Biology Mechanisms of Natural Selection Flashcards

Which condition is NOT required for Hardy-Weinberg equilibrium to apply to a population?

Answer: Small population size

Hardy-Weinberg equilibrium requires a large (ideally infinite) population, so small population size violates the assumptions.

A cheetah population that went through a severe bottleneck event would most likely show:

Answer: Reduced genetic variation

Bottleneck events drastically reduce population size, causing loss of alleles and reduced genetic variation.

Disruptive selection in a population tends to:

Answer: Favor both extreme phenotypes

Disruptive selection favors both extreme phenotypes while selecting against intermediate ones, potentially splitting a population.

Industrial melanism in peppered moths is a classic example of which evolutionary mechanism?

Answer: Directional selection

The shift from light to dark moths during industrialization illustrates directional selection favoring the darker phenotype in polluted environments.

Which statement best describes stabilizing selection?

Answer: It reduces variation by favoring intermediate phenotypes

Stabilizing selection favors the average phenotype and eliminates extremes, reducing overall variation in the population.

Gene flow between two previously isolated populations would most likely:

Answer: Decrease genetic differences between them

Gene flow introduces alleles from one population into another, making the populations more genetically similar over time.

Which best explains why recessive deleterious alleles persist in a population rather than being eliminated?

Answer: Natural selection cannot act on hidden recessive alleles in heterozygotes

When a deleterious allele is recessive, natural selection cannot eliminate it while it is 'hidden' in heterozygous carriers.