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- Wed Jan 21, 2015 12:00 am
#73603
Complete Question Explanation
Strengthen. The correct answer choice is (B).
The author gives us evidence about some of the local mourning dove nesting habitat being disturbed by sprinklers and abandoned by the birds, and concludes that loss of nesting habitat in the area is probably the cause of the decreased population of the birds in the overall area. We are tasked with finding an answer that would strengthen this causal claim. Good prephrases would probably evoke classic causal reasoning strategies, like eliminating an alternate cause, showing that where the cause is present the effect is also present, etc.
Answer choice (A): This answer might actually weaken the argument by presenting a possible alternate cause for the decreased population of mourning doves. Maybe it isn't a loss of habitat, but that they are now being hunted?
Answer choice (B): This is the correct answer choice. If it is true that the trees in the orchard that the doves abandoned where they only ones that they would want to nest in, this strengthens the claim that there has been an actual loss of habitat in the area. This answer thus eliminates a possible objection, that the doves could have nested somewhere else in the area, and that loss of habitat was therefore less likely to be a cause of their lower population. In essence, this answer means that there is now NO suitable habitat for the birds, and where the effect is present (fewer birds), the cause is also present (no habitat).
Answer choice (C): A tricky answer, one that looks a lot like "where the cause is present, the effect is also present." But is the effect present for Blue Jays? We don't know, because there is no indication that their population has actually decreased in the area! Answer B only confirms that another type of bird left the orchard, which does nothing to strengthen the claim that the loss of that habitat caused a drop in the local population.
Answer choice (D): Another tricky and attractive answer, some students will interpret this one as eliminating a possible alternate cause for the decline in population, a reduction in the local food supply. But it is not clear from this answer that the feeders actually are an important food supply for the birds, nor is it clear that the feeders are just as full as they were before the doves left the orchard. In any event, to the extent that this answer does appear to strengthen the argument, it does so far less than the correct answer, which guarantees that there is no longer any appropriate habitat for the doves.
Answer choice (E): An irrelevant answer, it does not matter where mourning doves often make their nests. This answer gives us no reason to believe that any significant loss of habitat has occurred, and it does not do anything to eliminate other possible causes of the decline in the local population of the birds.
Strengthen. The correct answer choice is (B).
The author gives us evidence about some of the local mourning dove nesting habitat being disturbed by sprinklers and abandoned by the birds, and concludes that loss of nesting habitat in the area is probably the cause of the decreased population of the birds in the overall area. We are tasked with finding an answer that would strengthen this causal claim. Good prephrases would probably evoke classic causal reasoning strategies, like eliminating an alternate cause, showing that where the cause is present the effect is also present, etc.
Answer choice (A): This answer might actually weaken the argument by presenting a possible alternate cause for the decreased population of mourning doves. Maybe it isn't a loss of habitat, but that they are now being hunted?
Answer choice (B): This is the correct answer choice. If it is true that the trees in the orchard that the doves abandoned where they only ones that they would want to nest in, this strengthens the claim that there has been an actual loss of habitat in the area. This answer thus eliminates a possible objection, that the doves could have nested somewhere else in the area, and that loss of habitat was therefore less likely to be a cause of their lower population. In essence, this answer means that there is now NO suitable habitat for the birds, and where the effect is present (fewer birds), the cause is also present (no habitat).
Answer choice (C): A tricky answer, one that looks a lot like "where the cause is present, the effect is also present." But is the effect present for Blue Jays? We don't know, because there is no indication that their population has actually decreased in the area! Answer B only confirms that another type of bird left the orchard, which does nothing to strengthen the claim that the loss of that habitat caused a drop in the local population.
Answer choice (D): Another tricky and attractive answer, some students will interpret this one as eliminating a possible alternate cause for the decline in population, a reduction in the local food supply. But it is not clear from this answer that the feeders actually are an important food supply for the birds, nor is it clear that the feeders are just as full as they were before the doves left the orchard. In any event, to the extent that this answer does appear to strengthen the argument, it does so far less than the correct answer, which guarantees that there is no longer any appropriate habitat for the doves.
Answer choice (E): An irrelevant answer, it does not matter where mourning doves often make their nests. This answer gives us no reason to believe that any significant loss of habitat has occurred, and it does not do anything to eliminate other possible causes of the decline in the local population of the birds.
