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From: jes1@akgub.UUCP
Newsgroups: sci.bio
Subject: Comment on punctuated equilibria
Message-ID: <829@akgub.UUCP>
Date: Wed, 8-Apr-87 10:40:22 EST
Article-I.D.: akgub.829
Posted: Wed Apr  8 10:40:22 1987
Date-Received: Sat, 11-Apr-87 07:50:44 EST
Organization: AT&T Technologies/Bell Labs, Atlanta
Lines: 34


	Niles Eldredge and Stephen Jay Gould say they have rejected
gradualism in favor of what they refer to as "punctuated equilibria."
They accept the breaks in the fossil record as being real, reflecting
the way evolution is actually recorded in the rocks; they are not
merely artifacts of a damaged crust. Eldredge and Gould claim that
the record is much better than tradition dictates. They paint a pic-
ture of long periods of biological stability punctuated by "rapid"
periods of speciation in isolated subpopulations - events we should
not expect to find depicted by the fossil remains. We are thus left
with the *illusion* of evolutionary jumps and an *undisturbed* ortho-
dox chronology. But the two scientists go on to make a revealing
confession: *both gradualism and punctuated equilibria are interpre-
tations based on preconceived ideas*!
	All that Eldredge and Gould have done is to contrive an *ad
hoc* hypothesis (punctuated equilibria) to explain the lack of fossil
evidence while still working within another hypothesis (speciation
by natural selection). The former would be an acceptable proposal
only if there were other evidence to support the latter - *which
there isn't*.
	By *running gradualism at fast forward*, Eldredge and Gould
see the *geological camera* as being unable to record its tracks.
They can have their cake and eat it too: the geological record is
not so bad after all, and the concept of speciation by natural selec-
tion is protected anyway - *even though it still isn't demonstrated*.
	Incidentally, it would seem that any belief (e.g., specia-
tion by natural selection) doggedly maintained after being thorough-
ly refuted amounts to a religion.

	Reference: N. Eldredge & S.J. Gould
		   "Punctuated Equilibria: An Alternative to Phyletic
		    Gradualism"
		    from *Models in Paleobiology*
		    ed. by T.J.M. Schopf (San Francisco 1972), p.91.