Everyone is a little different.
Speed, size and sensing vary between creatures.
OBSERVE / QUESTION / EXPERIMENT
Small changes.
Different futures.
A tiny habitat. Hungry creatures. Traits passed from parent to child. Discover how a population changes when its world does.
Enter the habitat ↘Traits travel through families.
Offspring inherit traits, sometimes with a random change.
The environment matters.
Food and energy costs affect who survives and reproduces.
CHOOSE A QUESTION
Nine ways to explore.
Each card starts a repeatable experiment.
OPEN MEADOW
What happens when food is plentiful?
Season 10.0 / 20 s
READY TO EXPLORE
AN EXPERIMENT HAS AN ANSWER, TOOThis habitat is quiet.
No creatures remain. Check the hunting and starvation counts. Try more food, fewer predators or a smaller energy cost, then restart.
GrazersLong ears · eat plantsPredatorsCoral ears & tails · hunt grazers
▣ Solid borders
Animals turn inward at the edge and stay in the habitat.
Low → high
Drag to orbit · shift-drag to pan · scroll or pinch to zoom. Tap a creature to meet it.
Living creatures3232 grazers · 0 predators0 births · 0 deaths
Food pieces left1105 energy in a full piece
Average energy8.012 to reproduce at season end
Completed seasons020 simulated seconds each
No deaths so far.Animal shapes show feeding roles. These are model creatures, not a simulation of real rabbits and foxes.
CHANGE ONE THING
Shape the conditions.
A fresh food supply appears every 20 simulated seconds.
Repeatable setup & starting population
Seed, starting grazers and predators apply when you restart. The same seed, settings and changes give the same result. A saved experiment resumes its exact state.
Ready. Press Play, or take one moment at a time.
BEFORE YOU TEST
What do you expect to happen?
Your note is included when you save the experiment. Watch several seasons, then compare your idea with the evidence.
LOOK FOR EVIDENCE
A population tells a story.
YOUR COMPARISON
Complete a season and keep a baseline. Change one condition, restart with the same seed, and compare at the same season.
REPEAT WITH OTHER SEEDS
Is this run typical? Repeat its starting settings with five seeds in the background. Your live experiment is not changed.
Read the exact numbers
UNDERSTAND THE MODEL
Useful traits come with trade-offs.
How this little world works · rules, limits & new words
Survive, then reproduce.
Each founder starts with 8 energy; each offspring receives 6 from its parent. It spends energy every moment. Grazers gain energy from plant food; hungry predators hunt grazers and gain some of their remaining energy. At zero, it dies. At a season boundary, a creature with at least 12 energy can give 6 to one offspring. Survivors stay in the habitat.
Traits stay fixed during an individual's life. Offspring copy one parent, with a separate mutation chance for each trait. Mutation adds a random amount up to ±0.25, bounded to 0.4–2.0. It does not know what would be useful.
Seasons are not generations.
A season lasts 20 simulated seconds. Parents and offspring can live together, so one season is not one biological generation. The inspector shows each creature's generation in its family. Grazer age colours move from mint (newborn) through amber (5 seasons) to violet (10+). Predators use coral, red and berry instead, with coral ears and tails that remain visible in every colour view. This displays elapsed age, not a change in inherited traits. Age itself does not kill creatures in this model.
Movement happens inside a flat, enclosed field. Animals turn inward at solid borders; their body size sets how close their centre can approach an edge. Food and prey are sensed using the direct distance, without shortcuts across borders. The 3D habitat shows the same model; height and decorative plants do not affect survival.
A model, not real biology.
Predator–prey interactions are simplified: predators hunt nearby grazers when hungry. There is no sexual reproduction, ageing-related death or real genetic sequence. A cap of 160 living creatures can block births. Chance and starting variation matter; one run cannot establish a general evolutionary advantage.