The development of Darwin's theory : natural history, natural theology, and natural selection, 1838-1859 / Dov Ospovat.

  • Ospovat, Dov.
Date:
1995, ©1981
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Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: The development of Darwin's theory : natural history, natural theology, and natural selection, 1838-1859 / Dov Ospovat. Source: Wellcome Collection.

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    Notes to pp. 204-у 53 On this basis one might wish to say (as one of my readers has) that Darwin's theory of variation remained fundamentally the same. But one would still have to recognize radical changes in emphasis. To me it seems that these radical changes are sufficiently important to warrant being called a new theory. The quoted passage is from DAR 45:42. See also Natural Selection, pp. 105-6; Variation under Domestication, 2:305; MLD, 1:197-8. 54 Mere variability, though the necessary foundation of all modifications, I believe to be almost always present, enough to allow of any amount of selected change (August 1862) {LLD, 2:180). See also MLD, 1:171. 55 The note in which this passage occurs is interesting enough to quote at length: In large continent, the individuals of each species from being exposed to variable conditions & from crossing [of] the sub sub-varieties, cannot be so perfectly adapted to conditions, as in island - this must hold good to whole fauna - therefore a species from neighboring islands, from being more closely conformable to these conditions [Darwin placed a question mark in the margin at this point], will exceed & beat out the continental species. - In old times there have been genera, families, &c. &c. If every species had heirs, the number would be infinitely great in times to come. - but if we suppose the number of individuals & diversions equal in two times, only a few individuals can have descendants, hence much extinction in proportion to metamorphosis: hence gradation not or only seldom discoverable in thick stratum. N.B. The adaptation of any species in same country, so that the perfection of adaptation in two countries may possibly vary. - : under a changing climate, species less conformable, than in old fixed climate (DAR 205.9:81, undated [the paper suggests this was written ca. 1840]). 56 Except, of course, in the sense that external changes may make a group less well adapted (or better adapted) than some other group, in which case it will be on its way to extinction (or expansion). This idea was present in Darwin's earliest speculations: В notebook, pp. 37-8, 205-6; С notebook, p. 151; Essay of 1844, p. 209. 57 DAR 205.9:304 (published in Natural Selection, p. 582 [there are no question marks in the original]). 58 Origin, p. 201. 59 Ibid., p. 102. 60 Natural Selection, p. 219. Cf. Essay of 1844, p. 153; and see Chapter 3, PP- 74-5- 61 The tone of his letter to Hooker on the subject (September 11, 1857) suggests that relative adaptation was still a new and exciting concept for Darwin: I have just been writing an audacious little discussion to show that organic beings are not perfect, only perfect enough to struggle with their competitors (DAR 114:211). 62 Natural Selection, pp. 247-8. 63 Ibid., p. 225; Darwin, Origin, p. 84. On Darwin's subsequent use of the 272