Exam 10: Population Dynamics

Refer to the figures. Figure 1 Figure 2 -Based on the changes in population size, during which time period(s) do you expect birth rates to be highest? During which time period(s) do you expect death rates to be highest? When should birth and death rates be most similar?

A population of lions in the Ngorongoro Crater of Tanzania is struggling to survive as a result of

In a population of three asexual lizards, each lizard has a 40% probability of not producing any offspring. What is the probability that all three lizards will produce no offspring, thus ensuring the population's extinction?

Population cycles in all small rodents are driven by

Refer to the figures. Figure 1 Figure 2 Figure 3 Suppose the population shows the pattern in Figure 3. Draw a new figure (this will be referred to as Figure 4) with a line that indicates how population size changed over time. What is the major difference between this pattern and the pattern in Figure 2? What are two factors that might be causing the pattern in Figure 4?

Suppose that only two females and a small number of males are left in a population of a highly endangered bird. Although all of these birds are healthy, by chance, both females fail to reproduce and the population goes extinct. This extinction is best described as a consequence of

Which of the following best describes an explosion of the number of individuals in a population?

Suppose you are studying two small lakes (lake 1 and lake 2) and how they change over time. A nearby farm accidentally spills fertilizer into lake 1. Around the same time, a non-native fish-eating turtle is introduced into lake 2. The ecosystems of both lakes are affected by these changes. What processes most likely explain how the lakes were affected?

During a hurricane, a large segment of an insect population is carried to a distant island where there are abundant resources and minimal predators. What type of growth would you likely expect in the time immediately following this colonization event?

Which pattern of population dynamics best describes the one exhibited by sheep introduced to the island of Tasmania?

Allstadt et al. (2013) found that population cycle collapse in Canadian populations of gypsy moths resulted from

When wolves were returned to Yellowstone National Park in 1995, they immediately began feeding on elk, reducing their numbers. This allowed aspen trees to increase in abundance, which ushered in the return of beaver populations. As beaver populations dammed streams, they slowed water flow and stabilized streambanks. The stabilization of streambanks increased riparian habitat in which songbirds could nest, and the ponds provided breeding habitat for amphibians. Explain this story using the concepts of top-down and bottom-up control.

The addition of excess nutrients into aquatic systems often disrupts the ecosystem. This phenomenon is known as

At low population densities, the flocking behavior of some species of birds is disrupted to the extent that the population growth rate is lower at very low densities than it is at somewhat higher densities. This is an example of

A population that experiences delayed density dependence will exhibit particular patterns of population dynamics depending upon r (the population growth rate under ideal conditions  the time lag in the effects of density dependence). At low levels of this interaction, the population should exhibit _______; at intermediate levels, it should display _______; and at still higher levels, it should exhibit _______.

A population of blowflies experiences logistic growth with delayed density dependence. Suppose that this population has an initial size of 4,295 and follows the standard equation for delayed density dependence with a 10-week delay and an intrinsic growth rate of 0.2 per week. If these conditions remain constant and the population is tracked for a long time, what type of population dynamics should it display? (Note: The cutoff r value for dampened oscillations is 0.368, and the cutoff for a stable limit cycle is 1.57.)

Refer to the figure. Figure 1 Use the data from the figure to draw a line graph (this will be referred to as Figure 2) that illustrates how population size changes over time. From time 1 to time 10, what type of logistic curve best fits this data? In your answer, address both the pattern of the line and the underlying cause of these patterns.

Although there are approximately 10,000 cheetahs left in the wild, biologists think that their numbers were much lower at some time in the past because cheetah populations have very little genetic variation. What is the most likely reason for the lack of genetic variability in cheetahs?

Refer to the figure. Based on the pattern seen in the figure, you could suggest that _______ growth and _______ population expansion was occurring.

In Nicholson's experiments with blowflies, population cycles most often occurred when adults