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.
> /-----------------------------------------------------------------------
> / This is the discussion list of the North American Native Fishes
> / Association (NANFA). Comments made on this list do not necessarily
> / reflect the beliefs or goals of NANFA. For more information about NANFA,
> / visit http://www.nanfa.org Please make sure all posts to nanfa-l are
> / consistent with the guidelines as per
> / http://www.nanfa.org/guidelines.shtml To subscribe, unsubscribe, or get
> / help, visit the NANFA email list home page and archive at
> / http://www.nanfa.org/email.shtml
/-----------------------------------------------------------------------
/ This is the discussion list of the North American Native Fishes
/ Association (NANFA). Comments made on this list do not necessarily
/ reflect the beliefs or goals of NANFA. For more information about NANFA,
/ visit http://www.nanfa.org Please make sure all posts to nanfa-l are
/ consistent with the guidelines as per
/ http://www.nanfa.org/guidelines.shtml To subscribe, unsubscribe, or get
/ help, visit the NANFA email list home page and archive at
/ http://www.nanfa.org/email.shtml