644 THE STRUCTURE OF EVOLUTIONARY THEORY
bat itself, or the muscles in a pair of strong arms. As nonmaterial objects suited for
recording, codices are units of bookkeeping.
The history of gene selectionism has provided a grand intellectual adventure
for evolutionary theory—from inception as a manifesto (Williams, 1966), through
numerous excursions into pop culture, to valiant (though doomed) attempts to
work through the logical barriers and to develop a consistent and workable theory
(Dawkins, 1982; Williams, 1992). "Pareto-errors" always inspire a good race. No
one really loses—though false theories like gene selectionism must eventually
yield—because the resulting clarifications can only strengthen a field, and
interestingly fallacious ideas often yield important insights. Without this debate,
evolutionary biologists might never have properly clarified the differing roles of
replicators and interactors, items for bookkeeping and units of selection. And we
might not have developed a consistent theory of hierarchical selection without the
stimulus of an opposite claim that genes could function as exclusive causal agents.
Some evolutionists, largely perhaps in fealty to their own pasts, continue to
use the language of gene selectionism, even while their revised accounts elucidate
and unconsciously promote the hierarchical view (see, in particular, Williams's
excellent fourth chapter, in his 1992 book, on selection upon multiple interactors at
several levels). Williams, to use a locution of our times, may still be talking the
talk of gene selectionism, but he is no longer walking the walk.
Nearly all-major participants in this discussion met at Ohio State University
in the summer of 1988. There I witnessed a wonderful little vignette that may serve
as an epitome for this section. George Williams presented his new views (the
substance of his 1992 book), and surprised many people with his conceptual move
towards hierarchy (within his unaltered terminology). I could not imagine two
more different personalities in the brief and telling interchange that followed.
Marjorie Grene—the great student of Aristotle, grande dame of philosophy, one of
the feistiest and toughest people I have ever known, and a supporter of the
hierarchical view—looked at Williams and simply said: "You've changed a lot."
George Williams, one of the calmest and most laconic of men, replied: "It's been a
long time."
Logical and Empirical Foundations for the
Theory of Hierarchical Selection
LOGICAL VALIDATION AND EMPIRICAL CHALLENGESR. A. Fisher and the compelling logic of species selection
R. A. Fisher added a short section entitled "the benefit of species" to the second
edition (1958) of his founding document for the Modern Synthesis: The Genetical
Theory of Natural Selection (first published in 1930). I do not know why he did so,
but the result could not be more favorable for fruitful debate—for Fisher, in these
few additional paragraphs, grants to the concept of species selection the two
requisite properties for any healthy and controversial theory.