Original toy model / a change of habitat
A world where the rules change once
Three habits share a small patch of ground. Let them live for 120 ticks. Then the food stops arriving in two groves and starts arriving everywhere. What survives the change?
A seed locks the random sequence. Reset to replay it. No world runs until you start it.
Ready. Food arrives in two groves. The rule changes at tick 120.
The ground
32 × 24 cells; edges wrap around. Individuals can share cells. Food dots are drawn first and may sit under an individual.
The trace
Horizontal: ticks, 0–360. Vertical: individuals, 0–180. The dashed line marks the single food-distribution change. Colours match the ground.
| Checkpoint | Seek | Drift | Wait |
|---|---|---|---|
| Start | 24 | 24 | 24 |
| Before change (119) | — | — | — |
| Now (0) | 24 | 24 | 24 |
The before-change checkpoint will be recorded at tick 119. The table reports actual individuals, not a score.
One rule, three habits
Each world begins with 24 individuals of each strategy, placed by the seed, with 14 energy units each. Five food units attempt to arrive each tick. Until tick 119 they arrive within three cells of either grove centre. From tick 120 onward they arrive uniformly across the world. Existing food remains where it was. Only the arrival distribution changes.
The complete rules
- Seekers inspect food up to five cells away and move one cell toward the nearest unit. Otherwise they wander. They spend 0.65 energy per tick.
- Drifters choose a random adjacent cell each tick and spend 0.50 energy. They have no food sensing.
- Waiters inspect up to two cells away. Without nearby food they stay put 70% of the time, otherwise wander. They spend 0.60 energy.
- Distances and movement use a wrapping grid and eight neighbours. Each food unit supplies 7 energy. At most one individual eats each cell's unit per tick; a seeded shuffle decides who acts first.
- At 26 energy an individual gives 12 energy to a same-strategy offspring in an adjacent cell. There is no mutation. Energy at or below zero means death. Nobody lives longer than 100 ticks.
- At most 180 individuals exist at once. Births pause at that ceiling. Food occupies at most one unit per cell; an attempted arrival on an occupied cell is lost. Initial food comprises 80 arrival attempts in the groves.
- The simulation ends at tick 360, or when every individual is extinct. It never introduces replacements or forces a winner.
This is an invented simulation, not a biological or psychological finding. Costs, sensing, food yield, lifespan and the ceiling are chosen design assumptions. Outcomes depend on these choices and the seed. A population change does not establish that a strategy is universally better, and a single run does not estimate an empirical effect.