The battle for Middle-Earth
In 2004, I was a member of an Australian and Indonesian team that reported the discovered remains of a one-metre tall adult human from the Indonesian island of Flores (DOI: 10.1038/nature02956). Named Homo floresiensis, but better known as the hobbit, the find was terribly exciting: the individual had a brain the size of a chimpanzee with many anatomical features that harked back to some of the earliest known humans. I was involved with the radiocarbon dating of the site and discovered that the main skeleton was only around 18,000 years old while a white volcanic ash laid down 13,000 years ago capped the final remains of this species. This may all sound a long time ago but geologically speaking it was yesterday; in Europe, Neanderthals appear to have died out by 30,000 years ago. Next to ourselves, the ages from Flores make the hobbits the most recently surviving species of human.
|The skull of Homo floresiensis: the Hobbit|
With the news coverage of the discovery, a few researchers voiced concern that the remains may represent a diseased individual and not a new species. This is par for the course when it comes to discovering new human species. When one of the first Neanderthals was found in 1856, one expert described it as a child who had had suffered from rickets, got bashed over the head and then struggled on through life with arthritis. In the case of the main Flores skeleton, critics proposed the individual had a dreadful complaint that leads to the under-development of the brain; an affliction called microcephaly. These anxieties have been put together in a new paper in the Proceedings of the National Academy of Sciences (DOI: 10.1073 pnas.0605563103). This paper has had quite a bit of airtime in the news. Although interesting, not everyone is convinced. Part of the reason is that since the discovery, there have been several more published papers on finds from Flores that support the original interpretation. At least nine individuals with similar dimensions have now been excavated from cave sediments spanning tens of thousands of years (DOI: 10.1038/nature04022); it seems pretty unlikely that a community suffering from such a dreadful complaint as microcephaly would have survived this length of time. Not only that, but the technology for making the stone tools found with the hobbit remains is the same as that discovered in one million year old deposits in central Flores (DOI: 10.1038/nature04618); consistent with the hobbits being descendents of the earliest colonists. And to top it all, analysis of the inside of the skull showed that these individuals had highly-developed brains that would have allowed the hobbits to solve problems and plan for the future (DOI: 10.1126/science.1109727). Whether they had the foresight to see this argument coming is another matter.