托福口语 Task 4

Today, we're going to talk about a fascinating concept in animal behavior called 'sensory bias' in mate selection. The main idea is that females often prefer males who display traits that happen to stimulate their pre-existing sensory preferences, even if those traits don't necessarily indicate better fitness. Let me give you two examples. First, consider the guppy, a small freshwater fish. Female guppies naturally have a strong preference for the color orange, likely because orange spots resemble their favorite food, small orange fruits that fall into the water. Males with brighter orange spots are more attractive to females, even though these spots don't signal health or strength. Second, think about the bowerbird. Female bowerbirds are attracted to the color blue, which is rare in their forest environment. Male bowerbirds build elaborate structures—called bowers—and decorate them with blue objects like berries, feathers, or even plastic items they find. The males with the most blue decorations win the females' attention, not because the blue objects prove anything about their genes, but simply because blue catches the female's eye.