LSAT Explanation PT 24, S2, Q15: The authors of a recent article

LSAT Question Stem

Which one of the following is the main point of the argument? 

Logical Reasoning Question Type

This is a Main Conclusion question. 

Correct Answer

The correct answer to this question is A. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. The passage begins by presenting a recent article's claim that there is no evidence supporting the idea that the rate of extinction of animal species is accelerating. This claim serves as a premise. The author of the passage then disputes this claim by stating "They are wrong, however." This statement serves as the conclusion. The author then provides data on fishes to support their conclusion, which serves as a premise.

In simpler terms, imagine a group of people who claim there's no evidence that a certain type of candy is becoming more popular. However, you disagree and provide data on the increasing sales of that candy to support your disagreement. The structure of this argument is similar to the one in the passage.

Now, let's discuss the question type and what it's asking us to do. This is a Main Conclusion question, which asks us to identify the main point of the argument.

Let's analyze each answer choice:

a) There is evidence that the rate of extinction of animal species is accelerating.

This answer choice directly supports the author's conclusion that the recent article's authors are wrong. The author provides data on fishes to demonstrate that there is evidence of accelerating extinction rates. This answer choice is correct.

b) The future rate of extinction of animal species cannot be determined from available evidence.

This answer choice may seem tempting, but it's not the main point of the argument. The author's focus is on disputing the claim that there's no evidence for accelerating extinction rates, not on the future rate of extinction. This answer choice is incorrect.

c) The rate of extinction of North American fishes is parallel to the rate of extinction of all animal species taken together.

While the author uses data on North American fishes to support their conclusion, this answer choice incorrectly assumes that the data on fishes is directly parallel to all animal species. The main point of the argument is not about establishing this parallel. This answer choice is incorrect.

d) Forty species and subspecies of North American fishes have vanished in the twentieth century.

This answer choice simply restates a premise provided by the author to support their conclusion. It's not the main point of the argument. This answer choice is incorrect.

e) A substantial number of fish species are in danger of imminent extinction.

This answer choice might seem related to the argument, but it's not the main point. The author is focused on disputing the claim that there's no evidence of accelerating extinction rates, not on the imminent extinction of fish species. This answer choice is incorrect.

In conclusion, the correct answer is A: There is evidence that the rate of extinction of animal species is accelerating. This answer choice aligns with the author's conclusion that the recent article's authors are wrong and provides a clear summary of the main point of the argument.