PCB4674 Exam 1: Evolutionary Biology 2026 – FSU
1. Which of the following best defines biological evolution?
A. The process by which individuals change during their lifetime to adapt to their environment.
B. The progressive movement of life toward a state of perfect complexity.
C. The sudden appearance of new species due to environmental cataclysms.
D. Any change in the inherited traits of a population that occurs from one generation to the next.
Answer: D
Rationale: Evolution is defined as change in the properties of populations of organisms
that transcend the lifetime of a single individual; it is the change in allele frequencies over
time.
2. What was the primary contribution of Darwin and Wallace to the study of
evolution?
A. They were the first to suggest that life changes over time.
B. They discovered the structure of DNA and how traits are inherited.
C. They proved that mutations are always beneficial to organisms.
D. They proposed natural selection as the mechanism for evolutionary change.
Answer: D
Rationale: While others suggested evolution occurred, Darwin and Wallace independently
proposed natural selection as the primary mechanism for descent with modification.
,3. A monophyletic group (clade) is defined as:
A. A group consisting of an ancestor and some, but not all, of its descendants.
B. A group that includes organisms from different lineages but not their common ancestor.
C. A group of organisms that share similar phenotypes but have different genotypes.
D. A group consisting of a common ancestor and all of its descendants.
Answer: D
Rationale: Monophyly refers to a group that includes the most recent common ancestor
and all of its descendants, identified by shared derived characters.
4. Which of the following is a synapomorphy?
A. A shared primitive trait inherited from a distant ancestor.
B. A trait that is unique to a single terminal taxon.
C. A shared derived character state used to define a clade.
D. A trait that evolved independently in two unrelated lineages.
Answer: C
Rationale: Synapomorphies are shared derived characters that provide evidence for
common ancestry and are the basis for building phylogenetic trees.
5. The similarity between the streamlined bodies of sharks (fish) and dolphins
(mammals) is an example of:
A. Homology
B. Synapomorphy
C. Convergent evolution
D. Phylogenetic inertia
Answer: C
Rationale: Convergent evolution occurs when unrelated lineages evolve similar traits
independently as adaptations to similar environments or lifestyles.
, 6. Vestigial structures, such as the tiny hind limb bones in whales, provide
evidence for evolution because:
A. They show that whales are currently evolving into land animals.
B. They prove that whales do not share a common ancestor with other mammals.
C. They are necessary for the whale’s survival in deep water.
D. They represent traits that were functional in an ancestor but have lost their original function.
Answer: D
Rationale: Vestigial structures are remnants of features that served important functions in
the organism’s ancestors, supporting the idea of descent with modification.
7. In a phylogenetic tree, what does a node represent?
A. A single individual organism.
B. The extinction of a lineage.
C. A point where a trait was lost.
D. The most recent common ancestor of the descending lineages.
Answer: D
Rationale: Nodes represent speciation events or points in time where a common ancestor
diverged into two or more descendant lineages.
8. Which method is primarily used to determine the absolute age of fossils or
rocks based on decay rates?
A. Stratigraphy
B. Radiometric dating
C. Relative dating
D. Paleomagnetism
Answer: B
Rationale: Radiometric dating uses the known decay rates of radioactive isotopes to
calculate the absolute age of geological materials.
1. Which of the following best defines biological evolution?
A. The process by which individuals change during their lifetime to adapt to their environment.
B. The progressive movement of life toward a state of perfect complexity.
C. The sudden appearance of new species due to environmental cataclysms.
D. Any change in the inherited traits of a population that occurs from one generation to the next.
Answer: D
Rationale: Evolution is defined as change in the properties of populations of organisms
that transcend the lifetime of a single individual; it is the change in allele frequencies over
time.
2. What was the primary contribution of Darwin and Wallace to the study of
evolution?
A. They were the first to suggest that life changes over time.
B. They discovered the structure of DNA and how traits are inherited.
C. They proved that mutations are always beneficial to organisms.
D. They proposed natural selection as the mechanism for evolutionary change.
Answer: D
Rationale: While others suggested evolution occurred, Darwin and Wallace independently
proposed natural selection as the primary mechanism for descent with modification.
,3. A monophyletic group (clade) is defined as:
A. A group consisting of an ancestor and some, but not all, of its descendants.
B. A group that includes organisms from different lineages but not their common ancestor.
C. A group of organisms that share similar phenotypes but have different genotypes.
D. A group consisting of a common ancestor and all of its descendants.
Answer: D
Rationale: Monophyly refers to a group that includes the most recent common ancestor
and all of its descendants, identified by shared derived characters.
4. Which of the following is a synapomorphy?
A. A shared primitive trait inherited from a distant ancestor.
B. A trait that is unique to a single terminal taxon.
C. A shared derived character state used to define a clade.
D. A trait that evolved independently in two unrelated lineages.
Answer: C
Rationale: Synapomorphies are shared derived characters that provide evidence for
common ancestry and are the basis for building phylogenetic trees.
5. The similarity between the streamlined bodies of sharks (fish) and dolphins
(mammals) is an example of:
A. Homology
B. Synapomorphy
C. Convergent evolution
D. Phylogenetic inertia
Answer: C
Rationale: Convergent evolution occurs when unrelated lineages evolve similar traits
independently as adaptations to similar environments or lifestyles.
, 6. Vestigial structures, such as the tiny hind limb bones in whales, provide
evidence for evolution because:
A. They show that whales are currently evolving into land animals.
B. They prove that whales do not share a common ancestor with other mammals.
C. They are necessary for the whale’s survival in deep water.
D. They represent traits that were functional in an ancestor but have lost their original function.
Answer: D
Rationale: Vestigial structures are remnants of features that served important functions in
the organism’s ancestors, supporting the idea of descent with modification.
7. In a phylogenetic tree, what does a node represent?
A. A single individual organism.
B. The extinction of a lineage.
C. A point where a trait was lost.
D. The most recent common ancestor of the descending lineages.
Answer: D
Rationale: Nodes represent speciation events or points in time where a common ancestor
diverged into two or more descendant lineages.
8. Which method is primarily used to determine the absolute age of fossils or
rocks based on decay rates?
A. Stratigraphy
B. Radiometric dating
C. Relative dating
D. Paleomagnetism
Answer: B
Rationale: Radiometric dating uses the known decay rates of radioactive isotopes to
calculate the absolute age of geological materials.
