Activity 2.3: Evidence-Based Arguments for the Meadow Simulation (40 min)

Ask students to take out their completed 2.2 Meadow Simulation Worksheet.

• Display Slide 3. Pass out one copy of 2.3 Evidence-Based Arguments Tool for the Meadow Simulation to each student. Review the Tool directions. Instruct students to use their data from the 2.2 Meadow Simulation Worksheet as well as what they learned from class discussion to complete the tool.
• Give students about 5-10 minutes to complete the process tool.

Display Slide 4 of the 2.3 Evidence-Based Arguments for the Meadow Simulation PPT. Divide students into pairs.

• Have each pair compare their evidence, conclusions, and unanswered questions for the questions on the Evidence-based Arguments Tool.
• Have partners discuss how their ideas are alike and different. Have students change or add to their responses, based on partner input.
• As students are sharing, circulate through the groups. Ask students about the patterns they observed.
• Pay attention to patterns in students’ ideas. You will want to begin moving towards class consensus in this activity.
• Partner work should take about 10 minutes.

This is the consensus-seeking discussion part of the Carbon TIME Discourse Routine for the Evidence-Based Arguments Tool.

Display Slide 5 of the 2.3 Evidence-Based Arguments for the Meadow Simulation PPT.

• Have students/pairs share their evidence and conclusions for the first row. Keep a class record, using the PPT slides or board. Ask students to update their answers using a different colored writing utensil. Discussions should move toward class consensus.
• Have students share unanswered questions. Discussions should move toward class consensus. Use the 2.3 Evidence-Based Arguments Tool for the Meadow Simulation to guide your goals for consensus. At this point in this unit you will begin to guide the path of inquiry toward tracing matter and energy in ecosystems.
• Class discussion should take about 10 minutes.

Display Slides 6 and 7 of the 2.3 Evidence-Based Arguments for the Meadow Simulation PPT.

• Class discussion may take another 10 minutes.

Use Slides 8 and 9 to review the two main conclusions that students should have on their Evidence-Based Arguments Tool:

1. The organic matter diagram that represents the maximum mass of all three populations after 100 years resembles a pyramid (this diagram is also called the organic matter pyramid). Ask students to share their ideas about why so much grass is necessary to support so few foxes. They will learn more about this in Lesson 3.
2. There are three possible final mass diagrams that could occur in the meadow ecosystem (the organic matter pyramid with all three populations, rabbits and grasses only, and grasses only). Students can share ideas about how the foxes and rabbits could all die (if the rabbit population dipped so low that the foxes died out, but there were still a few rabbits left to reproduce and repopulate the meadow).

Use Slide 10 to emphasize that the organic matter pyramid is an important pattern in ecosystems, but that we have not yet explained what causes this pattern. That will be the focus of Lesson 3.