托福口语 Task 4

Today, we're going to talk about a fascinating concept in biology called 'mimicry'. Now, mimicry is when one species evolves to look or behave like another species, often for survival. The key point is that mimicry can be used for defense, but the way it works can be quite different depending on the species. Let me give you two examples. First, consider the harmless milk snake. It has evolved to have the same red, yellow, and black banding as the venomous coral snake. Predators learn to avoid the coral snake's bright colors, and they also avoid the milk snake, even though it's harmless. This is called Batesian mimicry, where a harmless species imitates a dangerous one to fool predators. Second, there's the case of the monarch butterfly and the viceroy butterfly. Both are distasteful to birds, but they look strikingly similar. This is Müllerian mimicry, where two unpalatable species share similar warning signals. By looking alike, they both benefit because predators learn more quickly to avoid that pattern, reducing the number of each butterfly that gets eaten during the learning process. So, as you can see, mimicry can be a powerful survival strategy, but the underlying mechanisms and benefits can vary.