TOEFL Speaking Task 3

In biology, the concept of “mimicry” refers to the close external resemblance of one organism, the mimic, to another, the model, which confers a survival advantage. Often, this resemblance is visual and helps the mimic avoid predators that have learned to avoid the model. The advantage arises because predators mistake the mimic for the model, which may be toxic, dangerous, or otherwise unpalatable. Mimicry is an evolutionary adaptation driven by natural selection, where individuals with a closer resemblance to the model are more likely to survive and reproduce.

Professor: Let me give you a classic example. The harmless milk snake lives in the same region as the deadly coral snake. Both have similar bands of red, yellow, and black, but the order differs. Coral snakes have red touching yellow, while milk snakes have red touching black. Predators, like birds, learn to avoid coral snakes after a painful experience. They generalize that pattern to any snake with similar bright bands. So when a bird sees a milk snake, it hesitates and leaves it alone, even though the milk snake is harmless. This resemblance protects the milk snake from predators, allowing it to survive and reproduce more successfully. Over generations, milk snakes with banding more similar to coral snakes were favored, reinforcing the pattern. So the milk snake is a clear case of mimicry.