托福听力

🎧 听力原文

Listen to part of a lecture in a biology class. The professor is discussing animal communication. Professor: Today, let's talk about how some animals use visual signals, not just sounds or smells, to communicate. For example, consider the cuttlefish. Cuttlefish can change their skin color and pattern almost instantly. This ability serves multiple purposes. One is camouflage, to blend in with their surroundings and avoid predators. But another, perhaps more fascinating, purpose is communication. During mating season, male cuttlefish display a specific pattern on one side of their body to attract females, while the other side shows a different pattern to ward off rival males. This is called dual signaling. Interestingly, research shows that females prefer males who can perform this split display effectively. So, it's not just about having the signal; it's about the quality of the signal. The more precise and symmetrical the display, the more attractive the male is. This suggests that visual communication in cuttlefish is quite complex and has evolved under strong selective pressure.