This exercise should push students beyond observation toward interpretation, asking them to explain why different evolutionary outcomes occur and what counts as evidence for those explanations.

Learning goals​

• interpret more complex experimental outcomes
• evaluate whether observations support a proposed explanation
• discuss how experimental setup shapes conclusions

Step-by-step flow​

1. Begin with the previous exercise’s saved setup so everyone starts from the same baseline.
2. Apply a consistent selection treatment (e.g., add a resource reward or increase the penalty for a trait) and rerun for the same number of steps.
3. Collect the histogram data and reproduction counts for each condition.
4. Ask: what changed? Which evidence supports the selection explanation?

Suggested use​

Use this when students are ready for more analytical discussion and less guided orientation.

What students do​

• compare multiple outcomes under selection
• interpret patterns in population-level evidence
• argue for or against explanations using collected data

Legacy lab-book framing​

The legacy lab book presented this as Exploring Fitness and Population Change under Selection, emphasizing how patterns in populations can be interpreted as evidence about evolutionary processes.

Supporting materials​

• Exercise 3 PDF
• Legacy explainer video remained hosted off-site and should be migrated later
• Legacy explainer video is part of the archived playlist linked from the legacy site; please add it to docs/videos with a transcript-first page so students can still access the narrative.

Estimated time​

One to two class meetings depending on the depth of analysis expected.