634 THE STRUCTURE OF EVOLUTIONARY THEORY
sexual organisms do not replicate faithfully and therefore cannot be traced as
discrete entities across generations.) But this practical decision for counting does
not deprive the organism of status as a causal agent, nor does such a procedure
grant causality to the objects counted. The listing of accounts is bookkeeping—a
vitally important subject in evolutionary biology, but not a form of causality.
If, as I have argued (see also Wilson and Sober, 1994), the incoherence of
gene selectionism denotes a rare case in science of an influential theory felled by a
logical error—in this case the confusion of bookkeeping with causality— rather
than a fallacious proposal about the empirical world, then we must ask why so
many people fell into this error so readily, and why the fallacy did not become
more quickly apparent. I suspect that three major reasons underlie not only the
error of gene selectionism, but also the strong willingness, even the fervor,
expressed by so many evolutionists in embracing the concept. The first two reasons
may claim a social basis in traditions of scientific inquiry. But the third reason, and
surely the most intriguing from both a scientific and philosophical perspective,
emanates directly from the logical structure of hierarchies, the conceptual
framework that must replace gene selectionism.
The two reasons rooted in traditions of scientific procedure include the most
general of statements and a preference peculiar to traditions of Anglo-phonic
evolutionary biology. For the generality, I state nothing profound or original in
pointing out that a decision to privilege the level of genes plays into the strongest
of all preferences in Western science: our traditions of reductionism, or the desire
to explain larger-scale phenomena by properties of the smallest constituent
particles.
The allure of reductionism encourages the following kind of error, or sloppy
thinking: we correctly note that genes play a fundamental role in evolution (as
preferred items for a calculus of change—the bookkeeping function); we also
recognize that genes lie at the base of a causal cascade in the development of
organisms; finally, and most generally, we view genes as the closest biological
approach to an "atom" of basic structure, and therefore as the cardinal entity of a
reductionistic research program. From these statements, we easily slip into the
unwarranted inference that genes must also be fundamental units or agents in
natural selection, the primary causal theory of our profession—all the while
forgetting the criteria of individuality and interaction that define units or agents
within the logic of the theory itself.
The second, and more particular, reason flows from explicit traditions of the
Modern Synthesis, especially from the approach favored by Fisherian population
genetics (see Chapter 7). The heuristics of this field prospered greatly with models
that kept track of gene frequencies without worrying much about the locus of
selective action. A common fallacy in science then conflates a practical basis for
success with the causal structure of nature. Jim Crow (1994, p. 616), one of the
world's most thoughtful geneticists, expressed this point particularly well, but then
also failed to distinguish bookkeeping from causality. Writing "In praise of
replicators"—and well should we praise them, but, I would argue, as excellent
agents for accounting! —