I must point out that the idea that complex organisms are more fit
is strictly a human point of view easily explained by our seeming
preference for and love of the complex.
Why not the largest population? Or the most variety? The most
abundant forms of life of earth are also amongst the simplest.
Bacteria, viruses and nematodes, for instance. None complex, all
highly successful, and all would be very difficult to exterminate.
That may be the most evolutionarily significant trait.
Dinosaurs were highly complex, warm-blooded and social (some)
creatures. All are now gone (I don't believe birds are from
Theropods, but that's another thread). All of the major
extinctions are marked by the disappearance of the most "highly"
evolved of the organisms while the "primatives" just kept chugging
along. True, less complex forms bit the dust along with them,
but only some of those, not the entire clan. My point is that
perhaps the winner is the last one in the race, not the fastest
racer.
To view complexity as fitness is indeed anthropomorphic. Or, to
quote Emo Phillips, "I once thought that the brain was the most
wonderful thing of all of creation with it's complexity and
sophistication. Then, I thought 'Well, look what's telling me'".
I don't think that niches are discovered. They have always been
around. The frog that moves to another puddle is not then discovered
by parasites, it drags old ones along with it which then evolve
in unison. That tapeworm in your intestines is just a descendant
of the tapeworm that inhabited the intestines of some insectivore.
In terms of time, circumnavigating the globe is doodah, even for
a crawler. Bacteria growing at 1/100th inch an hour would
only take 20 million years.
It is also significant that most evolutionists talk about animals and
not plants. That could be because we are more philosophically in
tune with animals. We are mobile, they are mobile. Mobility is
a more complex mode than the sessile.
Complex need not mean more fit. Grass appeared rather late and yet
has dominated most of the planet. A wind-pollinated, parallel
veined simple plant. What of the delicate rarity of the very
complex orchid which mimics a specific wasp in order to pollinate?
Why is grass so much more successful, more fit? It simply learned
to grow from the bottom of the leaf, not the top.
A more fit tactic need not be more complex, just work better.
