LSAT Explanation PT 40, S3, Q2: Dr. Theresa Pagano, a biologist, has

LSAT Question Stem

Each of the following, if true, supports Dr. Pagano's reasoning EXCEPT: 

Logical Reasoning Question Type

This is a Strengthen question. 

Correct Answer

The correct answer to this question is C. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. Dr. Pagano observes a correlation between the northward shift of checkerspot butterflies and the northward shift of warm zones in the global climate. Based on this observation, she concludes that the changing climate is responsible for the northward movement of the butterflies. The structure of the argument is as follows:

Premise: The northward shift of the butterflies is almost perfectly correlated with the northward shift of the warm zones in the global climate.

Conclusion: The changing climate is responsible for the northward movement of the butterflies.

To make this concept more accessible, let's consider a simple example. Imagine you observe that every time you turn on your heater, your cat moves closer to it. You might conclude that the warmth from the heater is causing your cat to move closer.

An "Evaluate" question for this argument would be: "Is there any other factor, besides the changing climate, that could be causing the northward movement of the checkerspot butterflies?"

Now let's discuss the question type and what it's asking us to do. This is a StrengthenX question, meaning we need to find the answer choice that does NOT strengthen Dr. Pagano's argument.

a) If checkerspot butterflies are critically affected by small temperature changes, this supports Dr. Pagano's conclusion that the changing climate is causing their northward movement. This strengthens the argument and is therefore incorrect.

b) If climate affects the plants that checkerspot butterflies depend on, and these plants thrive best in warm climates, this also supports Dr. Pagano's conclusion. The changing climate indirectly affects the butterflies through their food source. This strengthens the argument and is therefore incorrect.

c) If checkerspot butterflies can adapt easily to a wide range of temperatures and geographic conditions, this suggests that the changing climate might not be the primary cause of their northward movement. This answer choice does NOT strengthen the argument, making it the correct choice.

d) If low average temperatures are correlated with a reduced checkerspot butterfly population, this suggests that the butterflies are affected by temperature changes, supporting Dr. Pagano's conclusion. This strengthens the argument and is therefore incorrect.

e) If other closely related butterfly species survive only in warm climates, this strengthens Dr. Pagano's conclusion by analogy, suggesting that checkerspot butterflies might also be affected by the changing climate. This strengthens the argument and is therefore incorrect.

In summary, the correct answer is (c), as it does not strengthen Dr. Pagano's argument that the changing climate is responsible for the northward movement of the checkerspot butterflies.