托福口语 Task 4

Today, we're going to talk about a fascinating concept in biology called 'mimicry.' Mimicry occurs when one species evolves to resemble another, often to gain a survival advantage. There are two main types of mimicry: Batesian and Müllerian. In Batesian mimicry, a harmless species imitates a dangerous or unpalatable one to avoid predators. For example, the harmless scarlet king snake has red, yellow, and black bands similar to the venomous coral snake. Predators learn to avoid the coral snake's colors, so they also avoid the king snake. In Müllerian mimicry, two or more unpalatable species evolve to look alike, which reinforces the warning signal to predators. For instance, several species of poisonous butterflies in the Amazon, like the Heliconius butterflies, share similar bright orange and black patterns. Since they are all toxic, predators quickly learn to avoid any butterfly with that pattern, benefiting all species involved. So, while Batesian mimicry involves a harmless species mimicking a harmful one, Müllerian mimicry involves harmful species mimicking each other.