托福口语 Task 4

Good morning. Today I want to talk about a fascinating behavioral adaptation in animals called 'autotomy' – the voluntary shedding of a body part as a defense mechanism. The key point is that this sacrifice is not random; it's a strategic trade-off that increases the animal's overall survival chances. Let me give you two examples. First, consider the common lizard. When a predator grabs its tail, the lizard can detach that tail. The tail continues to wiggle for a few seconds, distracting the predator while the lizard escapes. The lizard loses its tail, but it can regrow it later – though at an energy cost and with some loss of agility in the meantime. This is a clear example of sacrificing a non-essential part to save the whole. Second, think of the sea cucumber. When threatened, it can expel part of its internal organs – even its intestines – through its anus. The expelled organs are sticky and toxic, entangling and repelling the predator. The sea cucumber then regenerates these organs over several weeks. This is more extreme than the lizard's tail, but again, the benefit of immediate survival outweighs the long-term cost of regeneration.