Re: NANFA-- environment and the presidency

Christopher Scharpf (ichthos_at_charm.net)
Tue, 22 Feb 2000 18:06:10 -0400

> Of course, if they were already in decline, they may
>have run their evolutionary course and no matter what man does good or bad
>they could be candidates for extinction.

Let's be careful here. Just because a fish exists in low numbers, and/or in an
extremely limited range, does not necessarily mean that it has run its
"evolutionary course" and is a candidate for extinction. Species can and do
evolve to adapt to tiny niches in the environment. A species, such as the
Maryland darter, which is historically known from one riffle in one stream, is
just as valid as a more wide-ranging darter, such as the johnny or rainbow.

Besides, how is one to know if a fish's decline is "natural" when we've only
been sampling streams for 200 years? Without thousands of years of collection
data, there's no wat to tell whether a Recent fish is naturally going extinct.

Chris Scharpf
Baltimore

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