托福口语 Task 4

Today we're going to talk about a fascinating concept in biology called 'mimicry.' Mimicry is when one species evolves to look or behave like another species, often to gain a survival advantage. There are two main types: Batesian mimicry and Müllerian mimicry. Let me explain each with an example. Batesian mimicry occurs when a harmless species mimics a dangerous or unpalatable species to fool predators. For instance, the scarlet king snake, which is harmless, has red, yellow, and black bands very similar to the venomous coral snake. Predators learn to avoid the coral snake's bright colors, and they also avoid the king snake, thinking it's dangerous. On the other hand, Müllerian mimicry happens when two or more harmful species evolve to look alike. This benefits all of them because predators learn to avoid the shared warning pattern more quickly. For example, two species of poisonous butterflies in South America—the monarch and the viceroy—both have similar orange and black patterns. Even though both are toxic to birds, by resembling each other, they reinforce the warning signal, so birds need only one bad experience to learn to avoid both species.