Sexual selection is a mechanism ofevolution. Selection occurs through differentiation in the secondary sexual characteristics of males and females such as height, colour, or appendages (horns, crests, etc.). This is known as sexual dimorphism.
Sexual selection and dimorphism
Although the features of dimorphism may confer a survival disadvantage (predation, energy expenditure), they are selected by sexual partners and then transmitted to their offspring.
These features can also offer selective advantage such as the horns of sheep and goats as tools or protection against predators.
They can also demonstrate the genetic quality of a partner, which can sacrifice some of its metabolic energy to maintain these handicaps.
The characteristics are also the result of sexual competition between members of the same sex resulting in rituals and fighting to determine who will have preference in reproduction.
Sexual selection at work in a peacock's mating ritual. © Ethan Hein CC by-nc-sa 2.0
Sexual selection - 1 Photo