L4
讲座
1. What is the lecture mainly about?
Misconceptions about how fish evolved into land animals
Features of an important transitional animal species
Differences between the fossils of some transitional animal species
The effects of climate changes on the evolution of some animal species
2. According to the professor, what did the modification to the head enable Tiktaalik to do?（多选题）
Avoid predators more easily
Raise its head to breathe air
Swim more efficiently
Swallow larger-size prey
3. Why does the professor mention a crocodile?
To emphasize that crocodiles are an ancient species
To explain what Tiktaalik looked like
To complain that fossils are often misidentified
To contrast Tiktaalik with other transitional species
4. Why does the professor emphasize the discovery of wrist and hand bones in Tiktaalik?
It proved that Tiktaalik was the first creature that could walk on land.
It proved that several physical changes could occur at once in a transitional species.
It proved that important anatomical changes occurred in the fish stage.
It proved that Tiktaalik fossils were similar to fossils of other transitional species.
5. According to the professor, why did some fish begin to develop characteristics of land animals?
They needed to come on land to find prey.
Their bodies were no longer suited to living in water.
Many of their shallow aquatic environments dried up.
The amount of oxygen in shallow water was decreasing.
6. Why does the professor say this:
To remind students of the similarities between fish and land animals
To encourage students to come up with additional examples
To explain why the transition from fish to land animals was so complex
To introduce a discussion of body weight in various organisms
