Again:—
“Finally, we have seen that natural selection . . . explains that great and universal feature in the affinities of all organic beings, namely, their subordination in group under group. We use the element of descent in classing the individuals of both sexes, &c.; . . . we use descent in classing acknowledged varieties; . . . and I believe this element of descent is the hidden bond of connection which naturalists have sought under the term of the natural system” (p. 433).
Lamarck was of much the same opinion, as I showed in “Evolution Old and New.” He wrote:—“An arrangement should be considered systematic, or arbitrary, when it does not conform to the genealogical order taken by nature in the development of the things arranged, and when, by consequence, it is not founded on well-considered analogies. There is a natural order in every department of nature; it is the order in which its several component items have been successively developed.” [195a] The point, however, which should more particularly engage our attention is that Mr. Darwin in the passage last quoted uses “natural selection” and “descent” as though they were convertible terms.
Again:—
“Nothing can be more hopeless than to attempt to explain this similarity of pattern in members of the same class by utility or the doctrine of final causes . . . On the ordinary view of the independent creation of each being, we can only say that so it is . . . The explanation is manifest on the theory of the natural selection of successive slight modifications,” &c. (p. 435).
This now stands—“The explanation is to a large extent simple, on the theory of the selection of successive, slight modifications.” I do not like “a large extent” of simplicity; but, waiving this, the point at issue is not whether the ordinary course of things ensures a quasi-selection of the types that are best adapted to their surroundings, with accumulation of modification in various directions, and hence wide eventual difference between species descended from common progenitors—no evolutionist since 1750 has doubted this—but whether a general principle underlies the modifications from among which the quasi-selection is made, or whether they are destitute of such principle and referable, as far as we are concerned, to chance only. Waiving this again, we note that the theories of independent creation and of natural selection are contrasted, as though they were the only two alternatives; knowing the two alternatives to be independent creation and descent with modification, we naturally took natural selection to mean descent with modification.
Again:—
“On the theory of natural selection we can satisfactorily answer these questions” (p. 437).
“Satisfactorily” now stands “to a certain extent.”
Again:—