Final answer:
The fate of the A allele at a locus with differential fitness and a forward mutation from A to a is not clear-cut. While natural selection may favor the A allele, mutation introduces a competing force that can prevent fixation. The correct answer is 'None of the above,' as the outcome depends on the interplay of selective pressures and mutation rates. Therefore, the correct answer is e.
Step-by-step explanation:
When considering a locus with differential fitness associated with its genotypes, and a forward mutation from the A allele to the a allele, the fate of the A allele is not straightforward. If the fitness of AA and Aa genotypes are greater than the aa genotype, natural selection will favor the A allele, which could increase its frequency in the population. However, the presence of mutation from A to a introduces a countering force that can prevent the A allele from reaching fixation. Thus, combined effects of selection and mutation may lead to a balance where both alleles are maintained in the population at equilibrium frequencies.
In a scenario where AA and Aa have greater fitness than aa, but there is also a mutation from A to a, the A allele:
- a. will always go to fixation.
- b. will always be lost.
- c. will never go to fixation.
- d. will never change.
- e. None of the above.
The correct answer is 'e. None of the above,' as both selective pressures and mutation rates will influence allele frequencies, and the combined outcome can vary depending on their relative strengths and other evolutionary forces such as genetic drift.