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- Sat Jul 01, 2017 1:30 pm
#36777
Complete Question Explanation
Weaken—CE. The correct answer choice is (C)
In this stimulus, the author considers two variables which are correlated, and jumps to the conclusion
that there is a causal relationship:
to weaken a Cause/Effect argument. Since we know the supposed effect in this case (diminishing bird
population and diversity), we might want to keep alternative causes in mind as we consider the answer
choices.
Answer choice (A): This answer choice actually strengthens the argument in the stimulus. If there were
no other natural predators of this species, it seems more likely that the decrease was attributable to the
human presence on the island.
Answer choice (B): This choice strengthens the causal argument, by pointing out that when humans
were not present, species apparently did not disappear as quickly.
Answer choice (C): This is the correct answer choice. A deadly microbe could serve as an alternate
cause for the bird extinctions, thus weakening the causal argument in the stimulus.
Answer choice (D): The birds that the islanders ate likely lived on the island before the islanders’ arrival,
so evidence of the birds’ earlier existence has no effect on the causal argument. This response does not
weaken the author’s argument.
Answer choice (E): The inability to fly would likely make these birds an easier target for their new
human predators, so this answer choice would seem to strengthen the argument in the stimulus. This
choice certainly does not weaken the argument and is therefore incorrect.
Weaken—CE. The correct answer choice is (C)
In this stimulus, the author considers two variables which are correlated, and jumps to the conclusion
that there is a causal relationship:
- Premise: Human arrival on Tiliga Island coincided with decrease in population and diversity of
bird species on the island.
Conclusion: Therefore humans must have caused this decrease.
to weaken a Cause/Effect argument. Since we know the supposed effect in this case (diminishing bird
population and diversity), we might want to keep alternative causes in mind as we consider the answer
choices.
Answer choice (A): This answer choice actually strengthens the argument in the stimulus. If there were
no other natural predators of this species, it seems more likely that the decrease was attributable to the
human presence on the island.
Answer choice (B): This choice strengthens the causal argument, by pointing out that when humans
were not present, species apparently did not disappear as quickly.
Answer choice (C): This is the correct answer choice. A deadly microbe could serve as an alternate
cause for the bird extinctions, thus weakening the causal argument in the stimulus.
Answer choice (D): The birds that the islanders ate likely lived on the island before the islanders’ arrival,
so evidence of the birds’ earlier existence has no effect on the causal argument. This response does not
weaken the author’s argument.
Answer choice (E): The inability to fly would likely make these birds an easier target for their new
human predators, so this answer choice would seem to strengthen the argument in the stimulus. This
choice certainly does not weaken the argument and is therefore incorrect.
We have corrected the text above.