PrepTest 126, Section 1, Question 5
Many scientists believe that bipedal locomotion (walking on(100 more words not shown)
Which one of the following(8 more words not shown)
- AFor early hominids,(9 more words not shown)
- BBipedal locomotion would(6 more words not shown)
- CBipedal locomotion actually(11 more words not shown)
- DBipedal locomotion probably(9 more words not shown)
- EFor early hominids,(13 more words not shown)
Reading the argument
Standing up could help you see over tall grass. You might spot food or notice a predator before it reaches you. I can understand why scientists would connect walking on two feet with a move into grasslands.
But that doesn't settle why the change happened. Standing also could help an early hominid reach food in a forest. And the passage raises another possibility: standing upright might have improved the chance of finding a mate. A useful feature can have several benefits; naming one doesn't establish which benefit explains its origin. I'd want more evidence. Is there a fossil record that would help distinguish these possibilities? The passage doesn't answer that question, so we shouldn't choose a favorite origin story ourselves.
What we’re looking for
Now we're asked what the information most supports. We don't have to resolve the debate, and the answer doesn't have to summarize the entire passage. A smaller point that the passage actually establishes will do. Keep the uncertainty about origins separate from the benefits it tells us walking upright would have had.
Working the answers
- A
Helping with life in both environments doesn't tell us which environment was generally easier to live in. The passage never compares the overall hospitality of forests and grasslands. Either environment could have had other advantages or dangers.
- BCorrect
The passage gives us food benefits in both settings: seeing over grass helps locate food, and standing in a forest helps reach it. We can accept that walking on two feet would help gather food even while remaining unsure why it evolved. This is a supported detail; it doesn't need to settle the larger debate.
- C
The passage explicitly gives advantages in grasslands, including locating food and avoiding predators. Its uncertainty concerns whether those advantages explain the origin of bipedalism. Questioning an explanation for a feature isn't the same as denying that the feature would be useful.
- D
The forest explanation is a possibility. The author doesn't say it is probably correct, much less establish that the relevant hominids lived exclusively in forests. The alternative explanations remain open, so we can't promote one of them into the likely answer.
- E
Finding food and avoiding predators both appear as benefits. Nothing ranks one as more important to survival than the other. We might have opinions about that comparison, but this question asks what the passage supports. It never makes the comparison.
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