Thursday, September 01, 2005

Another TV show about Hobbits, Homo floresiensis

The ABC, here in Australia, showed a documentary recently on the "Hobbit" fossils from Indonesia. The thrust of the program was that the Hobbits, Homo floresiensis, were Homo erectus that experienced "island dwarfing" down to a tiny size. There was much "messing about in boats", or rather a bamboo raft, in the documentary, allegedly to show that Homo erectus could have crossed to Flores Island, where the Hobbits lived. Skulls of Homo erectus were compared to Homo floresiensis, and it was claimed that the latter resembled a much reduced version of the former.

The "island dwarfing" was supposedly due to a shortage of food on Flores, which also led apparently to smaller size in the local species of elephant.

Villagers on Flores told a story of how tiny Hobbit-like humans used to live on a nearby mountain until conflict with the villagers led to their demise a few generations ago.

I found none of this particularly impressive. Bamboo rafts seemed merely a diversion. To assign the small size of a hominid on Flores to "island dwarfing" seems to depend on an argument that Flores is a small island (it isn't); that there were few resources (despite the existence of rats, giant lizards and elephants); and that humans typically get small on islands (they don't). Also, why did a supposed shortage of resources produce small elephants but giant lizards?

When the Hobbits were recreated on the screen, their environment was shown as heavily forested. This is consistent with suggestions that the palaeoenvironment was in fact rainforest.

Here is my take on the situation. Evidence suggests that hominids, either Hobbits or their ancestors, lived on Flores over about 80,000 years until about 20,000 years ago. During this time they used a modern human toolkit. My proposal would be that they reached Flores as archaic Homo sapiens, the skulls of which bear some resemblance to the Hobbits in overall form. Under long selective pressure in a rainforest environment, they developed the typical traits of modern humans in that environment, notably dwarfism (Cf. Pygmies, Negritos). The force and duration of the selective pressure led to an extreme pygmoid type, which included diminution of the entire skeleton including the skull. The brain was "packed" with great efficiency, permitting normal intelligence despite a very small brain size, the use of a modern human tool kit and modern hunting capabilities.



This page is powered by Blogger. Isn't yours?