托福口语 Task 4

Today, we're going to talk about a fascinating concept in biology called 'mimicry'. Mimicry is when one species evolves to look or behave like another species, often to gain a survival advantage. There are many types of mimicry, but today I want to focus on two specific examples that illustrate how mimicry can be used for protection. First, consider the monarch butterfly. Monarchs are toxic to birds because they feed on milkweed, which contains toxins. Birds learn to avoid them after a bad experience. Now, there's another butterfly called the viceroy, which is not toxic, but it has evolved to look almost identical to the monarch. Because birds mistake the viceroy for the monarch, they avoid eating it too. This is called Batesian mimicry, where a harmless species mimics a harmful one. Second, let's look at the king snake. The king snake is not venomous, but it mimics the coral snake, which is highly venomous. The coral snake has a distinctive pattern of red, yellow, and black bands. The king snake has a similar pattern, but the order of the bands is different. Predators that have learned to avoid coral snakes also avoid king snakes. So, in both cases, mimicry provides protection from predators without the species having to develop its own defenses.