In a certain population of mice, a single gene controls fur color There are two possible alleles: B, which leads to a black fur, and W, which leads to white fur. Individuals with the genotype BB will have a black fur, individuals with the genotype WW will have white fur, and individuals with the genotype BW will have gray fur. Scientists recorded the fur color of 1,000 mice from the population They found that 200 mice nave black fur, 400 have gray fur, and 400 have white fur. Ten years later, the measurements are repeated Again, they recorded the fur color of 1,000 that 400 have black fur, 400 have gray fur, and 200 have white fur. mice. They found

Question

In a certain population of mice, a single gene controls fur color There are two possible alleles: B, which leads to a black fur, and W, which leads to white fur. Individuals with the genotype BB will have a black fur, individuals with the genotype WW will have white fur, and individuals with the genotype BW will have gray fur. Scientists recorded the fur color of 1,000 mice from the population They found that 200 mice nave black fur, 400 have gray fur, and 400 have white fur. Ten years later, the measurements are repeated Again, they recorded the fur color of 1,000 that 400 have black fur, 400 have gray fur, and 200 have white fur. mice. They found

Part A: Show the Hardy-Weinberg calculations for the beginning and ending populations. Include the values for the equation as well as the p and q values. Show your work.

Part B: Use the Hardy-Weinberg calculation to explain if this population is evolving or not. Then propose a hypothesis about the environment of these mice that would lead to these observations

Answer 1

Part A:

Beginning population:
- Black fur (BB): 200 mice
- Gray fur (BW): 400 mice
- White fur (WW): 400 mice

Total mice: 1000

Calculations:
- p + q = 1 (where p is the frequency of allele B and q is the frequency of allele W)
- p^2 + 2pq + q^2 = 1 (where p^2 represents the frequency of BB, 2pq represents the frequency of BW, and q^2 represents the frequency of WW)

Given:
- BB (black): 200/1000 = 0.2
- BW (gray): 400/1000 = 0.4
- WW (white): 400/1000 = 0.4

p = frequency of allele B = p^2 + 0.5(2pq) = 0.2 + 0.5(0.4) = 0.4
q = frequency of allele W = 1 - p = 1 - 0.4 = 0.6

Ending population:
- Black fur: 400 mice
- Gray fur: 400 mice
- White fur: 200 mice

Total mice: 1000

Calculations:
- p = frequency of allele B = (400 + 0.5*400)/1000 = 0.6
- q = frequency of allele W = 1 - p = 1 - 0.6 = 0.4

Part B:
From the Hardy-Weinberg calculations, we can see that the allele frequencies have changed in the population over time. Initially, the frequency of allele B was 0.4 and the frequency of allele W was 0.6. However, in the ending population, the frequency of allele B increased to 0.6 while the frequency of allele W decreased to 0.4. This indicates that the population is evolving.

Hypothesis: One possible hypothesis for this observation is that there may be environmental factors that favor mice with black fur over gray or white fur. For example, if the environment offers better camouflage for black fur mice, they may have a higher chance of survival and reproduction, leading to an increase in the frequency of allele B in the population over time.