Evolutionary Biology PCB4674 Exam 1 Practice 2026 – FSU
1. Which of the following best defines biological evolution?
A. The process by which an individual changes during its lifetime.
B. The sudden appearance of a new species without prior ancestors.
C. The change in allele frequencies in a population over generations.
D. The goal-oriented progression of life toward greater complexity.
Answer: C
Rationale: Biological evolution is defined as change in the heritable characteristics (allele
frequencies) of biological populations over successive generations.
2. Who is credited with the idea of ‘Inheritance of Acquired Characteristics’?
A. Charles Darwin
B. Alfred Russel Wallace
C. Jean-Baptiste Lamarck
D. Gregor Mendel
Answer: C
Rationale: Lamarck proposed that organisms could pass on traits acquired during their
lifetime to their offspring, a theory now largely superseded by Darwinian evolution.
3. In a population in Hardy-Weinberg equilibrium, what does ‘2pq’ represent?
A. The frequency of the dominant allele.
B. The frequency of the homozygous dominant genotype.
C. The frequency of the heterozygous genotype.
D. The frequency of the homozygous recessive genotype.
Answer: C
,Rationale: In the Hardy-Weinberg equation p^2 + 2pq + q^2 = 1, 2pq represents the
frequency of the heterozygotes.
4. Which mechanism of evolution is entirely random and has a larger effect in
small populations?
A. Genetic Drift
B. Natural Selection
C. Gene Flow
D. Mutation
Answer: A
Rationale: Genetic drift refers to random fluctuations in allele frequencies, which are much
more pronounced in small populations due to sampling error.
5. What is a synapomorphy?
A. A shared derived character state used to define a clade.
B. A unique character state found in only one taxon.
C. A shared ancestral character state.
D. The independent evolution of similar features in different lineages.
Answer: A
Rationale: A synapomorphy is a trait shared by two or more taxa and their most recent
common ancestor, helping to identify monophyletic groups.
6. Which of the following is an example of a post-zygotic reproductive barrier?
A. Temporal isolation
B. Hybrid sterility
C. Behavioral isolation
D. Mechanical isolation
Answer: B
Rationale: Post-zygotic barriers occur after fertilization. Hybrid sterility (like a mule)
prevents the hybrid from producing offspring, maintaining species boundaries.
, 7. The wings of a bat and the wings of a butterfly are examples of:
A. Homologous structures
B. Vestigial structures
C. Analogous structures
D. Synapomorphies
Answer: C
Rationale: Analogous structures result from convergent evolution where different species
evolve similar traits independently to serve the same function.
8. Which condition is NOT required for Hardy-Weinberg equilibrium?
A. Random mating
B. Small population size
C. No mutation
D. No natural selection
Answer: B
Rationale: Hardy-Weinberg equilibrium requires an infinitely large population to prevent
genetic drift from changing allele frequencies.
9. What does ‘fitness’ specifically refer to in an evolutionary context?
A. The relative contribution of an individual to the gene pool of the next generation.
B. The ability of an organism to survive until old age.
C. The physical strength and speed of an individual.
D. The complexity of an organism’s nervous system.
Answer: A
Rationale: Fitness is a measure of reproductive success; it is the ability of an individual to
survive and reproduce, passing its genes to the next generation.
1. Which of the following best defines biological evolution?
A. The process by which an individual changes during its lifetime.
B. The sudden appearance of a new species without prior ancestors.
C. The change in allele frequencies in a population over generations.
D. The goal-oriented progression of life toward greater complexity.
Answer: C
Rationale: Biological evolution is defined as change in the heritable characteristics (allele
frequencies) of biological populations over successive generations.
2. Who is credited with the idea of ‘Inheritance of Acquired Characteristics’?
A. Charles Darwin
B. Alfred Russel Wallace
C. Jean-Baptiste Lamarck
D. Gregor Mendel
Answer: C
Rationale: Lamarck proposed that organisms could pass on traits acquired during their
lifetime to their offspring, a theory now largely superseded by Darwinian evolution.
3. In a population in Hardy-Weinberg equilibrium, what does ‘2pq’ represent?
A. The frequency of the dominant allele.
B. The frequency of the homozygous dominant genotype.
C. The frequency of the heterozygous genotype.
D. The frequency of the homozygous recessive genotype.
Answer: C
,Rationale: In the Hardy-Weinberg equation p^2 + 2pq + q^2 = 1, 2pq represents the
frequency of the heterozygotes.
4. Which mechanism of evolution is entirely random and has a larger effect in
small populations?
A. Genetic Drift
B. Natural Selection
C. Gene Flow
D. Mutation
Answer: A
Rationale: Genetic drift refers to random fluctuations in allele frequencies, which are much
more pronounced in small populations due to sampling error.
5. What is a synapomorphy?
A. A shared derived character state used to define a clade.
B. A unique character state found in only one taxon.
C. A shared ancestral character state.
D. The independent evolution of similar features in different lineages.
Answer: A
Rationale: A synapomorphy is a trait shared by two or more taxa and their most recent
common ancestor, helping to identify monophyletic groups.
6. Which of the following is an example of a post-zygotic reproductive barrier?
A. Temporal isolation
B. Hybrid sterility
C. Behavioral isolation
D. Mechanical isolation
Answer: B
Rationale: Post-zygotic barriers occur after fertilization. Hybrid sterility (like a mule)
prevents the hybrid from producing offspring, maintaining species boundaries.
, 7. The wings of a bat and the wings of a butterfly are examples of:
A. Homologous structures
B. Vestigial structures
C. Analogous structures
D. Synapomorphies
Answer: C
Rationale: Analogous structures result from convergent evolution where different species
evolve similar traits independently to serve the same function.
8. Which condition is NOT required for Hardy-Weinberg equilibrium?
A. Random mating
B. Small population size
C. No mutation
D. No natural selection
Answer: B
Rationale: Hardy-Weinberg equilibrium requires an infinitely large population to prevent
genetic drift from changing allele frequencies.
9. What does ‘fitness’ specifically refer to in an evolutionary context?
A. The relative contribution of an individual to the gene pool of the next generation.
B. The ability of an organism to survive until old age.
C. The physical strength and speed of an individual.
D. The complexity of an organism’s nervous system.
Answer: A
Rationale: Fitness is a measure of reproductive success; it is the ability of an individual to
survive and reproduce, passing its genes to the next generation.
