Re: biology

From: Massie (mrlab@ix.netcom.com)
Date: Thu Jan 13 2000 - 18:30:18 EST

  • Next message: John W. Burgeson: "Re: Chance?"

    David Campbell wrote:
    >
    > >I
    > >> believe there are some ideas on the evolutionary precursors of
    > >> photosensitive pigments, but do not remember any detail.
    > >************
    > >You do not remember any details because you were never given any.
    >
    > Usually my memory is better than that. I could give you lots of details
    > about molecular evolution of the 18S gene in bivalves, as that is what I
    > actually study. Evolution of vision pigments is rather tangential. I'll
    > see what I can find as I have time, though.
    >
    > >And I would like to see some evidence to support it.
    >
    > There was an article a few years ago, I believe in American Scientist but
    > possibly Scientific American. New World monkeys normally have only one of
    > the red/green color pigments. A simple mutation will change from one to
    > the other. If an individual receives one version of the gene from one
    > parent and the other from the other, he will have full color visual
    > abilities.
    >
    > >> >From a morphological point of view, any sort of eye from a single
    > >> photosensitive cell on up is useful.
    > >**************
    > >Morphology involves making pencil drawings which ignore the real details.
    >
    > However, it is the information we have to go on at present. Also, the
    > genes have to express themselves in morphology.
    >
    > >********************
    > >How about being accurate.
    > >
    > >"Complex eyes appear in the follil record at several different times.
    > >Those who prefer to see evolution as the mechanism believe that this was
    > >due to evolution and those who see a designer prefer to see his action
    > >in this."
    > >******************
    >
    > The danger of pronouns! I see a Designer and prefer to see His action in
    > this mechanism of evolution as well as the rest of His creation.
    >
    > >I did not speak of timing as to when. I spoke to the rate of
    > >development giving the amount of time available. I am looking for a
    > >solid rate of development times time equals organ type arguement.
    >
    > For a certain amount of time to equal a certain level of development would
    > require evolution to always go the same way. This would also require some
    > quantified measure of organ development to really speak of a rate. I can
    > tell that some eyes are more complex than others, but I am not sure how one
    > could calculate what you request.
    >
    > >Assuming I accept this at face value, now do a calculation with mutation
    > >rate, subtract the bad mutations, and give us a number for the potential
    > >additional information rate per year.
    >
    > Mutation rate is not constant, nor is volume of biological information
    > well-defined. In a productive year, the amount of information could
    > double, but volume of information is not too meaningful. Useful new
    > information tends to be kept and bad mutations tend to be lost, so that
    > there is an accumulation and not just steady change. All this means that
    > the calculation of a precise rate requires more information that is
    > available, if not than can be available.
    >
    > David C.
    ***********

    David

    thank you. You have actually exactly answered my question.

    Bert M



    This archive was generated by hypermail 2b29 : Thu Jan 13 2000 - 18:36:24 EST