Ecology Exam 1 HW questions
fecundity
number and size of offspring
parity
number of reproductive events
Adaptations
represent compromises in the abilities of organisms to perform different and sometimes conflicting functions
Long-term patterns of evolution are shaped by large scale processes such as...
speciation, extinction, adaptive radiation.
ways evolution occurs quickly
Disease dynamics Invasive species, climate change, habitat loss Antibiotic and pesticide/herbicide resistance
Which of the following is not a possible reason why adaptations are not perfect? Select one: a. Gene flow can bring genetic variants into a population that are not perfectly adapted to the local environment. b. The population may lack the appropriate genetic variation to respond to natural selection. c. An allele that is favored by natural selection may cause other effects that are harmful. d. Populations are constrained by their evolutionary histories. e. All of the above are possible reasons why adaptations may not be perfect.
E
flucation
the rule for natural populations
Semelparous
-(monocarpic) once Preparation for reproduction is costly. Ex. salmon: reproduce a lot of eggs but only reproduce once and then die
Iteroparous
-(polycarpic) repeated low current reproduction results in maintaining high future reproduction. Ex. koala bears. Maintenance, reproduce more than once and survive to take care of young
lambda=
1+g. lambda = Nt+1/Nt
-three biggest tradeoff points:
1. When to begin to reproduce, 2. how often should one breed, and 3. How many offspring per breeding episode.
Assumptions/ limitations of science
specific causes for observed events, causes can be identified, general rules can describe observations, repeated events have same cause, perceptions are not individualistic, fundamental rules of nature are universal
Which of the following processes is the least likely to be the direct cause of appreciable change in allele frequencies over short periods of time? Select one: a. Directional selection b. Genetic drift in small populations c. Gene flow d. Mutation e. All of these processes are likely to cause appreciable evolutionary change over short periods of time.
D
Ecological/Evolutionary Responses to Climate Change
I. Cellular: individual responses II. Ecological: responses A. Adjust by migration: i.e. butterflies migrating to mexico B. Adjust via phenotypic plasticity C. Adjust via evolutionary change: i.e small lizards adapting ways to live higher in trees to stay away from predators. Also cyanide resistance III. If no response: possible extinction
Geometric growth:
Individuals added at one time of year (seasonal reproduction) Uses difference equations
Exponential growth:
Individuals added to population continuously (overlapping generations) Uses differential equations
Inflection point at
K/2. separates accelerating and decelerating phases of population growth; point of most rapid growth
hypothesis
Logical statement that potentially explains an event, or answers a question -can't be proven true
Life History
Schedule of an organism's life events relating to its growth, development, reproduction, and survival. Adaptive evolution will shape life history traits to maximize fitness given available resources and the ecological environment.
A lizard is blown out to sea during a hurricane. This type of storm occurs very infrequently—on average once every 100 years. The lizard washes up on the beach of a small island. The lizard finds some beetles on the beach. The lizard can get an average of about 20 calories from consuming a beetle. It takes the lizard 10 calories a minute to chase and catch beetles. What is the maximum amount of time that the lizard can spend catching each beetle and still survive? Select one: a. 2 minutes b. 6 minutes c. 10 minutes d. 20 minutes
a
A study that is investigating the neural mechanisms that allow individuals to differentiate between two smells is studying the _______ of this behavior. Select one: a. proximate causes b. ultimate causes c. adaptive behavioral response d. marginal value
a
Based on the results of studies of male widow bird tail length and mating success, what would you predict will likely happen to the male widow birds over many generations? Select one: a. Male average tail lengths will be longer. b. Male average tail lengths will be shorter. c. Male average tail lengths will stay the same. d. Male tails will be brighter colored.
a
In species where males provide the bulk of the parental care, males are most likely to Select one: a. be choosy about which females they mate with. b. be indiscriminant about which females they mate with. c. mate with as many females as possible. d. compete to mate with choosy females.
a
Suppose you are studying a species of primate. Female primates generally live in 5-km2 home ranges that overlap very little with neighboring home range territories. The primates can travel up to 5 km in one day and both males and females care for young. Which type of breeding system is most likely under these circumstances? Select one: a. Monogamy b. Polyandry c. Polygyny d. Promiscuity
a
Weight at birth of human babies has a genetic component. In one large study, survival in a cohort of babies during the first month of life was shown to be greatest for babies of average weight at birth and least for babies with very low or very high weights at birth. Survivors of the first month of life had lower variation in weight at birth than did all babies in the cohort. Differential survival of this kind could result in __________ on genes controlling weight at birth. Select one: a. stabilizing selection b. directional selection c. disruptive selection d. no selection
a
When a population grows according to the logistic model, at what population size does dN/dt equal zero? Select one: a. N = K b. N = K/2 c. N = r0 d. N = ∞
a
Which of the following statements about adaptive evolution is true? Select one: a. Gene flow can limit local adaptation. b. Adaptive evolution almost always requires hundreds of generations or more to be noticeable. c. The presence of genetic variation makes adaptive evolution more unlikely to occur. d. All of the above
a
Which of the following types of selection serves as a kind of genetic housekeeping, sweeping away harmful genetic variation? Select one: a. stabilizing selection b. directional selection c. disruptive selection d. all of the above e. none of the above
a
Which stages of life in a population are often found to suffer more from the adverse effects of density-dependent factors? Select one: a. juvenile stages b. adult stages c. both juvenile and adult stages about equally
a
Senescence
a decline in physiological function with age
law
a uniform or constant fact of nature that describes what happens in nature
theory
a widely accepted generalization about fundamental scientific concepts that explain why things happen
pre-adaptation
an adaptation which serves a different purpose from the one for which it evolved.
A population of prickly pear cacti has a size of 1,500 individuals. At this population size, density-dependent factors have limited the population's growth rate to only 1/3 what it was in the absence of the density-dependent regulation. Assuming that these cacti grow according to the logistic equation, what is the carrying capacity of this population? Select one: a. 1,500 b. 2,250 c. 2,500 d. 3,000 e. 4,500
b
A study focuses on the evolution of infanticide in carnivorous mammals. This study is investigating the _______ of this behavior. Select one: a. proximate causes b. ultimate causes c. adaptive behavioral response d. marginal value
b
After large seeds became more common, the average beak size of the medium ground finch increased in size over the course of a few years. This change was most likely a case of Select one: a. disruptive selection. b. directional selection. c. stabilizing selection. d. balancing selection. e. genetic drift.
b
In an exponentially (N(t) = N(0)ert) or geometrically (N(t) = N(0)λt) growing population with constant r or λ, is population stability ever reached? Select one: a. Yes, the population stops growing when resources or some other extrinsic factors become sufficiently limiting. b. No, a population growing in this fashion exhibits unrestricted growth.
b
In comparing exponential and geometric growth, which of the following statements is true? Select one: a. Lambda can be calculated from r, and is equivalent to the natural logarithm of r. b. Lambda can be calculated from r, and is equivalent to "e" raised to the r power. c. The multiplier r can be calculated from λ, and is equivalent to "e" raised to the λ power. d. Lambda is used in exponential growth curves. e. None of the above
b
In which mating system are males promiscuous and females are monogamous? Select one: a. Monogamy b. Polygyny c. Promiscuity d. Polyandry
b
On its current web site, the Population Reference Bureau offers a comparison between two countries, Italy and the Democratic Republic of the Congo in central Africa. Both countries had similar-sized populations in mid-2008, as shown in the following table. However, the two countries could not be more unlike one another in other demographic parameters. For example, the crude birth and death rates (B and D) for Italy are currently 9 and 10 per 1,000 persons, respectively. The comparable crude birth and death rates for the Democratic Republic of the Congo are 44 and 13 per 1,000 persons, respectively. The value of λ for Italy is slightly less than 1.0. What does this imply? Country Population B D λ r t2 Italy 60 million 0.009 0.010 0.999 -0.0010 -690 Congo 67 million 0.044 0.013 ? ? ? Select one: a. The population of Italy is increasing. b. The population of Italy is decreasing. c. The population of Italy is stable.
b
Population regulation occurs when Select one: a. the population has reached a stable age distribution. b. density-dependent factors have been operating on birth, death, and emigration rates. c. density-independent factors have been operating on birth, death, and emigration rates. d. the population is close to zero. e. None of the above
b
Seed types vary in energy and time required for an animal to process them: Type A (30 KCAL 0.5 hr), Type B (40 KCAL 1.5 hr), Type C (60 KCAL 2.0 hr). Rank the seed types in term of the bird's likelihood (from highest to lowest likelihood) of choosing this seed if it is trying to maximize its energy intake. Select one: a. A > B > C b. A > C > B c. B > C > A d. C > B > A
b
Suppose the net energy value of a food item is 30 units. The time invested in obtaining each food item is 22 units, and the time invested in processing each food item is 3 units. What is the profitability of this food source? Select one: a. 0.83 units b. 1.2 units c. 1.4 units d. 10 units
b
Suppose the net energy value of food item A is 6 units while the net energy value of food item B is 4 units. Obtaining item A takes 2 units of time and processing takes 2 units of time. Item B takes 2 units of time to obtain and 2 units to process. The difference in profitability between the two food items is Select one: a. 0. b. 0.5. c. 1.0. d. 2.5
b
The elf-orpine, a tiny plant that grows in shallow depressions on granite rock outcrops of the southeast, is a winter annual. Seeds are shed in early fall and germinate in moist patches of shallow sand. The plants grow slowly through the winter. They mature, flower, and produce seeds during the spring. The plants then die, but seeds are retained on the dead plants until early fall. Which of the two approaches below would be best suited to modeling population growth of the elf-orpine? Select one: a. continuous-time b. discrete-time
b
When a population grows according to a logistic model, at what size is its growth rate maximal? Select one: a. N = K b. N = K/2 c. N = r0 d. N = ∞
b
Which of the following describes how individuals of a prey species alter their foraging decisions in the presence of predators? Select one: a. A mouse spends more time foraging in open habitat when an owl is present. b. A deer spends more time foraging in open meadow when wolves are absent. c. A small fish spends more time feeding in an area frequented by heron. d. A mother bird feeds her nestlings more when cats are nearby
b
Which of the following traits cannot evolve by natural selection? Select one: a. A trait that increases the time during which females are reproductively competent b. A trait whose value in the offspring is not a reflection of its value in the parents c. A trait that increases the ability of an organism to survive low temperatures, at the expensive of survival at high temperatures d. A trait that increases the ability of an organism to survive high temperatures, at the expensive of survival at low temperatures e. All of the above can evolve via natural selection.
b
Which of the following types of selection results in the distribution of phenotypes in a population shifting toward a new optimum? Select one: a. stabilizing selection b. directional selection c. disruptive selection d. all of the above e. none of the above
b
Why did average beak size increase in surviving individuals of Darwin's medium ground finch (and their progeny) during a period of severe drought in the Galapagos? Select one: a. Individuals eating the harder seeds available during the drought developed larger beaks and passed this trait on to their offspring. b. Individuals with larger beaks could eat the harder seeds available during the drought and survived better than individuals with smaller beaks. c. Individuals with larger beaks are always at an advantage. d. The observed change in beak size was purely the result of chance.
b
You are studying nest building in two bird species. Species A builds a long hanging nest while species B builds a short nest that sits on top of tree branches. You interbreed the birds in the lab and then examine the nests that the offspring produce. QTL analysis showed that whether a nest is built to hang or sit is affected by one genetic locus. The length of the nest is also determined by the same genetic locus. What can you infer about the evolution of this behavior? Select one: a. It is a complex behavior that evolved out of a combination of two simpler behaviors. b. It is a complex behavior where different aspects of the behavior are affected by the same set of genetic instructions. c. It is a simple behavior that evolved out of a combination of even simpler behaviors. d. It is a learned behavior without a genetic component.
b
A declining population of an endangered butterfly is determined to have an exponential rate of decrease of r = -0.02. What is the corresponding value of λ for this population? Select one: a. greater than 1 b. exactly 1 c. greater than 0 and less than 1 d. exactly 0 e. less than 0
c
A larger beak improves the ability of a finch to eat large seeds, but it decreases its ability to eat smaller seeds. This phenomenon is an example of Select one: a. a maladaptive radiation. b. disruptive selection. c. an ecological trade-off. d. genetic drift. e. None of the above
c
A lizard is blown out to sea during a hurricane. This type of storm occurs very infrequently—on average once every 100 years. The lizard washes up on the beach of a small island. The lizard finds some beetles on the beach. Individual beetles on the island vary in size. It takes the lizard the same amount of energy to catch a beetle, regardless of the size of the beetle. Which beetle does optimal foraging theory predict the lizard will eat most frequently? Select one: a. Beetles that are smaller than average b. Beetles that are average size c. Beetles that are bigger than average d. The size of the beetles is unlikely to affect the lizard's foraging preferences
c
A lizard is blown out to sea during a hurricane. This type of storm occurs very infrequently—on average once every 100 years. The lizard washes up on the beach of a small island. The lizard finds some beetles on the beach. Which option is least likely to result in the survival of this specific individual on the island? Select one: a. The lizard becomes more efficient at catching beetles. b. The lizard searches for alternative food sources. c. The lizard evolves new adaptations that help it catch beetles d. The lizard picks the biggest beetles to catch.
c
A population of Drosophila mauritiana reproduces in synchrony at discrete time periods every generation, and generations occur at two-week intervals. The current population size is 1,000, and its geometric population growth rate is 3.0 per generation. What will the expected size of the population be after six weeks? Select one: a. 3,000 b. 9,000 c. 27,000 d. 81,000 e. 729,000
c
Adaptive evolution is a process that occurs Select one: a. within one individual's lifetime. b. when an individual is reproductively active. c. over multiple generations of individuals. d. during foraging activities.
c
Females that are choosy about which males they mate with gain Select one: a. only direct benefits from their mate choice. b. only indirect benefits from their mate choice. c. both direct and indirect benefits from their mate choice. d. no benefits from being choosy.
c
Highbush blueberry plants belonging to a particular species grow in a wide range of environments in North Carolina. Plants growing in acidic bogs are slower growing than plants on fertile, better-drained floodplains. In a reciprocal transplant study, plants from a bog were transplanted to a floodplain and plants from a floodplain were transplanted to a bog. The transplants from the bog performed better in the floodplain, but not as well as plants native to the floodplain. The transplants from the floodplain performed more poorly in the bog, about the same as plants native to the bog. What can we conclude from this experiment about the causes of differences in growth rate between the bog and floodplain populations? Select one: a. They are genetically determined. b. They reflect phenotypic plasticity. c. Both of the above conclusions are correct.
c
On its current web site, the Population Reference Bureau offers a comparison between two countries, Italy and the Democratic Republic of the Congo in central Africa. Both countries had similar-sized populations in mid-2008, as shown in the following table. However, the two countries could not be more unlike one another in other demographic parameters. For example, the crude birth and death rates (B and D) for Italy are currently 9 and 10 per 1,000 persons, respectively. The comparable crude birth and death rates for the Democratic Republic of the Congo are 44 and 13 per 1,000 persons, respectively. Use a formula to calculate dN/dt for the population of the Democratic Republic of the Congo in mid-2008 (to the nearest tenth of a million persons per year), assuming logistic growth and an estimated carrying capacity of 100 million. Country Population B D λ r t2 Italy 60 million 0.009 0.010 0.999 -0.0010 -690 Congo 67 million 0.044 0.013 ? ? ? Select one: a. 0.7 b. 1.0 c. 2.0 d. 3.0
c
On its current web site, the Population Reference Bureau offers a comparison between two countries, Italy and the Democratic Republic of the Congo in central Africa. Both countries had similar-sized populations in mid-2008, as shown in the following table. However, the two countries could not be more unlike one another in other demographic parameters. For example, the crude birth and death rates (B and D) for Italy are currently 9 and 10 per 1,000 persons, respectively. The comparable crude birth and death rates for the Democratic Republic of the Congo are 44 and 13 per 1,000 persons, respectively. Which of the following formulae would you use to solve the doubling time of a population? Country Population B D λ r t2 Italy 60 million 0.009 0.010 0.999 -0.0010 -690 Congo 67 million 0.044 0.013 ? ? ? Select one: a. dN/dt = rN b. N(t) = N(0)ert c. t2 = 0.69/r d. N(t) = N(0)λt e. r = logeλ (also r = lnλ)
c
When a population grows according to a logistic model, what happens if the population exceeds carrying capacity? Select one: a. The population resumes exponential growth. b. The size of the population remains constant. c. The size of the population begins to decline. d. The population goes extinct.
c
Which of the following equations describes the rate at which individuals are added to or removed from a population exhibiting exponential growth? Select one: a. N(t) = N(0)ert b. N(t) = N(0)λt c. dN/dt = rN d. λ = er e. r = b - d f. λ = 1 + B - D
c
Which of the following is the most essential condition under which a sexually selected trait may emerge? Select one: a. Females must be choosy. b. The trait must allow males to compete more effectively with other males. c. The trait must increase the mating success of the individuals with the trait. d. Males that exhibit the trait must provide parental care.
c
Which of the following processes changes allele frequencies by chance alone? Select one: a. Disruptive selection b. Stabilizing selection c. Genetic drift d. Both a and b e. Both b and c
c
Which of the following statements about the concept of natural selection is false? Select one: a. Natural selection is an evolutionary process whereby different individuals survive and reproduce at different rates based on particular characteristics they possess. b. According to the concept of natural selection, those who survive and reproduce at a greater rate pass on more of their genes to the next generation, as compared to those who have a lower survival and reproduction rate. c. The frequency of a trait favored by natural selection will increase over generations whether the trait is heritable or not. d. Only natural selection can produce adaptations consistently. e. All of the above are true; none is false
c
In a case where critical resources are clumped in space and males provide most of the parental care, the mating system is most likely to be Select one: a. monogamy. b. promiscuity. c. polygyny. d. polyandry.
d
A population of rabbits reproduces in synchrony at discrete time periods each year. If the current population is 150 and its geometric population growth rate is 1.4 per year, the expected size of the population after two years will be Select one: a. 140. b. 196. c. 210. d. 294. e. 384.
d
According to the conceptual model of optimal foraging, as foraging effort increases, Select one: a. net energy gain increases linearly. b. the profitability of the food item increases. c. the total energy obtained eventually becomes negative. d. cumulative energy investment in foraging increases at a constant rate.
d
In a case where critical resources are distributed evenly in space and males provide about half of the total parental care, the mating system is most likely to be Select one: a. polyandry. b. promiscuity. c. polygyny. d. monogamy.
d
phenotypic plasticity
is the ability of one genotype to produce more than one phenotype when exposed to different environments.
In the 1890s, the biologist Hermon Bumpus found that sparrows that had survived a Rhode Island storm were more likely to be of intermediate size than sparrows that had perished from the storm. This is most likely an example of Select one: a. genetic drift. b. disruptive selection. c. directional selection. d. stabilizing selection. e. gene flow.
d
The development of resistance to cyanide poisoning in California citrus scale is an excellent example of evolution by natural selection. Which of the following characteristics of this situation were critical to the evolutionary process? Select one: a. There was variation in cyanide resistance among individuals. b. There was inheritance of cyanide resistance. c. There were differences in fitness related to variation in cyanide resistance. d. All of the above were critical to the evolutionary process.
d
Tribbles reproduce in synchrony at regular intervals. When the logarithm of a particular tribble population was plotted against time, the result was a straight and increasing line. Which of the following statements is true? Select one: a. The tribble population is increasing in size geometrically. b. The λ of the tribble population is constant and greater than 1. c. If the actual population size were plotted against time, the result would be an increasing J-shaped curve. d. All of the above e. None of the above
d
Which of the following can produce new combinations of alleles in a population? Select one: a. Directional selection b. Stabilizing selection c. Genetic drift d. Recombination e. None of the above
d
Which of the following statements about logistic growth is true? Select one: a. The carrying capacity is the maximum population size that can be supported by the environment indefinitely. b. At low densities, logistic growth is similar to exponential growth. c. At the carrying capacity, there is no population growth in the logistic model. d. All of the above e. None of the above
d
The graph above shows the frequencies of the Asp-1 allele at several latitudes across the United States. The arrows (A and B) show different directions this _______ may move if the population were to respond to changes associated with global warming. If the populations do respond in the expected direction, we would expect to see movement in the _______ direction. Select one: a. adaptive radiation; A b. adaptive radiation; B c. cline; A d. cline; B e. population; A
d. look this up for graph: Hw 1, try 2, ?3
Natural Selection..
differentiates subpopulations
Natural selection generally tends to reduce genetic variation. Which of the following can maintain or even enhance the level of genetic variation present in a population? Select one: a. mutation b. immigration c. spatial/temporal environmental variation d. heterozygote superiority e. all of the above
e
On its current web site, the Population Reference Bureau offers a comparison between two countries, Italy and the Democratic Republic of the Congo in central Africa. Both countries had similar-sized populations in mid-2008, as shown in the following table. However, the two countries could not be more unlike one another in other demographic parameters. For example, the crude birth and death rates (B and D) for Italy are currently 9 and 10 per 1,000 persons, respectively. The comparable crude birth and death rates for the Democratic Republic of the Congo are 44 and 13 per 1,000 persons, respectively. If you know the geometric rate of growth, which of the following formulae woud you use to solve for r? Country Population B D λ r t2 Italy 60 million 0.009 0.010 0.999 -0.0010 -690 Congo 67 million 0.044 0.013 ? ? ? Select one: a. dN/dt = rN b. N(t) = N(0)ert c. tdouble = 0.69/r d. N(t) = N(0)λt e. r = logeλ (also r = lnλ)
e
Which of the following statements about evolution by natural selection is true? Select one: a. Populations evolve by natural selection. b. Individuals evolve by natural selection. c. Adaptations are the result of evolution by natural selection. d. Both a and b e. Both a and c
e
Which of the following statements about population growth is true? Select one: a. Exponential population growth is always faster than geometric population growth. b. We use the term "exponential growth" when the individuals in the population reproduce in synchrony at discrete intervals. c. A population that has a λ of 0.88 should grow in size. d. All of the above e. None of the above
e
gene flow ..
homogenizes subpopulations. i think genetic drift does this as well
......is the only evolutionary mechanism that consistently causes adaptive evolution.
natural selection
metapopulation
population divided by habitat heterogeneity into subpopulations with varying amounts of migration between patches.
