FA-65587 / Ecological population dynamics / Member archive

Levins metapopulation with habitat destruction: extinction ratio · case 02

Equilibrium occupancy falls as colonisation improves.

Member previewVariant 2 · 3 implementations · 7 checks per implementation

Case contract

Occupancy p: p += c*p*(1-D-p) - e*p each year, clamped to [0, 1-D]; equilibrium max(0, 1-D-e/c); return [equilibrium rounded 6, trajectory rounded 6]; None for c<=0, e<0 or D outside [0,1).

Why this case matters

Population projections set harvest quotas, conservation status and pest-control timing; a wrong update order, boundary or rate conversion silently changes management advice.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: butterfly network	`[0.0, [0.125, 0.154687, 0.18913, 0.227984, 0.27039, 0.314952]]`	`[0.6, [0.125, 0.154687, 0.18913, 0.227984, 0.27039, 0.314952]]`	Failed

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