Chapter 17 Flashcards
Initially devastating to Australian rabbits, myxoma virus became less lethal within a few years of
its introduction as a biological control agent. Why?
A) evolution of resistance on the part of rabbits
B) evolution of reduced virulence on the part of the virus
C) both of the above
C) both of the above
Coevolution, by definition, cannot occur between a biological population and an abiotic factor.
A) True B) False
A) True
Which of the following situations is most likely to meet the requirements of a strict definition of
coevolution?
A) the ability of hyenas to crack the bones of prey they have captured and killed
B) the ability of bears to climb forest trees
C) the ability of snowshoe hares to survive the harsh arctic winter
D) the ability of an insect herbivore to detoxify antiherbivore substances produced by its host
plant
D) the ability of an insect herbivore to detoxify antiherbivore substances produced by its host
plant
Which of the following antipredator defenses is more likely to be found in an animal that is
palatable to its predators?
A) crypsis B) aposematism
A) crypsis
Aposematic animals have conspicuous markings and bright colors, which serve as warnings to
would‐be predators. You find a brightlycolored butterfly that is unknown to you. Can you safely
conclude that this butterfly is distasteful to predators?
A) Yes, all conspicuously marked animals are distasteful to predators.
B) No, some conspicuously marked animals are palatable to predators.
B) No, some conspicuously marked animals are palatable to predators.
Which of the following biologists has been honored by having his name associated with a type
of mimicry in which a palatable model mimics an unpalatable model?
A) Charles Darwin B) Fritz Müller C) Gregor Mendel D) Henry Bates
D) Henry Bates
When one prey species mimics another unpalatable prey species (the model) to reduce its own
risk of predation, the mimic is always palatable to predators.
A) True B) False
B) False
When one prey species mimics another unpalatable prey species (the model) to reduce its own
risk of predation, the mimic is always a close relative of the model.
A) True B) False
B) False
The evolutionary biologist Charles Mode proposed a model of host‐pathogen evolution that
predicted cyclic change in frequencies of host resistance and pathogen virulence through time.
Which of the following was a key element in Mode’s model?
A) control of virulence and resistance by single dominant genes
B) costs associated with virulence and resistance, by themselves, to host and pathogen,
respectively
C) fitness of host or pathogen contingent on the genotype of the other
D) all of the above
D) all of the above
What kind of approach did Ehrlich and Raven take in their research on coevolution, published in
1964?
A) recording repeating patterns in nature and inferring from these coevolutionary
relationships
B) developing elegant mathematical models and testing their predictive ability
C) conducting carefully designed, controlled experiments on parasitoids and their hosts
D) none of the above
A) recording repeating patterns in nature and inferring from these coevolutionary
relationships
David Pimentel established an experimental population of houseflies from stock that had a long
history of prior experience with a parasitoid wasp. He also introduced parasitoid wasps into this
population and observed the change in numbers of the two species through time. The flies in
this experiment:
A) immediately went extinct.
B) exhibited dramatic oscillations.
C) exhibited a stable and relatively high constant population level.
D) none of the above
C) exhibited a stable and relatively high constant population level.
In Pimentel’s experiments with houseflies and their parasitoids (see previous question), he
created two treatments. In one treatment, the host population (houseflies) was not permitted
to evolve responses to the parasitoid, whereas evolution of host responses was permitted in
the other treatment. What happened to the parasitoid population in the treatment in which
host evolution was permitted?
A) The parasitoid population maintained constant fecundity and life span.
B) The parasitoid population exhibited reduced fecundity and shorter life span.
C) The parasitoid population exhibited an increase in both fecundity and life span.
D) none of the above
B) The parasitoid population exhibited reduced fecundity and shorter life span.
Which of the following statements correctly characterizes the status of pathogen resistance in
cultivated crops, such as wheat?
A) The system is in constant flux, as new virulent strains of pathogens appear and crop
breeders select resistant strains of the crop.
B) The system is stable because no new strains of the pathogen emerge.
C) The system is stable because strains of the crop have been produced that are resistant to all
strains of pathogens.
A) The system is in constant flux, as new virulent strains of pathogens appear and crop
breeders select resistant strains of the crop.
The rust‐wheat system has an essential element of coevolution envisioned by Charles Mode.
What is it?
A) Virulence of the rust and resistance in wheat are not heritable traits.
B) There is an interaction between the fitnesses of the genotypes of the host and the
genotypes of the pathogen.
C) Only the host is capable of an evolutionary response.
D) Only the pathogen is capable of an evolutionary response.
B) There is an interaction between the fitnesses of the genotypes of the host and the
genotypes of the pathogen.
As illustrated in the simple model of Figure 17.12, the balancing influences of consumer and
resource adaptation can achieve an evolutionary equilibrium. What is happening at this point?
A) Both consumer and resource cease evolving.
B) Both consumer and resource continue to evolve to maintain this equilibrium.
C) The consumer ceases to evolve but the resource continues to evolve in response to
continued consumption.
D) The resource ceases to evolve but the consumer continues to evolve in response to scarcity
of the resource.
B) Both consumer and resource continue to evolve to maintain this equilibrium.
Which hypothesis, introduced in Chapter 8 as part of the discussion of sexual reproduction,
applies well to the evolutionary equilibrium illustrated in Figure 17.12?
A) the “Red Queen” hypothesis C) the “Pimentel” hypothesis
B) the “Lotka‐Volterra” hypothesis D) the “Bates‐Müller” hypothesis
A) the “Red Queen” hypothesis
When consumer and resource populations in evolutionary equilibrium (see Figure 17.12)
experience a sudden environmental change that leads to a much higher rate of exploitation,
which population is likely to experience greater selective pressure and thus exhibit the greater
rate of evolutionary change?
A) the consumer B) the resource C) neither the resource nor the consumer
B) the resource
In studies conducted by David Pimentel and colleagues, houseflies and blowflies were grown
together in an experimental cage that permitted long‐term coexistence of the two species.
During one 70‐week study, blowflies remained at low levels throughout most of the
experiment, but, at about 50 weeks, they showed a dramatic population increase, at the
expense of the houseflies. The evolution of superior competitive ability by a rare competitor is
an example of what kind of selection?
A) frequency‐dependent
B) balancing
C) neutral
D) dominant/recessive
A) frequency‐dependent
Two species of grain beetles (identified only as 1 and 2) are collected in the field and
maintained under laboratory conditions for 1 year, encompassing many generations. Some of
the grain beetles are maintained in pure culture (P1 and P2) and others in mixed culture (M1
and M2), all under conditions of limiting food resources. At the end of the year, grain beetles of
species 1 from the mixed culture are tested for their competitive ability against the other
species from pure culture (M1 ‐ P2). A similar test is conducted, pitting grain beetles of species
1 from pure culture against the other species from pure culture (P1 ‐ P2). In which case would
you expect species 1 to show greater competitive ability with species 2?
A) M1 ‐ P2
B) P1 ‐ P2
C) M1 and P1 should exhibit identical competitive abilities against P2.
A) M1 ‐ P2
Character displacement:
A) refers to Aunt Edna’s forgetting where she put her sense of values.
B) refers to the evolution of different species in isolation.
C) can be identified by comparing populations in allopatry and sympatry.
D) is restricted to animal populations because it refers to feeding adaptations.
C) can be identified by comparing populations in allopatry and sympatry.
Related species that live together typically differ in the way they use resources. This is evidence
that these differences have evolved as a result of competitive interactions.
A) True B) False
B) False
Species 1 occurs in areas A and B, and its close relative, species 2, occurs in areas B and C.
Areas A, B, and C all have similar environmental conditions and habitats. Which of the following
might we reasonably expect?
A) The sympatric populations of species 1 and 2 in area B will differ less from each other than
the allopatric populations of these two species in areas A and C.
B) The sympatric populations of species 1 and 2 in area B will differ more from each other than
the allopatric populations of these two species in areas A and C.
C) The sympatric populations of species 1 and 2 in area B will differ about as much from each
other as the allopatric populations of these two species in areas A and C.
D) none of the above
B) The sympatric populations of species 1 and 2 in area B will differ more from each other than
the allopatric populations of these two species in areas A and C.
The ground finch genus Geospiza consists of several species distributed haphazardly across the
Galapagos Islands. When two or more Geospiza species occur on the same island, the beak size
ranges for these species:
A) are identical. B) tend to overlap considerably. C) exhibit no overlap.
. C) exhibit no overlap.
Geospiza fuliginosa occurs in isolation on Daphne Island and G. fortis occurs in isolation on Los
Hermanos Island in the Galapagos. Their bill size ranges overlap considerably (refer to Figure
17.17). In 1925, an overzealous tourist captured several individuals from each population and
successfully established these on nearby Cocos Island, where ground finches did not occur. In a
recent survey, you measured bill sizes from a large sample of both species on Cocos Island.
What did you find?
A) The two species retained bill size ranges identical to the parental populations.
B) The two species had diverged somewhat in their bill size ranges.
B) The two species had diverged somewhat in their bill size ranges.