Sexual selection is a mode of natural selection that acts on traits involved in mate choice and reproduction.
Intersexual selection is selection that occurs between the two sexes and serves to help an individual attract the opposite sex. Intrasexual selection is selection within a sex. This occurs when individuals compete against each other to acquire mates.
Runaway selection occurs in environments that favor survival, where resources are plentiful and predators are lacking.
Operational sex ratio is the proportion of sexually mature males to sexually mature females within a population.
Females invest a greater amount of energy into producing fewer eggs compared to sperm. The OSR of a population is also more often male-skewed. As a result, females are generally more selective than males.