Re: The Cambrian Explosion

John P Turnbull (jpt@ccfdev.eeg.ccf.org)
Mon, 11 Dec 95 13:51:08 EST

Denis Lamoureux wrote:
>
> I admire [Gould's] honesty as well. And in my many evolutions discussions
> with
> evolutionary colleagues I have experience this same candor and honesty.
> OK, Darwin got a lot of things wrong. Science has now gone beyond him,
> and Gould's position testifies it. But Gould remains a firm evolutionist.
>
> In Him,
> Denis
>

Yes, the new definition of "evolution" appears to be shifting to:
Evolution = Darwinism + non-Darwinism

Where the new term is not some minor augmentation to tie up loose
ends of an otherwise sound theory. It has become an all purpose
slack variable that has rendered the theory as impervious to
falsification as it is devoid of meaning. Those who accept this
new theory of evolution are quick to shift the entire load to this
new term as the _Time_ article testifies:

"What Darwin described in the _Origin of Species_,' observes Queen's
University paleontologist Narbonne, 'was the steady background kind
of evolution. But there also seems to be a non-Darwinian kind of
evolution that functions over extremely short time periods - and
that's where all the action is." (page 74)

Thus Darwinism proper is relegated to the explanation of trivial
side shows like minor variation in the sizes of finch beaks and
all the rest "where all the action is" is relegated to some vague
mechanism known only as a "fast transition."

This new theory of evolution has divided evolutionists. Those that
concern themselves with the abstract theory of the mechanisms, such
as Richard Dawkins, who insist, as did Darwin, that the ONLY plausible
mechanism is that which produces change by the gradual accumulation
of random variations combined with the effects of natural selection.
Darwin insisted that all temptations for accepting any form of
saltationism must be resisted on account that it endangers the very
mechanism that renders the theory plausible. On the other side
are the empiricists, like Stephen Jay Gould, who concern themselves with
a reconstruction of the actual history of life from the bits and pieces
of fossil evidence. The fact that these groups have diverged is no
trivial matter. The former group ignores the empirical facts, the latter
ignores Darwin.

Helena Cronin has attempted to salvage the theory of evolution in her
book _The Ant and the Peacock: Altruism and Sexual Selection from Darwin
to Today_ (Cambridge U. Press, 1991) within the strictest sense of
Darwinian gradualism. Stephen Jay Gould's review of her book and
subsequent exchanges is a must-read for anyone who doubts how profound
the rift has become between these two groups. Here is an excerpt from
Gould's review:

"If this uniformitarian vision of extrapolation fails, then we must
conclude that while adaptationism may control immediate changes in the
overt forms of organisms, it cannot render evolution at other scales.
The main excitement in evolutionary theory during the past twenty years
has not been - as Cronin would have us believe - the shoring up of
Darwinism in its limited realm (by gene selectionism or any other
patching device), but rather the documentation of the reasons why
Darwin's crucial requirement for extrapolation has failed.
Selectionism is not a general model for evolutionary change at most
scales." _The Confusion About Evolution_ in "The New York Review of Books",
Nov. 19, 1992.

Phillip Johnson cites this recent exchange in his book _Reason in the
Balance_ (IVP). The research notes are especially interesting:

"The second part of chapter four relies mainly on Stephen Jay
Gould's review article "The Confusion About Evolution," in
_The New York Review of Books_, Nov. 19, 1992. Gould was reviewing
Helena Cronin's _The Ant and the Peacock: Altruism and Sexual
Selection from Darwin to Today_ (Cambridge U. Press, 1991). The
review was so overheated that it drew indignant protests from
John Maynard Smith and Daniel Dennett, to which Gould replied with
his usual dexterity in _The New York Review of Books_, Jan.
14, 1993....Gould's review came very close to repudiating Darwinism
in favor of a concept of 'evolution' that resembles the pre-Darwinian
catastrophism of George Cuvier. I wrote to Gould after this review to
suggest that he is no more of a Darwinist than I am, and that he
refuses to acknowledge this only because he fears the metaphysical
consequences. He did not answer." (pp 227-228)

Gould is first and foremost a committed methodological naturalist.
As such, he is a committed evolutionist by necessity. But as long
as "non-Darwinian evolution" remains a vague non-descript term, referring
to Gould as a "firm evolutionist" carries little meaning.

-jpt

--

John P. Turnbull (jpt@ccfdev.eeg.ccf.org)Cleveland Clinic FoundationDept. of Neurology, Section of Neurological ComputingM52-119500 Euclid Ave.Cleveland Ohio 44195Telephone (216) 444-8041; FAX (216) 444-9401