托福口语 Task 4

Today we're going to talk about a fascinating concept in animal behavior called 'sensory exploitation.' This idea suggests that in some species, males have evolved certain traits not because they directly help in survival, but because they exploit pre-existing sensory biases in females. In other words, females already have a preference for certain signals, and males evolve to take advantage of that. Let me give you two examples. First, consider the guppy. Female guppies are naturally attracted to orange spots, which in their environment happen to resemble their favorite food—small orange fruits that fall into the water. Males with more orange spots are more likely to be chosen by females, even though the spots don't indicate better health or genes. Second, think of the túngara frog. Female frogs are drawn to a specific 'whine' sound, which is similar to the calls of a predatory bird they avoid. Males add a 'chuck' to their call, which actually makes them more attractive to females, even though it also makes them more noticeable to predators. In both cases, the males' traits evolved to exploit females' existing preferences, not to signal quality.