托福口语 Task 4

Today, we're going to talk about a fascinating concept in animal behavior called 'sensory exploitation.' This is when a male animal evolves a trait that appeals to a pre-existing sensory bias in the female, not because the trait signals quality, but simply because it triggers a response that females already have. Let me give you two examples. First, consider the guppy. Female guppies naturally prefer orange objects—this likely evolved because orange foods like certain fruits and insects are nutritious. Male guppies exploit this by developing bright orange spots. These spots don't indicate health or strength; they just match the females' existing preference for orange. Second, look at the túngara frog. Female frogs are attracted to a specific 'chuck' sound, which is similar to the sound of rain—a cue that signals good breeding conditions. Males produce this chuck at the end of their calls to exploit that attraction. In both cases, the males' traits are not about quality but about tapping into females' pre-existing sensory biases.