Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus?

A) Technological innovation in agricultural practices will permit exponential growth of the human population into the foreseeable future.

B) The environment is responsible for natural selection.

C) Earth changed over the years through a series of catastrophic upheavals.

D) Earth is more than 10,000 years old.

E) Populations tend to increase at a faster rate than their food supply normally allows.

E) Populations tend to increase at a faster rate than their food supply normally allows.

In the wild, male house finches (Carpodus mexicanus) vary considerably in the amount of red pigmentation in their head and throat feathers, with colors ranging from pale yellow to bright red. These colors come from carotenoid pigments that are found in the birds' diets; no vertebrates are known to synthesize carotenoid pigments. Thus, the brighter red the male's feathers are, the more successful he has been at acquiring the red carotenoid pigment by his food-gathering efforts (all other factors being equal). During breeding season, one should expect female house finches to prefer to mate with males with the brightest red feathers. Which of the following is true of this situation?

A) Alleles that promote more effective deposition of carotenoid pigments in the feathers of males should increase over the course of generations.

B) There should be directional selection for bright red feathers in males.

C) Alleles that promote more efficient acquisition of carotenoid-containing foods by males should increase over the course of generations.

D) Three of the statements are correct.

E) Two of the statements are correct

D) Three of the statements are correct.

The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The four-chambered hearts of birds and mammals are best described as

A) vestiges. B) the result of shared ancestry. C) homoplasies. D) structural homologies. E) molecular homologies.

C) homoplasies

) Upon being formed, oceanic islands, such as the Hawaiian Islands, should feature what characteristic, leading to which phenomenon?

A) a variety of empty ecological niches, leading to adaptive radiation

B) overcrowding, leading to rafting to nearby lands

C) adaptive radiation, leading to founder effect

D) mass extinctions, leading to bottleneck effect

E) major evolutionary innovations, leading to rafting to nearby continents

A) a variety of empty ecological niches, leading to adaptive radiation

What does the biological species concept use as the primary criterion for determining species boundaries?

A) molecular (DNA, RNA, protein) similarity

B) gene flow

C) niche differences

D) geographic isolation

E) morphological similarity

B) gene flow

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 shallow estuary on a warm-water coast

D) a midcontinental grassland with extreme climatic conditions

A) an isolated ocean island in the tropics

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from the air-breathing organ (a simple lung) of an ancestral fish is an example of

A) an evolutionary trend.

B) adaptive radiation.

C) exaptation.

D) changes in Hox gene expression.

E) paedomorphosis.

C) exaptation.

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) The drug caused the S. aureus DNA to change.
C) Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.
D) In response to the drug, S. aureus began making drugresistant versions of the protein targeted by the drug.
E) A patient must have become infected with MRSA from another community.

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

The next few questions refer to the following description. In the ocean, on either side of the Isthmus of Panama, are 30 species of snapping shrimp; some are shallow-water species, and others are adapted to deep water. There are 15 species on the Pacific side and 15 different species on the Atlantic side. The Isthmus of Panama started rising about 10 million years ago. In Figure 22.1, the isthmus separates the Pacific Ocean on the left (side A) from the Atlantic Ocean on the right (side B). The seawater on either side of the isthmus is separated into five depth habitats (1—5), with 1 being the shallowest. Figure 22.1 9) In which habitat should one find snapping shrimp most closely related to shrimp that live in habitat A4?

A) B4

B) either A3 or A5

C) any species from any one of the side A habitats

D) A3

E) A5

A) B4

Which of the following is a true statement concerning genetic variation?

A) It must be present in a population before natural selection can act upon the population.

B) It arises in response to changes in the environment.

C) A population that has a higher average heterozygosity has less genetic variation than one with a lower average heterozygosity.

D) It tends to be reduced by the processes involved when diploid organisms produce gametes.

E) It is created by the direct action of natural selection.

A) It must be present in a population before natural selection can act upon the population.

) What is true of natural selection?

A) Natural selection is a random process.
B) Mutations occur when directed by the good of the species; natural selection edits out
harmful mutations and causes populations to adapt to the beneficial mutations.
C) Mutations occur at random; natural selection can preserve and distribute beneficial
mutations.
D) Natural selection creates beneficial mutations.
E) The only way to eliminate harmful mutations is through natural selection.

C) Mutations occur at random; natural selection can preserve and distribute beneficial
mutations.

12) If the curve in Figure 21.3 shifts to the left or to the right, there is no gene flow, and the population size consequently increases over successive generations. Which of the following is (are) probably occurring? 1. immigration or emigration 2. directional selection 3. adaptation 4. genetic drift 5. disruptive selection

A) 1, 2, and 3

B) 2 and 3

C) 1 only

D) 4 only

E) 4 and 5

B) 2 and 3

Anopheles mosquitoes, which carry the malaria parasite, cannot live above elevations of 5,900 feet. Consider a hypothetical human population that is adapted to life on the slopes of Mt. Kilimanjaro. Mt. Kilimanjaro's base is about 2,600 feet above sea level and its peak is 19,341 feet above sea level. If the incidence of the sickle-cell allele in the population is plotted against altitude (feet above sea level), which of the following distributions is most likely, assuming little migration of people up or down the mountain?

D. linear arrow down

Heterozygote advantage should be most closely linked to which of the following?

A) directional selection

B) disruptive selection

C) sexual selection

D) random selection

E) stabilizing selection

E) stabilizing selection

) If the original finches that had been blown over to the Galápagos from South America had already been genetically different from the parental population of South American finches, even before adapting to the Galápagos, this would have been an example of

A) genetic drift and the founder effect.

B) the founder effect.

C) the bottleneck effect.

D) genetic drift.

E) all three of these.

A) genetic drift and the founder effect.

Which extinction event most likely lead to the most rapid loss of species?

A) The Permian mass extinction

B) The mass extinction of organisms due to the oxygenation of the early atmosphere

C) The current mass extincion brought about by human activity

D) The extinction event at the end of the Cretacesous

D) The extinction event at the end of the Cretacesous

Which factor most likely caused animals and plants in India to differ greatly from species in
nearby Southeast Asia?

A) The species became separated by convergent evolution.
B) India is in the process of separating from the rest of Asia.
C) The climates of the two regions are similar.
D) Life in India was wiped out by ancient volcanic eruptions.
E) India was a separate continent until 45 million years ago.

E) India was a separate continent until 45 million years ago.

Use Figure 21.2 to answer the following question. Figure 21.2
Soon after the island of Hawaii rose above the sea surface (somewhat less than 1 million years ago), the evolution of life on this new island should have been most strongly influenced by

A) genetic bottleneck.

B) habitat differentiation.

C) sexual selection.

D) founder effect.

D) founder effect.

19) When using a cladistic approach to systematics, which of the following is considered most important for classification?

A) the number of homoplasies
B) shared primitive characters
C) analogous primitive characters
D) overall phenotypic similarity
E) shared derived characters

E) shared derived characters

Which of these should decline in hybrid zones where reinforcement is occurring?

A) gene flow between distinct gene pools

B) the genetic distinctness of two gene pools

C) mutation rate

D) speciation

E) hybrid sterility

A) gene flow between distinct gene pools

21) Two species of frogs belonging to the same genus occasionally mate, but the offspring fail to develop and hatch. What is the mechanism for keeping the two frog species separate?

A) the prezygotic barrier called hybrid sterility

B) the postzygotic barrier called hybrid inviability

C) gametic isolation

D) the postzygotic barrier called hybrid breakdown

B) the postzygotic barrier called hybrid inviability

An organism has a relatively large number of Hox genes in its genome. Which of the following is true of this organism?

A) The organism must have multiple paired appendages along the length of its body.

B) These genes are fundamental, and are expressed in all cells of the organism.

C) Its Hox genes cooperate to bring about sexual maturity at the proper stage of
development.

D) The organism has the genetic potential to have a relatively complex anatomy.

E) Most of its Hox genes owe their existence to gene fusion events.

D) The organism has the genetic potential to have a relatively complex anatomy.

Adaptive radiations can be a direct consequence of four of the following five factors. Select the exception.

A) vacant ecological niches

B) an adaptive radiation in a group of organisms (such as plants) that another group uses as
food

C) colonization of an isolated region that contains suitable habitat and few competitor species

D) evolutionary innovation

E) genetic drift

E) genetic drift

Which of the following is not an observation or inference on which natural selection is based?

A) Individuals whose characteristics are best suited to the environment generally leave more

offspring than those whose characteristics are less well suited.

B) Species produce more offspring than the environment can support.

C) Poorly adapted individuals never produce offspring.

D) There is heritable variation among individuals.

E) Only a fraction of an individual’s offspring may survive.

C) Poorly adapted individuals never produce offspring.

Which of the following is the most accurate summary of Cuvier's consideration of fossils found in the vicinity of Paris?

A) extinction of species yes; evolution of new species yes

B) extinction of species yes; evolution of new species no

C) extinction of species no; evolution of new species yes

D) extinction of species no; evolution of new species no

B) extinction of species yes; evolution of new species no

If two modern organisms are distantly related in an evolutionary sense, then one should expect that

A) they should share fewer homologous structures than two more closely related organisms.

B) they shared a common ancestor relatively recently.

C) their chromosomes should be very similar.

D) they live in very different habitats.

E) they should be members of the same genus.

A) they should share fewer homologous structures than two more closely related organisms.

Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer, or more, than this have reduced fitness. Which of the following terms best describes this situation?
A) sexual selection
B) stabilizing selection
C) artificial selection
D) directional selection
E) disruptive selection

B) stabilizing selection

The most likely explanation for the high rate of sympatric speciation that apparently existed among the cichlids of Lake Victoria in the past is
A) pollution.
B) habitat differentiation.
C) sexual selection.
D) polyploidy.
E) introduction of a new predator.

C) sexual selection.

Which of the following must exist in a population before natural selection can act upon that population?
A) genetic variation among individuals
B) sexual reproduction
C) variation among individuals caused by environmental factors
D) Three of the responses are correct.
E) Two of the responses are correct.

A) genetic variation among individuals

Arrange the following from most general (i.e., most inclusive) to most specific (i.e., least inclusive):
1. natural selection
2. microevolution
3. evolution
4. sexual selection
A) 3, 1, 2, 4

B) 3, 2, 1, 4

C) 1, 2, 3, 4

D) 3, 2, 1, 4

E) 1, 3, 2, 4

B) 3, 2, 1, 4

The origin of a new plant species by hybridization, coupled with accidents during cell division,
is an example of
A) allopatric speciation.

B) habitat selection.
C) autopolyploidy.

D) sympatric speciation.

D) sympatric speciation.

The following questions refer to Figure 19.1, which shows an outcrop of sedimentary rock whose strata are labeled A-D.
Figure 19.1. 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) C

Based on the tree below, which statement is not correct?
A) Lizards are more closely related to salamanders than to humans.
B) Salamanders are a sister group to the group containing lizards, goats, and humans.
C) The salamander lineage is a basal taxon.
D) Salamanders are as closely related to goats as to humans.
E) The group highlighted by shading is paraphyletic.

A) Lizards are more closely related to salamanders than to humans.

Plant species A has a diploid number of 12. Plant species B has a diploid number of 16. A new species, C, arises as an autopolyploid from species A The diploid number for species C would probably be
A) 28.

B) 24.

C) 14.

D) 12.

E) 16.

B) 24.

The next few questions refer to the following description.
On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were
once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other
predator-poor ponds have mosquitofish that can swim continuously for a long time. When placed together in the same
body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences.
Which type of reproductive isolation operates to keep the mosquitofish isolated, even when fish
from different ponds are reunited in the same body of water?
A) behavioral isolation
B) gametic isolation
C) mechanical isolation
D) temporal isolation
E) habitat isolation

A) behavioral isolation

Which Taxonomic level was added most recently in reaction to information about molecular homologies?
A) Phylum

B) Domain

C) Order

D) Kindom

B) Domain

Rank the following from most general to most specific:
1. gametic isolation
2. reproductive isolating mechanism
3. sperm—egg incompatibility in sea urchins
4. prezygotic isolating mechanism
A) 2, 3, 1, 4

B) 4, 2, 1, 3

C) 2, 4, 1, 3

D) 4, 1, 2, 3

E) 2, 1, 4, 3

C) 2, 4, 1, 3

Which of these would, if it had acted upon a gene, prevent this gene from acting as a reliable
molecular clock?
A) genetic drift
B) mutations within introns
C) natural selection
D) most substitution mutations involving an exonic codon's third position
E) neutral mutations

C) natural selection

According to the concept of punctuated equilibrium,
A) given enough time, most existing species will gradually give rise to new species.
B) a new species accumulates most of its unique features as it comes into existence.
C) transitional fossils, intermediate between newer species and their parent species, should be abundant.
D) natural selection is unimportant as a mechanism of evolution.
E) evolution of new species features long periods during which changes are occurring, interspersed with short periods of equilibrium, or stasis.

B) a new species accumulates most of its unique features as it comes into existence.

Charles Darwin was the first person to propose
A) a mechanism for how evolution occurs.
B) that population growth can outpace the growth of food resources.
C) that Earth is older than a few thousand years.
D) a mechanism for evolution that was supported by evidence.
E) that evolution occurs.

D) a mechanism for evolution that was supported by evidence.

If the half-life of carbon-14 is about 5,000 years, then a fossil that has one-eighth the normal
proportion of carbon-14 to carbon-12 should be about how many years old?
A) 40,000

B) 625

C) 15,000

D) 20,000

E) 10,000

C) 15,000

If the early history of life on Earth is accurately depicted by Figure 20.3, then which statement is least in agreement with the hypothesis proposed by this tree?
A) The last universal common ancestor of all extant species is better described as a community of organisms, rather than an individual species.
B) Eukaryotes are more closely related to archaeans than to bacteria.
C) Archaean genomes should contain genes that originated in bacteria, and vice versa.
D) The origin of the three domains appears as a polytomy.

B) Eukaryotes are more closely related to archaeans than to bacteria.

Which of the following statements most detracts from the claim that the human appendix is a completely vestigial organ?
A) The appendix can be surgically removed with no immediate ill effects.
B) Individuals with a larger-than-average appendix leave fewer offspring than those with a
below-average-sized appendix.
C) The appendix might have been larger in fossil hominids.
D) The appendix has a substantial amount of defensive lymphatic tissue.
E) In a million years, the human species might completely lack an appendix.

D) The appendix has a substantial amount of defensive lymphatic tissue.

Which extinct species should be the best candidate to serve as the outgroup for the clade whose
common ancestor occurs at position 2 in Figure 20.1?
A) A

B) B

C) C

D) D

E) E

A) A most left choice

Put the following Taxonomic levels in the correct order from most inclusive to most specific
1. Order 2. Class 3. Phylum 4. Family
A) 4->1->2->3
B) 3->1->2->4
C) 3->4->2->1
D) 3->2->1->4
E) 1->3->4-.2

D) 3->2->1->4