I agree, Charles.
 
Canines are an excellent example of extremes in size. All that would be
necessary would be to neuter ALL of the breeds and mongrels of inter-
mediate size and... Presto! -- two species of canine. However, we would
interfere -- and sooner, rather than later, would be a safe bet.
 
Though it may seem far removed from our main theme of mollusks,
an example of 'linked' subspecies of squirrels could easily be
true of molluscs in a marine habitat: There is, as the example went,
a group of squirrels along one side of a mountain range. The sub-groups
at the ends of their range interbreed with the central group but
would be too different in behavior to interbreed. Then a Mount St.
Helens occurs in the middle of their common group's habitat, laying
waste to the habitat and the vast majority of the middle group of
squirrels. Voila! Nature has just "speciated" the group into two.
 
It doesn't take much to see that an underwater event could do the same
to any number of varieties of animals or plants... and most likely has.
There have been stupendous landslides and slumps in the history of
Oahu which have left only tiny portions of the original volcanos, which
are today know as the Koolau and Waianae mountains. These 'events'
were obviously devastating to the living species and -- my personal
lament -- obliterated the fossil records of the previous varieties
of cowries.
 
And I agree that "we should consider the names of organisms as
hypotheses" but that craving for certainty is often undeniable.
Not many souls want to go to their graves thinking that MAYBE they
got it right.
 
Aloha,
 
makuabob (a.k.a. Bob Dayle)