PrepTest 126, Section 3, Question 11
Biologist: Many paleontologists have suggested that the difficulty(36 more words not shown)
The biologist's argument is most(10 more words not shown)
- AIt fails to(30 more words not shown)
- BIt fails to(25 more words not shown)
- CIt overlooks the(25 more words not shown)
- DIt presumes without(19 more words not shown)
- EIt takes for(23 more words not shown)
Reading the argument
Why must humans adapt in the same way as other animals?
The paleontologists suggest that the challenge of ice ages helped drive changes in the human brain. Maybe. We could ask about timing or other possible causes before accepting that explanation. But the biologist rejects it for a different reason: most other species managed to adapt without evolutionary changes to their brains.
That doesn't settle what happened in humans. Imagine that the same environmental challenge produced one kind of adaptation in humans and a different adaptation in another species. The fact that a mammoth or a saber-toothed tiger didn't undergo our kind of brain change wouldn't show that humans couldn't. Different species can respond differently to the same condition.
What we’re looking for
For the flaw question, keep the target straight. We're evaluating the biologist's rejection, not the paleontologists' original proposal. The biologist treats the absence of this change in most other species as a reason to rule out this explanation for humans. That's the move the answer needs to question.
Working the answers
- A
This concerns whether one cause is the only way to produce a change. It would matter if the argument said that an ice age can produce brain changes, so those changes cannot happen without an ice age. The biologist doesn't argue that. The comparison is between species facing the condition, not between possible ways a single species could change.
- BCorrect
The condition is adapting to an ice age; the change is the evolution of the brain. That condition could produce the change in humans without producing it in other species. B directly challenges the assumption that their different response rules out the proposed explanation for us.
- C
This asks whether a condition needed for a change in one species is also needed in another. But the biologist hasn't claimed that an ice age is required for any species' brain to evolve. The problem is ruling out its effect in humans because other species adapted differently, not assuming that all species need the same trigger.
- D
The biologist doesn't claim that humans faced greater difficulties. The reasoning could be offered even if all the species faced equally difficult conditions. We need to challenge the assumed similarity in how they adapt, not attribute a comparison of difficulty that the argument never makes.
- E
This describes inferring a cause just because two things happened together. That could be an objection to a different argument for the paleontologists' theory. Our biologist is rejecting that proposed cause, using other species as the reason. E attacks a causal inference the biologist doesn't make.
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