Cronin traces two rival theories of sexual selection, which began with a split between Darwin and Wallace, the co-discoverer of natural selection, and has persisted, in various guises, to the present day.
Darwin was happy to start with the premise that females have certain preferences, which act as selection pressures favouring preferred characteristics in males – for example the peacock's tail. Wallace hated the idea. Describing himself as more Darwinian than Darwin,
Wallace thought the appeal to aesthetic preference was mystical and unscientific. Wallace could accept the idea of female choice, but only if females choose for useful characteristics in males. Darwin was happy for female preferences to be aesthetic.
Cronin traces the split between 'Wallacean' and 'Darwinian' sexual selection theories right through the nineteenth and twentieth centuries. The big gun on the Darwinian side in the twentieth century was the brilliant R A Fisher. Fisher dealt with Wallace's main objection, by incorporating female preference itself as under genetic control and subject to selection in its own right. Fisher ingeniously explained peacock tails and similar extravagances as a result of simultaneous evolution in females (evolution of their preference) and in males (evolution of that which is preferred). Fisher showed that the origin of female preference could be arbitrary. Once started, the mutual co-evolutionary process could take over, and could move into run-away mode, generating the splendour of peacocks and birds of paradise. Later theorists following Fisher and Darwin are Russ Lande and Mark Kirkpatrick.
At the same time, the Wallacean strand has been developed further by such theorists as Alan Grafen and W D Hamilton, building on the once-unfashionable ideas of A Zahavi.
If anything, I would say the Wallacean tendency is dominant among today's evolutionists, but the Darwin/Fisher strand of sexual selection theory is still very much alive.
Cronin also discusses the eclipse of sexual selection in the early and middle parts of the twentieth century, under the influence of such figures as Julian Huxley and Ernst Mayr. Sexual selection may once have been unfashionable among evolutionary biologists but it has been the trendy thing to work on for some decades now.
Helena Cronin's book is a superb welding of biological knowledge, historical insight, and logical thought. She herself was trained as a philosopher, but she rises magnificently above that handicap and her book is crystal clear and BEAUTIFULLY written. Strongly recommended: The Ant and the Peacock.