托福口语 Task 4

Today, we're going to talk about a fascinating concept in biology called 'mimicry', specifically when a harmless species evolves to imitate a dangerous or poisonous one. This is called Batesian mimicry. The main point is that this imitation helps the harmless species survive because predators learn to avoid the harmful appearance. Let me give you two examples. First, consider the scarlet king snake, which is harmless, but it has red, yellow, and black bands very similar to the venomous coral snake. Birds and other predators that have encountered the coral snake will avoid anything that looks like it, so the king snake benefits from this resemblance. Second, think about the hoverfly, which is a harmless insect that has yellow and black stripes, just like a wasp. Although the hoverfly cannot sting, its appearance makes predators think it can, so they leave it alone. In both cases, the key is that the mimic's survival depends on the predator having learned to avoid the model, so the mimic must be less common than the dangerous species to maintain the deception.