Exam: Darwin Evolution, Species, History (Chapters 22, 23, 24 25)


MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1)  Catastrophism, meaning the regular occurrence of geological or meteorological disturbances (catastrophes), was Cuvier's attempt to explain the existence of 1) ______
  A)  uniformitarianism.
  B)  natural selection.
  C)  the fossil record.
  D)  evolution.
  E)  the origin of new species.

2)  Which of the events described below agrees with the idea of catastrophism? 2) ______
  A)  The sudden demise of the dinosaurs, and various other groups, by the impact of a large extraterrestrial body with Earth
  B)  The development of the Galapagos Islands from underwater seamounts over millions of years
  C)  The gradual uplift of the Himalayas by the collision of the Australian crustal plate with the Eurasian crustal plate
  D)  The formation of the Grand Canyon by the Colorado River over millions of years
  E)  The gradual deposition of sediments many kilometers thick on the floors of seas and oceans

3)  What was the prevailing notion prior to the time of Lyell and Darwin? 3) ______
  A)  Earth is a few thousand years old, and populations are unchanging.
  B)  Earth is millions of years old, and populations are unchanging.
  C)  Earth is millions of years old, and populations rapidly change.
  D)  Earth is millions of years old, and populations gradually change.
  E)  Earth is a few thousand years old, and populations gradually change.

4)  During a study session about evolution, one of your fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconception? 4) ______
  A)  Spontaneous mutations can result in the appearance of new traits.
  B)  Only favorable adaptations have survival value.
  C)  Overproduction of offspring leads to a struggle for survival.
  D)  Disuse of an organ may lead to its eventual disappearance.
  E)  Characteristics acquired during an organism's life are generally not passed on through genes.

5)  Which group is composed entirely of individuals who maintained that species are fixed (i.e., unchanging)? 5) ______
  A)  Lyell, Linnaeus, and Lamarck
  B)  Aristotle, Linnaeus, and Cuvier
  C)  Linnaeus, Cuvier, and Lamarck
  D)  Aristotle, Cuvier, and Lamarck
  E)  Hutton, Lyell, and Darwin

6)  In the mid-1900s, the Soviet geneticist Lysenko believed that his winter wheat plants, exposed to ever-colder temperatures, would eventually give rise to ever more cold-tolerant winter wheat. Lysenko's attempts in this regard were most in agreement with the ideas of 6) ______
  A)  Hutton.
  B)  Plato.
  C)  Cuvier.
  D)  Lamarck.
  E)  Darwin.

The following questions refer to Figure 22.1, which shows an outcrop of sedimentary rock whose strata are labeled A-D.

Figure 22.1

7)  Who would have proposed that the boundaries between each stratum mark the occurrence of different localized floods? 7) ______
  A)  Cuvier
  B)  Hutton
  C)  Lamarck
  D)  Darwin
  E)  Lyell

8)  Darwin's mechanism of natural selection required long time spans in order to modify species. From whom did Darwin get the concept of Earth's ancient age? 8) ______
  A)  Georges Cuvier
  B)  Thomas Malthus
  C)  Alfred Wallace
  D)  Charles Lyell
  E)  John Henslow

9)  Which of these naturalists synthesized a concept of natural selection independently of Darwin? 9) ______
  A)  Gregor Mendel
  B)  Thomas Malthus
  C)  John Henslow
  D)  Alfred Wallace
  E)  Charles Lyell

10)  Charles Darwin was the first person to propose 10) ______
  A)  that evolution occurs.
  B)  that the Earth is older than a few thousand years.
  C)  a way to use artificial selection as a means of domesticating plants and animals.
  D)  a mechanism for how evolution occurs.
  E)  a mechanism for evolution that was supported by evidence.

11)  In Darwin's thinking, the more closely related two different organisms are, the 11) ______
  A)  less likely they are to have the same genes in common.
  B)  more similar their habitats are.
  C)  more similar they are in size.
  D)  less similar their DNA sequences are.
  E)  more recently they shared a common ancestor.

12)  Natural selection is based on all of the following except 12) ______
  A)  populations tend to produce more individuals than the environment can support.
  B)  individuals adapt to their environments and, thereby, evolve.
  C)  the best-adapted individuals tend to leave the most offspring.
  D)  genetic variation exists within populations.
  E)  individuals who survive longer tend to leave more offspring than those who die young.

13)  Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus? 13) ______
  A)  All species are fixed in the form in which they are created.
  B)  Earth is more than 10,000 years old.
  C)  The environment is responsible for natural selection.
  D)  Populations tend to increase at a faster rate than their food supply normally allows.
  E)  Earth changed over the years through a series of catastrophic upheavals.

14)  Which statement about natural selection is most correct? 14) ______
  A)  Different species that occupy the same habitat will adapt to that habitat by undergoing the same genetic changes.
  B)  Natural selection is the sole means by which populations can evolve.
  C)  Well-adapted individuals leave more offspring, and thus contribute more to the next generation's gene pool, than do poorly adapted individuals.
  D)  Adaptations beneficial at one time should generally be beneficial during all other times as well.
  E)  Adaptations beneficial in one habitat should generally be beneficial in all other habitats as well.

15)  Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection?
1. Well-adapted individuals leave more offspring than do poorly adapted individuals.
2. A change occurs in the environment.
3. Genetic frequencies within the population change.
4. Poorly adapted individuals have decreased survivorship.
15) ______
  A)  4 2 3 1
  B)  2 4 1 3
  C)  2 4 3 1
  D)  4 2 1 3
  E)  4 1 2 3

16)  A biologist studied a population of squirrels for 15 years. During that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over half of the squirrels born did not survive to reproduce, because of competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. Which inference(s) about this population might be true? 16) ______
  A)  The number of predators may have decreased.
  B)  The amount of available food may have increased.
  C)  The squirrels of subsequent generations should show greater levels of genetic variation than previous generations, because squirrels that would not have survived in the past will now survive.
  D)  A and B only
  E)  A, B, and C

17)  To observe natural selection's effects on a population, which of these must be true? 17) ______
  A)  One must observe more than one generation of the population.
  B)  Members of the population must increase or decrease the use of some portion of their anatomy.
  C)  The population must contain genetic variation.
  D)  A and C only
  E)  A and B only

18)  If the HMS Beagle had completely bypassed the Galapagos Islands, Darwin would have had a much poorer understanding of the 18) ______
  A)  ability of populations to undergo modification as they adapt to a particular environment.
  B)  tendency of organisms to produce the exact number of offspring that the environment can support.
  C)  unlimited resources that support population growth in most natural environments.
  D)  relative stability of a well-adapted population's numbers over many generations.
  E)  lack of genetic variation among all members of a population.

19)  During drought years on the Galapagos, small, easily eaten seeds become rare, leaving mostly large, hard-cased seeds that only birds with large beaks can eat. If a drought persists for several years, what should one expect to result from natural selection? 19) ______
  A)  Larger birds eating less so smaller birds can survive.
  B)  Small birds anticipating the long drought and eating more to gain weight and, consequently, growing larger beaks.
  C)  Small birds mutating their beak genes with the result that later-generation offspring have larger beaks.
  D)  More small-beaked birds dying than larger-beaked birds. The offspring produced in subsequent generations have a higher percentage of birds with large beaks.
  E)  Small birds gaining larger beaks by exercising their mouth parts.

20)  Which of the following statements is an inference of natural selection? 20) ______
  A)  An individual organism undergoes evolution over the course of its lifetime.
  B)  Subsequent generations of a population should have greater proportions of individuals that possess traits better suited for success in unchanging environments.
  C)  Habitats do not generally have unlimited resources.
  D)  Some of the variation that exists among individuals in a population is genetic.
  E)  Natural populations tend to reproduce to their full biological potential.

21)  Which of the following must exist in a population before natural selection can act upon that population? 21) ______
  A)  Sexual reproduction
  B)  Variation among individuals caused by environmental factors
  C)  Genetic variation among individuals
  D)  B and C only
  E)  A, B, and C

22)  Which of Darwin's ideas had the strongest connection to Darwin having read Malthus's essay on human population growth? 22) ______
  A)  The ability of related species to be conceptualized in "tree thinking"
  B)  That the ancestors of the Galapagos finches had come from the South American mainland
  C)  Descent with modification
  D)  Struggle for existence
  E)  Variation among individuals in a population

The following questions refer to the evolutionary tree in Figure 22.2.

The tree's horizontal axis is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V—Z) represent various common ancestors. Let's say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.

Figure 22.2

23)  How many separate species, both extant and extinct, are depicted in this tree? 23) ______
  A)  4
  B)  5
  C)  6
  D)  3
  E)  2

24)  According to this tree, what percent of the species seem to be extant (i.e., not extinct)? 24) ______
  A)  25%
  B)  75%
  C)  66%
  D)  33%
  E)  50%

25)  Which of the five common ancestors, labeled V—Z, has given rise to the greatest number of species, both extant and extinct? 25) ______
  A)  V
  B)  W
  C)  Y
  D)  Z
  E)  X

26)  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? 26) ______
  A)  W
  B)  X
  C)  Y
  D)  Z
  E)  V

27)  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? 27) ______
  A)  V
  B)  Z
  C)  Y
  D)  W
  E)  X

28)  Evolutionary trees such as this are properly understood by scientists to be 28) ______
  A)  facts.
  B)  hypotheses.
  C)  dogmas.
  D)  theories.
  E)  laws.

29)  Which statement best describes the evolution of pesticide resistance in a population of insects? 29) ______
  A)  Insects observe the behavior of other insects that survive pesticide application, and adjust their own behaviors to copy those of the survivors.
  B)  Individual members of the population slowly adapt to the presence of the chemical by striving to meet the new challenge.
  C)  Offspring of insects that are genetically resistant to the pesticide become more abundant as the susceptible insects die off.
  D)  All insects exposed to the insecticide begin to use a formerly silent gene to make a new enzyme that breaks down the insecticide molecules.

30)  DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Today, instead, DDT is largely useless against many insects. Which of these would have been required for this pest eradication effort to be successful in the long run? 30) ______
  A)  The frequency of DDT application should have been higher.
  B)  Larger doses of DDT should have been applied.
  C)  DDT application should have been continual.
  D)  All habitats should have received applications of DDT at about the same time.
  E)  None of the individual insects should have possessed genomes that made them resistant to DDT.

31)  Some members of a photosynthetic plant species are genetically resistant to an herbicide, while other members of the same species are not resistant to the herbicide. Which combination of events should cause the most effective replacement of the non-herbicide-resistant strain of plants by the resistant strain?
1. The presence of the herbicide in the environment
2. The absence of the herbicide from the environment
3. The maintenance of the proper conditions for one generation
4. The maintenance of the proper conditions for many generations
31) ______
  A)  2 and 4
  B)  1 and 3
  C)  2 and 3
  D)  1 and 4

The graph in Figure 22.3 depicts four possible patterns for the abundance of 3TC-resistant HIV within an infected human over time.

Figure 22.3

32)  If 3TC resistance is costly for HIV, then which plot (I—IV) best represents the response of a strain of 3TC-resistant HIV over time, if 3TC administration begins at the time indicated by the arrow? 32) ______
  A)  I
  B)  II
  C)  III
  D)  IV

33)  Of the following anatomical structures, which is homologous to the wing of a bird? 33) ______
  A)  Dorsal fin of a shark
  B)  Flipper of a cetacean
  C)  Wing of a butterfly
  D)  Tail fin of a flying fish
  E)  Hindlimb of a kangaroo

34)  If two modern organisms are distantly related in an evolutionary sense, then one should expect that 34) ______
  A)  they should share fewer homologous structures than two more closely related organisms.
  B)  they should be members of the same genus.
  C)  they live in very different habitats.
  D)  they shared a common ancestor relatively recently.
  E)  their chromosomes should be very similar.

35)  Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities? 35) ______
  A)  By proposing that humans, bats, and dolphins share a common ancestor
  B)  By the principle of convergent evolution
  C)  By identifying the bones as being homologous
  D)  A and C only
  E)  A, B, and C

36)  Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses? 36) ______
  A)  Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits.
  B)  Natural selection accounts for these losses by the principle of use and disuse.
  C)  Natural selection cannot account for losses, only for innovations.
  D)  The ancestors of these organisms experienced harmful mutations that forced them to find new habitats that these species had not previously used.

37)  Which of the following pieces of evidence most strongly supports the common origin of all life on Earth? 37) ______
  A)  All organisms have undergone evolution.
  B)  All organisms require energy.
  C)  All organisms show heritable variation.
  D)  All organisms reproduce.
  E)  All organisms use essentially the same genetic code.

38)  Logically, which of these should cast the most doubt on the relationships depicted by an evolutionary tree? 38) ______
  A)  Transitional fossils had not been found.
  B)  Relationships between DNA sequences among the species did not match relationships between skeletal patterns.
  C)  The skeletal remains of the organisms depicted by the tree were incomplete (i.e., some bones were missing).
  D)  Some of the organisms depicted by the tree had lived in different habitats.
  E)  None of the organisms depicted by the tree ate the same foods.

39)  Which of the following statements most detracts from the claim that the human appendix is a completely vestigial organ? 39) ______
  A)  The appendix might have been larger in fossil hominids.
  B)  The appendix can be surgically removed with no immediate ill effects.
  C)  The appendix has a substantial amount of defensive lymphatic tissue.
  D)  Individuals with a larger-than-average appendix leave fewer offspring than those with a below-average-sized appendix.
  E)  In a million years, the human species might completely lack an appendix.

40)  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 40) ______
  A)  homologous.
  B)  examples of convergent evolution.
  C)  adaptations to a common environment.
  D)  A and C only
  E)  B and C only

41)  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 41) ______
  A)  island forms and mainland forms descended from common ancestors.
  B)  island forms and mainland forms have identical gene pools.
  C)  the island forms and mainland forms are converging.
  D)  the islands were originally part of the continent.
  E)  common environments are inhabited by the same organisms.

42)  Monkeys of South and Central America have prehensile tails, meaning that their tails can be used to grasp objects. The tails of African and Asian monkeys are not prehensile. Which discipline is most likely to provide an evolutionary explanation for how this difference in tails came about? 42) ______
  A)  Botany
  B)  Biogeography
  C)  Aerodynamics
  D)  Physiology
  E)  Biochemistry

43)  The theory of evolution is most accurately described as 43) ______
  A)  an educated guess about how species originate.
  B)  an overarching explanation, supported by much evidence, for how populations change over time.
  C)  one possible explanation, among several scientific alternatives, about how species have come into existence.
  D)  an idea about how acquired characteristics are passed on to subsequent generations.
  E)  an opinion that some scientists hold about how living things change over time.

44)  Which of these is a statement that Darwin would have rejected? 44) ______
  A)  Environmental change plays a role in evolution.
  B)  Natural populations tend to produce more offspring than the environment can support.
  C)  Inherited variation in a population is a necessary precondition for natural selection to operate.
  D)  The smallest entity that can evolve is an individual organism.
  E)  Individuals can acquire new characteristics as they respond to new environments or situations.

45)  If, on average, 46% of the loci in a species' gene pool are heterozygous, then the average homozygosity of the species should be 45) ______
  A)  23%
  B)  54%
  C)  46%
  D)  92%
  E)  There is not enough information to say.

46)  Which of these is the smallest unit upon which natural selection directly acts? 46) ______
  A)  an individual's genome
  B)  a species' gene frequency
  C)  an individual's genotype
  D)  an individual's phenotype
  E)  a population's gene frequency

47)  Which of these evolutionary agents is most consistent at causing populations to become better suited to their environments over the course of generations? 47) ______
  A)  Genetic drift
  B)  Natural selection
  C)  Non-random mating
  D)  Gene flow
  E)  Mutation

48)  Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true? 48) ______
  A)  Each bird that survived the drought produced only offspring with deeper, stronger beaks than seen in the previous generation.
  B)  Each bird evolved a deeper, stronger beak as the drought persisted.
  C)  Each bird developed a deeper, stronger beak as the drought persisted.
  D)  Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted.
  E)  The frequency of the strong-beak alleles increased in each bird as the drought persisted.

49)  A trend toward the decrease in the size of plants on the slopes of mountains as altitudes increase is an example of 49) ______
  A)  geographic variation.
  B)  a bottleneck.
  C)  a cline.
  D)  genetic drift.
  E)  relative fitness.

50)  Which is a true statement concerning genetic variation? 50) ______
  A)  It arises in response to changes in the environment.
  B)  A population that has a higher average heterozygosity has less genetic variation than one with a larger average heterozygosity.
  C)  It must be present in a population before natural selection can act upon the population.
  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.

Use the following information to answer the questions below.

In a hypothetical population of 1,000 people, tests of blood-type genes show that 160 have the genotype AA, 480 have the genotype AB, and 360 have the genotype BB.
51)  What is the frequency of the B allele? 51) ______
  A)  0.001
  B)  0.002
  C)  0.600
  D)  0.100
  E)  0.400

52)  If there are 4,000 children born to this generation, how many would be expected to have AB blood under the conditions of Hardy-Weinberg equilibrium? 52) ______
  A)  1,920
  B)  100
  C)  2,400
  D)  2,000
  E)  960

The following questions refer to this information:

In the year 2500, five male space colonists and five female space colonists (all unrelated to each other) settle on an uninhabited Earthlike planet in the Andromeda galaxy. The colonists and their offspring randomly mate for generations. All ten of the original colonists had free earlobes, and two were heterozygous for that trait. The allele for free earlobes is dominant to the allele for attached earlobes.
53)  If four of the original colonists died before they produced offspring, the ratios of genotypes could be quite different in the subsequent generations. This would be an example of 53) ______
  A)  diploidy.
  B)  stabilizing selection.
  C)  genetic drift.
  D)  disruptive selection.
  E)  gene flow.

54)  If the frequency of a particular allele that is present in a small, isolated population of alpine plants decreases due to a landslide that leaves an even smaller remnant of surviving plants bearing this allele, then what has occurred? 54) ______
  A)  microevolution
  B)  genetic drift
  C)  a bottleneck
  D)  A and B only
  E)  A, B, and C

55)  The Darwinian fitness of an individual is measured most directly by 55) ______
  A)  its physical strength.
  B)  the number of "good genes" it possesses.
  C)  the number of its offspring that survive to reproduce.
  D)  how long it lives.
  E)  the number of mates it attracts.

56)  When we say that an individual organism has a greater fitness than another individual, we specifically mean that the organism 56) ______
  A)  competes for resources more successfully than others of its species.
  B)  utilizes resources more efficiently than other species occupying similar niches.
  C)  mates more frequently than others of its species.
  D)  lives longer than others of its species.
  E)  leaves more viable offspring than others of its species.

57)  If neutral variation is truly "neutral," then it should have no effect on 57) ______
  A)  our ability to measure the rate of evolution.
  B)  relative fitness.
  C)  average heterozygosity.
  D)  gene diversity.
  E)  nucleotide diversity.

58)  Which describes an African butterfly species that exists in two strikingly different color patterns? 58) ______
  A)  disruptive selection
  B)  artificial selection
  C)  stabilizing selection
  D)  sexual selection
  E)  directional selection

59)  Which describes brightly colored peacocks mating more frequently than drab peacocks? 59) ______
  A)  disruptive selection
  B)  stabilizing selection
  C)  directional selection
  D)  artificial selection
  E)  sexual selection

60)  Most Swiss starlings produce four to five eggs in each clutch. Those producing fewer or more than this have reduced fitness. Which of the following terms best describes this? 60) ______
  A)  directional selection
  B)  sexual selection
  C)  disruptive selection
  D)  artificial selection
  E)  stabilizing selection

61)  Fossil evidence indicates that horses have gradually increased in size over geologic time. Which of the following terms best describes this? 61) ______
  A)  sexual selection
  B)  artificial selection
  C)  directional selection
  D)  disruptive selection
  E)  stabilizing selection

62)  The average birth weight for human babies is about 3 kg. Which of the following terms best describes this? 62) ______
  A)  disruptive selection
  B)  directional selection
  C)  sexual selection
  D)  artificial selection
  E)  stabilizing selection

63)  A certain species of land snail exists as either a cream color or a solid brown color. Intermediate individuals are relatively rare. Which of the following terms best describes this? 63) ______
  A)  directional selection
  B)  sexual selection
  C)  stabilizing selection
  D)  disruptive selection
  E)  artificial selection

64)  Cattle breeders have improved the quality of meat over the years by which process? 64) ______
  A)  artificial selection
  B)  directional selection
  C)  stabilizing selection
  D)  A and B
  E)  A and C

In a very large population, a quantitative trait has the following distribution pattern:

Figure 23.1

65)  What is true of the trait whose frequency distribution in a large population appears above? It has probably undergone 65) ______
  A)  disruptive selection.
  B)  directional selection.
  C)  random selection.
  D)  stabilizing selection.
  E)  sexual selection.

66)  Male satin bowerbirds adorn structures that they build, called "bowers," with parrot feathers, flowers, and other bizarre ornaments in order to attract females. Females inspect the bowers and, if suitably impressed, allow males to mate with them. The evolution of this male behavior is due to 66) ______
  A)  artificial selection.
  B)  disruptive selection.
  C)  sexual selection.
  D)  frequency-dependent selection.
  E)  natural selection.

67)  When imbalances occur in the sex ratio of sexual species that have two sexes (i.e., other than a 50:50 ratio), the members of the minority sex often receive a greater proportion of care and resources from parents than do the offspring of the majority sex. This is most clearly an example of 67) ______
  A)  sexual selection.
  B)  disruptive selection.
  C)  frequency-dependent selection.
  D)  stabilizing selection.
  E)  balancing selection.

68)  There are those who claim that the theory of evolution cannot be true because the apes, which are supposed to be closely related to humans, do not likewise share the same large brains, capacity for complicated speech, and tool-making capability. They reason that if these features are generally beneficial, then the apes should have evolved them as well. Which of these provides the best argument against this misconception? 68) ______
  A)  A population's evolution is limited by historical constraints.
  B)  Adaptations are often compromises.
  C)  Evolution can be influenced by environmental change.
  D)  Advantageous alleles do not arise on demand.

69)  What is generally true of two very closely related species that have diverged from each other quite recently? 69) ______
  A)  Their reproductive isolation from each other is complete.
  B)  Genes are unable to pass from one species' gene pool to the other's gene pool.
  C)  They shared a common ancestor recently in evolutionary time.
  D)  They are unable to produce hybrid offspring upon interbreeding.

The questions below are based on the following description.

Several closely related frog species of the genus Rana are found in the forests of the southeastern United States. The species boundaries are maintained by reproductive barriers. In each case, match the various descriptions of frogs below with the appropriate reproductive barrier listed.
70)  Males of one species sing only when its predators are absent; males of another species sing only when its predators are present. 70) ______
  A)  habitat
  B)  gametic
  C)  behavioral
  D)  mechanical
  E)  temporal

71)  One species lives only in tree holes; another species lives only in streams. 71) ______
  A)  gametic
  B)  behavioral
  C)  habitat
  D)  mechanical
  E)  temporal

72)  Females of one species choose mates based on song quality; females of another species choose mates on the basis of size. 72) ______
  A)  gametic
  B)  behavioral
  C)  habitat
  D)  mechanical
  E)  temporal

73)  One species mates at the season when daylight is increasing from 13 hours to 13 hours, 15 minutes; another species mates at the season when daylight is increasing from 14 hours to 14 hours, 15 minutes. 73) ______
  A)  habitat
  B)  behavioral
  C)  mechanical
  D)  gametic
  E)  temporal

74)  Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms? 74) ______
  A)  hybrid breakdown
  B)  mechanical isolation
  C)  gametic isolation
  D)  reduced hybrid fertility
  E)  habitat isolation

75)  Theoretically, the production of sterile mules by interbreeding between female horses and male donkeys should 75) ______
  A)  cause convergent evolution.
  B)  strengthen postzygotic barriers between horses and donkeys.
  C)  weaken the intrinsic reproductive barriers between horses and donkeys.
  D)  result in the extinction of one of the two parental species.
  E)  eventually result in the formation of a single species from the two parental species.

76)  Races of humans are unlikely to evolve extensive differences in the future for which of the following reasons?
I. The environment is unlikely to change.
II. Human evolution is complete.
III. The human races are incompletely isolated.
76) ______
  A)  I and II only
  B)  I, II, and III
  C)  II and III only
  D)  III only
  E)  I only

77)  A defining characteristic of allopatric speciation is 77) ______
  A)  asexually reproducing populations.
  B)  geographic isolation.
  C)  large populations.
  D)  artificial selection.
  E)  the appearance of new species in the midst of old ones.

The following questions refer to the description below.

On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands, and is also found on the African mainland, located about 200 miles away. At higher elevations, and found only on Sao Tomé, is found the very closely related Drosophila santomea. The two species can hybridize, though male hybrids are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly outnumbered by D. santomea. Studies of the two species' nuclear genomes reveal that D. yakuba on the island is more closely related to mainland D. yakuba than to D. santomea (2n=4 in both species). Sao Tomé rose from the Atlantic Ocean about 14 million years ago.
78)  Which of these evolutionary trees represents the situation described in the paragraph above (NOTE: yakuba (I) represents the island population, and yakuba (M) represents the mainland population)? 78) ______

The following questions refer to the paragraph and graphs below.

In a hypothetical situation, the National Park Service, which administers Grand Canyon National Park in Arizona, builds a footbridge over the Colorado River at the bottom of the canyon. The footbridge permits interspersal of two closely related antelope squirrels. Previously, one type of squirrel had been restricted to the terrain south of the river, and the other type had been restricted to terrain on the north side of the river. Immediately before and ten years after the bridge's completion, ten antelope squirrels from both sides of the river were collected, blood samples were taken, and frequencies of alleles unique to the two types of antelope squirrels were determined (see graphs below).

79)  The results depicted in the graphs above are best accounted for by which of the following facts? 79) ______
  A)  Both types of squirrel are active during the day.
  B)  Both types of squirrel subsist largely on a diet of pine nuts and juniper seeds in this ecosystem.
  C)  Both types of squirrel share the same common ancestor.
  D)  There is more white fur on the tails of the northern squirrels than on the tails of the southern squirrels.
  E)  The Colorado River has been an effective geographic barrier to these two types of squirrels for several million years.

80)  According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that 80) ______
  A)  the species is now extinct.
  B)  speciation occurred rapidly in geologic time.
  C)  speciation occurred instantaneously.
  D)  the species will consequently have a relatively short existence, compared with other species.
  E)  speciation occurred in one generation.

81)  In order for speciation to occur, what is true? 81) ______
  A)  At least one gene, affecting at least one phenotypic trait, must change.
  B)  The number of chromosomes in the genome must change.
  C)  Changes to centromere location or chromosome size must occur within the genome.
  D)  Large numbers of genes that affect a single phenotypic trait must change.
  E)  Large numbers of genes that affect numerous phenotypic traits must change.

82)  Which gas was least abundant in Earth's early atmosphere, prior to 2 billion years ago? 82) ______
  A)  H2O
  B)  CH4
  C)  CO2
  D)  NH3
  E)  O2

83)  In their laboratory simulations of the early Earth, Miller and Urey observed the abiotic synthesis of 83) ______
  A)  DNA.
  B)  complex organic polymers.
  C)  genetic systems.
  D)  liposomes.
  E)  amino acids.

84)  Which of the following has not yet been synthesized in laboratory experiments studying the origin of life? 84) ______
  A)  amino acids
  B)  liposomes with selectively permeable membranes
  C)  protobionts that use DNA to program protein synthesis
  D)  liposomes
  E)  oligopeptides and other oligomers

The following questions refer to this hypothetical situation:

A female fly, full of fertilized eggs, is swept by high winds to an island far out to sea. She is the first fly to arrive on this island, and the only fly to arrive in this way. Thousands of years later, her numerous offspring occupy the island, but none of them resembles her. There are, instead, several species each of which eats only a certain type of food. None of the species can fly, for their flight wings are absent, and their balancing organs (i.e., halteres) are now used in courtship displays. The male members of each species bear modified halteres that are unique in appearance to their species. Females bear vestigial halteres. The ranges of all of the daughter species overlap.
85)  If the males' halteres have species-specific size, shape, color, and use in courtship displays, and if the species' ranges overlap, then the speciation events may have been driven, at least in part, by which of the following? 85) ______
  A)  allopolyploidy
  B)  species selection
  C)  sexual selection
  D)  autopolyploidy
  E)  habitat differentiation

86)  The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that 86) ______
  A)  a larger volume-to-surface area ratio is beneficial to all mammals.
  B)  evolution always tends toward increased complexity or increased size.
  C)  an unseen guiding force is at work.
  D)  evolution generally progresses toward some predetermined goal.
  E)  in particular environments, similar adaptations can be beneficial in more than one species.

87)  Fossil evidence indicates that several kinds of flightless dinosaurs possessed feathers. If some of these feather-bearing dinosaurs incubated clutches of eggs in carefully constructed nests, this might be evidence supporting the claim that 87) ______
  A)  all fossils with feathers are actually some kind of bird.
  B)  dinosaurs were as fully endothermal (warm-blooded) as modern birds and mammals.
  C)  the earliest reptiles could fly, and the feathers of flightless dinosaurs were vestigial flight surfaces.
  D)  the feathers were plucked from the bodies of other adults to provide nest-building materials.
  E)  their feathers originally served as insulation, and only later became flight surfaces.