What's also interesting is all the things that have not evolved. Some "livng fossils" are still among us. Horseshoe crabs, celocanths, nautilus. Hell, a lot of insects have hardly changed for ages. Crocodilians have changed little if any from the Jurassic Period, if I'm not mistaken.
The simple argument is that certain animals don't need to change. They do so well in their niche that random mutations do not improve them.
Evolutionary changes don't happen all in one way, either. White-furred animals not living in snowy regions - this is usually not good. They are rare, and the coloration puts them at a big disadvantage. But if the climate changes and snow becomes more dominant, they start to thrive. The moths that "changed color" because industrialization poluted trees and changed the color of the trees - this was a shift of dominance in moths that are either mostly black or mstly gray (if I remember the colors right).
Humans are vastly different now from other species because we can evolve by slight alterations in our brains (learning new skills is done by slight changes in neural pathways in the brain, for the most part) because of advanced communication skills. We can evolve by changing our "software" significantly (done easily and quickly) - we don't have to evolve our "hardware" any more. And as was noted earlier, we change our environment rather than changing ourselves - but you must add to this the idea that we, in a sense, "evolve selectively" and at a whim. We fly not by growing wings over generations - but rather by stepping inside an aircraft.
Anyway, there is a lot we still don't know about this. Einstein overturned centuries of happy acceptance of Newtoniaism by, in a nutshell, deducing there was a world "bigger" than our senses out there which required new thinking and a new physics to explain. On his heels and based on his work, to his chagrin, came the Quantum Physicians, who deduced a a world smaller than our senses had been able to detect - which also required a new physics and mindset to grasp. Expect Evolution itself to "evolve." We've only just started on this.
Edited, Jul 3rd 2006 at 6:56pm EDT by EvilGnomes
