Figure 24.2 -The Distribution of Pocket-Mouse Coat Colors in Several Arizona Populations

Multiple Choice

Figure 24.2

-The distribution of pocket-mouse coat colors in several Arizona populations is associated with substrate color.Some populations live on light-colored granite substrate,and others live on dark volcanic rock.In Figure 24.2,chart A shows the frequency of the melanic (dark) coat phenotype across six populations.Populations C,D,and E live on dark volcanic rock;populations A,B,and F live on light-colored granite.Chart B shows the frequency of the Melanocortin-1 receptor (Mc1r) allele across these populations.The Mc1r alleles,D and d,differ by four amino acids;mice with DD and Dd genotypes have dark coats,whereas mice with dd genotype are light colored.Which of the following statements best interprets the results shown in charts A and B?

A) Frequency of the D allele is closely associated with the melanic phenotype,but is unrelated to the presence of dark substrate color.
B) Frequency of the D allele is not associated with the melanic phenotype,but is associated with the presence of dark substrate color.
C) Frequency of the D allele is closely associated with both the melanic phenotype and the presence of dark substrate color.
D) Frequency of the D allele is associated neither with the melanic phenotype nor with the presence of dark substrate color.
E) Frequency of the D allele does not vary.