Week4 Draft2

Dominance of an allele does not predict the outcome of allelic frequencies. Dominance simply refers to the outcome of a phenotype. The common misconception in terms of dominance is that dominance determines which of two alleles will persist. It is misconceived that a dominant allele will go into fixation, and cause the recessive allele to disappear in the population. In fact, dominance cannot determine whether or not alleles go into fixation. It is through selection that determines the outcome of allelic frequencies. If the dominant allele was selected for, in that case, the allele frequency of the dominant allele will increase, otherwise, if there is no positive selection for that allele, it will remain at a constant frequency. Likewise, recessive alleles may also be selected for and its frequency may also increase. To reiterate, dominance only determines the outcome of the phenotype, and if acted upon by negative selection, could potentially disappear from the population.