'sick hobbit' theories proposed by other scientists. Some of the most convincing evidence came in a 2007 study when Falk compared the LB1 brain to several normal brains and several microcephalic brains. In every instance, the LB1 brain sorted with the normal category.
Even now, the debate on H. floresiensis has not yet reached a decisive conclusion, but Falk remains optimistic that there could be one in her lifetime. "What will settle this will be what settled the others," she said. "They have to find more fossils."
Source: The Cornell Daily Sun (18 November 2009)
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