Question

The D gene in pea controls plant height. DD and Dd plants are tall and dd plants are short. In a particular population of pea plants, 64% of the individuals are tall, and the population is at Hardy- Weinberg equilibrium. Suppose that a change in climate imposes a selection coefficient (s) of 0.25 on the tall plants. After one generation in this new environment, what is the estimated frequency of the D allele?

Answer 1

After one generation in the new environment, the estimated frequency of the D allele is approximately 0.89.

Step-by-step explanation:

In a population at Hardy-Weinberg equilibrium, the allelic frequencies can be determined using the formula: p² + 2pq + q² = 1

Where

p is the frequency of the dominant allele (D)

q is the frequency of the recessive allele (d).

Given that 64% of the individuals are tall (DD and Dd), we can assume that the frequency of the tall allele (D) is 0.8.

Now, the selection coefficient (s) of 0.25 on the tall plants means that the fitness of the tall plants is reduced by 0.25 compared to the short plants.

This can be represented by adjusting the allelic frequencies. Let's assume the new frequency of the D allele is x.

According to the equation, x² + 2(0.8)(x) + (1-2(0.8))(1-0.25) = 1.

Solving this equation, we find that x ≈ 0.89.

Therefore, the estimated frequency of the D allele after one generation in the new environment is approximately 0.89.