Zahavi principle of evolution...

Discussion in 'Biology & Genetics' started by aaqucnaona, Dec 9, 2011.


[Read OP first] Do u agree with the Zahavi priniciple?

  1. Yes, completely.

    0 vote(s)
  2. Partially, needs to be refined.

  3. No, but may have useful features.

    0 vote(s)
  4. No, completely, have alternative explainations.

    0 vote(s)
  1. aaqucnaona This sentence is a lie Valued Senior Member

    ...of displays, gestures and ritual behaviour in animals. I quote Dawkins from Viruses of the mind:

    "Zahavi suggests that peacocks, for instance, evolve their absurdly
    burdensome fans with their ridiculously conspicuous (to predators) colors,
    precisely because they are burdensome and dangerous, and therefore
    impressive to females. The peacock is, in effect, saying: ``Look how fit and
    strong I must be, since I can afford to carry around this preposterous tail.''
    To avoid misunderstanding of the subjective language in which Zahavi
    likes to make his points, I should add that the biologist's convention of
    personifying the unconscious actions of natural selection is taken for
    granted here. Grafen has translated the argument into an orthodox
    Darwinian mathematical model, and it works. No claim is here being made
    about the intentionality or awareness of peacocks and peahens. They can
    be as sphexish or as intentional as you please.
    Moreover, Zahavi's theory is general enough not to depend upon a
    Darwinian underpinning. A flower advertising its nectar to a ``skeptical''
    bee could benefit from the Zahavi principle. But so could a human
    salesman seeking to impress a client.

    The premise of Zahavi's idea is that natural selection will favor skepticism
    among females (or among recipients of advertising messages generally).
    The only way for a male (or any advertiser) to authenticate his boast of
    strength (quality, or whatever is is) is to prove that it is true by shouldering
    a truly costly handicap --- a handicap that only a genuinely strong (high
    quality, etc.) male could bear. It may be called the principle of costly

    What do u personally think about this? And what is the scientific consenses on this hypothesis [is it confirmed enough to be a principle, if not what observations would be necessary]? What are the alternative hypothesis?
  2. Google AdSense Guest Advertisement

    to hide all adverts.
  3. cosmictraveler Be kind to yourself always. Valued Senior Member

    I think it is a "preposterous tail" and would not give it much thought, Darwin had it right.
  4. Google AdSense Guest Advertisement

    to hide all adverts.
  5. Arioch Valued Senior Member

    Sexual selection works well for explaining the plumage of species like peacocks and birds of paradise.
  6. Google AdSense Guest Advertisement

    to hide all adverts.
  7. Rhaedas Valued Senior Member

    Natural selection is simply about spreading the genes. If the male gets his transferred and then dies because of the same mechanism, he still wins evolution. He doesn't have to live long to do this. If it works well enough for the general male population, that gene tends to get selected more and possibly enhanced.

    It doesn't have to make sense from an individual's point of view.
  8. tantalus Registered Senior Member

    principle of costly authentication
    First time I heard in given this title, I normally hear it referred to as the handicap hypothesis/principle. Nevertheless, it is accepted as a credible concept. Does it explain the peacock, well traditionally it has been the leader, but consider these links...

    and in case you weren't familiar with the more common name. here is the nearly alwalys useful wikipedia page
    In this case it is useful and offers some info on modelling of the subject.

    Even if empirical evidence (or lack of) undermines the handicap hypothesis in explaining the peacocks tail, it remains a potent concept in evolutionary biology imo.
    Last edited: Dec 10, 2011

Share This Page