erectus toolkit), and nontrending, despite classical (and false) claims to the
contrary by both experts, the Abbe Breuil and Andre Leroi-Gourhan, for the
25,000 year history of elegance in parietal cave art of France and Spain—and
extending into more distant fields like learning theory (plateaus and innovative
punctuations), studies of the dynamics of human organizations, patterns of human
history, and the evolution of technologies, including a fascinating account of the
history of books, through punctuations of the clay tablet, the scroll, the codex, and
our current electronic reformation (wherever it may lead), and long periods of
morphological stasis (graced with such vital innovations as printing, imposed upon
the unaltered phenotype of the codex, or standard "book").
- In a long and final section, I indulge myself, and perhaps provide some
useful primary source material for future historians of scientific conflicts, by
recording the plethora of non-scientific citations, ranging from the absurd to the
insightful, for punctuated equilibrium (including creationist misuses and their
politically effective exposure by scientists in courtroom trials that defeated
creationist legislative initiatives; and the treatment of punctuated equilibrium, often
very good but sometimes very bad, by journalists and by authors of textbooks—the
primary arenas of vernacular passage). I also trace and repudiate the "dark side" of
non-scientific reactions by professional colleagues who emoted at challenges to
their comfort, rather than reacting critically and sharply (as most others did, and as
discussed extensively in the main body of the chapter) to the interesting novelty,
accompanied by some prominent errors of inevitable and initial groping on our
part, spawned by the basic hypothesis and cascading implications of punctuated
equilibrium.
Chapter 10: The integration of constraint and adaptation: historical
constraint and the evolution of development- Although the directing of evolutionary change by forces other than natural
selection has loosely been described as "constraint," the term, even while
acknowledged as a domain for exceptions to standard Darwinian mechanisms, has
almost always been conceived as a "negative" force or phenomenon, a mode of
preventing (through lack of variation, for example) a population's attainment of
greater adaptation. But constraint, both in our science (and in vernacular English as
well), also has strongly positive meanings in two quite different senses: first, or
empirically, as channeled directionality for reasons of past history (conserved as
homology) or physical principles; and second, or conceptually, as an nonstandard
force (therefore interesting ipso facto) acting differently from what orthodoxy
would predict. - The classical and most familiar category of internal channeling (the first, or
empirical, citation of constraint as a positive theme) resides in preferred directions
for evolutionary change supplied by inherited allometries and their phylogenetic
potentiation by heterochrony. As "place holders" for an extensive literature, I
present two examples from my own work: first, the illustration of synergy with
natural selection (to exemplify the positive, rather than oppositional, meaning),
where an inherited internal channel builds two im-
Defining and Revising the Structure of Evolutionary Theory 81