Life Science
Module 3: Lesson 1-5
Introduction to Modeling and Ecosystems
Ecosystem Concepts
• What is an Ecosystem?
• Indirect interactions within ecosystems
• Direct interactions between organisms in
ecosystems
• Food chains and food webs
• Energy flows in ecosystems
• Trophic levels
• Biomass in ecosystems
Complex Adaptive Systems (CAS)
Ecosystems as Complex Systems
• Feedback: fish in a pond – negative feedback of
resources
• Sum of the parts is greater than the whole
• Emergent behavior in population patterns
Student Activity #1
Papercatchers
 Participatory Simulation of population growth
 Crumple up a piece of scrap paper
 Pick one person to represent the 1st member of
the population
 In one color, mark the table and graph with
generation 0, population 1
 When you hear “next generation!”, the 1st
member throws the paper 2 feet overhead and
tries to catch it
Student Activity #1
Papercatchers
If the 1st member catches it, they survive! And
they reproduce by picking an audience
member to be the 2nd member of the
population
If the 1st member doesn’t catch the paper,
they die! And they sit down.
Repeat for several generations
Student Activity #1
Papercatchers
 If the population crashes begin again!
 Sometimes if populations are small, populations
go extinct by chance.
 Once everyone is part of the population, it’s time
to look at the graph and reflect on the pattern!
 What type of pattern do you see?
 What would happen if we could play with an
unlimited number of people?
Student Activity #1
Papercatchers
Round 2!
Same as before, but you have to keep your
foot on the piece of newspaper.
What do you think will happen to the pattern
you saw before?
Use a different color marker to record
population sizes and generation numbers.
What happened in Round 2?
Student Activity #1
Papercatchers
Round 3!
The newspaper is now a sheet of printer
paper.
What do you think will happen?
What do you think the shape of the
population curve will be?
Record with a different color marker.
Student Activity #1
Papercatchers
How does this relate to ecosystems?
What could the paper catching represent in a
real ecosystem?
Student Activity #2: Preview the
Rabbits and Grass Model
• Open the Ecosystem Starter model in StarLogo Nova
– http://www.slnova.org/GUTS/projects/21061
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Model Observation Form
Run the Model and track Outcomes
What would an experiment look like?
What’s missing?
Life Science
Lesson 2: Rabbits and Grass Model
Understanding a computer model of a simple
ecosystem, designing and running experiments.
Student Activity #1
‘Looking under the Hood’ at the code
Use Model Observation Form
Refer to your StarLogo Nova Command Blocks
reference sheets from Module 1
New command blocks
Decode your piece of the code with your
partner
Share out!
Student Activity #1
Looking under the Hood
Trace the Execution of the CodeSetup- follow the commands in the Setup block
What happens 1st and then what comes next?
Forever- look at the procedures
What happens 1st and then what comes next?
Student Activity #2: Experimental
Design
Use the Student Activity Sheet & the
Experimental Design Form
• Challenge 1:
Choose a variable to experiment with, describe
your experiments and record data.
• Challenge 2:
Identify patterns in your collected data and
possible correlations.
Lesson 3: Adding a Predator
Lesson 3: Design & Run Experiments
Now that there is a change in the ecosystem
model (a new predator breed), use the
Experimental Design Form to plan your
experiment.
Computational Science Cycle
Designing and Developing Your Model
Work with a partner to design changes to the
ecosystem model. Use the Project Design Form.
What would make the computer model more
‘realistic’?
Ideas to consider:
energy levels, reproduction rates, initial
population sizes, competition, predation,
resources in the ecosystem, number of trophic
levels, types of interactions.
Final Steps- Designing and Running
Experiments
Identify the variables in your model
(independent & dependent variables)
Use the Experimental Design Form to plan and
describe your experiment that you will run using
your modified ecosystem model.
Questions to consider:
What will be the range of settings for your variable?
How many trials will you run? What data will you
collect?
Prepare to share out
Present your project and findings to a larger
audience.