Evolution clearly works. What and how it's driven, though, is a mystery to me, however.

In the case of niche life it's apparent that DNA is very, very aggressive at finding ways to exploit almost any energy source. It's almost as if DNA is corrosive, taking advantage of any 'weakness' in the ecosystem to propagate itself in some form.

And it's merciless. As Steven Jay Gould said, when the tiger chases the antelope and catches it tiger DNA wins - when the antelope gets away, antelope DNA wins. Either way it's DNA.

I suspect that within an organism DNA is always pushing, crowding, looking for ways to alter and change even while the historical processes for that organism are dominate. Those ways which are rewarded can eventually become dominant if they have an advantage, thus allowing changes to occur more slowly than generally recognized.

And in ant colonies, for instance, it's clear that individual ants are relatively unimportant - what is important, and what does survive is ant DNA. The colony exists to preserve that, and does.

In 'higher organism' the same differentiation exists. Many cells could have been a different type if there were a slightly different internal environment and there were a need for the different type.

While I'm as puzzled as you, Gould has impressed me. I'm convinced the key is the dynamic nature of DNA to exploit all possible avenues and the changes can be much, much more incremental than generally believed.

Arf