Monday, July 11, 2011

Stone-Age-Lizard-Ninjas

In the Smithsonian Museum of Natural History there is a hall generously sprinkled with replicas of skeleton fragments from human ancestors. Most of the fragments are skulls. The skull replicas suggest the calcium-rich armor that protected that organ most closely associated with actually being human.

The resolution with which the fossil record currently describes the evolution of the human species is far greater than I realized. New named hominids have popped up since I last really looked at the hominid fossils. The narrative of human evolution is developing character and plot.

One area that the Smithsonian described as a subplot was a bit out-of step with the central narrative. That area is now called Asia. Someplaces in Asia there are Homo erectus fossilizing themselves over a million years ago. Somplaces in asia the delicate craniums of modern looking Homo sapiens have been dated at an astonishing 68,000 years of age.

There is one place in Asia where a strange divergent race of morphologically striking homonids emerged. That place is the island of Flores in Indonesia.

The Smithsonian display suggested that Homo floresiensis existed from 95,000 to 17,000 years ago. It further suggests that homonids existed on the island of Flores for 800,000 years.

If Homo floresiensis is evolved from hominids that migrated to Flores 800,000 years ago then they represent a divergence from Homo erectus. If Homo floresiensis emerged 95,000 years ago they represent a divergence from Homo sapiens.

Homo floresiensis had a much smaller brain cavity than Homo sapiens. One part, however, is similar in development. That is the areas that are used for recognition and cognition. Homo floresiensis would probably have been capable of culture. If the capability for culture was conserved during the tremendous selective pressure that shaped Homo floresiensis it must have had a selective advantage. Culture must have played a part in the divergence of Homo floresiensis from whatever its source stock was. If the source of Homo floresiensis was us (Homo sapiens) then the divergence of Homo floresiensis may speak to possibilities in evolution that can effect our world.

Flores is the source of some important culture. I played my way to a recent world record on an Angklung named after the island of Flores.

One of the more persuasive explanations for the divergence of Homo floresiensis is that island isolation drove the divergence. Culture can easily multiply the effects of natural isolation. The divergence of Homo floresiensis due to cultural isolation could be a compelling potential addition to the narrative of our ancestry.

I picture Homo floresiensis as a strange warlike human. In my mind they tip spears with tropical poisons, and ride komodo dragons into battle with trespassing Homo sapiens. The authoritative forces of their rigid tribal structure select for smaller and smaller brains. They become the perfect warriors. Stone-age-lizard-ninjas.

Somewhere in Indonesia a small band of Homo floresiensis which avoided the extinction of the rest of their species may still crouch in the dark jungles of Flores. They listen intently to the sounds of their modern cousins creating a world of amazing expression. They hear music for the first time while furtively glancing into the world of Homo sapiens. It is likely that they hear Homo sapiens playing the popular locally-made percussion instrument called the angklung.

The angklung is specially made to lure stalking intelligences out of the wild. It produces a lovely intoxicating sound.

I picture Homo floresiensis listening intently to a angklung ensemble playing “We are the World” because that is the song I played to secure the world angklung ensemble record on July 9th 2011.

2 comments:

Joe said...

The interesting thing about Homo floresiensis from the Indonesian island of Flores is its dwarfism, say a meter tall as an adult. For evolution, we have many other examples, dwarf elephants and dwarf deer (now extinct) lived similar to floresiensis on islands. Huge bodies are an adaption when predators are present and inefficient for resource use, and when a species is isolated, say an island without predators, it is natural for the species (ignoring sexual selection for some as with sexual dimorphism) to have dwarfism occur over time. This is what likely occurred with floresiensis similar to dwarf deer, see
http://www.rci.rutgers.edu/~wayner/Principles%20of%20Ecology%20course/island%20morphological%20adaptation.pdf

adult onset atheist said...

Joe, your analysis of Island effect in evolution is interesting, but incomplete. It is certainly well supported in the fossil record of the island of Flores. A dwarf elephant is found there. However, your theory ignores the fact that many island-isolated animals experience a selective trending towards gigantism. This is the case with the the giant rat of Flores.

What is obvious is that there is a rapidly active effect of Island isolation. After a few generations there can be massive morphological deviations from mainland populations. http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0040321

That this level of deviation can occur in a very stable hominid population is quite interesting.