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Flashcards in Exam 3 Deck (52)
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1
Q

Which of the following is considered a scenario leading to sexual dimorphism in animals?
A) different life histories and ecological relationships of males and females
B) sexual selection mediated by contests among males for access to females
C) sexual selection mediated by direct exercise of female mate choice
D) all of the above

A

D) all of the above

2
Q

You are studying a species of bird that is often monogamous but sometimes exhibits polygyny. You have the choice of studying this species in several different habitats. Which of the following will you choose if you want the highest likelihood of finding polygyny?
A) a habitat in which territory qualities are nearly identical
B) a habitat in which territory qualities vary somewhat
C) a habitat in which territory qualities are highly variable
D) a habitat unsuitable for the formation of territories

A

C) a habitat in which territory qualities are highly variable

3
Q

In species with separate sexes, which sex can enhance more its evolutionary fitness by mating with many partners of the opposite sex?
A) males B) females C) Neither sex has an advantage in this respect.

A

A) males

4
Q

Of the two possible kinds of polygamy, which is by far the more common in animals?
A) polygyny (one male forms long-term bonds with more than one female)
B) polyandry (one female forms long-term bonds with more than one male)

A

A) polygyny (one male forms long-term bonds with more than one female)

5
Q

What happened when the tails of male widowbirds were artificially elongated?
A) These males were more successful in attracting mates than males with normal tails.
B) These males were less successful in attracting mates than males with normal tails.
C) These males were about equally successful in attracting mates as males with normal tails.

A

A) These males were more successful in attracting mates than males with normal tails.

6
Q

American woodcocks have a promiscuous mating system. Male woodcocks gather in a communal display ground called a “lek”. They engage in an elaborate and conspicuous display flight called “winnowing,” as they vie for matings with their female spectators. This mating ritual performed by the males is likely the result of sexual selection, but which kind of sexual selection is it?
A) direct exercise of mate choice by females
B) contests among males for access to females

A

A) direct exercise of mate choice by females

7
Q

Flocking behavior in European goldfinches has costs and benefits. Which of the following would be considered a cost associated with increasing flock size?
A) fewer head jerks per minute for individuals
B) increased total vigilance rate for the entire flock
C) reduced food handling time for individuals
D) increased flight time between food plants for individuals caused by more rapid resource depletion

A

D) increased flight time between food plants for individuals caused by more rapid resource depletion

8
Q

A crow attacks a red-tailed hawk flying nearby. Which of these two birds is the donor of the attacking behavior?
A) the crow
B) the red-tailed hawk

A

A) the crow

9
Q
Which of the following kinds of behavior is least likely to be favored by natural selection under any circumstance?
A) cooperative
B) altruistic
C) selfish
D) spiteful
A

D) spiteful

10
Q

If C is the cost of a particular behavior for the donor, B is the benefit of the behavior to the recipient, and r is the coefficient of relationship, what does the relationship C

A

C) conditions under which an altruistic behavior will increase in the population

11
Q

The famous evolutionary biologist J. B. S. Haldane said the following one evening while drinking at a pub: “I would jump into a river and risk my life to save two brothers, but not one. I would jump in to save eight cousins, but not seven.” To what important concept was he alluding?
A) An altruistic behavior does not begin to make evolutionary sense until the inclusive fitness associated with the behavior (from the donor’s perspective) is at least zero.
B) His rambling comments were clearly the product of intoxication and had no meaningful evolutionary interpretation.

A

A) An altruistic behavior does not begin to make evolutionary sense until the inclusive fitness associated with the behavior (from the donor’s perspective) is at least zero.

12
Q

Effective population size (Ne) is almost always lower than actual population size (N) because, for example:
A. sex ratios are equal
B. breeding systems are typically monogamous
C. family sizes vary, with some parents contributing more offspring
D. environmental conditions are constant

A

C. family sizes vary, with some parents contributing more offspring

13
Q

The number of alleles per gene, for example the number of MHC alleles in human populations, describes a measure of:
A) different life histories and ecological relationships of males and females
B) sexual selection mediated by contests among males for access to females
C) sexual selection mediated by direct exercise of female mate choice
D) all of the above

A

A) different life histories and ecological relationships of males and females

14
Q
The number of alleles per gene, for example the number of MHC alleles in human populations, describes a measure of:
A. inbreeding
B. natural selection
C. genetic diversity
D. outbreeding depression
A

C. genetic diversity

15
Q

Why are cheetahs an example of how low genetic diversity does not necessarily mean the population is headed for extinction?
A. While the genetic diversity continues to decline, there is no evidence of inbreeding depression.
B. The genetic diversity, while low, is not declining in part because females mate with many males.
C. They evolved with low genetic diversity to begin with, so they have adapted to it.
D. none of the above

A

B. The genetic diversity, while low, is not declining in part because females mate with many males.

16
Q

What is an extinction vortex?
A. the random decline of a population even if they have high genetic diversity
B. the inevitable trajectory of all species
C. a description of the self-reinforcing decline of large populations
D. the loss of genetic diversity, lowering fitness, which further reduces the population size

A

D. the loss of genetic diversity, lowering fitness, which further reduces the population size

17
Q
In the absence of natural selection, genetic drift will cause alleles to become fixed or lost most rapidly in the population(s) of which size?
A. 4
B. 40
C. 400
D. 4000
E. all of the above
A

A. 4

18
Q

In experiments with the plant Banksia spinulosa, Australian researchers Glenda Vaughton and Susan Carthew showed that individual plants:
A) can make distinctions among developing embryos on the basis of their genotypes.
B) cannot make distinctions among developing embryos on the basis of their genotypes.

A

A) can make distinctions among developing embryos on the basis of their genotypes.

19
Q

A small population of wolves founded by a single breeding pair on the Scandinavian peninsula in 1983 showed little vitality until 1991, when the population began to grow exponentially. What event in 1991 led to the increased vitality of the population?
A) several years of unusually mild winters
B) infusion of new genes into the pack by a single immigrant male
C) cessation of hunting by humans
D) recovery of the Scandinavian caribou herd
E) all of the above

A

B) infusion of new genes into the pack by a single immigrant male

20
Q

As illustrated in the research conducted by Price and Wasser on Delphinium nelsoni, (Figure 13.15, above) outbreeding is always desirable, even if matings occur between individuals separated by great distance.
A) True B) False

A

B) False

21
Q

If a farmer is choosing a predatory insect to control pest insects in her fields, she should choose a predator that has:
A) high reproductive capacity relative to the pest.
B) high dispersal capacity.
C) the ability to switch to alternate food resources.
D) all of the above

A

D) all of the above

22
Q

Scientists first noticed predator/prey oscillations because of disease patterns in humans.
A. True
B. False

A

B. False

23
Q

Huffaker’s experiment on predators and prey was important, because:
A) he showed scientists could recreate population cycles seen in nature in the laboratory.
B) he showed predators were the most important source of prey mortality.
C) he showed prey populations could oscillate in the absence of predators.
D) all of the above

A

A) he showed scientists could recreate population cycles seen in nature in the laboratory.

24
Q

Populations can be limited from:
A. ‘above’ by consumers
B. ‘below’ by resources
C. both A and B

A

C. both A and B

25
Q

In predator-prey population cycles:
A. the number of prey often peaks a few years before predator numbers peak.
B. the number of predators often peaks a few years before prey numbers peak.
C. neither A nor B

A

A. the number of prey often peaks a few years before predator numbers peak.

26
Q

In class, we learned about two sets of model equations developed by Alfred Lotka and Vito Volterra, two American population biologists. One set of paired equations describes dynamics of predator and prey, the other describes dynamics of two competitors:
Lotka-Volterra predator-prey model:
dV/dt = rV – cVP (V is the number of individuals of the victim, or prey)
dP/dt = acVP – dP (P is the number of individuals of the predator)
Lotka-Volterra competition model:
dN1/dt = r1N1 (K1 – (N1 + αN2)/K1) (N1 is the number of individuals of species 1)
dN2/dt = r2N2 (K2 – (N2 + βN1)/K2) (N2 is the number of individuals of species 2)
Which of these two models is based on the logistic model of population growth?
A) predator-prey model B) competition model

A

B) competition model

27
Q

Which of the two models in question 26 above is based on the exponential model of population growth?
A) predator-prey model B) competition model

A

A) predator-prey model

28
Q

In the Lotka-Volterra model for predator-prey interactions (question 26, above), what is one of the most interesting predictions for changes in population sizes of predator (P) and Prey (V) through time? (Hint: we see this pattern in natural populations of lynx and snowshoe hare in Canada.)
A) the predator always goes extinct
B) the prey always goes extinct
C) predator and prey exhibit endless population cycles

A

C) predator and prey exhibit endless population cycles

29
Q

In the Lotka-Volterra model for competitor interactions (question 26, above), what do the terms α and β stand for?
A) competition coefficients
B) population sizes of the two species
C) carrying capacities for the two species

A

A) competition coefficients

30
Q

In the Lotka-Volterra model for competitor interactions (question 26, above), imagine a situation where the carrying capacity for species 1 (K1) in the absence of species 2 is 100 individuals. Then imagine the same situation, except that now 40 individuals of species 2 are also present. In this case, dN1/dt = 0 when N1 = 80 individuals. What is α?
A) 0.0 D) 1.5
B) 0.5 E) 2.0
C) 1.0

A

B) 0.5

31
Q

Dr. Michael Reiskind showed us the figure above as one illustration of the possible outcomes of competing populations described by the Lotka-Volterra competition model. In this case, two populations, species 1 and species 2, compete for a limiting resource. What will be the outcome of competition in this case? (Hint: the words “starting conditions” in the choices below refer to the numbers of species 1 (N1) and species 2 (N2) present at the beginning of competition.)
A) Species 1 always outcompetes and eliminates species 2, regardless of starting conditions.
B) Species 2 always outcompetes and eliminates species 1, regardless of starting conditions.
C) One species will outcompete and eliminate the other, but the “winner” depends on starting conditions.
D) Both species coexist at equilibrium numbers, regardless of starting conditions.

A

B) Species 2 always outcompetes and eliminates species 1, regardless of starting conditions.

32
Q

As in the previous question, what will be the outcome of competition in the case above? Please choose from among the answers to the previous question.
A) Species 1 always outcompetes and eliminates species 2, regardless of starting conditions.
B) Species 2 always outcompetes and eliminates species 1, regardless of starting conditions.
C) One species will outcompete and eliminate the other, but the “winner” depends on starting conditions.
D) Both species coexist at equilibrium numbers, regardless of starting conditions.

A

D) Both species coexist at equilibrium numbers, regardless of starting conditions.

33
Q
In the two figures above, what are the straight lines within the graphs called?
A) carrying capacities
B) zero net-growth isoclines (ZNGIs)
C) competition coefficients
D) minimal conditions
A

B) zero net-growth isoclines (ZNGIs)

34
Q

A group of children at a birthday party sit around a table covered with pieces of candy. Each child must gather candy, one piece at a time, as fast as possible. No child is permitted to impede the access of another child to the remaining candy on the table. When the table has been cleared, the child with the most pieces of candy is declared the winner. This is an example of:
A) interference competition B) exploitative competition C) neither of these

A

B) exploitative competition

35
Q

Which of the following is an example of interference competition?
A) allelopathy in plants, such as the Australian pine in Florida or desert sage in California
B) mosquito larvae competing for bacteria in container habitats
C) Paramecium competing for bacteria in laboratory test-tubes
D) tropical rainforest trees competing for light

A

A) allelopathy in plants, such as the Australian pine in Florida or desert sage in California

36
Q
Black walnut (Juglans nigra) trees produce juglone, an aromatic organic compound that inhibits certain enzymes in other plants. As a result, few plant species are capable of germinating and becoming established under black walnut trees. What term do we use to describe the chemical competition that black walnut trees use to directly interfere with would-be competitors?
A) allelopathy B) fertilization C) Allee effect D) facilitation E) halitosis
A

A) allelopathy

37
Q

Which of the following experimental approaches did Joseph Connell use to determine the cause(s) of vertical zonation in two species of barnacles along the Scottish coast (refer to Figure 16.11, above)?
A) introduction of exotic barnacle species
B) introduction of exotic substrates, such as used tires
C) introduction of barnacle parasites
D) removal of one or the other of the species of barnacles
E) removal of macroscopic algae

A

D) removal of one or the other of the species of barnacles

38
Q

In the lower rocky intertidal zone of the Scottish coast, the barnacle Balanus is a much more effective competitor than the barnacle Chthamalus. We thus refer to the competition between Balanus and Chthamalus as asymmetric. Given this situation, how does Chthamalus persist on the rocks at all?
A) Chthamalus is more tolerant of stressful conditions
B) Chthamalus is less tolerant of stressful conditions

A

A) Chthamalus is more tolerant of stressful conditions

39
Q

In his study of invertebrate animal communities on rocky intertidal areas in the state of Washington, Robert Paine found that removal of the keystone predator (Pisaster, the sea star) led to __________ in community diversity.
A) an increase B) no change C) a decrease

A

C) a decrease

40
Q

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

A

D) the ability of an insect herbivore to detoxify antiherbivore substances produced by its host plant

41
Q

In 1859, a few European rabbits were introduced to Victoria, Australia. Within a very few years, populations reached hundreds of millions. As a means to control the rabbit population, the myxoma virus was introduced in 1950 and spread by mosquitoes. The virus proved to be an effective control agent and initially killed 99.8% of the infected rabbits. Which of the following resulted in later outbreaks being less effective in the control of rabbit populations?
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

A

C) both of the above

42
Q

Species 1 occurs on islands A and B, and its close relative, species 2, occurs on islands B and C. Islands A, B, and C all have similar environmental conditions and habitats. Which of the following might we reasonably expect, with respect to some trait related to resource acquisition?
A) The sympatric populations of species 1 and 2 on island B will differ less from each other than do the allopatric populations of these two species on islands A and C.
B) The sympatric populations of species 1 and 2 on island B will differ more from each other than do the allopatric populations of these two species on islands A and C.
C) The sympatric populations of species 1 and 2 on island B will differ about as much from each other as do the allopatric populations of these two species on islands A and C.
D) none of the above

A

B) The sympatric populations of species 1 and 2 on island B will differ more from each other than do the allopatric populations of these two species on islands A and C.

43
Q

When we observe an example of a mutualism, can we safely assume that the relationship is coevolved?
A) Yes B) No

A

B) No

44
Q

The number of species that occupy a relatively small, comparatively homogenous site is:
A) local or alpha diversity (α-diversity) B) regional or gamma diversity (γ-diversity)

A

A) local or alpha diversity (α-diversity)

45
Q

The number of species in a broader geographic region such as a local community, a continent, or even an entire ocean basin is:
A) local or alpha diversity (α-diversity) B) regional or gamma diversity (γ-diversity)

A

B) regional or gamma diversity (γ-diversity)

46
Q

Which of the following is a reasonable way to think about the relationship among α-diversity, β-diversity, and γ-diversity?
A) α-diversity x β-diversity = γ-diversity B) α-diversity - β-diversity = γ-diversity

A

A) α-diversity x β-diversity = γ-diversity

47
Q

In the equilibrium theory of island biogeography (please refer to schematic figure above), variation in numbers of species on islands of different sizes is seen as a function of differences in:
A) immigration rates. B) extinction rates.

A

B) extinction rates.

48
Q

In the equilibrium theory of island biogeography, variation in numbers of species on islands of different distances from the mainland is seen as a function of differences in:
A) immigration rates. B) extinction rates.

A

A) immigration rates.

49
Q

Simberloff and Wilson conducted a well-known experiment in which they fumigated small mangrove islands and observed the recovery through time of arthropod communities on these islands. They found that mangrove islands tended to recover to about the same number of species present pre-fumigation. Which proposition of the equilibrium theory of island biogeography did this observation support?
A) Islands distant from the mainland have fewer species than close islands.
B) Small islands have fewer species than large islands.
C) Each island has an equilibrium number of species.

A

C) Each island has an equilibrium number of species.

50
Q

Which of the following is a relatively rare example of speciation that occurs when one species evolves into two species without any physical separation?
A) sympatric speciation
B) allopatric speciation

A

A) sympatric speciation

51
Q

A single species is split into two physically isolated populations by continental drift, and each population becomes a distinct species. This is an example of speciation by:
A) dispersal
B) vicariance

A

B) vicariance

52
Q
Which biome has a plant community dominated by grasses and a climate characterized by an intermediate amount of rainfall, warm summers, and cold winters?
A) arctic tundra
B) temperate grassland
C) tropical savanna grassland
D) desert
A

B) temperate grassland