Sexual Selection Research Paper

Jacqulyn E. Lopez
Kevin Bessenbacher
English 101 M
October 8, 2012
Sexual Selection
For any evolution to gain some legacy, surviving is not enough without reproduction. In the world, over 90% of all the species have sexual reproduction. In this case, two individuals of a certain species from each sex have to mate so that they can produce offspring. Reproduction is seen as an expensive ordeal which has potential of exerting a considerable evolutionary pressure. This pressure was portrayed by Darwin as sexual selection operating through some members of a given species. In terms of mating, members of a given species may have an advantage over others in respect to mating hence resulting in a form of selection. The increase in the mating success
of an individual contributes in a great way to the selection of traits (Darwin 1887).
Sexual selection basically works in two major ways; through combat or display. Combat is situation in which there is a competition of members of one sex in gaining access of the other members of other sex. Display involves making a choice by the members of one sex towards the other sex. In respect to compact, males of a given species have a competition with each other in owing the females. This competition consequently results in development of larger as well as stronger males which enables them to have an advantage over the other males. Display basically refers to exhibition of some favorable features to some of the potential female mates for instance having brightly colored plumage like in a number of birds. Darwin said that this form of selection operates through a female choice in which females chose by themselves, the most striking males to be able to mate with (Brennan 2010). In sexual selection, it is only the genes of those individuals who are involved in a successful reproduction that end up being selected. This in a great way bears a number of considerations in that it has a high dependence on the ability of the individuals to have a survival of life exigencies which enables them to attain the reproductive age and have a great opportunity of being able to attract mate. The behavior as well as the appearance of any animal, is adapted in way which will not only help it survive but also acquire the largest number of desirable mates. The mating is directed in a manner in which some males have a preference to certain females (Brown 2009).
In sexually reproducing species, each and every available offspring has one father as well as one mother. This equates the average reproductive success involving both the males as well as the females. Any successful male has the potential of siring many off springs. On the other hand, any successful female will not be in a position to take away any reproductive opportunities from other females. This consequently leads to a quite smaller variance in respect to the female reproductive success. The increasing reproductive variance strengthens the effect of the sexual selection. These strong sexual selections consequently results in dimorphic exaggerated traits which are more elaborate in terms of sex having the highest number of the reproductive variance (Anderson 1994).
In most cases, a number of species give little or no care at all to their off springs. In species where the parental care is of great importance, the variance in respect to reproduction success will have effect only through a successful fertilization as well as the contribution given by each sex in regard to the care of the offspring. In cases where females provide more of the parental care in contrast to the males, the variance in males will be great. This is because females will be limited since they will be involved in caring of the newborn hence an increase in competition for the limited available females. In those species where we have bilateral care in order to have success raising of the offspring, variance in regard to the males’ reproductive success will be lower. The males are greatly engorged in providing parental care hence there is no much energy invested in being able to pursue some of the additional mating opportunities. In cases where the males are involved in giving the parental care, males themselves become the limiting resource for the available females. In this regard the variance in respect to reproduction success is great on females and hence females tend to look for the mating males or males to be able to care for their off springs (Anderson 1994).
Sexual selection is known to operate both as intra and inter sexually appearing as either sequentially as well as simultaneously.
Intrasexual selection involves members of the same sex having an attempt to outdo their rivals more often during a direct encounter. This selection is responsible for the evolving of some of the male features for instance deer antlers, beetle horns as well as individual males having large body size which is able to give them an advantage while fighting with a number of potential competitors. Intersexual selection basically results in a number of interactions between the sexes vey precisely involving the mate choice. Female tends to be choosy, whereby they tend to consider a number of morphological as well as behavioral traits from some given mates in order to be getting the best from them in terms of their fitness. This consequently makes males to compete with each other in order to gain female’s attention (Brennan
2010).
Females in a way increase their reproductive success by ensuring that they mate with a certain select males. This put them at a hand of fetching some benefits from them, for instance they are able to gain an increased access to food as well as cases of harassment from other males. In some instances females do not appear to have any sort of benefit from males. In such situations females end up gaining some indirect benefits through their off springs. These benefits are basically genetic but not resource based. The act of choosing some given males by the females, led to off springs having some genes which helps them in trying to increase their fitness and well-being. Males basically evolve some given traits together with displays which are able to advertise their ability to be able to have direct and indirect benefits in regard to females. Consequently females are able to recognize as well as develop preferences for these traits (Brown 2009).
Differences among a number of males give an opportunity to the females to be able to gather information about the genetic qualities of a number of males which can be inherited by their off springs. These genes are classified as good genes which are able to give offspring with a survival advantage. Sexual selection has been seen to have an effect on the reproductive success at a number of stages. Darwin in his discussions referred to it as pre-copulatory sexual selection while having an assumption that mating will consequently result in a reproductive success. Post-copulatory selection was considered to be the events which have their occurrence during mating times. In the case of females post-copulatory choice is considered as to be the ability of the females to be able to invest in their offspring in respect to the males whom they mate with. This choice is exerted by females in regard to their morphological, chemical as well as behavioral adaptations (Darwin 1887).
Even though both of the sexes are seeking to be able to have an optimum reproductive success, their genetic interest in a number of cases appears unaligned and hence resulting in a great conflict. In case of a trait which allows a male to be in a position to have high reproductive success in at the expense of the females will have a positive selection in the cases where females have some multiple males. These traits have the capability of being genetically transmitted and be spread across the population. Sexual conflict most often end up in an evolutionary arms race in which harm on a given sex will end up in an evolution of a number of counter trait in order to be able to mitigate on the harm of the affected sex (Darwin 1887).
Apart from the number of off springs left behind, the quality and the probable fitness in respect to the sired off springs is a measure of success of any organism. Sexual selection boosts the organism’s ability of being able to differentiate each other at the level of the species which is greatly referred to as the interspecies selection. The expansion involving the interspecies selection as well as the intraspecies selection is one of the forces behind the fission of the species. Sexual preference has been known to result to assortative mating as well as homogamy, this gives a great opportunity in which a group of individuals being invaded by diverse genes to put down their many effects and be able to have diverge genetically in respect to variations (Brennan 2010).
One of the important decision made in a life of any individual of a given species, is the ability of being able to choose a mate. One of the fundamental things that complicate life of many is being able to find a mate. These choices are quite important since they are able to be passed from one generation to another. Competition between members of the same sex in the power of being able to control mate or the resources which helps in attraction of mate is one of the emerging social dynamic as a result. Male parenting is basically found in an approximately less that 5 percent of all mammals. Due to the fact that males never provide any parental investment in a number of species therefore females consequently do not compete for the mates. The more men avail for offer to women the more they become valuable in regard to reproductive resource (Brown 2009).
Sexual selection has been a very vital practice in respect to the survival of individuals.
Sexual selection is quite powerful to be able to produce a number of features which are basically harmful to the survival of any individual. The power of sexual selection is brought about by genes which carries some survival traits helping the individual to move from one generation to another. Male and females interacts with their mates in two different ways. Male compete in order to have access to females while females choose which male is suitable for them to mate with. They are able to choose which sperm from the male will fertilize their eggs and even going to an existence of ejecting sperm from the undesirable mate (Brennan
2010).
Sexual selection is an important factor in the growth and survival of any species. Through sexual selection well adapted off springs are sired and unwanted traits are eliminated. A number of individuals use this sexual selection to be able to develop as well as to be well acquitted to the environment. Most off springs when born and are products of strong well to do parents they poses those traits and help them to grow and be strong. Therefore sexual selection is an important concept which should be well understood and used appropriately.

Work Cited
Andersson, Malte. Sexual Selection: Monographs in Behavior and Ecology. New Jersey: Princeton University Press, 1994.
Brennan, Patricia L. R. "Sexual Selection." The Nature Education, 2010: 1.
Brown, Emily. "Sexual Selection." Charles Darwin and Evolution, 2009: 1-2.
Darwin, Charles. The descent of man: and selection in relation to sex. Wabash: J. Murray, 1871.