LR Question 25 Explanation
QUESTION TEXT: By examining fossilized beetles, a research team has…
QUESTION TYPE: Necessary Assumption
CONCLUSION: A research team has determined the maximum summer temperatures in Britain over the past 22,000 years.
REASONING: The researchers looked at fossils of beetles that still exist in the present. The researchers then looked at the temperature tolerances of the present beetles. When several fossils of different species were dated to the same period researchers were able to tell what the max temperature was by using the temperature tolerances of present-day beetles.
ANALYSIS: The argument is assuming that temperature tolerances of the beetles haven’t changed over the years.
___________
- It doesn’t matter. We just need to know what the max temperature is for each species of beetle.
- They’re not assuming this. In fact, the researchers are able to date each fossil. They don’t have to make assumptions.
- The process doesn’t have to be more accurate for beetles as long as it is accurate for beetles.
- This sound nice but its wrong. The temperature tolerance of the least tolerant beetle would determine the max summer temperature. If a beetle that could only survive 20 degrees Celsius existed then summer temperatures couldn’t have been over 20. It doesn’t matter if other beetles could survive higher temperatures.
- CORRECT. The researchers based temperature tolerances on their knowledge of present day beetles. But 22,000 years is a long time. The fossilized beetles might have had different temperature tolerances from their present day counterparts. If so then the study is flawed.
Recap: The question begins with “By examining fossilized beetles, a research team has”. It is a Necessary Assumption question. Learn how to master LSAT Necessary questions on the LSAT Logical Reasoning question types page.
I see another assumption, which has a similarity to answer D. I do not see this assumption addressed in other forums.
This weird dating method seems to assume the beetles survived that max temp. But we are looking at fossils. I do not see an issue if Species A died at 110F, and Species B survived to 120F. The experiment assumes the max temp would have been 110F.
I get AC ‘D’ is overly specific in calculating an average.
AC ‘E’ is a necessary assumption, and therefore I guess the best choice. It appears only better than AC ‘D’ in that D is overly specific, yet addresses another necessary assumption.
You seem to have a good grasp of each answer choice, so I won’t re-explain D and E (though I’m happy to answer any questions if you have specific ones). But I think where your reasoning falls off is that D can’t be “overly specific” and still a necessary assumption. Those two things are mutually exclusive. Either it’s a necessary assumption or it’s wrong. D misinterprets the method used, so it’s not a necessary assumption.
Saying that “E is a necessary assumption but only better than D in that D is overly specific” is like saying “E is a necessary assumption but only better than D in that D is wrong (or D is not a necessary assumption).” That’s the entire point. If there’s a flaw with an answer choice that doesn’t align with the stimulus, that precludes it from being a necessary assumption, so it’s a wrong answer.
I also wouldn’t say D is “overly specific” – it entirely mischaracterizes the method used.