TOEFLスピーキング Task 3

In biology, the concept of ‘behavioral adaptation’ refers to an action or series of actions an organism performs that increases its chances of survival and reproduction. Unlike physical adaptations, which are structural, behavioral adaptations are learned or instinctive responses to environmental challenges. These behaviors are often shaped by natural selection, as individuals with beneficial behaviors are more likely to pass on their genes. Common examples include migration, mating rituals, and foraging strategies.

Professor: Let’s take a real example. The three-spined stickleback, a small fish, shows a fascinating behavioral adaptation to avoid predators. In some lakes, these fish live near the bottom where there are many aquatic insects that eat their young. Normally, sticklebacks swim in open water to feed, but in these predator-rich lakes, they’ve learned to stay near the bottom and only feed at night when the insects are less active. This change in timing and location reduces the chance of their offspring being eaten. Interestingly, this behavior isn’t instinctive from birth—young sticklebacks learn it by observing older fish. So, it’s a learned behavioral adaptation that directly improves survival rates in a specific environment.