Members of two different species possess a similar-looking structure that they use in a
similar fashion to perform the same function. Which information would best help distinguish
between an explanation based on homology versus one based on convergent evolution?
A) The two species live at great distance from each other.
B) The two species share many proteins in common, and the nucleotide sequences that code for
these proteins are almost identical.
C) The sizes of the structures in adult members of both species are similar.
D) Both species are well adapted to their particular environments.

The two species share many proteins in common, and the nucleotide sequences that code for
these proteins are almost identical.

Ichthyosaurs were aquatic dinosaurs. Fossils show us that they had dorsal fins and tails, as do
fish, even though their closest relatives were terrestrial reptiles that had neither dorsal fins nor
aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are
A) homologous.
B) examples of convergent evolution.
C) adaptations to a common environment.
D) Three of the responses above are correct.
E) Two of the responses above are correct.

Two of the responses above are correct.

Both ancestral birds and ancestral mammals shared a common ancestor that was terrestrial.
Today, penguins (which are birds) and seals (which are mammals) have forelimbs adapted for
swimming. What term best describes the relationship of the bones in the forelimbs of penguins
and seals, and what term best describes the flippers of penguins and seals?
A) homologous; homologous
B) analogous; homologous
C) homologous; analogous
D) analogous; analogous

homologous; analogous

What must be true of any organ that is described as vestigial?
A) It must be analogous to some feature in an ancestor.
B) It must be homologous to some feature in an ancestor.
C) It must be both homologous and analogous to some feature in an ancestor.
D) It need be neither homologous nor analogous to some feature in an ancestor.

It must be homologous to some feature in an ancestor.

What is true of pseudogenes?
A) They are composed of RNA, rather than DNA.
B) They are the same things as introns.
C) They are unrelated genes that code for the same gene product.
D) They are vestigial genes.

They are vestigial genes.

It has been observed that organisms on islands are different from, but closely related to,
similar forms found on the nearest continent. This is taken as evidence that
A) island forms and mainland forms descended from common ancestors.
B) common environments are inhabited by the same organisms.
C) the islands were originally part of the continent.
D) the island forms and mainland forms are converging.
E) island forms and mainland forms have identical gene pools.

island forms and mainland forms descended from common ancestors.

If one wanted to find the largest number of endemic species, one should visit which of the
following geological features (assuming each has existed for several millions of years)?
A) an isolated ocean island in the tropics
B) an extensive mountain range
C) a midcontinental grassland with extreme climatic conditions
D) a shallow estuary on a warm-water coast

an isolated ocean island in the tropics

A high degree of endemism is most likely in environments that are
A) easily reached and heterogeneous.
B) isolated and heterogeneous.
C) isolated and homogeneous.
D) isolated and extremely cold.
E) easily reached and homogeneous.

isolated and heterogeneous.

If x indicates the location of fossils of two closely related species, then fossils of their most-
recent common ancestor are most likely to occur in which stratum?
A) A
B) B
C) C
D) D

C

If x indicates the fossils of two closely related species, neither of which is extinct, then their
remains may be found in how many of these strata?
A) one stratum
B) two strata
C) three strata
D) four strata

two strata

Which pair would probably have agreed with the process that is depicted by this tree?
A) Cuvier and Lamarck
B) Lamarck and Wallace
C) Aristotle and Lyell
D) Wallace and Linnaeus
E) Linnaeus and Lamarck

Lamarck and Wallace

How many separate species, both extant and extinct, are depicted in this tree?
A) two
B) three
C) four
D) five
E) six

six

According to this tree, what percent of the species seem to be extant (in other words, not
extinct)?
A) 25%
B) 33%
C) 50%
D) 66%
E) 75%

66%

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
than to the temperate plants of Europe.

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.