- A The directed, seasonal migration pattern of animal populations moving regularly between distant seasonal habitats
- B Random change in allele frequencies in a population due to chance events, especially significant in small populations
- C Mutation that is deliberately directed by the organism itself toward a specific, predetermined adaptive outcome
- D Natural selection acting with roughly similar strength and predictability across populations of varying sizes
Correct answer: B. Random change in allele frequencies in a population due to chance events, especially significant in small populations
Explanation: Genetic drift: random, chance-based changes in allele frequencies, not due to selection. Most significant in small populations. Two special cases: Founder effect (small group colonizes new area) and Bottleneck effect (population reduced by disaster). Can lead to fixation or loss of alleles regardless of fitness.
Concept context
Origin of life, Darwin's theory, natural selection, speciation, and evidence for evolution.