LSAT Explanation PT 29, S1, Q11: It is well known that many

LSAT Question Stem

Of the following, which one most accurately expresses 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 C. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. The passage begins with a common assumption that only the most highly evolved species alter their environment in ways that aid their own survival. However, the author counters this assumption by providing an example of plankton, which generate a gas that forms clouds, leading to a cooler Earth's surface that benefits the plankton. The author argues that this characteristic of altering the environment for survival is not limited to the most highly evolved species.

Now, let's identify the parts of the argument. The premise is the example of plankton generating gas that forms clouds and cools the Earth's surface. The conclusion is that altering the environment for survival is not limited to the most highly evolved species.

The question type is Main Conclusion, which asks us to identify the statement that most accurately expresses the main point of the argument. Let's analyze each answer choice:

a) The Earth would be far warmer than it is now if certain species of plankton became extinct.

- This answer choice might be an inference, but it is not the main point of the argument. The main point is about the assumption regarding highly evolved species and their ability to alter the environment for survival.

b) By altering their environment in ways that improve their chances of survival, certain species of plankton benefit the Earth as a whole.

- This answer choice focuses on the benefits of plankton to the Earth, but it does not address the main point of the argument, which is about the assumption regarding highly evolved species and their ability to alter the environment for survival.

c) Improving their own chances of survival by altering the environment is not limited to the most highly evolved species.

- This answer choice directly addresses the main point of the argument, which is countering the assumption that only the most highly evolved species alter their environment for survival. This is the correct answer.

d) The extent of the cloud cover over the oceans is largely determined by the quantity of plankton in those oceans.

- While this statement is related to the example provided in the passage, it does not express the main point of the argument, which is about the assumption regarding highly evolved species and their ability to alter the environment for survival.

e) Species such as plankton alter the environment in ways that are less detrimental to the well-being of other species than are the alterations to the environment made by more highly evolved species.

- This answer choice introduces a comparison of the effects of alterations made by plankton and more highly evolved species, which is not the main point of the argument. The main point is about the assumption regarding highly evolved species and their ability to alter the environment for survival.

In conclusion, the correct answer is C, as it most accurately expresses the main point of the argument, which is that improving their own chances of survival by altering the environment is not limited to the most highly evolved species.