The Fruitful Facets of Galton's Polyhedron 441
the material of facts was not adequate to a correct decision. The mutation
theory claims to remove many of the difficulties, inherent to the Darwinian
doctrine, as e.g. the general occurrence of useless characters and the
impossibility of explaining the first beginning of a selection on the ground
of its usefulness (1922, p. 223).- The mutation theory is Darwinian. We must admit Darwin's errors on some
issues, even for important points. But we can't blame him, given the limitations of
knowledge in his time: "My work claims to be in full accord with the principles
laid down by Darwin and to give a thorough and sharp analysis of some of the
ideas of variability, inheritance, selection, and mutation, which were necessarily
vague at his time. It is only just to state, that Darwin established so broad a basis
for scientific research upon these subjects, that after half a century many problems
of major interest remained to be taken up" (1905, p. ix). - Darwin recognized both fluctuating and mutational variation, but he never
formulated a judgment about their relative importance (a direct contradiction of
claim 1 on the dominance or exclusivity of mutational variation): "Darwin almost
always speaks of these two types in his discussion on selection but never separates
them, and is always in doubt as to their relative importance in the origin of species"
(1909a, volume 1, p. 31).
In a variation upon this position, de Vries sometimes claimed that Darwin's
agnosticism about the relative importance of these two types of variation holds no
significance for evolution, and indicates no weakness in Darwin's logic, because
the issue of how variation arises becomes subordinate to the role of natural
selection once we feel confident that organisms will generate sufficient variation in
any case: "Darwin has left the decision on this difficult and obviously subordinate
point to his followers" (1909b, p. 84). - Darwin recognized both fluctuating and mutational variation and regarded
both modes as important. Wallace later restricted "Darwinism" to the fluctuating
mode alone (de Vries, 1905, p. 8). True Darwinians, who continue to recognize
both modes, tend to be favorable towards the Mutation Theory (though they must
revise their views on the relative significance of fluctuating variation):
Unlike the prevailing form of the theory of selection, the doctrine of
mutation lays stress on sudden or discontinuous changes, and regards only
these as active in the formation of species. The Darwinian form of the
theory of selection regards both these and fluctuating variations as
operative in the origin of new forms, whilst Wallace favors the other
extreme, according to which all formation of species goes by a slow and
gradual process of change. The two schools of thought naturally adopt
different attitudes towards the doctrine of mutation. It is at once rejected by
Wallace's adherents, whilst those who incline to Darwin's own form of the
theory are less unreservedly inimical; many of them have even greeted it
with open arms (1909a, volume 2, p. 599).