托福口语 Task 4

Today, I want to talk about a fascinating concept in biology known as 'mimicry.' Mimicry occurs when one species evolves to resemble another species, often to gain a survival advantage. There are two main types: Batesian mimicry, where a harmless species mimics a harmful one to avoid predators, and Mullerian mimicry, where two harmful species evolve to look alike, reinforcing the warning signal to predators. Let me give you two examples. First, consider the harmless milk snake, which has red, black, and yellow bands, mimicking the deadly coral snake. Predators learn to avoid the coral snake's colors, so they also avoid the milk snake. Second, think of two species of stinging wasps—the yellow jacket and the paper wasp. Both have similar black-and-yellow stripes. By looking alike, they share the cost of teaching predators to avoid them, which benefits both species. So, the key point is that mimicry is a survival strategy shaped by predator behavior, and it can evolve in different ways depending on whether the mimic is harmless or harmful.