Re: parabiosis? (was Stone Age man wasn't so dumb , etc)

From: Stephen E. Jones (sejones@iinet.net.au)
Date: Tue Feb 15 2000 - 17:24:47 EST

  • Next message: Cliff Lundberg: "Re: parabiosis? (was Stone Age man wasn't so dumb , etc)"

    Reflectorites

    On Tue, 15 Feb 2000 01:50:59 -0800, Cliff Lundberg wrote:

    >SJ>In my modification of Pearce's theory, I interpret the "man" of Genesis 1 as
    >>the species Homo sapiens extending back ~ 120 kya, and the physical
    >>`ancestor' of the entire human race.

    CL>Is it no longer believed that Genesis 1 & 2 are a combination of Genesis
    >in the scripture of the priests of Moses and in that of the priests of Aaron?
    >I thought that was widely accepted.

    I have never heard of this. My Bibe search program reveals no "priests of
    Moses"? Maybe Cliff can post some references to this theory?

    >>CL>Of course this is a point against man-from-chimp.

    >SJ>Strangely enough, here I disagree with Cliff. I don't think any leading
    >>evolutionist maintains that "man" came from a "chimp", but that both
    >>"man" and "chimp" shared a common ancestor. This I provisionally accept
    >>as probable on the evidence.

    CL>I didn't mean that *I* am for man-from-chimp. I'm all for pushing
    >divergences back in time and all against forcing known forms
    >into phylogenetic sequences. I'd push 'em all back to the Cambrian
    >if it weren't for the molecular evidence.

    I have no particular agenda "for pushing divergences back in time". I am
    generally happy with the existing scientific *evidence* (as opposed to
    materialistic-naturalistic *interpretations*). On my "two books of God" (ie.
    nature and Scripture) the scientific evidence will always tend to confirm
    Scripture and vice-versa. And so it always has.

    >SJ>But again to be fair to the evolutionary biologists there has been
    >>some speculation about "mechanisms explaining the Cambrian Explosion".
    >>Stanley has speculated it was due to the emergence of predators:

    CL>Some speculation, but none that the establishment has any use for.
    >
    >FTR, my own notion is that segmentation is the key to the Cambrian
    >Explosion. The macroevolutionary mechanism forming the gross
    >morphology of vertebrates and arthropods is simply siamese-twinning
    >(aka parabiosis), a process through which trains of segments can be
    >quickly generated, followed by mutations causing loss and distortion
    >of segments--a process which was drastic at first but soon became
    >more gradual and Darwinian.

    I am aware of Cliff's parabiosis theory (parabiosis...2: anatomical and
    physiological union of two organisms. http://m-w.com/cgi-bin/dictionary),
    The online Encyclopaedia Britannica does not even mention it. Is there any
    fossil or genetic evidence for it? Has any biologist ever maintained it? Is
    there any example of a Siamese twinning which is heritable in a sexually
    reproducing species? If there was, would it have any long-term survival
    value?

    Maybe parabiosis has limited applicability to some highly segmented forms
    like arthropods and snakes? But I doubt that it is applicable to less highly
    segmented forms like vertebrates.

    Indeed parabiosis sounds a bit like the phenotypic side of polyploidy which
    only works consistently in asexual species and even then only causes
    changes at lower taxonomic levels (e.g. species and genus).

    But even if parabiosis were the cause of the Cambrian Explosion, it would,
    like all naturalistic theories on the Cambrian Explosion, still have to explain
    why eukaryotes originated ~ 1.2 bya and then nothing much happened for
    nearly 600 mya, and then in ~ 5 million years between ~ 575 and ~570
    mya, *everything* happened!

    Steve

    --------------------------------------------------------------------
    "Essentially, the same amino acid chain being found also in other animals
    and even in plants, we have a case in histone-4 where more than 200 base
    pairs are conserved across the whole of biology. The problem for the neo
    Darwinian theory is to explain how the one particular arrangement of base
    pairs came to be discovered in the first place. Evidently not by random
    processes, for with a chance 1/4 of choosing each of the correct base pairs
    at random, the probability of discovering a segment of 200 specific base
    pairs is 4^200, which is equal to 10^-120. Even if one were given a random
    choice for every atom in every galaxy in the whole visible universe the
    probability of discovering histone-4 would still only be a minuscule
    ~10^40." (Hoyle F., "Mathematics of Evolution", [1987], Acorn
    Enterprises: Memphis TN, 1999, pp102-103).
    Stephen E. Jones | sejones@iinet.net.au | http://www.iinet.net.au/~sejones
    --------------------------------------------------------------------



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