托福口语 Task 4

Today, we're going to talk about a fascinating concept in biology called 'mimicry.' Now, mimicry is when one species evolves to resemble another species, often for protection. There are two main types: Batesian mimicry and Müllerian mimicry. Let me give you two examples to clarify. First, consider the harmless scarlet kingsnake. It has bright red, yellow, and black bands, very similar to the venomous coral snake. Predators learn to avoid the coral snake's colors, and the kingsnake, though harmless, benefits from this resemblance. That's Batesian mimicry, where a harmless species mimics a dangerous one. Second, think of the monarch butterfly and the viceroy butterfly. Both are distasteful to birds because they eat toxic plants as caterpillars. They resemble each other, and this shared warning coloration helps both species. Predators quickly learn to avoid any butterfly with those colors, so both species benefit. This is Müllerian mimicry, where two dangerous species mimic each other to reinforce the warning signal. So, the professor's main point is that mimicry can evolve in different ways depending on whether the mimicking species is harmful or harmless.