What best defines intersexual selection?

Intersexual selection is primarily defined by the preferences or choosiness exhibited by one sex, typically females, when selecting mates from the other sex. This process often drives the evolution of specific traits that are favored by the choosy sex, leading to the development of elaborate features in males, such as bright plumage in birds or impressive courtship displays. The underlying mechanism promotes genetic diversity and can enhance the survival of the species by ensuring that the most fit individuals reproduce.

In the context of evolutionary biology, intersexual selection emphasizes the importance of female choice in shaping male traits, which is critical for understanding behaviors and physical characteristics in many species. This concept is different from competition among males, which falls under intrasexual selection, where males fight or compete for access to females. Random mating does not involve selective pressures based on mate preferences, while selection based on territory is more indicative of competition among males rather than intersexual dynamics.