Punctuated Equilibrium and the Validation of Macroevolutionary Theory 1011
by neontologists, and serving as a basis for enlarged discussion, we clearly explained
the differences in scaling between micro- and macroevolutionary rates.
- As acknowledged on pages 1002-1004,1 did use some prose flourishes that,
in a context of considerable suspicion and growing jealousy, probably fanned the
flames of confusion. Although I never stated anything unclearly, and committed no
logical errors that could legitimately have inspired a resulting misreading, I should
have toned down my style in a few crucial places. - We may have sown some confusion by using partially overlapping
terminology for a specific theory (punctuated equilibrium), and for the larger
generality (punctuational styles of change) in which that theory lies embedded. But
this taxonomic usage does stress a legitimate commonality that we wished to
emphasize. We also chose and used our terms with explicit consistency and clear
definitions—so careful reading should have precluded any misunderstanding.
The testing and development of punctuated equilibrium—a well defined and
circumscribed theory about the origin and deployment of speciation events in
geological time—has always been our major concern. But as students of evolution,
we have also been interested in the range of applicability for the geometric
generalization represented by this theory—the unfolding of change as occasional
punctuation within prevailing stasis, rather than as gradualistic continuity—to other
scales of space and time, and for other causes and phenomena of life's history. We
have called this more general and abstract style of change "punctuational," and have
referred to the hypothesis favoring its generality as "punctuationalism."
We have always been careful and clear about the differences between our
specific theory of punctuated equilibrium and the general proposition of
punctuational change. (In fact, we strove to be explicit, even didactic, about this
distinction because we recognized the confusion that might arise otherwise.) But
perhaps the words are too close to expect general understanding of the distinction,
particularly from hostile critics who have invested their emotional ire in the legend
that we have been pursuing an imperialistic, grandstanding quest to enshrine
punctuated equilibrium as a new paradigm for all the evolutionary sciences.
Still, as a statement of a basic intellectual principle, why should we allow
ourselves to be forced into suboptimal decisions by the least thoughtful and most
emotionally driven forms of misunderstanding among critics? Punctuationalism is the
right and best word for the general style of change expressed by punctuated
equilibrium as a specific example at a circumscribed level and phenomenology. As
long as we take special care to be clear and explicit about the distinction, why should
we sacrifice this most appropriate form of naming? I believe that we have been
scrupulous in characterizing and highlighting this point, right from our first
introduction in 1977, when we began a section entitled "Towards a general
philosophy of change" with these words: "Punctuated equilibria is a model for
discontinuous tempos of change at one biological level only: the process of speciation
and the deployment of species in