440 THE STRUCTURE OF EVOLUTIONARY THEORY
- The mutation theory is fully Darwinian. (Darwin might have flirted with a
false idea about the efficacy of fluctuating variation, but he ultimately recognized
the primacy, if not the exclusivity, of mutational variation.)
It is in fullest harmony with the great principle laid down by Darwin. In
order to be acted upon by that complex of environmental forces, which
Darwin has called natural selection, the changes must obviously first be
there. The manner in which they are produced is of secondary importance
and has hardly any bearing on the theory of descent with modification. A
critical survey of all the facts of variability of plants in nature as well as
under cultivation had led me to the conviction, that Darwin was right in
stating that those rare beneficial variations, which from time to time happen
to arise—the now so-called mutations—are the real source of progress in
the whole realm of the organic world (1909a, volume 1, p. 74).This comment advances the stubborn position that so frustrated A. C. Seward,
and inspired his justified rejoinder at Darwin's birthday party. De Vries' argument
must be designated as a remarkable example of "stonewalling," a word just
entering the English language in de Vries' time (according to the OED) from a
combination of British cricket slang, Australian political terminology, and the
memory of Confederate General Stonewall Jackson. In the light of Darwin's firm
and consistent emphasis on imperceptibly gradual change, and his equally clear
denial of the efficacy of "sports" (a term that de Vries acknowledged as
synonymous with his mutations), how could de Vries count Darwin as a
saltationist? De Vries admits that Darwin didn't really say the proper words, but he
then claims that Darwin must have intended to do so: "Darwin's view, although he
never definitely formulated it, was that it was these occasional single variations
which brought about the continual differentiation of living forms" (1909a, volume
1, pp. 86-87). De Vries then attributed the truly Darwinian belief in gradualism to
Wallace and other less worthy epigones: "Wallace's view is that the material for
species forming selection is furnished by fluctuating variability; and that these
infinitesimal differences are gradually heaped up in the same direction until
ultimately they attain the dimensions of specific differences" (ibid., p. 87)—a good
definition of Darwin's actual view!
- The mutation theory is Darwinian, while also incorporating a few minor
glosses and corrections of Darwin's own views.
The mutation theory is intended to be a support and corollary to the
selection theory of Darwin. There can be no doubt that Darwin correctly set
forth the essential steps in the evolutionary process and that changes in his
views mostly relate to those minor points, for which, at this time,
consonance with this necessary foundation. By this proper criterion, de Vries' saltational
mechanism can only be labeled as anti-Darwinian (as the most astute of all
commentators, Vernon Kellogg, recognized and illustrated)—whatever de Vries'
psychological need for fealty to a personal hero.