Punctuated Equilibrium and the Validation of Macroevolutionary Theory 1019
systems in steady state are not only common but also so highly resistant to
change.THE MOST UNKINDEST CUT OF ALL. If none of the foregoing charges can bear
scrutiny, strategists of personal denigration still hold an old and conventional tactic in
reserve: they can proclaim a despised theory both trivial and devoid of content. This
charge is so distasteful to any intellectual that one might wonder why detractors don't
try such a tactic more often, and right up front at the outset. But I think we can
identify a solution: the "triviality caper" tends to backfire and to hoist a critic with his
own petard—for if the idea you hate is so trivial, then why bother to refute it with
such intensity? Leave the idea strictly alone and it will surely go away all by itself.
Why fulminate against tongue piercing, goldfish swallowing, skateboarding, or any
other transient fad with no possible staying power?
Nonetheless, perhaps from desperation, or from severe frustration that
something regarded as personally odious doesn't seem to be fading away, this charge
of triviality has been advanced against punctuated equilibrium, apparently to small
effect. To cite a classic example of backfiring, Gingerich (1984a, 1984b) tried to
dismiss punctuated equilibrium as meaningless and untestable by definition—and to
validate gradualism a priori as "commitment to empiricism and dedication to the
principal [sic] of testability in science" (1984a, p. 338), with stasis redefined,
oxymoronically in my judgment, as "gradualism at zero rate" (1984a, p. 338).
Gingerich then concludes (1984b, p. 116): "Punctuated equilibrium is unsealed, and
by nature untestable. It hardly deserves recognition as a conjecture of 'major
importance for paleontological theory and practice.'... Hypotheses that cannot be
tested are of little value in science."
But how can Gingerich square this attempted dismissal with his own dedication
of a decade in his career to testing punctuated equilibrium by fine-scale quantitative
analysis of Tertiary mammals from the western United States (Gingerich, 1974,
1976)? These studies, which advanced a strong claim for gradualism, represent the
most important empirical research published in the early phase of the punctuated
equilibrium debate. Gingerich then recognized punctuated equilibrium as an
interesting and testable hypothesis, for he spent enormous time and effort testing and
rejecting our ideas for particular mammalian phylogenies. He then argued explicitly
(1978, p. 454): "Their [Eldredge and Gould's] view of speciation differs considerably
from the traditional paleontological view of dynamic species with gradual
evolutionary transitions, but it can be tested by study of the fossil record."
Among Darwinian fundamentalists (see my terminology in Gould, 1997d),
charges of triviality have been advanced most prominently and insistently by
Dawkins (1986, p. 251) who evaluates punctuated equilibrium metaphorically as "an
interesting but minor wrinkle on the surface of neo-Darwinian theory"; and by
Dennett (1995, p. 290) who calls punctuated equilibrium "a false-alarm revolution
that was largely if not entirely in the eyes of the beholders."