Evolution Exam 1 (PCB 4674) 2026 – FSU
1. Which of the following is NOT one of Darwin’s four postulates of evolution by
natural selection?
A. Individuals within populations are variable.
B. Survival and reproduction are non-random.
C. Acquired traits are inherited by the next generation.
D. Variation is passed on to offspring.
Answer: C
Rationale: Darwin’s postulates focus on natural variation, heritability, and differential
reproductive success; the inheritance of acquired traits was Lamarck’s idea.
2. In a phylogenetic tree, a group that includes an ancestor and all of its
descendants is called:
A. Paraphyletic
B. Monophyletic
C. Polyphyletic
D. Homoplastic
Answer: B
Rationale: A monophyletic group, or clade, consists of an ancestral species and all its
descendants.
,3. Which process is the ultimate source of all new genetic variation?
A. Natural Selection
B. Mutation
C. Genetic Drift
D. Gene Flow
Answer: B
Rationale: While selection and drift change allele frequencies, only mutation creates
entirely new alleles.
4. The biological fitness of an individual is best measured by:
A. Its physical strength and speed.
B. Its ability to resist disease.
C. Its lifespan.
D. The number of offspring it contributes to the next generation.
Answer: D
Rationale: In evolutionary terms, fitness is defined by reproductive success relative to
others in the population.
5. Which of the following is an example of a vestigial structure?
A. The wing of a bird.
B. The flipper of a whale.
C. The tailbone in humans.
D. The eye of an eagle.
Answer: C
Rationale: Vestigial structures are remnants of features that served a function in the
organism’s ancestors but are no longer functional.
, 6. If a population is in Hardy-Weinberg equilibrium, which of the following is
true?
A. Allele frequencies remain constant over generations.
B. Allele frequencies change from generation to generation.
C. Evolution is occurring rapidly.
D. Natural selection is favoring heterozygotes.
Answer: A
Rationale: Hardy-Weinberg equilibrium describes a non-evolving population where allele
frequencies do not change.
7. Genetic drift has the most significant impact on which type of population?
A. Large populations
B. Small populations
C. Populations with high mutation rates
D. Populations in Hardy-Weinberg equilibrium
Answer: B
Rationale: Genetic drift, which is random change in allele frequencies, is much more
pronounced in small populations due to sampling error.
8. The ‘Modern Synthesis’ integrated Darwinian natural selection with:
A. Mendelian genetics
B. Lamarckian inheritance
C. Plate tectonics
D. The fossil record
Answer: A
Rationale: The Modern Synthesis bridged the gap between Darwin’s selection and
Mendel’s laws of inheritance.
1. Which of the following is NOT one of Darwin’s four postulates of evolution by
natural selection?
A. Individuals within populations are variable.
B. Survival and reproduction are non-random.
C. Acquired traits are inherited by the next generation.
D. Variation is passed on to offspring.
Answer: C
Rationale: Darwin’s postulates focus on natural variation, heritability, and differential
reproductive success; the inheritance of acquired traits was Lamarck’s idea.
2. In a phylogenetic tree, a group that includes an ancestor and all of its
descendants is called:
A. Paraphyletic
B. Monophyletic
C. Polyphyletic
D. Homoplastic
Answer: B
Rationale: A monophyletic group, or clade, consists of an ancestral species and all its
descendants.
,3. Which process is the ultimate source of all new genetic variation?
A. Natural Selection
B. Mutation
C. Genetic Drift
D. Gene Flow
Answer: B
Rationale: While selection and drift change allele frequencies, only mutation creates
entirely new alleles.
4. The biological fitness of an individual is best measured by:
A. Its physical strength and speed.
B. Its ability to resist disease.
C. Its lifespan.
D. The number of offspring it contributes to the next generation.
Answer: D
Rationale: In evolutionary terms, fitness is defined by reproductive success relative to
others in the population.
5. Which of the following is an example of a vestigial structure?
A. The wing of a bird.
B. The flipper of a whale.
C. The tailbone in humans.
D. The eye of an eagle.
Answer: C
Rationale: Vestigial structures are remnants of features that served a function in the
organism’s ancestors but are no longer functional.
, 6. If a population is in Hardy-Weinberg equilibrium, which of the following is
true?
A. Allele frequencies remain constant over generations.
B. Allele frequencies change from generation to generation.
C. Evolution is occurring rapidly.
D. Natural selection is favoring heterozygotes.
Answer: A
Rationale: Hardy-Weinberg equilibrium describes a non-evolving population where allele
frequencies do not change.
7. Genetic drift has the most significant impact on which type of population?
A. Large populations
B. Small populations
C. Populations with high mutation rates
D. Populations in Hardy-Weinberg equilibrium
Answer: B
Rationale: Genetic drift, which is random change in allele frequencies, is much more
pronounced in small populations due to sampling error.
8. The ‘Modern Synthesis’ integrated Darwinian natural selection with:
A. Mendelian genetics
B. Lamarckian inheritance
C. Plate tectonics
D. The fossil record
Answer: A
Rationale: The Modern Synthesis bridged the gap between Darwin’s selection and
Mendel’s laws of inheritance.
