A group of mice was released into a large field to which no other mice had access. Immediately after the release, a representative sample of the mice was captured, and the fur color of each individual in the sample was observed and recorded. The mice were then returned to the field. After twenty years, another representative sample of the mice was captured, and the fur color of each individual in the sample was again recorded. Which of the following best explains the change in the frequency distribution of fur color phenotypes in the mouse population, as shown in the figures above?
A) The allele for gray fur color is unstable, and over twenty years most of those alleles mutated to become
alleles for black fur.
B) The field was composed primarily of light-colored soil and little vegetation, affording gray mice protection from predators.
C) Sexual selection led to increased mating frequency of black and brown versus gray and brown.
D) The gray mice were hardest to capture and so were underrepresented in the twenty-year sample.

Ellis-van Creveld syndrome is a recessive genetic disorder that includes the characteristics of short stature and extra fingers or toes. In the general population, this syndrome occurs in approximately 1 in 150,000 live births. In a particular isolated population, however, the incidence of this syndrome among live births is 1 in 500.

Assume that both the isolated population and the general population are in Hardy-Weinberg equilibrium with respect to this syndrome. Which of the following best describes the difference between the frequency of the allele that causes the syndrome in the general population and the frequency of the allele in the isolated population?

A. The frequency of the Ellis-van Creveld allele is 0.002 in the isolated population and 0.0000066 in the general population,which suggests that selection for this trait is occurring in both populations.
B. The frequency of the Ellis-van Creveld allele is 0.0447 in the isolated population and 0.0026 in the general population, showing that the rate of genetic mutation is highest among individuals in the isolated population.
C. The frequency of the Ellis-van Creveld allele is 0.002 in the isolated population and 0.0000066 in the general population, which demonstrates gametic incompatibility between the populations.
D. The frequency of the Ellis-van Creveld allele is 0.0447 in the isolated population and 0.0026 in the general population, which suggests that genetic drift has occurred in the isolated population.D. The frequency of the Ellis-van Creveld allele is 0.0447 in the isolated population and 0.0026 in the general population, which suggests that genetic drift has occurred in the isolated population.

The higher the proportion of loci that are "fixed" in a population, the lower is that population's
A) nucleotide variability only.
B) genetic polyploidy only.
C) average heterozygosity only.
D) nucleotide variability, average heterozygosity, and genetic polyploidy.
E) nucleotide variability and average heterozygosity only.