托福口语 Task 3

In biology, the term 'behavioral adaptation' refers to an action or series of actions that an organism performs to increase its chances of survival and reproduction in its natural environment. Unlike physical adaptations, which involve structural changes, behavioral adaptations are learned or instinctive responses to environmental challenges. These behaviors can include migration, hunting strategies, or social cooperation. They are often triggered by specific stimuli and have evolved over time because they enhance an organism's fitness.

Professor: Let me give you a clear example from a study on meerkats. Meerkats are small mammals in Africa that live in groups. One key behavioral adaptation is their sentinel behavior. When the group is foraging for food, one meerkat will climb to a high vantage point—like a rock or a bush—and scan the area for predators. This sentinel lets out a distinct alarm call if it spots a hawk or a snake. But here’s the interesting part: the sentinel does not eat while on duty. It sacrifices its own feeding time to warn others. This behavior increases the group’s overall survival because members can escape danger quickly. In return, the sentinel benefits because the group is often its relatives, so by protecting them, it indirectly passes on shared genes. This is a perfect example of a behavioral adaptation shaped by natural selection.