From: tycchow@riesz.mit.edu (Timothy Y. Chow)
Subject: Abiogenesis of multicellular organisms
Organization: None.  This saves me from writing a disclaimer.
Date: Wed, 18 Nov 92 03:31:40 GMT

Here's something that I don't understand very well, and haven't been able to
find discussed in any detail anywhere.  Consider an organism that

1. Does not exist today but whose fossils do exist;
2. Appears "suddenly" in the fossil record;
3. Is the only representative of its phylum in the fossil record;
4. Is macroscopic.

I don't know of any examples offhand, but I'm sure they exist.  Call this
organism the Lone Wolf.  Consider now:

(*) The Lone Wolf arose from non-living matter by some unknown
    (naturalistic, non-teleological, etc.) process.

Nobody believes (*).  My question is, why not?  Possible dialogue between
Imaginary Antagonist and me follows.

IA: Unless you provide a mechanism, (*) is just vague hand-waving, almost
    meaningless.
ME: But nobody knows of a mechanism for abiogenesis, yet many believe
    the corresponding statement (*) for the first living organism.  If we
    know that there exists *some* mechanism for abiogenesis, but we don't
    know what it is, what is to stop this mechanism from generating the
    Lone Wolf?
IA: We have to postulate at least one instance of abiogenesis, but after
    that we can explain the appearance of the Lone Wolf by evolution.  Thus
    there is no need to postulate additional cases of abiogenesis.
ME: So the reason people don't believe (*) is simply out of Occam's Razor
    or a similar parsimony principle?  Do you mean that there is no evidence
    against (*) but that we disbelieve it on aesthetic grounds alone?  This
    seems to be an arbitrary, subjective reason for dismissing (*).
IA: No, there *is* evidence for common ancestry of all organisms, at least
    all multicellular organisms.
ME: But don't these arguments for common ancestry rely on comparative
    genetics or comparative anatomy or biogeography?  We have no genetic
    data on the Lone Wolf, and there aren't any organisms similar enough
    to it to make a convincing case for common ancestry, especially given
    its "sudden" appearance in the fossil record.
IA: Well, it's possible that there was another act of abiogenesis that
    gave rise to a line of descent that resulted in the Lone Wolf, and
    that we have lost all record of the Lone Wolf's predecessors.  I'll
    grant you that much.
ME: O.K., but why won't you grant me (*) flat out?  Is it simply because
    the Lone Wolf is macroscopic or multicellular that its abiogenesis
    seems implausible?  But even single-celled organisms are incredibly
    complex and their abiogenesis defies all our attempts at plausible
    explanation.  If we can stomach that, why can't we stomach the
    abiogenesis of the Lone Wolf?  Are we back to parsimony and subjective
    feelings again?
IA: This whole discussion is just philosophical nonsense.  Until you flesh
    out your theory to the point where it has testable predictions, there
    is no reason for scientists to take you seriously.
ME: I can see your point.  Do you think that it's worth much effort to
    think hard to derive some testable consequences of (*)?
IA: Frankly, no.  I think macroevolution provides a satisfactory explanation
    of all existing life, given one act of abiogenesis.
ME: Is it really satisfactory?  According to your view, the Lone Wolf arose
    from some single-celled organism through some line of descent involving
    unknown sequences of changes.  How is this more satisfactory than saying
    that the Lone Wolf arose from non-living matter through a sequence of
    unknown physical/chemical processes?
IA: Look, isn't it much more plausible that the Lone Wolf arose from some
    other organism similar to it than from non-living matter?
ME: It certainly seems more plausible, but that's probably just a subjective
    feeling that I get because all organisms I see come from other organisms.
    But again, once we grant that abiogenesis has occurred, however
    implausible it may seem, why can we not grant (*)?  We seem to be going
    in circles again.

I would appreciate it if someone clears up this confusion for me.
-- 
Tim Chow     tycchow@math.mit.edu
Where a calculator on the ENIAC is equipped with 18,000 vacuum tubes and weighs
30 tons, computers in the future may have only 1,000 vacuum tubes and weigh
only 1 1/2 tons.                               ---Popular Mechanics, March 1949
Newsgroups: talk.origins