Final answer:
The selection for the ability to compete with members of the same sex to mate with the opposite sex is termed intrasexual selection. This type of selection can lead to the evolution of traits that enhance mating success, which includes physical strength or elaborate mating displays.
Step-by-step explanation:
The term for the selection process where members of the same sex compete with each other to attract mates from the opposite sex is intrasexual selection. This type of competition often involves mating displays and rituals, such as rams butting heads, where the winner earns the right to mate. Intersexual selection, on the other hand, occurs when individuals of one sex choose mates based on a variety of traits, which might lead to the development of secondary sexual characteristics that do not necessarily enhance survival but are deemed attractive.
Intrasexual selection can lead to the evolution of characteristics that allow individuals to compete more effectively for mating opportunities. Examples include the development of large antlers in deer used to fight other males, or complex mating calls in frogs to demonstrate fitness to females. These characteristics may require a significant energy investment but result in the selection of the fittest and often the most dominant individuals for reproduction.