LSAT Explanation PT 31, S2, Q12: Some biologists believe that the capacity

LSAT Question Stem

Which one of the following most accurately describes the role played in the passage by the claim that nonmarine reptiles have scales? 

Logical Reasoning Question Type

This is an Argument Part question. 

Correct Answer

The correct answer to this question is A. 

LSAT Question Complete Explanation

Let's first analyze the argument in the passage. The argument discusses the development of the capacity for flight in reptiles. There are two main groups of biologists mentioned: those who believe flight first developed in marine reptiles and those who believe it first developed in tree-dwelling reptiles. The author sides with the latter group, as evidenced by the statement "Other biologists rightly reject this suggestion." So, the conclusion of the argument is: The capacity for flight did not first develop in marine reptiles.

Now, let's break down the premises that support this conclusion:

1. Feathers are developed from scales (according to some biologists).

2. Bats have no scales, and nonmarine reptiles also have scales.

3. Tree-dwelling reptiles developed wings to assist their leaps from branch to branch (according to some biologists).

The question type is Argument Part, asking us to identify the role played by the claim that nonmarine reptiles have scales in the passage. Let's evaluate each answer choice:

a) It is cited as evidence against the claim that the capacity for flight first developed in marine reptiles.

This answer choice is correct. The fact that nonmarine reptiles have scales is presented as evidence against the idea that flight first developed in marine reptiles due to the presence of scales.

b) It is cited as evidence against the claim that the capacity for flight first developed in land-dwelling animals.

This answer choice is incorrect because the passage does not argue against the development of flight in land-dwelling animals. Instead, it focuses on the disagreement between marine and tree-dwelling reptiles.

c) It is cited as evidence against the claim that the capacity for flight first developed in tree-dwelling reptiles.

This answer choice is incorrect because the passage does not use the fact that nonmarine reptiles have scales as evidence against the development of flight in tree-dwelling reptiles. In fact, the author sides with the tree-dwelling reptile theory.

d) It weakens the claim that tree-dwelling reptiles were the first kind of reptile to develop the capacity for flight.

This answer choice is incorrect because the claim that nonmarine reptiles have scales does not weaken the tree-dwelling reptile theory. Instead, it supports the author's conclusion that flight did not first develop in marine reptiles.

e) It corroborates the observation that some mammals without scales, such as bats, developed the capacity to fly.

This answer choice is incorrect because the passage does not use the fact that nonmarine reptiles have scales to support the observation that mammals without scales can fly. Instead, it is used to argue against the marine reptile theory.

Therefore, the correct answer is A. The claim that nonmarine reptiles have scales is cited as evidence against the claim that the capacity for flight first developed in marine reptiles.