Biology question

Question

Define and give a detailed example of intrasexual selection. How will this affect the phenotypes of subsequent generations?

Answer 1

Intrasexual selection is competition between members of the same sex for mates. Usually this involves males competing for females. One example of intrasexual selection is the selection for large antlers in male deer. Large, strong antlers allow male deer to compete with rivals for access to females. Males with larger and stronger antlers are more likely to defeat males with stronger and weaker antlers. The males with the large, strong antlers can win the competition and gain access to female mates. Over time, if males with the largest, strongest antlers are superior in competition and gain more female mates, these males will produce more offspring. Subsequent generations will have males with increasingly larger, stronger antlers due to intrasexual selection for this phenotype.

Answer 2

Understanding the term intrasexual selection in this question is key. Intrasexual selection occurs when two members of the same sex fight for dominance. Examples include male primates that fight for the female. The stronger one will prevail. This is of particular interest for the female because those traits that make the male dominant will be passed to the offspring meaning that the phenotypes and genotypes will possess some of the alleles that make the male dominant. In the role of evolution, this is of particular importance as those traits will be passed making the species stronger.

Answer 3

Intrasexual selection means there is selection (or competition) within the same sex of a species. An example would be a physical altercation (i.e. male deer fighting for the chance to breed). When the male that is more fit "wins" the competition, it means his genes will be passed along as he has earned the chance to breed. The subsequent generations will continue to carry those genes. There are phenomena where the desired trait is hyperexpressed to where it turns detrimental.Take the deer example: the male deer want large horns to be capable of winning a fight, but if the horns become too large they can get hung on various things and also be too heavy to maneuver at all which results in decreased fitness.

Answer 4

Intrasexual selection refers to competition between the same gender of one species. Usually this competition applies to the competition of mates during reproduction. For example, one male must fight the other male and win to see who gets to mate with a certain female in the species.

This can greatly affect the phenotype of the subsequent generation because of the survival of the fittest. The male that won the fight most likely has more favorable genetics, whether it be longer horns or a larger size, these phenotypes will be passed on to the next generation. On the other hand, the "weaker" male will not be able to mate as easily and most likely will have its phenotype lost/not passed on.