The impact on physical anthropology of the diminutive hominid Homo floresiensis cannot be overstated. The discovery in a rock shelter on the Indonesian island of Flores, announced in the October 28 issue of Nature, included a near-complete skeleton of an adult female found in close context with stone tools. Bones and teeth of seven other individuals were also uncovered. Standing three feet tall, floresiensis appears to be the result of "island dwarfing," wherein species isolated in resource-poor areas shrink over time so that their consumption needs are fewer. Archaeologists believe floresiensis, whose cohabitation on the island with Komodo dragons and pygmy stegodons must have resembled a Ray Harryhausen movie, were wiped out by a volcanic eruption.
What boggles the mind is not so much the size of the "lady of Flores" but her expiration date of 18,000 years ago; the youngest of the eight has been dated to 13,000 years ago. The fact that floresiensis's time on this Earth overlapped our own means every college textbook written on the subject of human evolution will have to be thrown out the window.
Homo erectus, our immediate predecessor (and apparently that of floresiensis as well), appeared in east Africa about 1.9 million years ago and almost immediately migrated across the Sahara, which cycled between wet savanna and dry desert stages during the Ice Age, and then eastward into Asia. By 800,000 years ago they had settled in Europe as well, a delay that may be attributable to the colder climate. Erectus was much like us, walking on two legs, but characterized by an oblong skull with heavy brow ridges and a massive jaw. They possessed stone technology and may have tamed fire, which in turn may explain their eventual conquering of chilly Europe (though erectus was still a hairy nudist).
Somewhere between 400,000 and 250,000 years ago, Homo erectus evolved into Homo sapiens sapiens. In Europe and southwest Asia, sapiens shared the landscape with Homo neanderthalensis, a stout, muscular group that is often classified as a subspecies of sapiens. Neandertals existed from at least 200,000 to 32,000 years ago; the reason for their exit is a mystery. Were they edged out by the more adaptable sapiens sapiens? Did they over-specialize in their environment and stagnate?
For many years the leading idea of human evolution was the multi-regional model. This theorized that different continental groups of erectus evolved into Homo sapiens on their own, with enough gene swapping across land masses to ensure no one group outpaced the others. Then in the mid-90s the Eve hypothesis dealt a major blow to the theory, based on a project that measured divergence in mitochondrial DNA among women from across the globe.
Although still controversial -- being essentially a mathematic equation, there was dispute not over the final calculation but in some of the assumptions used in the formula -- the Eve hypothesis has served to largely displace the multi-regional theory with the out-of-Africa theory, which states that the African Homo erectus evolved into Homo sapiens, who then spread into the greater world following erectus's footsteps.
Neandertals, who in the multi-regional model are a transitional form between the European erectus and European sapiens, instead become a dead-end in the out-of-Africa theory -- descendants of the European Homo erectus who went nowhere. Sapiens sapiens displaced not only Neandertals but all forms and descendants of non-African erectuses.
Floresiensis throws in a kink in both theories. While it proves that the evolution of erectus into distinct regional forms (like Neandertals in the out-of-Africa theory) was possible, it also casts doubt on whether the "gene swapping" of the multi-regional model or the displacement by sapiens of other hominids in the out-of-Africa scenario was as complete as the theories' authors would have us believe. If their demise as the result of a volcano is true, then floresiensis is certainly guilty of over-specialization. But their co-existence with Homo sapiens suggests that a meeting between us and other humans does not inevitably result in a turf war; so perhaps the extinction of the Neandertals had nothing to with us.
The floresiensis skeletons were half-jokingly dubbed "hobbits" by some of the archaeologists who found them, a bon mot that has seized the imagination of headline writers across the mediasphere. "Lilliputians" would have been more appropriate. After all, according to the well-traveled mariner Lemuel Gulliver, the island of Lilliput was also located in Indonesia.
The author writes frequently on archaeology and travel and is a TCS contributor.