1. Darwin, C. The Descent of Man, and Selection in Relation to Sex (Murray, London, 1871).
2. Basolo, A. L. Science 250, 808–810 (1990).
3. Basolo, A. L. Science 253, 1426–1427 (1991).
4. Bradbury, J. W. & Anderson, M. B. (eds) Sexual Selection: Testing the Alternatives (Wiley, Chichester, UK, 1987).
5. Maynard Smith, J. in Sexual Selection: Testing the Alternatives (eds Bradbury, J. W. & Anderson, M. B.) 9–20 (Wiley, Chichester, UK, 1987).