1. Extinction is a process that can depend on a variety of ecological, geographical, and physiological variables. These variables affect different species of organisms in different ways, and should, therefore, yield a random pattern of extinctions. However, the fossil record shows that extinction occurs in a surprisingly definite pattern, with many species vanishing at the same time.
Which of the following, if true, forms the best basis for at least a partial explanation of the patterned extinctions revealed by the fossil record?
(A) Major episodes of extinction can result from widespread environmental disturbances that affect numerous different species.
(B) Certain extinction episodes selectively affect organisms with particular sets of characteristics unique to their species.
(C) Some species become extinct because of accumulated gradual changes in their local environments.
(D) In geologically recent times, for which there is no fossil record, human intervention has changed the pattern of extinctions.
(E) Species that are widely dispersed are the least likely to become extinct.
2.(Z)When a new restaurant, Martin’s Cafe, opened in Riverville last year, many people predicted that business at the Wildflower Inn, Riverville’s only other restaurant, would suffer from the competition. Surprisingly, however, in the year since Martin’s Cafe opened, the average number of meals per night served at the Wildflower Inn has increased significantly.
Which of the following, if true, most helps to explain the increase?
A. Unlike the Wildflower Inn, Martin’s Cafe serves considerably more meals on weekends than it does on weekdays.
B. Most of the customers of Martin’s Cafe had never dined in Riverville before this restaurant opened, and on most days Martin’s Cafe attracts more customers than it can seat.
C. The profit per meal is higher, on average, for meals served at Martin’s Cafe than for those served at the Wildflower Inn.
D. The Wildflower Inn is not open on Sundays, and therefore Riverville residents who choose to dine out on that day must either eat at Martin’s Cafe or go to neighboring towns to eat.
E. A significant proportion of the staff at Martin’s Cafe are people who formerly worked at the Wildflower Inn and were hired away by the owner of Martin’s Cafe.
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