AP BIOLOGY

Detailed explanation-1: -Unlike natural selection, genetic drift does not depend on an allele’s beneficial or harmful effects. Instead, drift changes allele frequencies purely by chance, as random subsets of individuals (and the gametes of those individuals) are sampled to produce the next generation.

Detailed explanation-2: -Which evolutionary mechanism-independent of natural selection, recombination, or mutation-will most likely result in rapid, random changes in gene frequencies? Speciation, a process in which a new biological species arises, occurs in stages and results in a species with an improved “fit” for its environment.

Detailed explanation-3: -Genetic drift involves changes in allele frequency due to chance events – literally, “sampling error” in selecting alleles for the next generation. Drift can occur in any population of non-infinite size, but it has a stronger effect on small populations.

Detailed explanation-4: -Mutation. Mutation is a source of new alleles in a population, thus it leads to an increase in variation among the members of the population. Mutation is a change in the DNA sequence of the gene.

Detailed explanation-5: -Diversifying (or disruptive) selection: Diversifying selection occurs when extreme values for a trait are favored over the intermediate values. This type of selection often drives speciation. Diversifying selection can also occur when environmental changes favor individuals on either end of the phenotypic spectrum.