Аудирование TOEFL

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Listen to part of a lecture in a biology class. The professor is discussing the behavior of fireflies. Professor: We often think of fireflies as producing light for the purpose of attracting mates. And that is true for most species. However, recent research has revealed a fascinating twist. Some female fireflies, particularly those of the genus Photuris, mimic the flash patterns of other species. They do this to lure in males of those other species—not for mating, but for dinner. Yes, they are predatory. They attract a male, and then they capture and eat him. This behavior is called aggressive mimicry. What is interesting is that the males of the prey species are not completely defenseless. They have evolved to be more cautious. They may fly in a zigzag pattern or pause before approaching a flashing female. So the predator-prey relationship has led to a sort of arms race in flash patterns. Each species tries to outsmart the other. This shows that even simple signals, like flashes of light, can be shaped by complex ecological pressures. Any questions?