Sexual Selection Is a Form of Natural

Sexual selection is a form of natural selection that deserves attention because of the complexities involved with that selection. Sexual selection focuses on the idea that certain traits give competitors an edge. Studies around the world attempt to clarify the elements involved with this type of selection.

Probably the most fundamental explanation of sexual selection is that of choosing a mate that is most likely to survive and a mate that is fertile. But sexual selection goes deeper than that, making an interesting case of study. This paper will focus on female selection and try to examine the reasoning behind it.

Darwin realized that something else was going on when it came to mate selection, as demonstrated though the example of the male and female peacocks. Other examples to back this theory up are female finches zebra finches choosing male zebra finches whose legs were decorated with black or red bands as opposed to male zebra finches with blue or green bands on their legs. (Burley 1235-1236)

It has long been known that sexual selection is a combination of many different things that go on the animal psyche. Clearly animals that are larger, louder, more colorful, and more novel than average are preferred over the norm. But even such decisions are based on biases. According to Ryan, birds that eat blue berries may evolve blue-sensitive eyes, which would tend to favor blue ornamentation; whereas birds that eat red berries may evolve red-sensitive eyes that favor red ornamentation. (Ryan 156-195) These observations stir up much interest concerning why certain selection are made.

Sexual selection typically takes two forms. Intrasexual selection and intersexual selection. Intrasexual selection involves behaviors which affect the outcome of the competition among a groups' members in relation to access to the opposite sex. This type of behavior is seen among competitive males who fight over territories, for example. Intersexual selection refers to secondary sexual characteristics that make an animal attractive. Examples of intersexual selection refers to displays of courtship and plumage. (Starr 184-185)

Animals respond to color, form, pheromones, and touch; all elements that can be shaped by a personal bias. One theory that deserves attention is Fisher theory (or runaway sexual selection) that suggests individuals with large sexual ornaments have a higher mating success but lower survival than those with smaller ornaments. The Fisher theory also indicates the relevant traits involved in this selection show heritable genetic variation and that there is a connection between the traits and the preferences. (Fisher 184-192)

The interesting fact about runaway sexual selection is that it is a process in which there appears to be an obvious set of characteristics, which of course, make for it a little more difficult to study. What can be gathered from this process is that choices do seem to favor conditions in which the species will reproduce.