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Re: Hybrid sunnies
Always remember that it is our biological species concept. There is no
reason why the natural world has to obey our concept. My favorite exceptions
among fishes are the swordtails and platys. Many of the "species" can
interbreed, and they produce perfectly viable offspring. Nevertheless, as I
understand it, they behave like respectable species in the wild. Some
taxonomists would say that the ability to interbreed is a primitive
character and does not indicate a particularly close relationship (I
personally have a bit of trouble with this concept). This is one of the
reasons why Ed Wiley and others have the promoted the evolutionary species
concept. This concept adds the idea of pursuing a distinct evolutionary fate
and downplays the idea of interbreeding. This simply means that a lineage
that is an "evolutionary species" is primarily evolving on its own without
significant genetic pollution (if you will) from other evolutionary species.
Don't even get me started with plants; they have absolutely no respect for
our species concept.
This could be a good topic for a discussion, but I don't believe the best
minds in evolutionary biology have reached a consensus at this point.That's
what keeps the subject interesting.
From: Josh Wiegert <jwiegert at nexus_v-wave.com>
To: nfc at actwin_com <nfc at actwin_com>
Date: Saturday, October 03, 1998 11:02 AM
Subject: Re: Hybrid sunnies
> The bioloigcal species concept states that if an individual can reprodue
>with another individual (and, obviosuly, they're opposite sexes) and
>produce VIABLE offpsring, then they are teh saem species. Viable
>indicates that not only must these fry not be three headed, kinked spined
>mutants that'll die in an hour (i.e., blood red parrot cichlids.. YUCH) in
>the natural world, but they must be able to reproduce and produce
>offspring that'll survive. With a lot of lower organisms, this concept
>really messes with out species ideas. Fish, a "higher" organism, time and
>time again like to screw with this. I'm uncertain if these sunfish can
>interbreed and continue to produce viable offspring. It would truly come
>to no surprise to me if they could. Biologists can't even figure out what
>it means to be alive (definitiaion 1 includes fire and crystals.
>definition 2 includes cars. Definition 3 says a mule is not alive.
>Definition 4 says ... ), let alone what ti really means to be of the same
>J. L. Wiegert
> Dubotchugh yIpummoH. bI'IQchugh Yivang!
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>On Sat, 3 Oct 1998, Richard E Matheson wrote:
>> -----Original Message-----
>> From: R W Wolff <raywolff at juno_com>
>> To: nfc at actwin_com <nfc at actwin_com>
>> Date: Saturday, October 03, 1998 1:20 AM
>> Subject: Re: Hybrid sunnies
>> >Longears, or any lepomis for that matter, will hybridize....
>> Damned disrespectful of our species concept aren't they? I don't think we
>> should let them get away with it! Perhaps education is the key; if they
>> hybridization was wrong, perhaps they would do the right thing.
>> Actually, the scientific literature contains many examples of
>> in fishes. In a some (many?) cases this seems to happen in somewhat
>> disturbed situations such as when a damn separates some individuals from
>> normal spawning grounds of their species and/or forces them into
>> close quarters with a related species (I think some famous person said
>> you can't be with the one you love, love the one you're with). In sunnies
>> and some minnows it seems to be a relatively normal byproduct of their
>> spawning behavior, but, as Ray Wolff said, the hybrids don't seem to
>> for many generations. Although I have not rechecked the literature on
>> point, I would suspect that many of them are either sterile or have
>> reduced fertility.