Listen to part of a lecture in a biology class. Professor: Today we’re going to talk about mimicry, specifically Batesian mimicry. This is a phenomenon where a harmless species evolves to imitate the warning signals of a harmful species to avoid predators. For example, the viceroy butterfly mimics the monarch butterfly. Monarchs are toxic to birds because they feed on milkweed, which contains cardiac glycosides. Birds learn to avoid monarchs after a bad experience. The viceroy, which is not toxic, gains protection by looking similar. However, recent research has shown that this is not a perfect example—viceroys are actually distasteful to some birds as well. So, true Batesian mimicry requires that the mimic is completely harmless. Another classic example is the scarlet king snake, which mimics the coral snake. Coral snakes have a distinct pattern of red, yellow, and black bands. King snakes are harmless but share the same color pattern. Birds that have encountered coral snakes avoid the king snake. This is a clear case of Batesian mimicry. Now, what’s interesting is that the mimicry works best when the model is common and the mimic is rare. If the mimic becomes too common, predators may start to associate the pattern with a safe meal, and the protection breaks down. This is called frequency-dependent selection. Any questions?
❓ 题目 What does the professor say about the viceroy butterfly’s mimicry of the monarch butterfly?
A. It is a perfect example of Batesian mimicry.
B. It is not a classic case because the viceroy is also distasteful.
C. It works because both species are toxic to birds.
D. It relies on the viceroy being more common than the monarch.
✅ 正确答案
It is not a classic case because the viceroy is also distasteful.