Logical Reasoning

PT122 · S1 · Q8 Vervet monkeys use different alarm

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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.

Given that

Vervet monkeys use alarm calls to warn each other of nearby predators.

Why is it that

They use different calls depending on whether the danger comes from land or from the air?

Evaluate

When it comes to animal traits / behaviors, we assume they are the result of natural selection and so we assume that they exist because they carry some sort of adaptive value (i.e. they help the organism to survive and eventually reproduce).

Goal

We need some distinction between predators attacking via land vs. via air, so that we can understand why it would be useful for vervet monkeys to have different calls.

8.

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

  1. By varying the pitch of

    No Impact

    Signaling how many predators are coming is a different distinction from signaling where they are coming from. This doesn't give us any story for why it's useful for the vervet monkey to have too different warning calls for predators, based on land vs. air.

    3% picked this

  2. Different land-based predators are responsible

    Irrelevant Comparison

    This compares land predators to one another. We need a distinction between land predators / air predators (such that they merit different warning calls to other vervet monkeys), not a distinction between one land predator and another.

    0% picked this

  3. No predators that pose a

    No Impact

    Knowing that no predator attacks from both directions makes the two categories clean, but it does not explain why distinguishing them is useful.

    19% picked this

  4. Correct

    Vervet monkeys avoid land-based predators

    Why this is right

    If the escape maneuver depends on where the threat comes from, a warning that names the direction tells every monkey which way to run. That explains why it's useful to have two different warning calls.

    Skill tested: Paradox · how this choice captures the argument's function is the move to repeat next time.

    76% picked this

  5. Certain land-based predators feed only

    Irrelevant Comparison

    What a predator eats besides vervet monkeys has no bearing on what a vervet monkey should do when it shows up. A specialist and a generalist predator are equally dangerous in the moment of attacking a vervet monkey, so this difference gives the monkeys no reason to warn each other differently depending on whether it's a land or air predator. There's no value to, "Watch out -- it's a predator that feeds on many different animals that's attacking you right now!"

    1% picked this

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