Species as Individuals in the Hierarchical Theory of Selection 625
not required, any more than individuals within a population need interact
ecologically to be subject to individual selection. The reproductive success
or failure of a soil arthropod, with an expected lifetime dispersal of a few
meters, will hardly influence prospects for a conspecific a hundred meters
away. But the descendants of these two individuals might compete, and
genes passed on by one may ultimately prevail over those passed on by the
other. Selective elimination of one and survival of the other a hundred
meters away is individual selection as long as the two arthropods can be
assigned to the same population and their genes to the same gene pool. ... In
the same way, two gene pools in allopatry can be subject to natural
selection if, as must always be true, their descendants might be alternatives
for representation in the biota... The ultimate prize for which all clades
are in competition is representation in the biota.The internal incoherence of gene selectionism
I regard the heyday of gene selectionism as an unusual episode in the history of
science—for I am convinced that the theory's central argument is logically
incoherent, whatever the attraction (and partial validity) of several tenets, and
despite the value of a mental exercise that tries to reconceptualize all nature from a
gene's point of view. Close textual analysis* of this theory's leading documents
reveals persistent internal problems, explicitly recognized by authors and
invariably met by arguments so flawed in construction that even the defenders
seem embarrassed, or at least well aware of the glaring insufficiency.
I am not alone in noting this peculiar situation, and in calling for some serious
consideration by historians. Wilson and Sober (1994, p. 590) write: "The situation
is so extraordinary that historians of science should study it in detail: a giant
edifice is built on the foundation of genes as replicators, and therefore as the
'fundamental' unit of selection, which seems to obliterate the concept of groups as
organisms. In truth, however, the replicator concept cannot even account for the
organismic properties of individuals. Almost as
*This kind of textual exegesis, a standard mode of scholarly work in the humanities,
should be pursued more often in scientific discussion as well. Scientists tend to reject
such an approach, I suppose, because we believe that forms of argument and rhetorical
styles only lend a superficial patina to the "real" substance of logic and evidence, and
therefore can teach us nothing of interest. I think that we have thereby missed a major
source of insight about the operation of science—a source that would not only deepen our
understanding of history and procedure, but would also help us to judge and analyze such
contemporary issues as the logic of selectionist theory. If we locate consistent slips,
foibles, jagged edges, strains, or near apologies—as presented verbally—then we can
often pinpoint weaknesses in logic or failure of empirical support. I show, in this section,
that all major supporters of gene selectionism fall into such verbal patterns at the theory's
main loci of inconsistency. In previous books, I have tried to use this mode of analysis to
explicate such issues as the nature of geological time (Gould, 1987b), the logic of
biological determinism (1981a), and the concept of evolutionary progress (1996a) and
predictability (1989c).