Which of the five common ancestors, labeled V-Z, has given rise to the greatest number of
species, both extant and extinct?
A) V
B) W
C) Z
D) Both W and Z can be considered to have given rise to the greatest number of extant and
extinct species.
E) Both X and Y can be considered to have given rise to the greatest number of extant and
extinct species.

Both X and Y can be considered to have given rise to the greatest number of extant and
extinct species.

Which of the five common ancestors, labeled V-Z, has been least successful in terms of the
percent of its derived species that are extant?
A) V
B) W
C) X
D) Y
E) Z

W

Which of the five common ancestors, labeled V-Z, has been most successful in terms of the
percent of its derived species that are extant?
A) V
B) W
C) X
D) Y
E) Z

Z

Evolutionary trees such as this are properly understood by scientists to be
A) theories.
B) hypotheses.
C) guesses.
D) dogmas.
E) facts.

hypotheses.

If the six ground finch species have evolved most recently, then which of these is the most
logical prediction?
A) They should be limited to the six islands that most recently emerged from the sea.
B) Their genomes should be more similar to each other than are the genomes of the five tree
finch species.
C) They should share fewer anatomical homologies with each other than they share with the tree
finches.
D) The chances of hybridization between two ground finch species should be less than the
chances of hybridization between two tree finch species.

Their genomes should be more similar to each other than are the genomes of the five tree
finch species.

According to a 1999 study, the vegetarian finch is genetically no more similar to the tree
finches than it is to the ground finches, despite the fact that it is placed in the same genus as the
tree finches. Based on this finding, it is reasonable to conclude that the vegetarian finch
A) is no more closely related to the tree finches than it is to the ground finches, despite its
classification.
B) should be re-classified as a warbler finch.
C) is not truly a descendent of the original ancestral finch.
D) is a hybrid species, resulting from a cross between a ground finch and a tree finch.

is no more closely related to the tree finches than it is to the ground finches, despite its
classification.

Which of the following is not an observation or inference on which natural selection is based?
A) There is heritable variation among individuals.
B) Poorly adapted individuals never produce offspring.
C) Species produce more offspring than the environment can support.
D) Individuals whose characteristics are best suited to the environment generally leave more
offspring than those whose characteristics are less well suited.
E) Only a fraction of an individual’s offspring may survive.

Poorly adapted individuals never produce offspring.

Which of the following observations helped Darwin shape his concept of descent with
modification?
A) Species diversity declines farther from the equator.
B) Fewer species live on islands than on the nearest continents.
C) Birds live on islands located farther from the mainland than the birds’ maximum nonstop
flight distance.
D) South American temperate plants are more similar to the tropical plants of South America
than to the temperate plants of Europe.
E) Earthquakes reshape life by causing mass extinctions.

South American temperate plants are more similar to the tropical plants of South America

Within six months of effectively using methicillin to treat S. aureus infections in a
community, all new infections were caused by MRSA. How can this result best be explained?
A) S. aureus can resist vaccines.
B) A patient must have become infected with MRSA from another community.
C) In response to the drug, S. aureus began making drugresistant versions of the protein targeted
by the drug.
D) Some drug-resistant bacteria were present at the start of treatment, and natural selection
increased their frequency.
E) The drug caused the S. aureus DNA to change.

Some drug-resistant bacteria were present at the start of treatment, and natural selection
increased their frequency.

The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the
corresponding bones in whales have very different shapes and proportions. However, genetic
data suggest that all three kinds of organisms diverged from a common ancestor at about the
same time. Which of the following is the most likely explanation for these data?
A) Humans and bats evolved by natural selection, and whales evolved by Lamarckian
mechanisms.
B) Forelimb evolution was adaptive in people and bats, but not in whales.
C) Natural selection in an aquatic environment resulted in significant changes to whale forelimb
anatomy.
D) Genes mutate faster in whales than in humans or bats.
E) Whales are not properly classified as mammals.

Natural selection in an aquatic environment resulted in significant changes to whale forelimb
anatomy.

DNA sequences in many human genes are very similar to the sequences of corresponding
genes in chimpanzees. The most likely explanation for this result is that
A) humans and chimpanzees share a relatively recent common ancestor.
B) humans evolved from chimpanzees.
C) chimpanzees evolved from humans.
D) convergent evolution led to the DNA similarities.
E) humans and chimpanzees are not closely related.

humans and chimpanzees share a relatively recent common ancestor.