Re: NANFA-- Re: Pupfish

Bruce Stallsmith (
Sun, 10 Jun 2001 17:01:02 -0400

>The idea that a fish can go from diabolis to not-diabolis within a few
>generations brings to the forefront of my mind the question of what
>constitutes a species, and whether our idea of how evolution works
>is correct.
>Jackson, MS
I think that with diabolis we're dealing with a fish adapted by selection to
an extreme environment, and removing them from the rigors of that
environment allows unusually fast changes in gene frequencies. I would guess
that the wild population carries a low level of genetic variation with fish
that express the less common genes usually weeded out as juveniles or adults
(raw natural selection...). But in refugia, these uncommon genes could
quickly become more common through increased survivorship of their carriers.
A new species? Maybe not. But certainly a differentiated population.

--Bruce "Darwin's Bulldog" Stallsmith
Huntsville, AL, US of A

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