DARWIN, CHARLES. 1809-1882.
DARWINS DRAFT MANUSCRIPT ON SEXUAL SELECTION.
Autograph Manuscript, 1 p, folio, [c.1868], from an early draft of The Descent of Man, and Selection in Relation to Sex, headed "Sexual Selection" and numbered leaf 21, 22 lines including 8 cancellations and 9 insertions, on blue paper, very pale foxing.
Phenomenal passage showing the development of Darwins theories on the mechanics of sexual selection. Darwin began work on The Descent of Man late in 1867. A letter from Darwin to A.R. Wallace in February of 1868 reports his work on sexual selection with specific reference to the themes here, dating the manuscript to around that time. Darwin discusses two causes driving sexual selection: the disparity in number of each sex in some animals; and the practice of polygamy in others. He makes clear that both are means to impel natural selection and hence evolution. This passage is published, with revisions, as pp 265-266, part II, chapter VIII of The Descent of Man.
Darwin writes that although the proportion between the sexes fluctuates only slightly in most animals, "with some few animals in a state of nature
the proportions seem to fluctuate in a sufficient degree to influence the course of sexual selection. For any advantage gained during certain years, or in certain locations, by the males, which were able to conquer other males, or were the more attractive to the females, would tend to be transmitted to their offspring; & there is no apparent cause tending to eliminate subsequently an advantage once gained in this manner. / The practice of Polygamy leads to the same results as an actual inequality in the number of the sexes; for if each male secures two or more females, many males will not be able to pair; & the latter assuredly will be the weaker & less attractive individuals. Many mammals & some few birds are polygamists, but with the members of the lower Classes I have found no account of this."
The above passage resonates with the social controversy that Darwins work engendered. The seeming approbation of the practice of polygamy no doubt offended some notions of Victorian respectability and made credible those like St. George Mivart who spread the view that Darwins theories threatened societys moral foundation.
A physically similar draft passage, numbered leaf 22, was sold at Christies (November 20, 2002, lot 94). Despite the numbering, the two leaves do not appear to be consecutive, leading to the supposition that Darwin himself preserved from this draft only those leaves that he felt to be of importance. The greater part of the manuscript material relating to The Descent of Man is in the University Library of Cambridge further indicating that these leaves were chosen and given away personally by Darwin.
Provenance: Jeremy Norman (Sotheby's London, December 11, 1992, lot 141).