ophy might be regarded as a footnote to Plato). Evolutionary biology possesses the
great good fortune to embrace such a figure—Charles Darwin, of course—at the
center of its origin and subsequent history. Thus, Darwin emerges again and again,
often controlling the logic of discussion, throughout this book—in his own full
foundational exegesis (Chapter 2); but then, in later chapters, as the principal
subject, and best possible exemplification, of other important subbranches on all
three boughs of his essential logic (his reluctant acceptance of higher levels of
selection in Chapter 3; his formalist contrast to his own functionalism in stressing
"correlations of growth" in Chapter 4; his views on direction and progress in the
history of life in Chapter 6, and, even in the book's second half on modern
developments, for his discussion of discordance between historical origin and
current utility as a point of departure for my treatment of exaptation in Chapter 11,
and his attempt to underplay and undermine mass extinction as an introduction to
my critique of uniformitarianism and extrapolationism in the final Chapter 12).
Who could ask for a more attractive and effective coordinating "device" to tie the
disparate strands of such an otherwise disorderly enterprise together than the genial
and brilliant persona of the man who first gave real substance to the grandeur in
this view of life?
Whatever my dubiety about the role and efficacy of abstracts (too often, as we
would all admit in honest moments, our only contact with a work that we
nonetheless then feel free to criticize in full assurance of our rectitude), I cannot
deny that a work of this length, imbued moreover with a tendency to penetrate
byways along a basic route that seems (at least to this author) adequately linear and
logical, demands some attempt to list its principal claims in textual order. Hence, I
now impose upon you the following abstract:
Chapter 2: An exegesis of the origin- All major pre-Darwinian evolutionary theories, Lamarck's in particular,
contrasted a primary force of linear progress with a distinctly secondary and
disturbing force of adaptation that drew lineages off a main line into particular and
specialized relationships with immediate environments. In his most radical
intellectual move, expressing both the transforming depth and the conceptual
originality of the theory of natural selection, Darwin denied the existence of a
primary progressive force, while promoting the lateral force of adaptation to near
exclusivity. In so privileging uniformitarian extrapolation as an explanatory device,
Darwin imbued natural selection, the lateral force, with sufficient power to
generate evolutionary change at all scales by accumulating tiny adaptive
increments through the immensity of geological time. - The Origin of Species exceeds all other scientific "classics" of past centu-
ries in immediate and continued relevance to the basic theoretical formulations and
debates of current practitioners. Careful exegesis of Darwin's logic and intentions,
through textual analysis of the Origin, therefore assumes unusual importance for
the contemporary practice of science (not to mention its undeniable historical value
in se).
Defining and Revising the Structure of Evolutionary Theory 59