Question

Consider the ADH locus in Drosophila (fruit flies). There are two alleles at this locus in the finite population of D. melanogaster that is living on Belle Isle. This population has an effective size of 52. One of the alleles at the ADH locus is selectively favored on Belle Isle, because it allows fruti flies to better digest pawpaw fruit that has fermented. Allele frequencies at the ADH locus are affected by natural selection or genetic drift but not both. true or false?

Answer 1

The statement that allele frequencies at the ADH locus are influenced by either natural selection or genetic drift, but not both, is false. Both forces can simultaneously impact allele frequencies in a population.

Step-by-step explanation:

The statement that allele frequencies at the ADH locus in Drosophila melanogaster are affected by either natural selection or genetic drift but not both is false. In a given population, multiple forces can act simultaneously to change allele frequencies. Natural selection favors alleles that provide a survival or reproductive advantage, such as the allele allowing fruit flies to better digest fermented pawpaw fruit on Belle Isle. At the same time, genetic drift can cause random fluctuations in allele frequencies, particularly in small populations like the one with an effective size of 52 on Belle Isle. Therefore, allele frequencies are typically influenced by both natural selection and genetic drift, along with other factors like mutation, gene flow, and non-random mating as part of population genetics.

In summary, allele frequencies are dynamically influenced by various evolutionary forces. While one allele may be selectively favored due to environmental factors, genetic drift can still cause random changes in the allele frequencies within the population.