Re: NANFA-- Re: Pupfish

Bruce Stallsmith (
Tue, 12 Jun 2001 09:30:07 -0400

><< But in refugia, these uncommon genes could
> quickly become more common through increased survivorship of their
> A new species? Maybe not. But certainly a differentiated population.
> >>
>If they were returned to the wild would they revert back to their original
Maybe... in refugia you're talking about a small population (~300 adults) in
which there's a risk of both genetic drift and founder effect, i.e. gene
frequencies can also change accidentally or because the population was
started with individuals carrying low genetic diversity. Genetic drift could
happen in the natural population of _diabolis_ too, of course, since there
is usually an adult population of ~500. But it doesn't seem to have happened
in nature for whatever reason.

Both of the above-mentioned possible problems are major concerns with
"arking" any sexually reproducing organism. Zoos try to get around this with
meticulously maintained breeding records so they maximize outcrossing to
maintain genetic diversity. If you start with an already endangered species,
by definition the gene pool has probably been pretty thinned out to start
with. One can only hope that by luck a species/population will survive such
a bottleneck.

--Bruce Stallsmith
Huntsville, AL

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