CLEP Biology Mechanisms of Natural Selection 3

Question 1

Sexual selection differs from natural selection primarily because it:

Accepted Answer

Involves competition for mates rather than survival

Answer

Sexual selection specifically involves differential reproductive success based on mate competition or mate choice, not merely survival.

Question 2

The concept of 'fitness' in evolutionary biology specifically refers to:

Accepted Answer

Reproductive success relative to other individuals

Answer

Evolutionary fitness is defined as an individual's ability to survive and reproduce relative to others in the population.

Question 3

Which scenario illustrates the founder effect?

Accepted Answer

A few birds colonize a distant island and establish a new population

Answer

The founder effect occurs when a small group establishes a new population, carrying only a subset of the original genetic variation.

Question 4

Heterozygote advantage (overdominance) maintains two alleles in a population because:

Accepted Answer

Heterozygotes have higher fitness than either homozygote

Answer

When heterozygotes are more fit than either homozygote, both alleles are preserved through balancing selection.

Question 5

Which of the following would INCREASE the rate of evolution by natural selection?

Accepted Answer

High heritability of traits

Answer

High heritability means traits are strongly passed from parent to offspring, making natural selection more effective at changing allele frequencies.

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