Population Ecology evo-edu.org

Stage- and age-structured population modeling resources for growth, decline, survivorship, and fecundity.

Application

Life Cycle Modeler

Use a direct responsive matrix-model workbench to compare stage-specific survival and fecundity, while preserving the older popdyn route as a legacy reference.

Learner guide Teacher guide About and provenance Open legacy popdyn
First challenge Run the defaults, then lower juvenile survival and compare whether long-term totals change more than when you lower adult fecundity.
Key habit Ask which stage matters most to growth or decline instead of treating all individuals as interchangeable.
Legacy memorialized The older popdyn route remains available as a legacy reference while this direct workbench replaces the iframe workflow.

Run Actions

Controls you will use first

Keep run, save, export, and import actions separate from the life-history parameters so the first useful comparison is clear.

Current Run Status

Final total 0.0
Growth trend steady
Largest stage Stage 1
Final stage count 3

Try This First

Step 1 Run the defaults and decide whether the population grows, stabilizes, or declines.
Step 2 Reduce Stage 1 survival and compare the final total.
Step 3 Restore Stage 1, then reduce fecundity and compare which change mattered more.

Main Display

Stage structure and total population over time

The stage lines show how each life stage changes across steps. The purple line tracks the total population so you can compare stage structure with overall growth or decline.

Stage 1 Stage 2 Stage 3 Total population
What to notice A small change in one stage can reshape long-term totals more than a larger-looking change elsewhere.
Compare mechanisms Change one survival or fecundity term at a time so you can identify which stage drives the difference.
Notebook links Adaptation Common Descent
Step snapshots
Interpretation prompt

Run the baseline case first, then compare one changed parameter.

Settings

Life-history parameters

These values control three stages through fecundity, survival, recurrence, and starting population. Use them to model different demographic strategies.