Analyzing Darwin's Theories Of Sexual Selection

The term "sexual selection" was proposed by Darwin. He contrasted in a sense, natural selection sexual selection because, as he said, sexual selection occurs not as a result of the struggle for existence, as in the case of natural selection and the struggle for the possession of individuals of the same sex. And, as a rule, the struggle between the males for possession of the females. Since then, continuing fierce debate about this phenomenon - sexual selection, and still many researchers, for example, believe that sexual selection does not need to be isolated and does not need to be separated from the natural selection, it's just part of the process.
Darwin realized that many of the characteristics that he had observed in animals, cannot be explained by evolutionary adaptation to external conditions. For example, the luxurious plumage of males of some birds (eg peacock) is clearly non-adaptive, makes owners more vulnerable to predators and requires consumption of more nutrients to maintain the shape and color. Darwin realized that evolution - it is rather a problem of differences in breeding than the differences in survival.
Any inherited traits help in competition for pairing, tend to increase the incidence and prevalence in the population, even if they are somewhat complicate the survival of the individual.
Darwin identified two categories of sexual selection. The first - a contest for the right males mating with the females, sometimes called male-male competition. This kind of competition contributes to the development in the evolution of all the signs that help males to win other males. These include horns, stronger muscles and more intelligent brains. Another form of sexual selection - a choice of female sexual partner. In this case the features that the female prefers males during evolution becoming more
pronounced.
For example, females' preference for male birds with colorful plumage in the course of evolution has led to extravagant color feathers males of these species. Preferences define the females and behavioral capacities such as intelligence male or their ability to produce food.
Sexual selection - is not an independent factor of evolution, but only a particular case of intraspecific natural selection. Sexual selection has a restricted distribution and is manifested mainly in vertebrates.

One can predict that intersexual selection will be most pronounced in relation to gender, pay less attention to children. That is why women are so selective, and men compete against each other for the right to be elected.

This explains why men more typically aggressive behavior, while women more developed qualities such as a tendency to educate and teach. In species where the primary concern for posterity rests with the male (eg, sea horse, which bears eggs in a particular body cavity) females are aggressive and compete with each other, and males choose females.