Simulators / APES Unit 1 / Topic 1.1
Species Interactions Simulator
Run predation, parasitism, mutualism, commensalism, and competition, then test the sign of each interaction the way ecologists do: with controls and repeated trials. Free, with no login.
Is the sign + , – , or 0?
Each trial runs Species 1 alone, Species 2 alone, and the pair together, then compares the average population over years 40 to 60. A sign counts only if the change is at least 5% and larger than the trial-to-trial spread.
| Species | Alone (mean ± SE) | Together (mean ± SE) | Change | Sign |
|---|
Take it to class
Interaction Court
The simulator shows how the signs are measured. Interaction Court is the classroom activity that goes with it: students become a panel of judges and rule on real-world cases using evidence.
Ten case files
Each case has a photo, field notes, and a data exhibit, covering predation, parasitism, mutualism, commensalism, competition, and resource partitioning.
Sealed appeals
New evidence arrives and can overturn the panel's own rulings, so students see how scientists revise a claim.
Teacher guide and key
A scoring guide, a pacing plan for one 55-minute class, and an AP-style free-response practice question on designing an investigation.
About the model: two hypothetical species and nothing else. It is built to show the pattern of each interaction, not to predict a real ecosystem. For an AP course, pair it with real data, such as the lynx and hare counts in Interaction Court.