Narrator: Listen to part of a lecture in a biology class. Professor: Today we're going to talk about a fascinating adaptation in the animal kingdom: mimicry. Specifically, we'll focus on the monarch butterfly and its mimic, the viceroy. For years, scientists believed the monarch was toxic to predators because it feeds on milkweed, which contains cardiac glycosides. The viceroy, however, was thought to be harmless, and it simply mimicked the monarch's bright orange and black pattern to avoid being eaten. This is called Batesian mimicry, where a harmless species imitates a dangerous one. But recent research has turned this idea on its head. It turns out that the viceroy is also distasteful to birds, but it gets its toxins from a different plant, willows. This means the relationship is actually Müllerian mimicry, where two unpalatable species share a similar warning pattern. This discovery highlights how our understanding of ecological interactions can change with new evidence. So, when we study mimicry, we must consider the actual chemistry and behavior of both species, not just their appearances.
❓ Question What is the main point the professor makes about the viceroy butterfly?
A. It is a harmless species that mimics the monarch to avoid predators.
B. It feeds on the same plants as the monarch, making it toxic.
C. It is also unpalatable, so its similarity to the monarch is an example of Müllerian mimicry.
D. It mimics the monarch only in appearance but not in behavior.
✅ Correct Answer
It is also unpalatable, so its similarity to the monarch is an example of Müllerian mimicry.
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