The allele for black noses in wolves is dominant over the allele for brown noses. There is no known selective advantage for one nose color over another in wolves. If this remains true, which of the following statements is most likely TRUE about the change in wolf nose colors over many generations? A. Black noses will become more common than they are now B. Black noses will stay about the same frequency as now C. Black noses will become less common then they are now D. Brown noses will disappear after enough generations have passed.

The correct answer is B.

Explanation

Dominant does not mean it will increase in frequency by itself. If there is truly no selective advantage for black versus brown noses, then natural selection is not changing the allele frequencies. Under the Hardy–Weinberg principle, when there is no selection (and no mutation, migration, nonrandom mating, or strong genetic drift), allele and genotype frequencies remain approximately constant from generation to generation. That means the proportion of black- and brown-nosed wolves will stay about the same over time.

Why the other choices are wrong:

• A (black noses will become more common): Dominance alone does not cause an allele to increase in frequency without selection or another force.
• C (black noses will become less common): There’s no reason for a decrease if no selective pressure favors brown.
• D (brown noses will disappear): Recessive alleles can persist hidden in heterozygotes (carriers) and won’t vanish just because they’re recessive.

Caveat: In very small populations, genetic drift (random changes) can shift allele frequencies over time, so slight changes are possible; but given the condition “no known selective advantage,” the most likely outcome is that frequencies stay about the same.