The Structure of Evolutionary Theory

(Michael S) #1

The Fruitful Facets of Gallon's Polyhedron 429


to the theory of mutation on the other hand useless or even disadvantageous ones
may also appear" (1909a, volume 1, pp. 209-210)



  1. Slow Darwinian changes cannot be observed on human and experimental
    time scales, but the mutation theory brings evolution into the domain of
    observational science; "the origin of species may be seen as easily as any other
    phenomenon" (1905, p. 26). Emphasizing a direct contrast between the virtues of
    his operational theory and the fatal intractability of Darwinian gradualism (here
    attributed to Wallace, for de Vries could not bear to saddle his hero with such a
    negative assessment), de Vries brands gradualism as obstructionist, and
    compliments his own view as liberating: "I shall try to prove that sudden mutation
    is the normal way in which nature produces new species and new varieties. These
    mutations are more readily accessible to observation and experiment than the slow
    and gradual changes surmised by Wallace and his followers, which are entirely
    beyond our present and future experience.


5 - 9B. At the apex of this phylogeny, De Vries shows the 7 mutant forms derived from
Oenothera Lamarckiana. The rest of the diagram illustrates De Vries' general view of evolution;
with most lineages stable nearly all the time, but entering short mutational episodes when several
new species may arise virtually at the same time. From Volume 2 of De Vries' Mutation Theory.
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