托福口语 Task 4

Today, we're going to talk about a fascinating concept in animal behavior called 'sensory exploitation.' This theory suggests that certain traits in animals evolved not because they help the animal survive, but because they exploit pre-existing biases in the sensory systems of other animals, particularly for mating purposes. Let me give you two examples. First, consider the male túngara frog. Females are naturally attracted to the 'chuck' part of the male's call because it stimulates a part of their brain that responds to low-frequency sounds, which in nature might indicate a predator. Males that add the 'chuck' are more successful at attracting mates, even though it makes them more vulnerable to predators. Second, think about the swordtail fish. Females have an innate preference for a long, sword-like extension on the tail, likely because it mimics a food source. Males that have a longer sword are more likely to be chosen, even though the sword makes swimming harder. In both cases, the trait evolved to exploit what females already had a sensory bias for.