406 THE STRUCTURE OF EVOLUTIONARY THEORY
most arguments in a context of refutation—with Darwinian natural selection as the
prime target, particularly the themes of insensibly gradual change and selective
pressure guided by utility. In so proceeding, Bateson expresses no hostility for
Darwin himself. Moreover, his strategy in separating Darwin's factual and
theoretical achievements in order to render high personal praise also makes sense
in this context. Bateson's style of refutation extends far beyond biology into
broader and contemporary themes of science. Bateson regarded himself as an
experimental modernist, upholding ideals of tractable science against a sterile
speculative tradition that had taken hold in two areas of natural history—the
guesswork of phyletic reconstruction and the hypothetical assignment of adaptive
utility.
Bateson's attitude towards natural selection and adaptation provides a good
indication of his procedures and prejudices. As stated above, Bateson uses several
facts of discontinuous variation to downplay selection as a creative force. Consider
just two arguments:
- If rare and discontinuous variants may originate as well formed and
potentially useful at their sudden appearance, why assume that normal forms must
be gradually crafted to perfection by natural selection: "The existence of sudden
and discontinuous variation, the existence, that is to say, of new forms having from
their first beginning more or less of the kind of perfection that we associate with
normality, is a fact that disposes, once and for all, of the attempt to interpret all
perfection and definiteness of form as the work of selection. The study of variation
leads us into the presence of whole classes of phenomena that are plainly incapable
of such interpretation" (1894, p. 568). - If variation is inherently discontinuous and often large in effect, then
selection can only choose among alternatives presented by internal causes, and
therefore cannot operate as a creative force in evolutionary change. (Here, of
course, Bateson merely recounts the standard argument on "creativity" advanced
by nearly all non-Darwinian theorists.) Bateson, for example, writes about butterfly
wingtips that exhibit either red or purple, but nothing in between: "It is easier to
suppose that the change from red to purple was from the first complete, and that
the choice offered to selection was between red and purple" (1894, p. 73).
But Bateson devotes his main thrust of argument to a methodological
theme—to designating the tradition of adaptationist "story telling" as a poor
substitute for experiment and proof. Some of the most powerful statements against
this conventional, and still all too common, form of evolutionary conjecturing may
be found in Bateson's 1894 book and later writings.
Bateson acknowledges the allure and fascination of adaptationist conjecture:
"This study of adaptation and of the utility of structures exercises an extraordinary
fascination over the minds of some... The amount of evidence collected with this
object is now enormous, and most astonishing ingenuity has been evoked in the
interpretation of it" (1894, p. 10).
Yet this so-called evidence, Bateson then asserts, represents little more than a
set of conjectures about possible benefits, not a proof of actual (and gradual)
construction for utility: