托福口语 Task 4

Today, we're going to talk about a fascinating concept in biology called 'mimicry'—specifically, how some animals have evolved to imitate other species to survive. There are two main types: Batesian mimicry, where a harmless species mimics a dangerous one to avoid predators, and Mullerian mimicry, where two harmful species evolve to look alike, reinforcing the warning signal. Let me give you an example. First, consider the king snake. It's non-venomous, but it has bright red, yellow, and black bands similar to the deadly coral snake. Predators like birds learn to avoid the coral snake's pattern, so they also avoid the king snake. This is Batesian mimicry. Second, think about two species of stinging wasps—the yellow jacket and the paper wasp. Both are venomous and share similar black-and-yellow stripes. By looking alike, they share the cost of teaching predators to avoid them, because fewer individuals need to be attacked for predators to learn. This is Mullerian mimicry. So, the main point is that mimicry can occur either by bluffing or by cooperation, and both strategies increase survival.