Question

The frequency of recessive deleterious allele q is 0.06 in a population of fruit flies. You examine many individuals over many generations and measure that the mutation rate of p to q is 0.00005. What would the strength of selection against the q allele need to be for the frequency of q=0.06 to be maintained by selection-mutation balance?

1) 0.14
2) 0.0014
3) 0.014
4) 1.14

Answer 1

To maintain the frequency of a recessive deleterious allele q=0.06 in the presence of a mutation rate of 0.00005, the strength of selection against the q allele that would be required for selection-mutation balance is approximately 0.0009, with the closest provided answer being 0.0014. the closest answer to the provided options being 0.0014 (option 2).

Step-by-step explanation:

The subject of the student's question is related to population genetics, particularly focused on the concept of selection-mutation balance. In this scenario, we're given the frequency of a recessive deleterious allele (q) in a population and a mutation rate from the dominant allele (p) to the recessive allele (q).

The selection-mutation balance refers to the idea that the mutation rate can introduce harmful alleles (like q) into a population, but natural selection can act against those alleles. To find the required strength of selection to maintain the allele frequency at q=0.06 despite the mutation rate of 0.00005, we use the selection-mutation balance equation:

s = µ / q (1 - q)

Where s is the selection coefficient, and µ is the mutation rate. Inserting the given values:

s = 0.00005 / (0.06 × (1 - 0.06))

Solving this equation yields s = 0.00005 / 0.0564 which is approximately 0.000887, and can be rounded to 0.0009, the closest answer to the provided options being 0.0014 (option 2).