Mutual attraction between the sexes is an important factor in reproduction. The males and females of many animal species are similar in size and shape except for the sexual organs and secondary sexual characteristics such as the breasts of female mammals. There are,… Mutual attraction between the sexes is an important factor in reproduction.
Table of Contents Sexual Selection Darwin considered traits selected according to their role in mating to be separate from those acted on by natural selection.
He considered this a different type of selection that he called "sexual selection. Contest Contests are competitions between members of the same sex for access to the other sex. This competition may take many different forms.
A common example is direct combat between males. These fights may determine hierarchies in which the dominant males get first access to sexually receptive females or to establish territories, whose resources help attract females.
In cases like these, horns, antlers, or other combative devices are acted upon by sexual selection because they are directly involved in helping an individual obtain a mate. Choice While contests involve direct physical competition between members of the same sex, choice involves competition for attention from the opposite sex.
For example, the tail feathers of the peacock are a sexually selected trait, but they are not used to attack or fend off other males. Instead, they are intended to attract peahens.Sexual selection: Sexual selection, theory in postulating that the evolution of certain conspicuous physical traits—such as pronounced coloration, increased size, or striking adornments—in animals may grant the possessors of these traits greater success in obtaining mates.
From the perspective of natural selection. In contrast to features that result from natural selection, a structure produced by sexual selection results in an advantage in the competition for mates.
Learn More in these related Britannica articles. Sexual selection is a "special case" of natural selection. Selection makes many organisms go to extreme lengths for sex: peacocks (top left) maintain elaborate tails, elephant seals (top right) fight over territories, fruit flies perform dances, and some species deliver persuasive gifts.
In the examples of natural and sexual selection found below, I illustrate how selection acts on each of these life history traits. Understanding natural and sexual selection entails visualizing the relationship between a phenotypic trait and one of these components of the life history.
The Concepts of Natural Selection and Sexual Selection in Evolution Darwin wasn't the first to come up with the idea that evolution took place; many others had thought that was the case, but had no reasonable explanation for how it could happen. Jul 28, · Let's find out what Sexual Selection is all about in this brief but comprehensive educational video.
First, we'll discover how Sexual Selection differs from Natural Selection.