INTRODUCTION

Sexual selection is a vast topic – the most researched set of ideas in the biology of social behaviour since the 1970s. A thorough, modern, single-source review of sexual selection is Andersson (1994). In the ten years since Andersson, much has been learned about sexual selection. Papers bearing on sexual selection in the primary literature (see, for example, Animal Behaviour, Behavioral Ecology, Behavioral Ecology and Sociobiology, Proceedings of the Royal Society) are overwhelmingly common. Their breadth and depth will not disappoint interested neophytes. Because the range of scholarship in sexual selection is so large, it is probably impossible for a single author in a single paper to present more than an idiosyncratic review of the study of sexual selection. My long-standing sensitivity to the sometimes left-out roles of females in sexual selection has affected my view of studies on the subject, and focused my attention particularly on sex roles, which is what I discuss in this chapter. I make no claims that the view here is more than my own; though, of course, I hope it is useful to others. I urge readers – newcomers, especially – to sample widely in the old and new titles of sexual selection, to think critically about all the assumptions of sexual selection theories, and to devise experiments or controlled observational tests capable of rejecting our dearest assumptions, if they are in fact false.