General Ecology Final Exam Key Points
1.
Predation 1
a. Be able to list and explain the 8 hypotheses for patterns of species
diversity.
b. Understand why we consider omnivores and herbivores in the same
general way we consider predators.
c. What is involved in predation? Prey detection, prey recognition, prey
capture modes.
d. How do prey avoid detection and/or capture?
e. Plant herbivore interactions: Chemical defense, synchronous set, structural
adaptations
f. Optimal foraging: Energy maximizers and time minimizers.
g. Generalist vs. specialist.
h. Marginal value theorem
2.
Predation 2
a. Functional Response vs. Numerical Response
b. 3 forms of functional response: Linear, Asymptotic, Logistic
c. Note, these are density independent, density dependent, and density
dependent but with varying affects.
d. What conditions lead to stable coexistence of predator and prey?
e. What causes oscillatory behavior in predator prey systems?
f. What effect do prey refugia have on the system?
3.
Optimality and tolerance
a. Review the examples of Crotaphytus in Missouri, and Glaucomys in
Mexico.
b. Merriam’s life zones.
4.
Diversity and Stability
5.
Competition 1
a. Be able to perform a phase plane analysis for a 2 species competitive
system.
b. Under what conditions is the system stable?
c. What is meant by K and alpha compatibility?
d. What was a ‘weakness’ with the work of MacArthur and Brown?
e. What is the compression hypothesis?
f. What is the competitive exclusion principle?
g. What is the consequence of dependence between 2 resource axes?
6.
Coevolution
a. Know the example of rabbits and myxoma virus in Australia.
b. Understand the importance of the evolutionary response in invasive
systems like zebra mussels, Cuban treefrogs, and house mice.
c. Know the examples of finches in Jamaica and Linnets in Finland.
d. Know the consequences of genetic re-organization in laboratory
experiments of houseflies abnd blowflies.
e. Understand the graph of rate of evolution vs. rate of exploitation for
predator and prey.
f. What is the taxon cycle?
7.
Community Ecology
a. What is a community?
b. Are communities co-evolved units, or assemblages of species with similar
sets of overlapping tolerance limits?
c. Do communities replace each other as units?
d. What is meant by community structure?
Ecology Mini-Exam
1.
A functional response is defined as:
a. As prey density increases, each predator can consume more prey
b. As prey density increases, predators increase in number, and that larger
number of predators consumes more prey.
c. As prey density increases, their death rate increases resulting in the loss of
predators.
d. As predator density increases, selection for prey increases and prey
become more efficient at reproduction.
2.
T/F
Consider the figure below. This figure illustrates that Sorex had a
large numerical response to increased prey density, while Peromyscus and
Blarina had a small numerical response to increased prey density.
3.
If prey consumption is logistic with respect to prey density, then the
functional response is a
a. Type I Functional response
b. Type II Functional response
c. Type III Functional response
4.
T/F
Only the Type III functional response is density dependent in a
way that promotes population regulation.
5.
The Type III functional response is the one most likely to regulate prey
populations.
6.
What causes a Type III functional response?
a. Factors that cause low hunting efficiency at low prey density.
b. Failure to develop an appropriate search image without positive
reinforcement.
c. Presence of prey refugia at low densities.
d. All of the above.
7.
Perform the phase-plane analysis on the figure below, and indicate whether
the system is stable or not.
8.
T/F
In a coevolutionary system, an increase in fitness for one species
results in a decrease in fitness for the other species.
9.
Good examples of coevolution include the following:
a. Rabbits and Myxoma virus in Australia
b. Pepperd moths (Biston betularia) in England
c. Linnets in Finland
d. Safron Finches in Jamaica
e. Swamp rabbits in Missouri
10.
Consider the graph below: If predator densities are high, then
a. Evolutionary response on the part of the prey should be low.
b. Evolutionary response on the part of the prey should be high.
c. Evolutionary response on the part of the predator should be low.
d. Evolutionary response on the part of the predator should be high.
11.
Consider a system in which there are two predators. For example, bats might
take an insect when it flies, and shrews may take the insect when it lands on
the ground. From an evolutionary perspective, what problem does this pose?
a. The insect will be easily confused.
b. Insect densities will be too low for a meaningful evolutionary response.
c. The possible evolutionary responses may be constrained by the differing
selective regimes imposed by eachpredator.
d. The level of selection will be to great, and the insect will go extinct
locally.
12.
Which of the following is NOT one of our hypotheses for community species
diversity?
a. Competition
b. Predation
c. Primary production
d. Global warming
e. Stability of primary production
f. Evolutionary time
g. Ecological time
h. Habitat diversity
i. Climatic stability
13.
T/F
In an ecological sense, predation and herbivory are just different
levels of the same phenomenon. The critical difference is that predation
terminates future fecundity while herbivory generally reduces it.
14.
Adaptations to avoid predation include
a. Hard shells or spines
b. Expanded auditory bullae
c. Poison glands in the skin
d. Saltatorial locomotion
e. Herding behabior
f. Behavioral displays
15.
T/F
16.
Consider the equation below:
Amongst foragers, we can identify two basic types: Time
minimizers and energy maximizers.
1 E1  2 E2
T 1   h   h 
1 1
2 2
Recall that λ represents encounter rate, h represents handling time, E is
calories, and T is time spent foraging. Imagine a predator has 2 prey items
available.
E

Prey Item 1 Prey Item 2
10
100
Calories
0.1
.05
Encounter rate
5
50
Handling time
Should the predator be a generalist or a specialist?
.
17.
Consider the figure for the marginal value theorem. As travel time between
patches decreases, what should happen to patch residence time?
18. Recall the example of the introduction of rabbits to Australia. Although initially
promising, efforts to control the rabbit population with the myxoma virus were
not successful. This was because (circle all that apply)
a. All rabbits have a natural resistence to the myxoma virus.
b. The virulence of the virus decreased over time.
c. Surviving rabbits had some level of resistence to the virus.
d. Climate change during the period of attempted control favored the rabbits.
e. The effectiveness of the virus was limited by the availability of alternative
hosts.
19. T / F As the rate of exploitation by the predator increases, the rate of evolution
on the part of the prey species increases, while the rate of evolution on the part of
the predator decreases.
20. Consider history of the Linnet in Finland. Recall that the bird was on the verge of
extinction in Finland as agricultural practices changed. However, the bird is once
again abundant. Why?
a. The Finns have made major efforts at preserving the species.
b. Agricultural practices have reverted to more environmentally friendly
forms.
c. There has been a genetic re-organization in Linnets, and the birds are now
using different habitats.
d. The birds have learned to exploit garbage around inner city areas.
e. People are putting out feeders specifically for Linnets.
21. Consider the following animals. In terms of foraging, are they time minimizers
(T) or energy maximizers (E).
a. _____ Cow
Why?___________________________________
b. _____ Panda bear
Why?___________________________________
c. _____ Lion
Why?___________________________________
d. _____ Racoon
Why?____________________________
22. T / F
A community is a group of populations that occur together
23. T / F
It is difficult to define where a community ends.
24. Communities are evolutionary units
a. True
b. False
c. This has not yet been determined in most cases.
25. If communities are co-evolved units, then we infer that communities replace each
other as units.
a. True
b. False
c. This has not yet been determined.
26. Consider the following communities: Ponerosa Pine Woodland, Pinyon Juniper
Woodland, Creosote Scrub, Sage Brush Scrub, Mojave Desert.
a. These are examples of communities as evolutionary units.
b. These are examples of Merriam’s Life Zones
c. These are random assemblages of species
d. These are assemblages of independent species.
27. Consider the figure below. The top figure indicates _____, while the bottom
figure indicates _____.
a. Co-evolved Communities
b. Random assemblages of species
c. Merriam’s Life Zones.
d. Tolerance limits to the local physiognomy.
28. Does the sharp demarcation between coniferous and deciduous forest indicate
communities as co-evolved units, or a spatial unit?
a. Co-evolved unit.
b. Spatial unit.
29. T / F As you travel north in the Sierra Mts., the elevation at which the
Ponderosa Pine community begins becomes higher and higher.
30. T / F The evolutionary history of each species in a community is essentially
independent of other species in the community.
31. T / F The distribution of plant species is more strongly correlated with
environmental gradients than with the distribution of other species.
32. Consider the phase plane given below. Indicate the equilibrium point(s) if it/they
they exist. If an equilibrium point exists, indicate whether it is stable.
33. A functional response is defined as:
a. As prey density increases, each predator can consume more prey
b. As prey density increases, predators increase in number, and that larger
number of predators consumes more prey.
c. As prey density increases, their death rate increases resulting in the loss of
predators.
d. As predator density increases, selection for prey increases and prey
become more efficient at reproduction.
34. T / F Consider the figure below. This figure illustrates that Sorex had a small
numerical response to increased prey density, while Peromyscus and Blarina had
a large numerical response to increased prey density.
35. What causes a Type III functional response?
a. Factors that cause low hunting efficiency at low prey density.
b. Failure to develop an appropriate search image without positive
reinforcement.
c. Presence of prey refugia at low densities.
d. All of the above.
36. T / F In a coevolutionary system, an increase in fitness for one species results in
a decrease in fitness for the other species.
37. Consider the following communities: Ponderosa Pine Woodland, Pinyon Juniper
Woodland, Creosote Scrub, Sage Brush Scrub, Mojave Desert.
a. These are examples of communities as evolutionary units.
b. These are examples of Merriam’s Life Zones
c. These are random assemblages of species
d. These are assemblages of independent species.
38. Consider the graph below: If predator densities are high, then
a. Evolutionary response on the part of the prey should be low.
b. Evolutionary response on the part of the prey should be high.
c. Evolutionary response on the part of the predator should be low.
d. Evolutionary response on the part of the predator should be high.
39. If communities are co-evolved units, then we infer that communities replace each
other as units.
a. True
b. False
c. This has not yet been determined.
40. Consider the figure below. The top figure indicates _____, while the bottom
figure indicates _____.
a. Co-evolved Communities
b. Random assemblages of species
c. Merriam’s Life Zones.
d. Tolerance limits to the local physiognomy.
41. T / F Consider the equation for species richness: S  cA Z . This equation
illustrates a linear relationship between area and species richness.
42. T / F The graph below indicates that as islands get larger, they support more
species.
43. T / F The distribution of plant species is more strongly correlated with
environmental gradients than with the distribution of other species.
44. When sampling the species in a community, it is typical that
a. Most species are relatively common, and a few are rare.
b. A few species are relatively common, and many are rare.
c. There is always one common species and the rest are rare.
d. All species are rare.
45. Consider the food webs drawn below. Circle the food web that is likely to be
most stable.
46. Consider the graph below. On the graph, indicate (AND LABEL) the equilibrium
number of species for a small island that is far from the mainland, and a large
island that is near to the mainland.