QUESTION TEXT: A species in which mutations frequently occur…
QUESTION TYPE: Flawed Parallel Reasoning
CONCLUSION: Frequent mutations ➞ survive
REASONING:
- Frequent mutations ➞ adaptations
- Survive ➞ adaptations
ANALYSIS: This argument takes two conditional statements that share a necessary condition. Then it incorrectly assumes that one of the sufficient conditions leads to the other. Look for this structure:
A ➞ C
B ➞ C
Therefore, A ➞ B.
___________
- Sturdy ➞ properly built ➞ every stone supports another stone
Conclusion: sturdy walls must have every stone supporting another stone
This is a good argument, assuming the conclusion only refers to stone walls. - This is a different flaw; it flips between polar opposites:
* Performed before a completely different audience every time. (i.e. total difference)
* Performed before the same audience every time (i.e. total similarity)
There can be a middle ground: audiences that are somewhat different, but not entirely different. You might get the same reaction from two audiences if they were 98% similar. - CORRECT. This matches exactly:
Perfectly honest
➞ tell truth
Morally upright ➞ tell truthConclusion: Perfectly honest
➞ morally upright - Productive ➞ well drained ➞ good soil
Conclusion: productive ➞ good soil
This is a good argument! - Healthful diet ➞ well balanced ➞ fruits and vegetables
Conclusion: Healthy ➞ fruits and vegetables
This is a bad argument, but it makes a different flaw. Here, the author switches between “healthful diet” and “healthy”. Those are not the same thing. Maybe it’s possible to be healthy despite not eating a healthful diet!
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