PrepTest 123, Section 3, Question 25
Some anthropologists argue that the human species could(52 more words not shown)
The reasoning in the argument(11 more words not shown)
- Aconfuses a condition's(26 more words not shown)
- Btakes for granted(28 more words not shown)
- Cgeneralizes, from the(26 more words not shown)
- Dfails to consider(18 more words not shown)
- Efails to consider(29 more words not shown)
Reading the argument
Maybe that species died out for another reason.
The anthropologists say humans couldn't have survived without the ability to cope with different natural environments. That makes adaptability a requirement. It doesn't make adaptability a guarantee that nothing can wipe a species out.
So when the author points to an adaptable related species that became extinct, I'm not seeing the contradiction. The species could have coped with different environments and still lacked something else it needed. Its extinction doesn't show that humans could have survived without adaptability.
Try a school example. Suppose a school requires an exam score for admission. I submit a score, but the school rejects me. Have I shown that the score wasn't required? No. I might have submitted a score that was too low, or I might have fallen short in another part of the application. Having one required thing doesn't mean I've done enough to get in.
What we’re looking for
The author makes that same mistake with survival: something described as needed is treated as though it should be enough. That's my prediction for the flaw answer. The wording may get abstract, so we'll plug in the ability to cope with different environments and the result of surviving as we read.
Working the answers
- ACorrect
The required condition is the ability to cope with diverse environments. The result is survival. The first case is humans: the anthropologists say that without this ability, humans could not have survived.
The author then looks at a similar case, the related species, and treats having the ability as though it should have been enough to ensure survival. When that species dies out anyway, the author calls the anthropologists wrong. But failing despite having a requirement doesn't show the requirement was unnecessary. Just as a required exam score doesn't guarantee admission, required adaptability doesn't guarantee survival.
- B
The author doesn't assume that another species had this ability simply because humans had it. The passage says there is evidence that the related species thrived in diverse environments. B invents a different inference about how we established the other species' ability; that isn't the step being used to reject the anthropologists' claim.
- C
The author doesn't conclude that all related species survived the same conditions. The example is a species that became extinct, and the conclusion rejects the anthropologists' claim about what humans needed. C describes a sweeping survival claim the author never makes.
- D
Another disadvantage could help explain why the related species died out. That is a reasonable possibility to raise, and it fits the thought that adaptability needn't be enough. But the author isn't trying to give a complete explanation of this species' extinction. The author is using its extinction to reject a claim about what humans required.
A identifies the exact error in that use of the example. Even if we never discover why the other species died out—or whether a characteristic of that species was responsible—we can still see that having a required ability doesn't guarantee survival. D suggests one possible explanation for the extinction; A explains why the extinction doesn't refute the original claim.
- E
This starts with a condition that produced a result and asks whether it was needed in another case. Our argument starts with a claim that the ability was needed for humans to survive, then treats it as enough to make the related species survive. Those are different moves. E doesn't describe the author's shift from “can't survive without it” to “should survive with it.”
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