Later, John
--- Steffen Hellner <steffen-in-hellner.biz> wrote:
> To me genetics is overestimated. Look-in-Cyprinodon
> diabolis. Extremely
> small population, isolated for aeons, when released
>-in-Hoover Dam it
> suddenly developed the ancient body shape and size
> back. If that inzest
> doesn4t eliminate the ancient form over thousands of
> years, what can captive
> rearing for some generations mean? Not much from my
> point of understanding.
> If there is no competition then genes are extremely
> lazy in regard of
> changing.
>
>
>
>
> Am 12.05.2006 19:33 Uhr schrieb "Jerry Baker" unter
> <nanfa-in-bakerweb.biz>:
>
> > Moontanman-in-aol.com wrote:
> >> I have to disagree, release a large number of
> domestic goldfish into the
> >> wild, in a pond or even a stream. In a very few
> generations you will have
> >> wild
> >> type goldfish again. I've seen it happen in even
> small ponds. animals are
> >> often
> >> genetically more plastic than we give them
> credit for.
> >
> > Indeed. The whole argument that captivity induces
> genetic drift, and
> > therefor bad, is a tautology. Of course there is
> genetic drift because
> > that's what happens when one population of a
> species is separated from
> > another. It might not have anything to do with
> captivity and just be the
> > process of natural evolution continuing along
> slightly different courses
> > in isolated populations. Sure, the conditions of
> captivity can influence
> > the evolutionary path, but that shouldn't matter
> much as long as the
> > animals remain able to survive in their natural
> environment. Without
> > constantly providing for genetic exchange between
> two populations held
> > in isolation, of course they're going to drift.
> Keep them separated long
> > enough and they may evolve into separate species.
> That's the way it works.
> >
> > It seems to me that trying to keep a population of
> some threatened or
> > endangered creature genetically stable is as
> foolish as was the old way
> > that the National Park Service used to try and
> prevent any changes in
> > the forests. After a while the exclusion of fire
> and other disturbances
> > was destroying the very forests they thought they
> were protecting. I
> > don't think it would be helpful to actively
> prevent a species from
> > experiencing the genetic drift that might allow it
> to adapt and survive.
John Cox of Cumberland Killifish
Honey Robber beekeeping and removal services
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