Campbell Biology

Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson

Chapter 26

Phylogeny and the Tree of Life - all with Video Answers

Educators

Chapter Questions

Problem 1

In a comparison of birds and mammals, the condition of having four limbs is
a. 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.

Nicole Murray

Nicole Murray

Numerade Educator

Problem 2

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.

Bryan Lynn

Numerade Educator

Problem 3

In Figure $26.4,$ which similarly inclusive taxon descended from the same common ancestor as Canidae?
a. Felidae
b. Mustelidae
c. Carnivora
d. Lutra

Jessica Macaluso

Jessica Macaluso

Numerade Educator

Problem 4

Three living species $X, Y,$ and $Z$ share a common ancestor $T,$ as do extinct species U and V. A grouping that consists of species
T, X, Y, and Z (but not U or V) makes up
a. a monophyletic taxon.
b. an ingroup, with species U as the outgroup.
c. a paraphyletic group.
d. a polyphyletic group.

Bryan Lynn

Numerade Educator

Problem 5

Based on the tree below, which statement is not correct?
a. The salamander lineage is a basal taxon.
b. Salamanders are a sister group to the group containing lizards, goats, and humans.
c. Salamanders are as closely related to goats as to humans.
d. Lizards are more closely related to salamanders than to humans.

Nicole Murray

Numerade Educator

Problem 6

If you were using cladistics to build a phylogenetic tree of cats, which of the following would be the best outgroup?
a. wolf
b. domestic cat
c. lion
d. leopard

Nicole Murray

Numerade Educator

Problem 7

The relative lengths of the frog and mouse branches in the phylogenetic tree in Figure 26.13 indicate that
a. frogs evolved before mice.
b. mice evolved before frogs.
c. the homolog has evolved more rapidly in mice.
d. the homolog has evolved more slowly in mice.

Nicole Hewett

Numerade Educator

Problem 8

Darwin suggested looking at a species' close relatives to learn what its ancestors may have been like. How does his suggestion anticipate recent methods, such as phylogenetic bracketing and the use of outgroups in cladistic analysis?

Rashmi Sinha

Numerade Educator

Problem 9

(a) Draw a phylogenetic tree based on characters $1-5$ in the table below. Place hatch marks on the tree to indicate the origin(s) of characters $1-6 .$ (b) Assume that tuna and dolphins are sister species and redraw the phylogenetic tree accordingly. Use hatch marks to indicate the origin(s) of characters $1-6 .$ (c) How many evolutionary changes are required in each tree? Which tree is most parsimonious?

Nicole Murray

Numerade Educator

Problem 10

In a short essay ( $100-150$ words), explain how genetic information-along with an understanding of the process of descent with modification-enables scientists to reconstruct phylogenies that extend hundreds of millions of years back in time.

Courtney Burson

Courtney Burson

Numerade Educator

Problem 11

This West Indian manatee (Trichechus manatus) is an aquatic mammal. Like amphibians and reptiles, mammals are tetrapods (vertebrates with four limbs). Explain why manatees are considered tetrapods even though they lack hind limbs, and suggest traits that manatees likely share with leopards and other mammals (see Figure $26.12 \mathrm{b}$ ). How might early members of the manatee lineage have differed from today's manatees?

Courtney Burson

Courtney Burson

Numerade Educator