The Modern Synthesis as a Limited Consensus 57 1
Lerner felt so confident that he proclaimed natural selection necessarily
dominant a priori, not merely validated by evidence: "There is no longer any doubt
that natural selection is more than a theoretical possibility—it is unquestionably a
logically imperative necessity in any accounting for evolution" (1959, p. 174). He
acknowledges, of course, that selection cannot manufacture, but can only shape,
the physical material of organisms, but he compares selection's role to
Michelangelo's claim that a great sculptor works to liberate beautiful forms from
the blocks of stone that begin as their raw material—a lovely, poetic rendition of
the standard argument for selection's creativity (see Chapter 2). In so doing, Lerner
trivializes the role of potential constraints, even suggesting that a sow's ear might
not represent an impossible starting point for a silk purse:
In the same way, natural selection does not originate its own building
blocks in the form of mutations of genes. But from them it does create
complexes; it solves in a diversity of ways the great variety of problems
that successful individuals and populations face; it builds step by step, even
if by trial and error, entities of infinite complexity, ingenuity, and be one
inclined to say so, beauty. Granted that it needs appropriate raw materials,
that it may not necessarily be able to make a silk purse out of a sow's ear;
yet, interacting with other evolutionary mechanisms, it has created the
human species out of stuff which in its primordial stage may have looked
no more promising (1959, p. 179).Lerner's conclusion bears more than a whiff of similarity to the apostolic
creed, suitable for multiple repetition by the faithful: "Evolution is the most
fundamental biological law yet discovered. Natural selection is the basic
mechanism implementing it. The principle of descent with modification,
creatively, albeit opportunistically, husbanded by natural selection, is as firmly
established as any concept in biology" (1959, pp. 181-182). (I don't disagree with
the content; I just don't feel fully at ease with the triumphalist presentation.)
If Lerner verges on the overconfident, some centennial expressions treated
any conceivable alternative with disdain. I have already cited Mayr's assertion of
"complete unanimity" in competent professional opinion and of the "colossal
ignorance" of remaining doubters. In Chicago, Mayr even resorted to theological
language in citing "the opposing evils of Lamarckism and saltationism" (Mayr,
1960, p. 350). Others noted, but with some sense of unfairness, the vilification of
Lamarck. C. H. Waddington regretted that "Lamarck is the only major figure in the
history of biology whose name has become, to all intents and purposes, a term of
abuse" (1960, p. 383); while Marston Bates noted that "Lamarck remains some
kind of horrible example of wrong thinking in the introductory textbooks" (1960,
p. 548).
But the prevailing tenor of these symposia does not display pugnaciousness
towards opponents (which would imply an existing and meaningful conflict of
uncertain resolution), but smugness in the confidence that a total victory has, at
last, been achieved after a long battle (cigars and a drink around the