Question

allele frequency refers to the fraction of individuals with a particular version of a given gene. what effect does natural selection have on the allele frequency of a population?
a. it increases the frequency of alleles that improve a species’ survival in a particular environment.
b. it greatly reduces the total population, which increases the effects of genetic drift on allele frequency.
c. it causes random changes and the allele frequency of certain traits may increase or decrease.
d. it causes the allele frequency to resemble that of a small number of individuals that become separated from the total population.

Explanation:

The question is about allele frequency change due to random events affecting a small population, which is genetic drift. Option D describes a scenario where a small number of individuals (founders) start a new population, causing allele frequency changes (founder effect, a type of genetic drift). Option A is natural selection, B is about quality affecting population (not drift), C is random change but not specific to small population founding. So D matches genetic drift (founder effect).

Answer:

D. It causes the allele frequency to resemble that of a small number of individuals that become separated from the total population.