PrepTest 151, Section 3, Question 9
Until recently it was widely believed that only(51 more words not shown)
The reasoning in the argument(11 more words not shown)
- Aequates mere interest(9 more words not shown)
- Btakes for granted(15 more words not shown)
- Ctakes ignorance of(12 more words not shown)
- Doverlooks a crucial(11 more words not shown)
- Epresumes that because(13 more words not shown)
Reading the argument
Did the animals gain a new ability, or did we just find out about it?
Parthenogenesis means reproduction by a female alone. More interest in the subject has led researchers to discover it in species where they didn't expect it. That establishes a change in what we know. It doesn't establish that sharks or Komodo dragons only recently became capable of doing it.
What we’re looking for
For all we know, those species could have had the ability for thousands of years without anyone recognizing it. The discoveries would still be new, even though the ability wasn't. So my prediction for the flaw is a confusion between learning that something occurs and showing that it has newly begun to occur.
Working the answers
- A
Interest and understanding aren't the two things being confused. The argument doesn't say merely becoming interested gives us knowledge; it mentions actual discoveries. The unsupported step comes afterward, when those discoveries are treated as evidence that the ability itself has spread to more species.
- B
The author isn't arguing that one event caused another just because it happened first. We aren't told that researchers' interest caused the animals to acquire the ability, for example. The conclusion claims an increase, and the problem is using new awareness to establish that change in reality.
- CCorrect
The wording may initially seem odd: the conclusion says the number is increasing, rather than explicitly saying something did not occur. But think about what that increase requires. The author treats species we didn't previously know could reproduce this way as species that previously could not do so.
That is the hidden claim about the past. Our former ignorance is being used as evidence of former absence. If sharks and Komodo dragons already had the ability, discovering it now wouldn't show an increase in the number of capable species. C describes the same awareness-versus-reality mistake from its earlier-time side.
- D
The argument isn't treating sharks and Komodo dragons as equivalent and using a fact about one to prove a fact about the other. Both are presented as newly discovered cases. Differences between the species don't resolve the question of when either acquired the ability.
- E
The author doesn't claim the new research is better simply because it's newer. We can accept that the discoveries are accurate and still question what they establish about the past. The mistake is treating a newly discovered ability as a newly acquired one, not ranking new research above old research.
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