Darwin, Beauty and Sexual Selection
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| William Hart (1830-1908) Goldie’s Bird of Paradise (Paradisea decora), detail |
And ‘Sexual Selection’ was devised
To show that female animals possess
The sensual passions in refined excess:
Though males be wooers, females can reject,
And from the mass the favour’d one select.
Thus sexual lust all nature regulates,
And wanton matrons choose their ardent mates
The willing maidens favour handsome males,
So beauty triumphs, and love’s power prevails.
Charles William Grant, Our Blood Relations, or, the Darwinian Theory (1872)
Darwin’s sensitivity to the beauty of the natural world was apparent from his earliest years, and inspired his work as a naturalist. However, only in 1871, in The Descent of Man, and Selection in Relation to Sex, did he publish his views as to why so many beautiful forms existed in nature. He put forward a theory of ’sexual selection’, showing how animals had evolved features that made them more attractive to the opposite sex and hence more successful in breeding.
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| James Tissot (1836–1902) The Artists’ Wives, (detail, 1885) |
He explained that many males developed ’secondary sexual characteristics’, unique to each species, which could give them an advantage over their rivals. Among mammals, ’sexual weapons’ such as antlers and tusks were used in battles with opponents. Among birds, however, the process was usually much less ‘pugnacious’, to use Darwin’s term. The male attracted the female by an elaborate display of beautiful features, particularly brightly coloured or patterned feathers, and she chose to mate with the one that she found most attractive. In humans, he wrote, the roles were reversed, and the female, at least in ‘civilised’ societies, was the more ‘ornamented’ of the sexes.
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| Martin Johnson Heade (1819–1904) Cattleya Orchid and Three Hummingbirds (detail, 1871) |
In accounting for the role that beauty played within mate choice, Darwin arrived at two conclusions that would prove both controversial and disturbing. He believed that (with the notable exception of humans) the females did the choosing, and that animals as well as humans had a taste for the beautiful.
However, as well as decorative beauty, Darwin recognised there was another kind of beauty in nature: fitness of form for purpose. In his book On the Various Contrivances by which British and Foreign Orchids are fertilised by Insects (1862), he demonstrated that the orchid’s exceptionally complex structures were products of natural selection, beautifully adapted to ensure the plant’s survival.