Chapter 23

Draw a phylogenetic tree of three groups of organisms and explain how a nested pattern of similarity can be seen in the tree and how it might arise.

Distinguish among monophyletic, paraphyletic, and polyphyletic groups, and give an example of each.

List the levels of classification, from the least inclusive (species) to the most inclusive (domain).

Define "homology" and "analogy" and describe two traits that are homologous and two that are analogous.

Name a type of homology that is useful in building phylogenetic trees and explain why this kind of homology, and not others, is useful.

Describe three ways that an organism can leave a record in sedimentary rocks and explain why this means that there are gaps in the fossil record.

Explain how the fossil record can be used to determine both the relative and the absolute timescales of past events.

Describe how mass extinctions have shaped the ecological landscape.