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- Thu Apr 14, 2016 11:58 am
#23048
Complete Question Explanation
Assumption. The correct answer choice is (B)
The stimulus reports that what is probably a jawbone of a forest-dwelling primate has been found in Namibia, and concludes that the dry, treeless expanses in that area must have replaced forests.
The argument leaps from what is probable to what is certain, and excludes a number of possibilities. Perhaps the jawbone of the ape was transported to the area in some fashion. Perhaps there was an intervening type of landscape. Since you are asked to identify an assumption, you should look for either the leap from the probable to the certain or for one of the many ignored possibilities.
Answer choice (A): The argument does not need to assume anything about modern apes, since the argument concerns apes 10 to 15 million years ago.
Answer choice (B): This is the correct answer choice. The certainty that the forest-dwelling ape lived in Namibia makes it more likely that Namibia was forested, and if the ape had not lived in Namibia, the ape's fossil might not help prove that Namibia was once forested. For the jawbone to be evidence of the ecology at one time in Namibia, it is necessary that the relevant animal be somehow associated with Namibia.
Answer choice (C): The argument states that the fossil is 10 to 15 million years old, but the argument does not need to assume that no older fossils exist. Actually, if older fossils of apes existed in Namibia, that could improve the argument.
Answer choice (D): Since the researchers deliver their data only concerning ancient apes, similarities to modern apes are irrelevant.
Answer choice (E): The stimulus does not concern whether the apes themselves triggered the collapse of the forest ecology. This choice confuses the issue, and is incorrect.
Assumption. The correct answer choice is (B)
The stimulus reports that what is probably a jawbone of a forest-dwelling primate has been found in Namibia, and concludes that the dry, treeless expanses in that area must have replaced forests.
The argument leaps from what is probable to what is certain, and excludes a number of possibilities. Perhaps the jawbone of the ape was transported to the area in some fashion. Perhaps there was an intervening type of landscape. Since you are asked to identify an assumption, you should look for either the leap from the probable to the certain or for one of the many ignored possibilities.
Answer choice (A): The argument does not need to assume anything about modern apes, since the argument concerns apes 10 to 15 million years ago.
Answer choice (B): This is the correct answer choice. The certainty that the forest-dwelling ape lived in Namibia makes it more likely that Namibia was forested, and if the ape had not lived in Namibia, the ape's fossil might not help prove that Namibia was once forested. For the jawbone to be evidence of the ecology at one time in Namibia, it is necessary that the relevant animal be somehow associated with Namibia.
Answer choice (C): The argument states that the fossil is 10 to 15 million years old, but the argument does not need to assume that no older fossils exist. Actually, if older fossils of apes existed in Namibia, that could improve the argument.
Answer choice (D): Since the researchers deliver their data only concerning ancient apes, similarities to modern apes are irrelevant.
Answer choice (E): The stimulus does not concern whether the apes themselves triggered the collapse of the forest ecology. This choice confuses the issue, and is incorrect.