The Fruitful Facets of Galton's Polyhedron 413
To begin with, we must relegate selection to its proper place. Selection
permits the viable to continue and decides that the nonviable shall perish;
just as the temperature of our atmosphere decides that no liquid carbon
shall be found on the face of the earth: but we do not suppose that the form
of the diamond has been gradually achieved by a process of selection. So
again, as the course of descent branches in the successive generations,
selection determines along which branch evolution shall proceed, but it
does not decide what novelties that branch shall bring forth (1909, p. 96).In a briefer epitome, Bateson had previously written (1904, in 1928, p. 238):
"Selection is a true phenomenon; but its function is to select, not to create."
Bateson then launches a two-pronged attack. In a first methodological critique,
bordering on meanness (despite his cogent point), Bateson inverts Darwin's intent
in proposing small-scale, continuous, isotropic variability as the source of
evolutionary change. Darwin used this claim as a brilliant ploy for tractability in a
context of ignorance about the nature of variation (see pp. 141-146)—for the
assumption of isotropy allowed variation to play the role of supplying "raw
material" only, thus permitting the search for mechanisms of evolutionary change
to proceed notwithstanding. (An insistence that knowledge of the mechanisms of
variation must underlie any explanation of phyletic change would have stymied the
development of evolutionary theory and practice, for Darwin's world knew
effectively nothing about the causes of variation, and possessed no techniques for
obtaining the requisite information.) But for Bateson, the Darwinian claim of
isotropy could only impede the development of a proper theory—for Bateson
believed that the causes of change lay in variation, and an appeal to look elsewhere
must therefore foreclose progress. Moreover, the Darwinian's favored "elsewhere"
too often encouraged sterile exercises in adaptational guesswork, rather than a
rigorous approach to assessing utility. Making an analogy to his favorite work of
Voltaire (see p. 397), Bateson wrote:
While it could be said that species arise by an insensible and imperceptible
process of variation, there was clearly no use in tiring ourselves by trying to
perceive that process. This labor saving counsel found great favor. All that
had to be done to develop evolution theory was to discover the good in
everything, a task which, in the complete absence of any control or test
whereby to check the truth of the discovery, is not very onerous. The
doctrine "que tout est au mieux" [that all is for the best—the Leibnizian line
that Voltaire places in the mouth of Dr. Pangloss] was therefore preached
with fresh vigor, and examples of that illuminating principle were
discovered with a facility that Pangloss himself might have envied, till at
last even the spectators wearied of such dazzling performances (1909, pp.
99 - 100).In a second substantive critique, Bateson sought to limit the domain of natural
selection—a standard tactic based upon an argument of relative frequency.