(germinal selection in his terms), if only in the context of modern reductionistic
breakdowns of Darwinism to selection among "selfish genes." But they had missed
his later reversal and expansion to a full hierarchical model, despite Weismann's
own emphasis. Similarly, de Vries's clear understanding of Darwinian logic had
also been ignored because de Vries, as an opponent of the efficacy of Darwinian
organismal selection (a painful decision for him, given his psychological fealty to
Darwin, also explored herein), applied the logic to higher levels, and even devised
the term "species selection" (Chapter 5, pp. 446-451)—a concept and coining
previously entirely unremarked by historians (much to the embarrassment of
scientists, including yours truly, who coined and explicated the same term much
later in full expectation of pristine originality!).
Similarly, my sense of the logic in conflicts between constraint and adaptation
(or internal vs. external, or formal vs. functional approaches) on the second branch
helped me to pinpoint, or to make sense of, several important historical events and
arguments that have not been properly treated or understood. Historians of science
had not previously discussed orthogenetic theories in this fairest light, and had not
distinguished the very different formulations of Hyatt, Eimer, and Whitman in
terms of their increasingly greater willingness to accommodate Darwinian themes
as well (see Chapter 5). The same framework allowed me to identify the crucial
importance, and brilliant epitomization, of this issue in the final paragraphs of
Chapter 6 ("Difficulties on Theory") in Darwin's Origin, a significance that had not
been highlighted before.
I also traced the dichotomy of anglophonic preferences for functionalist
accounts vs. continental leanings towards formalism back through the evolutionary
reconstruction of the argument in the mid 19th century into the creationist
formulations of Paley vs. Agassiz (Chapter 4), thus illustrating a pedigree for this
fundamental issue in morphology that evolution may have recast in causal terms,
but did not budge in basic commitments to the meaning of morphology. Among
the little tidbits that emerge from such analyses, I even discovered that Darwin
borrowed his clearest admission of co-opted utility from non-adaptive origins
(unfused skull sutures in mammalian neonates, essential for passage through the
birth canal, but also existing in birds and reptiles born from more capacious eggs)
from the longer and more nuanced descriptions of Richard Owen, Britain's
anomalous defender of formalism.
I also included some historical analyses in the book's second half on modern
advances because I thought they could make an original contribution to arguments
usually developed only in contemporary terms and findings. I have already
mentioned my analysis of how the initial pluralism of the Modern Synthesis
(embracing any mode of change consistent with known genetic mechanisms)
hardened through subsequent editions of the founding volumes into pronounced
preferences for adaptationist accounts framed only in terms of natural selection
(Chapter 7). In addition, I think that my reexhumation of the debate between
Falconer and Darwin on fossil elephants provides a
52 THE STRUCTURE OF EVOLUTIONARY THEORY