LSAT Explanation PT 41, S1, Q8: Vervet monkeys use different alarm calls

LSAT Question Stem

Which one of the following, if true, contributes most to an explanation of the behavior of vervet monkeys described above? 

Logical Reasoning Question Type

This is a Paradox question. 

Correct Answer

The correct answer to this question is D. 

LSAT Question Complete Explanation

The question type for this problem is Paradox, which means we are looking for an answer choice that helps explain or resolve the paradox presented in the passage. The passage tells us that vervet monkeys use different alarm calls to warn each other of nearby predators, depending on whether the danger comes from land or from the air. Our task is to find an explanation for this behavior.

To make this concept more relatable, let's think of it like a group of people who use different warning signals for different types of dangers, such as one signal for a fire and another for an intruder. The question now becomes, why would they need different signals for different dangers?

Now let's examine the answer choices:

a) By varying the pitch of its alarm call, a vervet monkey can indicate the number of predators approaching.

- This choice provides additional information about the monkey's call, but it doesn't explain why they need two different warning signals for land and air predators. So, this answer choice is incorrect.

b) Different land-based predators are responsible for different numbers of vervet monkey deaths.

- This choice doesn't offer a reason for having two different predator calls; it just tells us that different land-based predators cause different numbers of deaths. This doesn't help explain the behavior, so it is incorrect.

c) No predators that pose a danger to vervet monkeys can attack both from land and from the air.

- This answer choice doesn't resolve the paradox; in fact, it makes it more puzzling. If there were a common predator that could attack from both land and air, that could explain the need for different calls. Since this choice says there isn't such a predator, the paradox remains unresolved, making this choice incorrect.

d) Vervet monkeys avoid land-based predators by climbing trees but avoid predation from the air by diving into foliage.

- This is the correct answer choice. It provides a logical reason for the monkeys to have different warning calls: they have different strategies for dealing with land and air predators. This would explain why they developed two separate alarm calls, one for each type of predator.

e) Certain land-based predators feed only on vervet monkeys, whereas every predator that attacks vervet monkeys from the air feeds on many different animals.

- This choice reinforces the fact that there are both land and air predators of vervet monkeys, but we already knew that from the passage. It doesn't explain why they have two different warning calls, so it doesn't answer the question and is incorrect.

In conclusion, the correct answer choice is (d), which provides a clear explanation for the vervet monkeys' behavior of using different alarm calls for land and air predators. They have different strategies for dealing with each type of predator, so it makes sense for them to have separate warning signals.