Re: ID challenge

From: Iain Strachan (iain.strachan.asa@ntlworld.com)
Date: Thu May 08 2003 - 16:23:25 EDT

  • Next message: Jim Armstrong: "Re: Evolutionary rate"

    Michael Roberts wrote, in part:

    > This seems to me to give no more than Dawkins' computer models in the
    Blind
    > Watchmaker.

    It seems we have a rare point of agreement here. In the "Discussion"
    section, I read the following:

    ------------------------ begin quote -------------------
    Some readers might suggest that we 'stacked the deck' by studying the
    evolution of a complex feature that could be built on simpler functions that
    were also useful. However, that is precisely what evolutionary theory
    requires, and indeed, our experiments showed that the complex feature never
    evolved when simpler functions were not rewarded.
    ------------------------ end quote ---------------------

    In other words, you have to stack the deck because Evolution won't work
    unless the deck is stacked. But this is a circular argument and it proves
    nothing about whether in fact the deck is stacked in this way in nature; all
    they have done is make a simulation that takes that prior assumption for
    granted.

    Examination of the paper shows that they attributed higher degrees of
    fitness to organisms that could perform more complex logic operations, with
    the "reward" being 2^n where n was the number of logic operations combined.
    The EQU function required 5 operations, so was rewarded with 32 points; but
    intermediate rewards of 2,4,8,& 16 were also allowed for simple functions.

    The fact that the complex feature could not evolve if the simpler functions
    were not rewarded is a tacit admission that irreducibly complex systems
    cannot evolve. With the intermediate rewards, the system is _not_
    irreducibly complex. Knock out one of the 5 logic operations and there are
    still 4 left, with a "reward" of 16 points, which is better than nothing and
    gives the organism "energy" in order to reproduce. However, if you knock
    out any of the components of Behe's mousetrap, then you have a
    non-functional device.

    The debate hinges around whether there really are such things as irreducibly
    complex objects in nature & that is still open to question, one which is not
    addressed by the simulation of the evolution of a non-irreducably complex
    system.

    In short, the simulation shows that a GA can do hill-climbing, provided the
    gradients aren't too precipitous, but we knew that from the "Weasel"
    simulation ages ago.

    Iain.



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