Listen to part of a lecture in a biology class. Professor: Today we're going to talk about mimicry in animals, focusing on a fascinating example: the monarch butterfly and the viceroy butterfly. For years, scientists believed that the viceroy mimicked the monarch's bright orange and black pattern to warn predators that it was poisonous, just like the monarch. This is called Batesian mimicry, where a harmless species imitates a toxic one. However, recent research has challenged this idea. It turns out that the viceroy is also toxic to many birds, though its toxins are different from the monarch's. This means that both species are unpalatable, and their similar appearance is a case of Müllerian mimicry, where two or more toxic species share a warning pattern to reinforce learning in predators. This discovery highlights how scientific understanding evolves as new evidence emerges. So, the classic example we all learned in textbooks wasn't entirely wrong, but it was incomplete.
❓ 質問 What is the main point the professor makes about the viceroy butterfly?
A. A. It is a harmless species that imitates the monarch's pattern for protection.
B. B. It is toxic to predators, making it an example of Müllerian mimicry with the monarch.
C. C. It has evolved to look like the monarch only in recent decades.
D. D. Its toxicity is identical to that of the monarch butterfly.
✅ 正解
B. It is toxic to predators, making it an example of Müllerian mimicry with the monarch.
TOEFL Listening Tips
Skim the questions first to predict the content
Watch for signal words in lectures and conversations (however, actually, in fact)
For main idea questions, focus on the beginning; for detail questions, focus on examples and data
For attitude questions, pay attention to the speaker's tone and word choice
Take notes on keywords; don't try to write down every word