Richard Wein wrote:
>In case anyone should think that Cliff is representative of philosophical
>naturalists in having a "built-in prejudice in favor of naturalistic
>explanation", I'd like to point out that I don't share his prejudice. I
>reject the ID explanation precisely because it is *less* parsimonious.
>...
>The most parsimonious explanation is not simply the one which can be
>stated in fewest words.
There must be some correlation between parsimony in the real
world and description of the real world. Simpler mechanisms and
fewer assumptions should mean fewer words in the description.
>It's the one which leaves least unexplained.
That sounds like the 'most complete' explanation.
I never liked this topic--I recall having to learn terms like explicans
and explicandum, definiens and definiendum, terms which are never
employed outside of philosophy of science courses and which are
forgotten after the exam. It just seemed to me that in a general sense
ID was a highly parsimonious explanation, as it relies totally on one
simple assumption and it can explain anything and everything.
>>The point is that this is a mechanism that explains how a sudden increase
>>in the complexity of an organism could occur. Irreducible-complexity
>>arguments depend on the straw man of pure gradualism. If symbionts in
>>an ecosystem can suddenly become one organism, that is a leap in
>>complexity.
>
>I'm not sure I would call that a sudden leap in complexity. The complexity
>existed already, in two separate organisms. All (!) that happened was that
>two complex entities were combined into one. But you could say this is a
>semantic matter.
'Complexity' is hard to pin down, but the primary thing is to have a
picture of what is or was going on. Maybe the ecosystem loses complexity
when symbionts integrate and a more complex individual arises, maybe not,
it depends on definitions.
>>The general model could apply above the cellular level. It's a little weird
>>to think that metazoan organs were once free symbionts, but why not?
>
>I think "weird" is understating it. It's bizarre! Still, I suppose bizarre
>things do happen. But have you thought out any plausible scenarios for how
>this could have happened in the case of particular organs?
To me the origin of metazoan or cellular complexity is so completely
opaque I expect the real truth to be rather weird and unexpected,
counterintuitive and possibly gross.
I don't have theories about particular organs, but I can certainly imagine
an aquatic ecosystem of organisms with specialized abilities to move, to
filter, to perceive and react, to digest, to emit chemicals etc living in tight
symbioses. How could genomic integration of metazoa occur? I'd have
to presume successful zygosis of disparate organisms would involve
endomitotic duplication of each chromosome to form the normal diploid
set. Subsequent reproduction would be through the familiar means.
Against objections I can only say things may have been a little wild
during the formation of our metazoan fauna.
>>It's logically more satisfactory than thinking these complexes evolved
>>gradually.
>
>Why? What's your objection to gradual evolution of organs? Do you deny that
>*any* complexity can evolve gradually?
Maybe. If 'complex' means having many parts, how do you *gradually* move
from having x number of parts to having x+1 number of parts? Objections to
the gradual evolution of interdependent complexes are familiar, they're
basically
about the problem of incipience.
As with the number of bones we have, the number of organs seems to be
diminishing. We see vestigial organs, but do we see nascent incipient
organs? Anybody sprouting a handy eye in the back of the head? This
implies to me that there was a special formative era, and that subsequent
evolution is a limited refining process distinct from the wilder original
time of 'creation'.
--Cliff Lundberg ~ San Francisco ~ 415-648-0208 ~ cliff@cab.com
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