托福口语 Task 4

Today, we're going to talk about the concept of 'functional adaptation' in animals. Specifically, I want to discuss how some animals have developed physical features that serve multiple purposes, enhancing their survival in unexpected ways. Let me give you two examples. First, consider the African elephant. Its large ears are not just for hearing; they are also used for thermoregulation. By flapping them, the elephant increases blood flow to the thin blood vessels in the ears, which helps dissipate heat and cool the body in the hot savanna. Second, think about the humpback whale. Its pectoral fins, which are unusually long, are not only for steering but also have tubercles—bumps on the leading edge. These tubercles improve water flow over the fin, reducing drag and increasing maneuverability, allowing the whale to make sharp turns when hunting schools of fish. So, these examples show that a single physical trait can evolve to fulfill multiple critical functions.