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Re: Fw: [Genetics-Psittacine] What's in a name?

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  • Inte Onsman
    ... Deon, Clive understood me vey well. I couldn t have said it better myself. Inte MUTAVI
    Message 1 of 3 , Sep 1, 2001
      At 16:15 31-8-2001 -0400, you wrote:
      >Message text written by INTERNET:Genetics-Psittacine@yahoogroups.com
      >
      >Deon wrote:
      >
      >>>Will you please elaborate on selective types, what exactly is meant by
      >that. Do you mean that one allele may have different colour morphs due to
      >the action of modifiers, and that one colour morph may be isolated and
      >selectively bred by having it possessing an aggregate package of modifiers
      >in the closed population?<<
      >
      >You've perhaps overstated it a little using the words 'different colour
      >morphs' , but I think this is essentially what Inte is saying. Many genes
      >vary in their expression depending on their interaction in a particular
      >genetic setting. By manipulating that genetic setting by inbreeding and
      >selection a breeder can, so to speak, 'choose' a favoured expression of
      >that gene and 'fix' it within the closed inbred population.
      >
      >This has many similarities with the way exhibition breeders create their
      >strains of birds which can be quite dramatically different to the overall
      >population. And the pinnacle of such achievements is the development of the
      >enormous variety of dog breeds.
      >
      >In such cases however the 'improvements' are very quickly lost when these
      >selected forms move from the controlled environment and interbreed with the
      >general population. They 'revert to type'.
      >
      >Unless the originator of a selected form can persuade others of its special
      >nature and encourage them to take up its breeding it can have no long term
      >future.
      >
      >and:
      >
      >>>If I understand it correctly, this poses a very interesting situation
      >with the American and S.A. Pieds. Say they are the same mutation that have
      >evolved separately in two completely unrelated closed populations. They
      >should then each have its own set of modifiers established in each
      >respective population pool as we must accept that both strains evolved in
      >closed populations. It is then quite possible for each to have a unique
      >appearance. When interbred the modifiers will become mixed up and some will
      >not be expressed in the first generation, producing pied offspring that
      >have a different phenotype to the original pools respectively. <<
      >
      >That is the conclusion I believe many of us have reached on the evidence
      >available.
      >
      >Clive.



      Deon,

      Clive understood me vey well. I couldn't have said it better myself.



      Inte
      MUTAVI
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