Xxx chornesky

Andersson's (1994) general definition of sexual selection applies to all forms of hermaphrodites as well as taxa, such as protists, that lack anisogamy, making it appropriate to test hypotheses about the origins of sexual selection (contrary to Grant 1995).

The first questions to address, then, are the nature of sexual selection and how it might apply to hermaphrodites.Of those definitions, 4 involve sexual dimorphism (sex differences) and 2 refer only to males.However, the essence of sexual selection as Darwin defined it is selection through competition for mates.Fuller treatment of the theory came in where he defined sexual selection as depending “on the advantage which certain individuals have over the same sex and species, in exclusive relation to reproduction” (Darwin 1871, p 256).As Andersson (1994) has pointed out, this definition can be applied to all organisms, including plants, since as in ecology, the effect of competition will be the same whether it occurs as interference competition (male-male combat, for example), scramble competition (sperm competition; pollen competition), or indirectly such as competition to be chosen by females or by pollinators (see Levitan 1998; Skogsmyr and Lankinen 2002; Delph and Ashman 2006; Thomson 2006).