>
>Agreed. This is why creationists take "comfort" in Gould's quotes.
>Fundamentally Gould is a pre-Darwinian saltationist:
>
Michael Ruse has an interesting essay on punctuationalism,
"Is the Theory of Punctuated Equilibrium a New Paradigm?"
in <The Darwinian Paradigm>, Routledge, 1989.
He divides the evolution of punctuationalism into three
phases. Below is a brief summary of part of the second
and third phases:
The second phase came as the decade drew towards its end,
reaching its apotheosis in 1980 with Gould's notorious
'Is a new and general theory of evolution emerging?'(1980).
There had to be something new going on here, for, far from
portraying himself as an orthodox Darwinian, Gould assured
us that the synthetic theory of evolution is effectively dead.
Basically, I see a major de-emphasis of the importance of
organic adaptation and a consequent downplaying of the role
of natural selection. Gould certainly was also starting to
toy with the idea of macromutations of some sort (perhaps
due to chromosomal rearrangements) , with species' changes
occurring in one or a couple of generations. Significantly,
the father figure had changed from Charles Darwin to Richard
Goldschmit (1940), one of the few English-speaking saltationists
of the past half-century, and intellectual rival to the synthetic
theory's greatest living exponent, Ernst Mayr. [...]
I should say that Gould today (personal communication)
categorically denies that he himself was ever a saltationist
in Goldschmidt's or anyone else's sense. And it is certainly
true that never in print did he enrol under a saltationist
banner. What I think one can fairly say, however, is that
Gould (especially) was starting to think of evolution's
processes through a lens or filter of discontinuity
(to use a metaphor). In his own mind, he was starting to
highlight the essential abruptness of evolution, as opposed
to its continuity - just as (say), a man falling in love
might start to regard a woman in a new light, as a person
of sexual attraction rather than as a lawyer or professor.
Neither the continuity nor the profession is denied absolutely.
They just no longer seem so important.
Then, fairly quickly after this, we move to the theory's third,
and I think to date, final form. There is a pull-back from
extremism, particularly with respect to the formation of new
species. Thoughts of macromutation decline - indeed we are
told that we were mean to think they were there in the first
place - and we learn that although 50,000 years may seem like
a long time to a fruit-fly geneticist, to a paleontologist
it is but a blink of the eyelid [...]
However, altough there may be pull-back there is certainly no
retreat. Now we are presented with a _hierarchical_ view of
the evolutionary process. Down at the level of the individual
organism we have natural selection working away, although much
of its emphasis seems to be that of keeping things in line.
(Below the level of the individual, at the level of the gene,
we may have drift, working in ways that Japanese evolutionists
suggest.) Adaptation counts, although it is only one thing,
along with a lot of constraints on development and adult form.
Change generally comes at time of speciation, and although
full-scale mutations are out, there is a feeling that changes
in rates of development could have significant and fairly
instant effects. (There are interesting parallels here with
E.O. Wilson's (l975a) much-criticized multiplier effect.)
And what is important is that, as we pull back and look at
species, we see that their evolution has patterns and dynamics
of its own, at a level higher than that of the individual.
These are patterns that sit upon and are connected to the
individual bu which are in no sense reducible to the
individual. Against the well-known views of the geneticist
Theodosius Dobzhansky (1951), macrovolution is _not_
micro-evolution writ large.
Now a couple of points. Given that Gould denies being or ever
having been a saltationist, your flat assertion that he is
is unconvincing.
Second, the final paragraph sounds very much like the views
given by many of the "self-organizationalists". Looking through
the literature I have found some symposia on self-organization
in which Gould has contributed a paper. My guess is that Gould
may consider self-organization to be the mechanism that replaces
random variation + natural selection as the means for producing
organized complexity.
Off the subject a little, I can't resist including the following
humorous anecdote from Ruse's essay, from the epilogue:
Several years ago, I spent a year in the Museum of Comparative
Zoology at Harvard. On my first day there, I was being shown
the ant collection by that already-mentioned distinguished
evolutionist who was so contemptuous of punctuated equilibria
theory. He held up some particular specimen of ant and started
to hold forth on some intricate adaptation. 'What a remarkable
example of desjgn!' he cried out. Then he stopped, looked at
me sheepisly and grinned. 'For goodness sake! Don't ever tell
Steve Gould that I said that.'
SJ:===========
>
>Indeed, as creationists and non-creationist anti-Darwinians have
>been saying for years! Gould's problem is that he has nothing to
>put in its place. If adaptionism does not build organised complexity,
>and Gould's species selection (even if it exists) cannot, then where
>does it come from? Could it be...shock! horror! shudder!...God? :-).
>
And if the self-organizationalists are successful? What will
you conclude? That God wasn't involved? Actually, while they
have a long way to go, I think they have had enough success in
explaining the emergence of organized complexity to make you
squirm a little ;-).
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Brian Harper |
Associate Professor | "It is not certain that all is uncertain,
Applied Mechanics | to the glory of skepticism" -- Pascal
Ohio State University |
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