>On the other hand, most of the plausible shapes for organisms and
>appendages have been tried.
Whatever is the basis for that statement? What is plausible? In whose
estimation? This statement makes as much sense as Gould saying "Any
competent engineer could design a better hand than the human hand,"etc.
Where is the evidence to back up the assertion?
>Since the Cambrian, no mass extinction has
>been massive enough to provide as many possible body plans not already
>being used.
Huh?
If something with a given body plan, lifestyle, etc. already
>exists, it's going to be difficult for something else to evolve into the
>same niche. The new kind is unlikely to be as good as the existing kind at
>what the existing one does, so it will get outcompeted and not evolve in
>that direction.
How then could 600 species of Drosophila possibly evolve in the Hawaiian
Islands?