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 dangerous one to avoid predators, and Müllerian mimicry, where two harmful species evolve to look alike, reinforcing predator avoidance. Mimicry is an adaptive trait shaped by natural selection.

Professor: Today, let's look at a real example of mimicry. Consider the monarch butterfly and the viceroy butterfly. Monarchs are toxic to birds because they feed on milkweed, storing toxins. Birds learn to avoid them after tasting one. Viceroys, on the other hand, are not toxic, but they closely resemble monarchs in color and pattern. This is Batesian mimicry—viceroys gain protection because birds mistake them for monarchs and avoid eating them. Interestingly, recent research shows that viceroys may also be mildly toxic, suggesting a possible shift toward Müllerian mimicry, but the classic case remains a clear illustration of Batesian mimicry.