>Hi, Conch-Lers!
>
>Thanks to everyone for the discussion on Strombus alatus vs.
>Strombus pugilis.   I think one of the most interesting points was
>raised by Paul Monfils, I believe - that we are dealing with not two
>but one species.    Of course, this would depend on whether or not
>the hybrids mentioned are fertile or infertile.     I think this is
>one of the most interesting aspects of speciation.
>In most cases we can't test for the proof of one species vs. two
>because of the geographic isolation of the two species, e.g.
>"Pecten" ventricosus and "Pecten" gibbus.   Though they may have
>arisen from one ancestral species, when the Atlantic and Pacific met
>between North and South America, we assume that enough time has
>passed that the two have evolved far enough away from each other
>that they could not interbreed with fertile offspring, the ideal
>"biological" definition of a species.    It is interesting to
>speculate how many separate species in the world may not be seperate
>at all, were they living
>side by side and free to interbreed.

Well, fertility of hybrids is not a test of specific distinctness. I
believe there is a fertile mule known...
--
Andrew Grebneff
165 Evans St, Dunedin 9001, New Zealand
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