Birds and mammals have a four-chambered heart, but most reptiles have a three-chambered heart. How does this fact affect the construction of phylogenetic trees for these groups?

Which statement below is true about an outgroup?

Unlike a regular phylogenetic tree, phylogenetic trees with branch lengths proportional to time can be used to __________.

Paralogous genes __________.

Which statement below is true of parsimonious trees?

If you wanted to determine the lineage of plants that have evolved on a relatively young archipelago—approximately 15,000 years old—what type of nucleic acid should you compare?

In a comparison of birds and mammals, the condition of having four limbs isa. a shared ancestral character.b. a shared derived character.c. a character useful for distinguishing birds from mammals.d. an example of analogy rather than homology.

To apply parsimony to constructing a phylogenetic tree,a. choose the tree that assumes all evolutionary changes are equally probable.b. choose the tree in which the branch points are based on as many shared derived characters as possible.c. choose the tree that represents the fewest evolutionary changes, in either DNA sequences or morphology.d. choose the tree with the fewest branch points.

Fill in the blanks on the phylogenetic tree (on the facing page) to show current hypotheses for the origin of multicellular organisms. a. b. c. d. e. f.