Question

Define pleiotropy – how does this affect the response to selection acting on alleles, particularly in antagonistic pleiotropy?

Answer 1

Pleiotropy is a phenomenon when one gene influences and control the phenotype of two or more unrelated traits.
Particularly, in antagonistic pleiotropy, a gene controlling two or more traits, among them at least one of them beneficial to the organism and one of the trait is detrimental to the fitness of the organism.
Antagonistic pleiotropy is a signature of fitness trade-offs. This means that genes that are pleiotropic in nature controlling some beneficial and detrimental traits and persisting to exist through natural selection. This will prevent the organism to attain perfection for the benefit of the gene, it also must possess some fault or imperfections. As an example, if we look into the nest of female rodents living with other females we will observe some females will end up feeding young ones of another female due to parental drive.