In this lesson, students think about what might happen to plants and animals if their environment changed and they were faced with conditions to which they were not well adapted. First, students read The Great Kapok Tree: A Tale of the Amazon Rain Forest by Lynne Cherry. Then they watch a video about camouflage and learn that praying mantises are well suited for life in the rain forest. Next, students play a predator/prey game to simulate what might happen to the praying mantis if the rain forest were cut down. Finally, they use a Web activity to explore what would happen to living things if the concentration of oxygen in the air changed.
Organisms can survive only in environments that meet their needs. The earth has many different environments, or biomes, and each has unique environmental conditions. These conditions, which include temperature, rainfall, soil quality, salinity, pH, and predators, present challenges to the living things born into that environment. Organisms have evolved features (structures and behaviors) that make them well adapted to tackle the challenges of the environment they live in. Changes in an organism's environment may result in death, migration, or survival of a few well-adapted individuals in the population.
1. Read aloud or have students read "The Great Kapok Tree: A Tale of the Amazon Rain Forest" by Lynne Cherry. Discuss the following:
2. Show students the Evolution of Camouflage video and discuss the following:
3. Place a large piece of green print fabric on a table. Scatter the green paper squares randomly across the fabric. Have students gather around the table and stand with their backs to the fabric. Tell them not to turn around yet.
Explain to the class that the green print fabric represents the trees in the rain forest, the green squares represent praying mantises, and students are birds that feed on these insects. When you give the signal, students will turn around quickly and grab as many bugs as they can. They will get only five seconds to feed. When you say stop, students must turn back around. Give the signal when you and students are ready.
4. After students feed, have them count how many praying mantises are left on the fabric.
5. Replace the green fabric with the brown fabric and scatter the green paper squares across the fabric again. Explain to students that the brown fabric represents the rain forest after all the trees have been cut down. Have students repeat the feeding experiment.
6. After students feed, have them count how many praying mantises are left on the table this time. Discuss the results of the experiment.
7. After students feed, have them count how many praying mantises are left on the table this time. Discuss the results of the experiment.
8. Distribute a copy of the Handout: Atmospheric Oxygen Web Activity Worksheet (PDF) worksheet to each student. Have them answer the first two questions.
9. Have students conduct the Atmospheric Oxygen activity and answer the remaining questions on the handout. Then discuss their answers to the questions.
10. For homework, have students explain to their families why it's so important to preserve the tropical rain forest. Ask them to brainstorm things they as a family can do to help. (To encourage students to follow through, you might require them to bring in their brainstormed list signed by all family members participating in the activity.)