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Campbell Biology

Lisa A. Urry

Chapter 26

Phylogeny and the Tree of Life



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.

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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 L.
Numerade Educator

Problem 3

VISUAL SKILLS In Figure $26.4,$ which similarly inclusive taxon
is represented as descending from the same common ancestor
as Canidae?
$$\begin{array}{ll}{\text { (A) Felidae }} & {\text { (C) Carnivora }} \\ {\text { (B) Mustelidae }} & {\text { (D) Lutra }}\end{array}$$

Tim T.
Numerade Educator

Problem 4

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

Bryan L.
Numerade Educator

Problem 5

VISUAL SKILLS Based on the tree below, which statement is
not correct?
(A) Goats and humans form a sister group.
(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

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Problem 6

If you were using cladistics to build a phylogenetic tree of cats,
which of the following would be the best outgroup?
$$\begin{array}{ll}{\text { (A) wolf }} & {\text { (C) lion }} \\ {\text { (B) domestic cat }} & {\text { (D) leopard }}\end{array}$$

Bryan L.
Numerade Educator

Problem 7

VISUAL SKILLS 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 mice.
(C) the homolog has evolved more rapidly in mice.
(D) the homolog has evolved more slowly in mice.

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Problem 8

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

Bryan L.
Numerade Educator

Problem 9

SCIENTIFIC INQUIRY $\bullet$ DRAW IT (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) Determine how many
evolutionary changes are required in each tree. Identify the
most parsimonious tree.

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Problem 10

$(100-150$ 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.

Bryan L.
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 $\mathrm{b} ) .$ Discuss how early members of the manatee lineage might have differed from today's

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