BIO320
Evolutionary Biology
Midterms Exam Review (Qns & Ans)
2025
1. Which of the following mechanisms is a primary driver of
evolution and involves changes in allele frequencies due to
random sampling effects?
- A. Natural selection
- B. Genetic drift
- C. Gene flow
- D. Mutation
ANS: B. Genetic drift
©/2025
, Rationale: Genetic drift involves changes in allele
frequencies due to random sampling effects, especially in small
populations, and can lead to significant evolutionary changes over
time.
2. What is the main concept of natural selection as proposed by
Charles Darwin?
- A. Survival of the strongest
- B. Inheritance of acquired characteristics
- C. Differential reproductive success based on heritable traits
- D. Random mutations
ANS: C. Differential reproductive success based on heritable
traits
Rationale: Natural selection, as proposed by Darwin,
involves differential reproductive success based on heritable
traits, where advantageous traits increase an organism's fitness
and are more likely to be passed on to future generations.
Fill-in-the-Blank Questions
3. The __________ effect occurs when a small group of
individuals establishes a new population, leading to reduced
genetic variation compared to the original population.
©/2025
, ANS: Founder
Rationale: The founder effect occurs when a small group of
individuals establishes a new population, resulting in reduced
genetic variation compared to the original population due to the
limited number of alleles represented.
4. __________ is the process by which species evolve from a
common ancestor through the accumulation of differences over
time.
ANS: Divergent evolution
Rationale: Divergent evolution is the process by which
species evolve from a common ancestor, accumulating differences
over time and leading to the formation of new species.
True/False Questions
5. True or False: Gene flow involves the movement of alleles
between populations through migration.
ANS: True
Rationale: Gene flow involves the movement of alleles
between populations through migration, which can reduce genetic
©/2025
, differences between populations and increase genetic diversity
within a population.
6. True or False: Convergent evolution occurs when unrelated
species evolve similar traits due to similar environmental
pressures.
ANS: True
Rationale: Convergent evolution occurs when unrelated
species evolve similar traits independently due to similar
environmental pressures, leading to analogous structures.
Multiple Response Questions
7. Which of the following are types of natural selection? (Select
all that apply)
- A. Stabilizing selection
- B. Directional selection
- C. Disruptive selection
- D. Artificial selection
ANSs: A, B, C
©/2025
Evolutionary Biology
Midterms Exam Review (Qns & Ans)
2025
1. Which of the following mechanisms is a primary driver of
evolution and involves changes in allele frequencies due to
random sampling effects?
- A. Natural selection
- B. Genetic drift
- C. Gene flow
- D. Mutation
ANS: B. Genetic drift
©/2025
, Rationale: Genetic drift involves changes in allele
frequencies due to random sampling effects, especially in small
populations, and can lead to significant evolutionary changes over
time.
2. What is the main concept of natural selection as proposed by
Charles Darwin?
- A. Survival of the strongest
- B. Inheritance of acquired characteristics
- C. Differential reproductive success based on heritable traits
- D. Random mutations
ANS: C. Differential reproductive success based on heritable
traits
Rationale: Natural selection, as proposed by Darwin,
involves differential reproductive success based on heritable
traits, where advantageous traits increase an organism's fitness
and are more likely to be passed on to future generations.
Fill-in-the-Blank Questions
3. The __________ effect occurs when a small group of
individuals establishes a new population, leading to reduced
genetic variation compared to the original population.
©/2025
, ANS: Founder
Rationale: The founder effect occurs when a small group of
individuals establishes a new population, resulting in reduced
genetic variation compared to the original population due to the
limited number of alleles represented.
4. __________ is the process by which species evolve from a
common ancestor through the accumulation of differences over
time.
ANS: Divergent evolution
Rationale: Divergent evolution is the process by which
species evolve from a common ancestor, accumulating differences
over time and leading to the formation of new species.
True/False Questions
5. True or False: Gene flow involves the movement of alleles
between populations through migration.
ANS: True
Rationale: Gene flow involves the movement of alleles
between populations through migration, which can reduce genetic
©/2025
, differences between populations and increase genetic diversity
within a population.
6. True or False: Convergent evolution occurs when unrelated
species evolve similar traits due to similar environmental
pressures.
ANS: True
Rationale: Convergent evolution occurs when unrelated
species evolve similar traits independently due to similar
environmental pressures, leading to analogous structures.
Multiple Response Questions
7. Which of the following are types of natural selection? (Select
all that apply)
- A. Stabilizing selection
- B. Directional selection
- C. Disruptive selection
- D. Artificial selection
ANSs: A, B, C
©/2025
