Bob.
Looking over your message suggests to me that you are looking for a
one-size-fits-all explanation. I noted an explanation that I did not
expect in Science, 21 July, pp. 441ff and 369f. The preferred food plants
have produced different beaks in males and females of a species of
hummingbirds. I doubt that run of the mill explanations can be bent to
fit this one.
T'other Dave
On Sat, 26 Aug 2000 06:46:04 EDT RDehaan237@aol.com writes:
>
> In a message dated 8/24/2000 10:37:13 AM,
> bivalve@mail.davidson.alumlink.com
> writes:
>
> << Numerous evolutionary mechanisms have been proposed for
> generating rapid
> diversification, including key innovations (eyesight, predation,
> planktivory,
> hard skeletons, etc.) and environmental factors (global warming,
> increased
> oxygen levels, etc.). Conversely, various factors have been
> suggested as
> constraining later evolution, including the filling of niches and
> increased
> genomic integration and stability.
> >>
>
> Dave:
>
> The objection to all such mechanism is that they comprise what
> Walter Remine
> calls a smorgasbord of explanations, from which one selects the one
> that
> seems most plausible. Are you really satisfied that after you list
> all these
> possible mechanisms, plus the etc., that you really know anything
> more than
> you knew before? These are really only hypotheses at best that
> still need to
> be tested. Just listing them is no more than the first step, like
> brainstorming. How does one test them?
>
> Thanks,
>
> Bob
>
> Bob
>
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