Question 1

Which of the following best describes a monophyletic group in a phylogenetic tree?

Accepted Answer

A group that includes an ancestor and all of its descendants.

Question 2

According to the principle of parsimony, which phylogenetic tree is preferred when constructing evolutionary relationships?

Accepted Answer

The tree that requires the fewest evolutionary changes.

Question 3

Which of the following is a limitation of the fossil record that can bias our understanding of evolutionary history?

Accepted Answer

Organisms with hard parts are more likely to fossilize than those with soft bodies.

Question 4

What is adaptive radiation?

Accepted Answer

A rapid evolutionary diversification within one lineage, producing many descendant species with different adaptations.

Question 5

Which of the following events is most closely associated with the Cambrian explosion?

Accepted Answer

A rapid diversification of animal body plans and the appearance of most major animal phyla.

Question 6

Which of the following is NOT a reason why the fossil record is incomplete?

Accepted Answer

All organisms are equally likely to be preserved as fossils.

Question 7

What evidence supports the hypothesis that an asteroid impact caused the End-Cretaceous mass extinction?

Accepted Answer

A worldwide layer of iridium-rich clay dating to 66 million years ago.

Question 8

Which of the following best explains why adaptive radiations often follow mass extinction events?

Accepted Answer

Mass extinctions open up ecological niches, allowing surviving lineages to diversify and fill new roles.

Question 9

Which of the following is a real-world example of convergent evolution observable in a phylogenetic tree?

Accepted Answer

The independent evolution of wings in bats and birds.

Question 10

Which of the following statements about the principle of parsimony in phylogenetic analysis is correct?

Accepted Answer

It favors the tree with the least number of evolutionary changes.

Question 11

A fossil is found in a sedimentary rock layer that is 250 million years old. Which period does this fossil most likely date to?

Accepted Answer

Permian

Question 12

Which of the following is a key innovation that contributed to the adaptive radiation of flowering plants?

Accepted Answer

The evolution of flowers, which allowed for more efficient pollination.

Question 13

Which of the following best describes the difference between a homology and a homoplasy in phylogenetic analysis?

Accepted Answer

A homology is a trait inherited from a common ancestor, while a homoplasy is a trait that evolved independently.

Question 14

Which of the following is a direct result of the End-Cretaceous mass extinction?

Accepted Answer

The extinction of non-avian dinosaurs.

Question 15

Which of the following is most likely to be preserved as a fossil?

Accepted Answer

A clam shell buried rapidly in sediment.

Question 16

Which of the following best explains why oxygen levels in the atmosphere were important for the Cambrian explosion?

Accepted Answer

Higher oxygen levels allowed for larger and more active animals.

Question 17

Which of the following is a correct interpretation of a phylogenetic tree?

Accepted Answer

The closer two species are on the tree, the more recently they shared a common ancestor.

Question 18

Which of the following is a plausible reason why some lineages survive mass extinction events while others do not?

Accepted Answer

Some lineages have traits that allow them to survive in drastically changed environments.

Question 19

Which of the following is a real-world example of how the fossil record can be biased?

Accepted Answer

Fossils of river-dwelling animals are more common than those of mountain-dwelling animals.

Phylogenies and the History of Life: Study Notes

Study Guide - Practice Questions