Our exploration of the Tyee Campus ecosystem concluded with a return to modeling energy flow using Microsoft Excel 2013. Students worked individually to construct an energy flow model using a worksheet which provided the calorie requirements of a variety of organisms found on our campus. The worksheet also included the Excel formulas to connect the various pieces of data into a model. The lesson provided students with an opportunity to practice using the formula functions in Excel, taught them how to create a linked graph of the data, and asked them to derive explanations about why organisms are found in numbers approximating what might be anticipated by their understanding of the trophic pyramid.
On the first day of class this week, students took a quiz to demonstrate mastery of the Systems and Networks section of the unit. Afterward, students worked individually to construct one or more networks from a list of seemingly random biotic and abiotic factors. The list was actually populated by the names of the various cryptocurrencies students will receive at the end of the unit.
The next day, students shared the strategies they used to construct their networks. Specifically, we discussed what their edges represented – what was moving through their system. Many students modeled energy cycling by creating a food web. Others sought to include the abiotic factors and modeled things like the Earth-Moon-Sun system or the Water Cycle, integrating the biotic factors into that schema. During work time, students worked in groups of up to 4 students to integrate their individual systems into a larger representation of an ecosystem. This activity created the foundation for the computer modeling activity in the next lesson.
With a guest speaker scheduled for Friday, we once again are limited to only three days of class this week. For the third and final lesson of the week, students learned to use formulas to dynamically link individual cells in a Microsoft Excel 2013 spreadsheet. Students began by making a list of the organisms in their group models. Next, they assigned quantity values to each organism to represent the amount of each type of organism that must be consumed by a predator of that organism to sustain the predator. Students shared possible strategies that could be used to estimate those values. Students then created formulas to relate the organisms. The relationship formulas enable future modeling predictions based on scenarios that might occur. For example, we could model what might happen if an invasive species enters an ecosystem and reduces the quantity of one of the organisms in the network.
The sequencing of the Systems Biology unit has been adjusted from the original plan to account for scheduling realities. As a student teacher at Highline high School, our principal would frequently say, “Monitor and adjust.” Such insight! Our updated unit flow will now look something like:
1. Introduction to Systems
2. Ecosystems and Modeling
3. Integration of Economics into Ecosystems
4. Human Body Systems