托福口语 Task 4

Today, we're going to talk about a fascinating concept in biology called 'mimicry'. Mimicry occurs when one species evolves to resemble another species, often to gain a survival advantage. There are two main types of mimicry: Batesian and Müllerian. Let me give you two examples to clarify. First, consider the harmless milk snake. It has evolved to look like the venomous coral snake, with similar red, yellow, and black bands. Predators, having learned to avoid the coral snake, also avoid the milk snake. This is Batesian mimicry, where a harmless species mimics a dangerous one. Second, think of two species of stinging wasps—the yellow jacket and the paper wasp. Both are actually dangerous, but they share similar warning colors—bright yellow and black stripes. Predators that have encountered one species learn to avoid both, and each species benefits from the other's reputation. This is Müllerian mimicry, where two harmful species mimic each other. So, the key point is that mimicry can arise in different ways, depending on the level of danger of the species involved.