North American Fruit Explorers mailing list at ibiblio

[Pat Meadows <pat@containerseeds.com>]

On Sat, 16 Apr 2005 04:17:44 -0500, you wrote:

>Ginda,
>
>I always wondered about the role of disease in the disappearance of my
>Golden Toads.  The area I lived in in Costa Rica was visited by thousands of
>biologists over the years, many of whom collected herps and other biological
>material from all over the country.  Perhaps one of them introduced a
>disease from some other amphibian population.  It seems odd, though, that a
>disease would completely overwhelm a species--if an animal is susceptible to
>a disease aren't there usually at least a few resistant ones in a
>population?
>

If only a few are resistant and survive, then they may no
longer be a viable breeding population:  no longer able to
find mates and reproduce enough to keep the species going.
Very small populations are also subject to genetic problems
caused by inbreeding.  

So a few could be resistant yet the species could still
become extinct.

Pat
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