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, but I want to focus on two: Batesian mimicry and Müllerian mimicry. Let me explain with examples. First, Batesian mimicry occurs when a harmless species imitates a dangerous or poisonous one to avoid predators. For instance, the scarlet king snake is non-venomous, but it has red, yellow, and black bands that closely resemble the venomous coral snake. Predators, like birds, learn to avoid the coral snake's bright warning colors, and they also avoid the king snake, thinking it's dangerous. This protects the king snake from being eaten. Second, Müllerian mimicry happens when two or more harmful species evolve to look similar, reinforcing the warning signal. A classic example is the monarch and viceroy butterflies. Both are toxic to birds, and they share similar orange and black wing patterns. Since predators learn to avoid them after a bad experience with one, they avoid both, which benefits both species. So, the main point is that mimicry can evolve in different ways—either by deceiving predators or by sharing the cost of warning them—both leading to increased survival.