Wednesday, September 18, 2019

Sexual Selection and Sexual Conflict Essay -- Mating Biology

Charles Darwin characterized sexual selection as â€Å"variance in the number of mates†. The purpose of sexual selection is to perfect the secondary sexual characteristics, which are the morphological differences between the two sexes. On the other hand the primary sexual characteristics are the differences between the reproductive genital systems of the two sexes. Sexual selection instead of adapting the individual to the environment, like natural selection, it does enhance traits involved in mate acquisition. Sexual conflict, on the other hand, occurs when males and females have different reproductive interests and deriving from the urge of sexual reproduction. This is boosted by promiscuity when males and females have several partners. (www1, www2, www4) Futuyma (1998) defines sexual selection as â€Å"selection that arises from differences in the mating success (number of mates that bear offspring)†. Sexual struggle can be divided into two categories. The first category is the struggle between individuals of the same sex (generally males) in order to be victorious against their rival by killing it or make it retreat. In this category the females remain passive. The second category is the struggle between individuals of the same sex but this time this happens in order to attract individuals of the opposite sex. There are also some theories for the existence of sexually selected traits. There is the intrasexual selection, in which males compete aggressively with each other for access to the females. It includes weapons such as horns, antlers, tusks and spurs, which are examples of sexual dimorphism. Weapons are mainly male characteristics and some possible explanations for their existence are: protection against predators, used for co... ...he same sex as they compete for mates and also between the sexes as individuals choose their partners. Sexual conflict arises because strategies that maximize the fitness of one sex can reduce the fitness of the other. To sum up, sexual conflict can lead to sexually antagonistic co-evolution, in which one sex evolves a favorable trait, which is countered by a countering trait in the other sex. (www5, www6) Works Cited †¢ http://www.zoology.ubc.ca/~otto/PopGen500/Discussion3/Overheads.html http://bio.research.ucsc.edu/~barrylab/classes/animal_behavior/SELECT.HTM#anchor460576 : http://aarongoetz.netfirms.com/My%20Articles/SexualConflict-bookreview-atg.pdf†¢ http://www.medicalnewstoday.com/articles/21967.php http://onlinelibrary.wiley.com/doi/10.1002/9780470015902.a0003669.pub2/abstract †¢ http://onlinelibrary.wiley.com/doi/10.1038/npg.els.0001718/abstract

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