RE: Random thoughts

From: Marcio Pie (pie@bu.edu)
Date: Tue Oct 30 2001 - 07:39:58 EST

  • Next message: Moorad Alexanian: "Re: Random thoughts"

    Hi Moorad. Thanks for your response.

    > >> The following has been whirling in my brain for some time. I believe that
    > >> the study and attempts of predicting our weather is a much simpler
    > problem
    > >> than the study and attempts of predictions one can make in evolutionary
    > >> theory. It is well-known that the study of our weather leads to
    > >> deterministic chaos, via the Lorenz equation and the so-called butterfly
    > >> effect. Now, why doesn't the same occur in any theory that attempts to
    > >> predict the outcome from natural selection and random mutations?
    > >
    > >Because they represent different classes of phenomena. Chaos is
    > >deterministic; you can predict the future exactly if you know the
    > >equations and the initial conditions. OTOH, evolution has a very strong
    > >component of randomness, both through mutations and drift.
    >
    >One cannot make long range prediction in system that are very sensitive to
    >initial conditions. In addition, randomness would make forward or backward
    >prediction even less possible.

    You can make long range prediction if you know exactly the equations and
    the initial conditions. That's why it is called deterministic chaos. That's
    not true for stochastic processes.

    > >> In
    > >> particular, why can't two totally different species, say a gnat and
    > man, be
    > >> the evolved outcome of a common entity in the past? In addition, why
    > should
    > >> two species that are close in DNA space now be considered to have evolved
    > >> from the same entity in the past?
    > >
    > >They could, but that wouldn't be the most parsimonious explanation given
    > >the available evidence. I think most biologists are aware of that.
    >
    >That is the point that from the available evidence one cannot derive a
    >definite conclusion.

    Of course not. But there's very little room in science where your concept
    of "definite conclusion" can be applied. Isn't it possible that I'm
    actually an E.T., trying to convince you of some evolutionary process to
    weaken your mind so that my planet can take over the earth? Now, serious.
    What kind of evidence would convince you?

    > >> I believe that such complex systems are
    > >> chaotic and attempts of predictions are totally baseless. Also, working
    > >> backwards in time is useless and arbitrary. Moorad
    > >
    > >Complex systems are not chaotic. Some people from the so-called
    > >"complexity sciences" suggest that the place where organisms should be is
    > >in the border between order and chaos. Too much homeostasis prevents
    > >evolution; not enough homeostasis would lead crutial processes such as
    > >development to be too fragile.
    >
    >I think that is just more jargon and less science. That is the difficulty
    >with
    >a theory that is just words and can never attain the rigor of a true science.

    I can't understand you, Moorad. You ask something, I give you my answer,
    you dismiss it as "just more jargon and less science". What's the jargon
    you are referring to? chaos? homeostasis? order? I chose terms which you
    would be more familiar with, being a physicist. If I wanted to hide behind
    jargon I could start talking about gene regulatory networks and stuff like
    that. My impression is that you are demanding a level of rigor from
    evolutionary theory that can only be found in parts of physics. Is ecology
    a true science? how about linguistics? how about political science? If you
    really think that science is either physics or stamp collecting, I can
    understand why you think that evolutionary theory is not science. Anyway, I
    look forward to know what kind of evidence would convince you that
    evolutionary theory is scientific. Alternatively, you can show me how ID
    would do a better job, both in terms of explanation and in prediction.

    Peace,

    Marcio

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Marcio R. Pie
    Department of Biology
    Boston University
    5 Cummington St.
    Boston, MA 02215

    Phone: (617) 353-6974
    FAX: (617) 353-6340
    http://people.bu.edu/pie/



    This archive was generated by hypermail 2b29 : Tue Oct 30 2001 - 07:45:34 EST