 Global Connections
with David Suzuki
Hobbit joins the family tree
Last year, researchers excavating a site on the Indonesian island of Flores stunned the scientific community with their discovery of what appeared to be the skeleton of a miniature human. Now, detailed analysis of the fossil's skull has shown that the creature appears to be a new species.
At the time of the original discovery, scientists debated over just what had been found. Only about eight skeletons were discovered at the site and only one, nicknamed "Hobbit", had an intact skull. Although she had many features of a modern human - she walked upright, for example - she also had the prominent brow ridge and receding chin more associated with less advanced hominids. Plus, she was only a metre (three feet) tall and had a brain the size of a chimpanzee.
Yet, in spite of her diminutive brain size, Hobbit appeared to behave like more modern species. She was found alongside charred animal bones that hinted at the use of fire and cooking, for example. And relatively advanced stone tools - the type of tools normally associated with prehistoric modern humans - were also found nearby. So did she represent a new species? Dating back just 18,000 years, that would mean these creatures would have lived at the same time modern humans were settling down all over the globe.
But nothing like Hobbit had ever been found before and certainly nothing like her was expected to appear on a remote Indonesian island. That's why some scientists argued that she was likely not a new species at all, but rather a pygmy modern human or a modern human suffering from the small-brain disorder microcephaly.
According to a new report to be published in the journal Science, detailed scans of the inside of Hobbit's skull have shed new light on the issue. Researchers compared the inside of the fossil skull to the skulls of a chimpanzee and other primates, a pygmy human, a microcephalic human, and others. The results show that that Hobbit and her cohorts are indeed most likely a new species.
Hobbit's brain may have been small, but it was remarkably complex. Researchers used a series of CT scans to create a three-dimensional model of the interior of her skull. They found that faint impressions left by the brain in the lining of the skull show highly convoluted and folded frontal lobes - areas of the brain associated with higher levels of cognition. They also found large temporal lobes, which are associated with speech and hearing. None of their findings were consistent with the hypothesis that Hobbit was a pygmy or a microcephalic.
So, if Hobbit and the rest of the Flores people do represent a new species, what were they like? Were they really hunting and gathering on this isolated island at the same time that modern humans were spreading around the world? Where did they come from and what ultimately led to their demise?
While we may never know what caused their extinction, researchers say the Flores people possibly descended from a common human ancestor, Homo erectus, and evolved over time into a diminutive size due to geographic constraints. But they also acknowledge another distinct possibility - that both species in fact evolved from a shared common ancestor, one that we have yet to discover.
In recent years, the evolutionary tree of humanity has become increasingly crowded and complex. Rather than proceeding in a smooth, linear fashion, there are numerous branches and a number of dead-ends. Hobbit represents the latest addition to the family tree, but no doubt she will not be the last.
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