Question

fur color in rabbits
generation brown fur mottled fur white fur
1 45 0 1
2 47 2 3
3 48 10 1
4 45 18 2
5 44 26 3
6 42 34 2
7 40 45 4
8 38 58 3
9 33 67 5
10 22 89 4
a student wants to know the effect a mutation might have on a species survival. the change causes a rabbit to have mottled brown fur. the student runs a computer simulation for ten generations. what possible conclusions can you draw? choose all that apply.
a evolution occurred because the allele frequency changed over time.
b evolution is not occurring, mutation just introduced a new trait in the gene pool.
c the rabbits with mottled brown fur have a selective advantage that gives them more camouflage from predators.
d the mottled brown fur mutation is neutral because the other fur color traits still appear in the rabbit population.
e the mutation had a positive effect, allowing those rabbits with the mottled brown fur to survive and reproduce better than those with the brown or white fur.

Explanation:

• Option A: Evolution is defined as a change in allele frequencies over time. The table shows the number of rabbits with different fur colors (and thus different alleles) changing across generations (e.g., mottled fur rabbits increase, brown fur decrease), so allele frequencies are changing, indicating evolution.
• Option B: Contradicts Option A; since allele frequencies are changing, evolution is occurring, so B is incorrect.
• Option C: The number of mottled fur rabbits increases over generations, suggesting they are better at surviving (e.g., camouflage from predators helps them avoid being eaten, so they can reproduce more). This implies a selective advantage.
• Option D: A neutral mutation would not lead to a significant change in the frequency of the trait. But mottled fur rabbits are increasing, so the mutation is not neutral (it has a positive effect), so D is incorrect.
• Option E: The count of mottled fur rabbits rises (from 0 in generation 1 to 89 in generation 10) while brown and white fur counts decrease or stay low, showing mottled fur rabbits are surviving and reproducing better, so the mutation has a positive effect.

Answer:

A. Evolution occurred because the allele frequency changed over time.
C. The rabbits with mottled brown fur have a selective advantage that gives them more camouflage from predators.
E. The mutation had a positive effect, allowing those rabbits with the mottled brown fur to survive and reproduce better than those with the brown or white fur.