Question

1. How does sexual selection explain the presence of elaborate secondary sexual characteristics (e.g., male lion manes or a peacocks tail)?

Answer 1

Sexual selection is a type of natural selection in which the member of one sex chooses a mate possessing a particular characteristic that is more attractive than that of its competitors. The animal with the said characteristic, is more successful compared to its competitors and therefore produces more offsprings. Generally, males benefit from mating often and having a monopoly to a group of fertile females. Females ,although they produce limited offsprings, can choose fit partners to obtain maximum benefit from energy used in reproduction.

In some animals, there is the presence of elaborate secondary sexual characteristics or sexual dimorphism (differing in the appearance of both the sexes apart from primary sexual organs) which may not posses any fitness advantage, but has been evolved due to sexual selection.

For example, in peafowls, the peacock posses an elaborate, colourful tail that may slow it down and requires high energy to maintain, yet it has been selected. This can be explained by sexual selection. It is proposed that peahens preferentially mated with peacocks with an elaborate tail as it attracted them. This led to the production of higher number of offsprings with the same characteristics, that would probably grow up with the same advantage in reproduction. This is known as the positive feedback mechanism and drove the selection of such secondary sexual features. Thereby, this gave elaborate sexual features a clear advantage in sexual fitness, enabling its selection