Final answer:
Females engage in sexual selection when choosing sexual partners, a process which often involves intersexual selection and preferences for certain traits that indicate good genes or high parental investment potential. These traits often influence the evolution of species and are distinct from intrasexual selection, which involves competition among members of the same sex.
Step-by-step explanation:
When females choose sexual partners, they are engaging in a process known as sexual selection. This type of selection can be very complex as it might involve a variety of cues, such as visual signals, behavioral displays, or other traits that appeal to the choosing sex. An example of this is when female bowerbirds select mates based on the quality and complexity of the nests males build, which are often decorated with small blue objects. Such choices often involve preferences for certain secondary sexual characteristics that can lead to the enhancement of mating success in the chosen partners.
Intersexual selection is a key component of sexual selection, where individuals of one sex, typically females, choose mates of the other sex. These choices can greatly influence the evolution of species as females often select traits they find desirable, which can include indications of good genes or high parental investment potential. These traits, though sometimes costly in terms of survival, often confer an advantage in the reproductive arena. Females are likely to be more selective than males because of the greater investment they typically have in producing and rearing offspring.
This careful mate selection can contrast with intrasexual selection, where individuals of the same sex compete for access to mates. Examples include rams butting heads where the victor gains mating rights. Nonetheless, both intersexual and intrasexual selection drive the evolution of mating strategies and reproductive success within a species.