Sexual Selection

What is the main difference between natural selection and sexual selection?

Sexual selection involves non-random differential reproduction related to attracting mates.

What does the term 'Sex' refer to in a biological context?

'Sex' can refer to the act of sexual reproduction or to the set of phenotypic and genotype traits related to reproduction.

What is meant by secondary sex characteristics?

Features unique to one sex in a species that do not directly contribute to reproduction, such as horns and coloration.

What is sexual dimorphism?

Characteristics that make the two sexes of the same species look different.

What is intrasexual selection?

Competition within a sex for access to members of the opposite sex.

What defines intersexual selection?

An individual's choice of partner affects reproductive fitness based on genetic contributions to offspring.

Why are females typically the 'choosy sex'?

Females invest more in reproduction, having larger and costlier eggs, and seek the best alleles for their offspring.

What role do nuptial gifts play in mate selection?

They serve as material gifts that can trigger mating behavior and provide either direct or indirect survival benefits to offspring.

What is the significance of courtship behavior in mate selection?

It consists of fixed sequences of behaviors that can indicate the quality of a potential mate.

How do territorial behaviors relate to mate selection?

Territorial defense indicates the quality of resources available, impacting the choosy sex's decision to mate.

What are the three main mating systems?

Monogamy, polygamy (including polygyny, polyandry, and polygynandry), and promiscuity.

What is the relationship between mating systems and parental care?

Mating systems evolve based on the needs of offspring and whether one or both parents are needed for survival.

How does sexual selection lead to evolution?

It occurs through heritable genetic variations in traits that contribute to reproductive success, via intrasexual and intersexual selection.

What is promiscuity in the context of mating systems?

A mating system where there are no pair bonds and organisms only come together during copulation.

What is the role of sexual conflict in mating systems?

Sexual conflict occurs when one sex engages in behaviors to maximize mating success, often seen in males, impacting reproductive strategies.

What factors drive the evolution of different mating systems?

The needs of the young for protection and food influence whether monogamy, polygamy, or promiscuity evolves.