Sexual selection is a process that occurs when certain traits increase an individual’s ability to attract and/or compete for mates, leading to higher reproductive success. Unlike natural selection, sexual selection is driven by the selective preferences of potential mates, rather than environmental pressures.
Sexual selection can lead to the evolution of elaborate traits and behaviors that may not have any obvious survival advantage. For example, the bright plumage of male peacocks or the intricate courtship rituals of bowerbirds are thought to have evolved through sexual selection.
There are two main types of sexual selection: intersexual selection and intrasexual selection. Intersexual selection occurs when members of one sex (typically females) choose mates based on certain traits, such as physical attractiveness or display behavior. Intrasexual selection occurs when members of the same sex (typically males) compete for access to mates.
The evolution of mating systems is also influenced by sexual selection. Mating systems refer to the ways in which individuals in a population mate with one another. For example, monogamy refers to a mating system in which individuals form long-term pair bonds, while polygyny refers to a mating system in which males mate with multiple females. The evolution of these different mating systems can be influenced by factors such as the availability of resources, the distribution of individuals in a population, and the level of parental care required by offspring.