Question

Give 2 examples of intrasexual selection of a feature that has evolved via this process in females.

Answer 1

Sexual selection is a mode of natural selection in which members of one biological sex choose mates of the other sex to mate with (intersexual selection),and compete with members of the same sex for access to members of the opposite sex (intrasexual selection).Intrasexual selection can refer to the act of competing with members of one’s own sex (for status, tangible resources, or directly for access to mates) as well as the evolutionary process that shapes the traits employed in this competition. female-female intrasexual competition, that is, when females compete with each other for mates.

This competition results in cost to female fecundity, such as a reduction in fertility due to decreased direct benefits, sperm limitation, or time and resources spent competing for a mate.

These competition leads to development to traits to fight for mates. Ornaments, weapons and aggressive behaviours may evolve in female animals by mate choice and intrasexual competition for mating opportunities.

Female competition and aggression- Females compete for resources needed to survive and reproduce, and for preferred mates.

Within animal populations, competition is often particularly acute among individuals of the same sex because such individuals require the same limited resources to maximize their reproductive success. For example, adult females may require safe nest sites or other limited resources for reproduction.

Although female aggression takes diverse forms, under most circumstances relatively low-risk competitive strategies are favoured, most probably due to constraints of offspring production and care. In social species, dominance relationships and threats of punishment can resolve social conflict without resort to direct aggression, and coalitions or alliances may reduce risk of retaliation. Consistent with these trends, indirect aggression is a low cost but effective form of competition among young women. Costs are also minimized by flexibility in expression of competitive traits, with aggressive behaviour and competitive signalling tailored to social and ecological conditions.

Female ornamental trait-

Females have been selected for ornamentation as the benefit of producing the ornamentation, namely male paternal care, outweighs the costs, such as the energy requirements. Most notably, their venter becomes more colourful during breeding season. Males tend to prefer females with more colourful venters, with research showing that there is a positive association between this ornament and the condition of the female. As this ornamentation reliably indicates mate quality, it can be considered an honest signal.In the phalaropes and the Eurasian dotterel, females are more brightly colored than males, and it is the males who are primarily responsible for parental care.