Sexual selection is a mode of
natural selection where typically members of one
biological sex choose mates of the other
sex with whom to
mate (intersexual selection) and competition between members of the same sex to
sexually reproduce with members of the opposite sex (intrasexual selection). These two forms of selection mean that some individuals have better
reproductive success than others within a
population either from being more attractive or preferring more attractive partners to produce
offspring. For instance in the breeding season
sexual selection in frogs occurs with the males first gathering at the water's edge and making their
mating calls: croaking. The females then arrive and choose the males with the deepest croaks and best territories. Generalizing, males benefit from frequent mating and monopolizing access to a group of fertile females. Females have a limited number of offspring they can have and they maximize the return on the energy they invest in reproduction.