Narrator: Listen to part of a lecture in a biology class. Professor: Today we're going to talk about mimicry, specifically Batesian mimicry. This is a phenomenon where a harmless species evolves to resemble a harmful or distasteful species to avoid predators. A classic example is the scarlet king snake, which mimics the venomous coral snake. The coral snake has red, yellow, and black bands, with the red and yellow touching. The king snake has similar colors, but the red and black touch. Predators learn to avoid the coral snake's bright warning colors, and they also avoid the king snake, even though it's harmless. However, mimicry isn't always perfect. Some mimics only resemble the model in general color patterns, not exact details. This suggests that predators might not be very discerning, or that the mimic gains enough protection without perfect imitation. Recent studies show that imperfect mimics are actually more common than perfect ones. Why? One theory is that predators avoid any pattern that vaguely resembles a dangerous animal, so perfect mimicry isn't necessary. Another idea is that perfect mimics might be too costly to evolve if the predator's learning is not very precise. So, in nature, evolution favors 'good enough' mimicry, not perfection.
❓ Pregunta What is the main point the professor makes about Batesian mimicry?
A. Perfect mimicry is essential for survival.
B. Predators always distinguish mimics from models.
C. Imperfect mimicry is common and often sufficient for protection.
D. Mimicry only occurs in snakes.
✅ Respuesta correcta
Imperfect mimicry is common and often sufficient for protection.
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
