[1]1
Desborough
Market Harborough
24th May 1875
Dear Sir,
I am not a naturalist, and it may therefore be presumptious in me to offer a suggestion to one like you. Pray excuse me & put my letter in the fire if the suggestion I am about to make seems to you to have no value.
If it be that as many individuals of a given species die annually as are born, ought it not to be a law that the rate of variation of any two[?] species should bear some proportion to the average number of the species born young? Suppose a species of bird A, be such that a pair produces 5 young ones annually, and another species B produces 15 young per pair, i.e. per pair existing in breeding season2, the species B must offer to a breeder 3 times as many to select from as A will, and 3 times as many for natural selection to act upon. Ought not then B3 to be improved[?] more & more rapidly than A? Then should not B, in a given period result in diverging into more new species than A?
Probably this may have been considered by naturalists, but if so I have not ascertained [2]4 that it has. Certainly if such a law could be proved it would strengthen the Theory of Natural Selection.
If I am right in supposing such a law should exist, would it not appropriate[l]y find a place in your section in the "Different effects of Natural Selection in Animals and in Man"5?
I see that you give great weight, in this section, to the self-dependance of animals. Excuse me if I ask what difference the cause of death can make, provided it be a cause which selects the weakest, on the assumption that the number annually surviving be the same? If this self-dependance of one species succeed that of another one can suppose that in the latter many of the strong may give their lives in defence of the weak, and that thus the less sympathetic species may retrograde and stand still. This, however, I do not apprehend to be your meaning.
Again apologising for venturing to make suggestions to you, I am
Dear Sir | Yours faithful[l]y | John Hickman6 [signature]
Alfred Russel Wallace7
Wallace, A. R. (1870). Contributions to the Theory of Natural Selection, Macmillan &Co., London.i-xvi, 1-384 [pp. 311-317] <https://archive.org/details/contributionstot00wall> [accessed 24 March 2015]. The book was reprinted in February 1875, which may have prompted this letter.
Wallace incorporated Hickman's observations in the book he published the following year. Wallace, A. R. (1876). The Geographical Distribution of Animals; With A Study of the Relations of Living and Extinct Faunas as Elucidating the Past Changes of the Earth's Surface. 2 volumes. Macmillan & Co., London. Vol 1: pp. i-xxiv, 1-503. [p.158] <http://wallace-online.org/content/frameset?pageseq=1&itemID=S718.1&viewtype=text> [accessed 24 March 2015].
Status: Draft transcription [Letter (WCP2321.2211)]
For more information about the transcriptions and metadata, see https://wallaceletters.myspecies.info/content/epsilon
Please cite as “WCP2321,” in Beccaloni, G. W. (ed.), Ɛpsilon: The Alfred Russel Wallace Collection accessed on 28 April 2024, https://epsilon.ac.uk/view/wallace/letters/WCP2321