Exam 56: Conservation Biology and Global Change

A land developer and several ecologists are discussing how a parcel of private land should be developed with housing while saving 20 hectares as natural habitat. The land developer suggests that the 20 hectares be divided into 20 separate 1-hectare areas, spread out across the area. The ecologists suggest that it would be better to have one intact parcel of 20 hectares on one side of the larger area. What is the significance of these different arrangements of the 20 hectares?

Use the graphs to answer the question. Archeological, fossil, and geological data provide information on the Mayan populations and their environment in Mexico, in the Caribbean state of Yucatán. The graphs depict population size, percentage of the land that was forested, and the amount of soil erosion. Based on the figure, what can you conclude about the history of land use in the southern Yucatán?

Which of the following statements regarding extinction is accurate?

Erwin and Scott used an insecticidal fog to knock down insects from the top section of a L. seemannii tree. The researchers identified over 900 species of beetles among the individuals that fell. Erwin also projected that this entire tree from top to bottom is host to about 600 arthropod species that are unique to this tree species and not found on any other tree species. There are approximately 50,000 species of tropical trees. Although it could not be entirely accurate, what would be the best way to estimate the total number of arthropod species?

Loss of biodiversity matters not only with regard to mammals or other vertebrates, but also microbes. Why are microbes worthy of discovery and protection from extinction?

The main cause of the increase in the amount of carbon dioxide in Earth's atmosphere over the past 150 years is ________.

Which of the following factors could cause the largest increase in the effective population size of a species?

Which of the following strategies would most rapidly increase the genetic diversity of a population in an extinction vortex?

Use the following figure to answer the question. Based on the species-area plot in the figure, if habitable area on an island were reduced from 10,000 square kilometers (km²)to 1,000 km², roughly what percentage of the species would disappear?

Which of the following strategies would most rapidly increase the genetic diversity of a population in an extinction vortex?

What is the biological significance of genetic diversity between populations?

Use the following figure to answer the question. Examine the figure, which notes the average barrels of oil used per person per year in different countries. What can be concluded?

Easter Island is an extremely isolated island in the Pacific, about 3,500 km from South America. Although there are no forests on the island now, archeological studies, fossil pollen, and other data show that Easter Island was once home to forests containing giant palms and other trees. Some scientists think that the removal of the giant palms caused the forest ecosystem to collapse. Which of the following factors might have caused this collapse?

What strategy was used to rescue Illinois prairie chickens from a recent extinction vortex?

Why are changes in the global carbon cycle important?

Which of the following observations provides the best evidence of a biodiversity crisis?

Suppose you attend a town meeting at which some experts tell the audience that they have performed a cost-benefit analysis of a proposed transit system that would probably reduce overall air pollution and fossil fuel consumption. The analysis, however, reveals that ticket prices will not cover the cost of operating the system when fuel, wages, and equipment are taken into account. As a biologist, you know that if ecosystem services had been included in the analysis, the experts might have arrived at a different answer. Why are ecosystem services rarely included in economic analyses?

What is the single greatest threat to biodiversity?

Use the following figure to answer the question. According to the figure, which two consecutive years had the largest change in the population growth rate?

Which of the following conditions is the most likely indicator of a population in an extinction vortex?