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Generalization to Avoid Predators

For animals to avoid predators and stay safe, they need to be able to identify which other animals might be dangerous predators. Animals can sometimes recognize new predators by their similarity to predators they are familiar with. This phenomenon is known as generalization. When they encounter an unfamiliar animal that has the same characteristics as a known predator, they generalize by behaving the same way they would to avoid the known predator. An animal's ability to generalize can vary based on how similar the unfamiliar animals are to the original predators; the more similar they are, the more likely the animal is to generalize.
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Narrator: Now, listen to part of a lecture in a biology class.
Speaker 2: Now, this can be seen in a certain type of small fish called the minnow.
Minnows are hunted by a larger fish called a lake trout.
Some minnows have learned to react to the smell of lake trout, mainly by gathering close together and not moving around much,
because this makes it harder for lake trout to find and eat the minnows.
So, scientists explored the phenomenon we've been talking about by conducting an experiment.
They exposed a group of minnows to the odors of two different kinds of fish that the minnows had never seen before.
One kind was another species of trout called a brook trout, which even though a different species, was still similar in some ways to lake trout.
The other kind of fish was not a trout at all.
It was a totally different kind of fish. So, when the minnows smelled the brook trout, they knew it smelled similar to the lake trout.
So, they behaved the same way as when they smelled the lake trout.
That is, they gathered close together and didn't move much, even though they'd never encountered the brook trout before.
But when they smelled the other type of fish, the one that wasn't a trout, they behaved normally.
They did not respond as if they sensed they were in danger.
Question
Explain how the example of minnows and trout illustrates the concept of generalization to avoid predators.