Mike
>Showing that trying to pin down natural selection is like trying
>to nail jello to the wall. Rapid change, gradual change, no change -
>it's all expected from natural selection.
Chris
Darwin thought, following Lyell, that evolution proceeded slowly, more or
less smoothly, even though the principle of evolution itself does *not*
imply that it will be uniform. In fact, it implies that it will vary
according to environmental features and according to the evolutionary
mechanisms at hand. Evolutionary theory, as such, and out of context, does
not imply any particular speed of evolution, any more than the fact that a
car is rolling along a downhill street implies that it will roll at some
specific speed irrespective of the slope and other factors (such as whether
the street is covered in deep snow, etc.).
I'm not a fan of punctuated equilibrium, but I don't know of any reason in
the basic nature of the Universe, to believe that evolution would have to
proceed always at some preset speed regardless of factors such as climate,
nutrient availability, crowding, presence or absence of oxygen, degree of
predation, etc. Keep in mind that the more restrictive the selective forces,
the *slower* evolution will proceed.