PCB4674 Final Exam: Evolution 2026 – FSU
1. Which of the following is the primary mechanism of evolution proposed by
Charles Darwin?
A. Natural selection
B. Genetic drift
C. Gene flow
D. Mutation
Answer: A
Rationale: Charles Darwin proposed natural selection as the primary mechanism for
evolution, where individuals with favorable traits are more likely to survive and reproduce.
2. What term describes a trait that is similar in two species because of
inheritance from a common ancestor?
A. Homologous structure
B. Homoplastic structure
C. Analogous structure
D. Vestigial structure
Answer: A
Rationale: Homology refers to traits inherited from a common ancestor, whereas analogy
refers to traits that look similar due to convergent evolution.
,3. In a population in Hardy-Weinberg equilibrium, if the frequency of the
recessive allele (q) is 0.4, what is the frequency of the homozygous dominant
genotype?
A. 0.36
B. 0.16
C. 0.48
D. 0.60
Answer: A
Rationale: If q = 0.4, then p = 0.6. The frequency of the homozygous dominant genotype
(p^2) is 0.6 * 0.6 = 0.36.
4. Which evolutionary force is most likely to decrease genetic variation within a
small population due to random sampling?
A. Natural selection
B. Gene flow
C. Mutation
D. Genetic drift
Answer: D
Rationale: Genetic drift is the change in allele frequencies due to chance, and its effects are
much stronger in small populations, often leading to a loss of genetic variation.
5. A ‘monophyletic’ group is defined as one that:
A. Includes an ancestor and some of its descendants
B. Includes descendants but excludes the common ancestor
C. Includes a common ancestor and all of its descendants
D. Includes species with similar traits regardless of ancestry
Answer: C
Rationale: A monophyletic group, or clade, consists of an ancestral species and all of its
descendant species.
, 6. The biological species concept defines a species based on:
A. Morphological similarity
B. Ecological niche
C. DNA sequence identity
D. Reproductive isolation
Answer: D
Rationale: The biological species concept defines a species as a group of populations
whose members have the potential to interbreed and produce viable, fertile offspring.
7. Which of the following is an example of a post-zygotic reproductive barrier?
A. Temporal isolation
B. Behavioral isolation
C. Hybrid sterility
D. Gametic isolation
Answer: C
Rationale: Post-zygotic barriers occur after fertilization. Hybrid sterility (e.g., a mule)
prevents the hybrid from passing genes to the next generation.
8. The process by which unrelated species evolve similar traits due to similar
environmental pressures is called:
A. Convergent evolution
B. Divergent evolution
C. Parallel evolution
D. Coevolution
Answer: A
Rationale: Convergent evolution occurs when different lineages evolve similar features
independently, often as adaptations to similar lifestyles.
1. Which of the following is the primary mechanism of evolution proposed by
Charles Darwin?
A. Natural selection
B. Genetic drift
C. Gene flow
D. Mutation
Answer: A
Rationale: Charles Darwin proposed natural selection as the primary mechanism for
evolution, where individuals with favorable traits are more likely to survive and reproduce.
2. What term describes a trait that is similar in two species because of
inheritance from a common ancestor?
A. Homologous structure
B. Homoplastic structure
C. Analogous structure
D. Vestigial structure
Answer: A
Rationale: Homology refers to traits inherited from a common ancestor, whereas analogy
refers to traits that look similar due to convergent evolution.
,3. In a population in Hardy-Weinberg equilibrium, if the frequency of the
recessive allele (q) is 0.4, what is the frequency of the homozygous dominant
genotype?
A. 0.36
B. 0.16
C. 0.48
D. 0.60
Answer: A
Rationale: If q = 0.4, then p = 0.6. The frequency of the homozygous dominant genotype
(p^2) is 0.6 * 0.6 = 0.36.
4. Which evolutionary force is most likely to decrease genetic variation within a
small population due to random sampling?
A. Natural selection
B. Gene flow
C. Mutation
D. Genetic drift
Answer: D
Rationale: Genetic drift is the change in allele frequencies due to chance, and its effects are
much stronger in small populations, often leading to a loss of genetic variation.
5. A ‘monophyletic’ group is defined as one that:
A. Includes an ancestor and some of its descendants
B. Includes descendants but excludes the common ancestor
C. Includes a common ancestor and all of its descendants
D. Includes species with similar traits regardless of ancestry
Answer: C
Rationale: A monophyletic group, or clade, consists of an ancestral species and all of its
descendant species.
, 6. The biological species concept defines a species based on:
A. Morphological similarity
B. Ecological niche
C. DNA sequence identity
D. Reproductive isolation
Answer: D
Rationale: The biological species concept defines a species as a group of populations
whose members have the potential to interbreed and produce viable, fertile offspring.
7. Which of the following is an example of a post-zygotic reproductive barrier?
A. Temporal isolation
B. Behavioral isolation
C. Hybrid sterility
D. Gametic isolation
Answer: C
Rationale: Post-zygotic barriers occur after fertilization. Hybrid sterility (e.g., a mule)
prevents the hybrid from passing genes to the next generation.
8. The process by which unrelated species evolve similar traits due to similar
environmental pressures is called:
A. Convergent evolution
B. Divergent evolution
C. Parallel evolution
D. Coevolution
Answer: A
Rationale: Convergent evolution occurs when different lineages evolve similar features
independently, often as adaptations to similar lifestyles.
