托福口语 Task 4

Today we're going to talk about a fascinating concept in biology called 'mimicry', where one species evolves to resemble another. There are two main types: Batesian mimicry and Mullerian mimicry. Let me give you concrete examples. First, consider the scarlet king snake, which is harmless. It has evolved to look almost identical to the venomous coral snake. Both have red, yellow, and black bands, but in different orders. Predators learn to avoid the coral snake's bright warning colors, and because the king snake looks so similar, predators also avoid it. This is Batesian mimicry, where a harmless species gains protection by imitating a dangerous one. Now, for Mullerian mimicry, think of two different species of stinging wasps: the yellow jacket and the paper wasp. Both are actually dangerous—they can sting. Over time, they've evolved to share similar black-and-yellow warning patterns. This benefits both because predators only need to learn one warning signal to avoid all stinging wasps, reducing the number of attacks each species faces. So, the key point is that mimicry can involve either a harmless species copying a harmful one, or two harmful species converging on the same warning signal.