托福口语 Task 3

In biology, the concept of 'mimicry' refers to the close external resemblance of one organism to another, which confers a survival advantage. Often, a harmless species mimics a dangerous or unpalatable one to deter predators. This is called Batesian mimicry. The mimic gains protection because predators learn to avoid the model species and mistakenly avoid the mimic as well. The effectiveness relies on the predator’s prior experience with the model and the mimic’s similarity in appearance, behavior, or both.

Professor: Let me give you a classic example from the rainforest. The harmless king snake is a Batesian mimic of the venomous coral snake. Coral snakes have bright red, yellow, and black bands, and predators like birds learn to avoid them after a painful or lethal encounter. The king snake, however, is not venomous, but it has the same striking band pattern—red, yellow, and black—in nearly the same order. When a young hawk first sees a king snake, it hesitates, because the pattern reminds it of the coral snake it once attacked and regretted. This hesitation allows the king snake to slither away unharmed. In areas where coral snakes are rare, king snakes are attacked more often, proving that the mimicry only works when the predator has learned to fear the model.