托福口语 Task 3

In biology, the concept of 'mimicry' refers to the resemblance of one organism to another, often to gain a survival advantage. There are two main types: Batesian mimicry, where a harmless species imitates a harmful one to deter predators, and Müllerian mimicry, where two harmful species evolve to look alike, reinforcing avoidance learning in predators. Both types rely on predators learning to associate certain visual cues with danger.

Professor: Let me give you an example from a rainforest in South America. There’s a butterfly called the monarch, which tastes terrible to birds because it eats toxic plants. After a bird tries to eat a monarch, it gets sick and learns to avoid that butterfly’s bright orange and black pattern. Now, there’s another butterfly, the viceroy, which is actually harmless—it doesn’t eat toxic plants. But over time, the viceroy evolved to look almost identical to the monarch, with the same orange and black pattern. So, birds that have already learned to avoid monarchs also avoid viceroys. This gives the viceroy a survival advantage without any toxicity.