托福口语 Task 4

Today, we're going to talk about a fascinating concept in biology called 'mimicry.' Specifically, I want to focus on a type of mimicry where a harmless species evolves to look like a dangerous or unpalatable one to avoid predators. This is known as Batesian mimicry. Let me give you two clear examples. First, consider the scarlet king snake. It is non-venomous, but it has bright red, yellow, and black bands that closely resemble the highly venomous coral snake. Predators, like birds, learn to avoid the coral snake's colors after a bad experience, and they then also avoid the king snake, even though it's harmless. Second, think about the hoverfly. It has black and yellow stripes like a wasp, but it has no stinger. Birds that have been stung by a wasp will steer clear of any insect with that pattern, so the hoverfly benefits from this false warning. In both cases, the harmless species gains protection simply by looking like a more dangerous one.