托福口语 Task 4

Today, we're going to discuss a fascinating concept in biology called 'mimicry,' specifically when a harmless species evolves to resemble a harmful one. This is known as Batesian mimicry. The main point is that this adaptation increases the harmless species' chances of survival because predators learn to avoid the harmful appearance and then also avoid the harmless look-alike. Let me give you two clear examples. First, consider the scarlet king snake, which is non-venomous and harmless. It has bright red, yellow, and black bands, very similar to the venomous coral snake. Predators, like birds, that have had a bad experience with the coral snake will steer clear of anything that looks like it, including the king snake. Second, there's a type of moth called the clearwing moth. It has transparent wings and a black and yellow striped body, mimicking a wasp. Wasps can sting, so birds avoid them. The clearwing moth, by looking like a wasp, is also avoided, even though it can't sting at all. In both cases, the harmless species gains protection by imitating a dangerous one.