CARRANZA, J. 2009. Defining sexual selection as sex-depent selection. Animal Behaviour 77: 749-751.
After almost 150 years of research, the very definition of sexual selection remains unclear. The term sexual selection was coined in 1859 by Darwin (1859), who described it in more detail in his later book (Darwin 1871), as an explanation for the evolution of those characters of males of some species that did not seem to contribute to survival in the struggle for existence, those features previously referred to by Hunter (1837) as ‘secondary sexual characters’. From that date, sexual selection has become a sexy topic that has attracted huge interest among behavioural ecologists and evolutionary biologists. However, as Clutton-Brock (2004, page 26) stated, ‘one of the problems in writing about sexual selection today is that the term is used in so many different ways’, and recent debate on the basic structure of sexual selection theory (Roughgarden et al. 2006; Kavanagh 2007; Clutton-Brock 2007) indicates that its definition has probably never been clear enough.