托福口语 Task 4

Today we're going to talk about a fascinating concept in animal behavior known as 'sensory exploitation.' This occurs when a male animal's courtship signal evolves to exploit a pre-existing sensory bias in the female, rather than the signal being a new invention. Essentially, the male's display triggers a response that females already have for other reasons. Let me give you two examples. First, consider the water mite. Female water mites are naturally attracted to vibrations that mimic their prey, because it helps them find food. Male water mites have evolved to produce similar vibrations during courtship, which tricks the females into approaching, facilitating mating. Second, think about the swordtail fish. Females of a closely related species already have a preference for longer bodies, likely because larger mates offer advantages. In swordtails, males have evolved a long 'sword' extending from their tail fin, which exaggerates this existing preference. When females see a male with a longer sword, their pre-existing preference is triggered, making them more likely to choose that male. So in both cases, males are not creating a new attraction but are tapping into an existing sensory system.