Seeds of Hierarchy 249
considering the principle of divergence as a problem in levels of selection can
resolve Wallace's puzzling lack of appreciation.
As Kottler (1985) has shown, Wallace and Darwin were not identical peas
from the pod of natural selection. They battled long and hard on several crucial
issues, mostly involving Wallace's panselectionism vs. Darwin's more subtle view
of adaptation (Gould, 1980d). One key area of disagreement centered upon the
target of natural selection. Darwin labored to work out a consistent theory that
virtually restricted selection to struggles among organisms (see Chapter 2 for his
interesting reasons). Wallace, as Kottler shows, never grasped the centrality, or
even the importance, of the issue of levels and agency for a theory of natural
selection. He moved from level to level as the situation seemed to imply, choosing
whatever target of selection would best support his panselectionist leanings. (For
example, he ascribed hybrid sterility to species selection in order to preserve his
conviction that features of such importance must originate as active adaptations;
whereas Darwin, committed to a consistent theory of organismal selection,
regarded hybrid sterility as an incidental side consequence of accumulated
differences arising by ordinary selection in two initially isolated lineages—see p.
131.) Thus, if Wallace ever pondered the principle of divergence to the point of
recognizing an issue in levels of selection, he would not have responded, as
Darwin did, with such a sustained, almost impassioned, quest for resolution.
Wallace would not have identified any problem at all, for he never grasped the
thorny issue of a need to specify levels in the first place. A simple statement about
divergence would have sufficed—as Wallace indeed provided. Darwin, in his over
reliance upon organismal selection, may never have reached the finish line in
explicating the principle of divergence; but Wallace scarcely got off the blocks.
Coda
No one would argue that persistence in history makes anything right or even
worthy—lest cruelty, murder and mayhem win our imprimatur by a misplaced
criterion of longevity. Still, in the world of ideas, long pedigrees through disparate
systems, and recurrence in the face of attempted avoidance; usually signify
something about the power of an idea, or its necessary place in the logic of a larger
enterprise.
Causal—and not merely descriptive—accounts of hierarchy have infused
evolutionary biology in this way from the beginning of our subject. Lamarck
initiated this conceptual rubric with a version in the invalid mode of causal
differences based on opposition between levels. Darwin knew what he didn't like
about this style, and his theory—preserved unchanged to our own orthodox
commitments today—sinks a strong foundation in an active rejection of hierarchy
in this inherently combative mode. Weismann and Darwin himself—the two
greatest evolutionists and deepest thinkers with an explicit commitment to the
single-level theory of natural selection—tried to extend the logic of this idea to
encompass every important issue in evolution. Both