Place organisms in a world with limited food. Watch as traits mutate and the fittest survive.
Evolution Simulator is a free online natural selection simulation where you watch organisms with mutable traits compete for limited food. Over generations, traits like speed, size, sense range, and metabolism evolve as organisms that are better adapted to the environment survive and reproduce more successfully.
Configure the starting population, food availability, and mutation rate, then watch organisms navigate their environment. Each organism burns energy based on its traits and must eat to survive. When energy is high enough, organisms reproduce with slightly mutated traits. Live charts track how average trait values shift over generations — you can literally see natural selection happening in real time.
Natural selection occurs when organisms with traits better suited to their environment survive and reproduce more successfully. Over many generations, beneficial traits become more common in the population. In this simulator, you can see this process happen in real time as organisms compete for limited food.
Four traits mutate between generations: Speed (how fast organisms move), Size (how big they are — bigger organisms need more food), Sense Range (how far they can detect food), and Metabolism (energy efficiency). Each trait has trade-offs, and natural selection determines which combinations thrive.
In real life, significant evolutionary change takes thousands to millions of years. In this simulator, you can observe measurable trait changes within 10-25 generations, which takes just a few minutes. The speed of evolution depends on mutation rate, selection pressure (food scarcity), and population size.
If you enjoyed this, try these: Pandemic Simulator · Solar System Builder · Gravity Playground · What Are the Odds?
Last updated: March 2026 · whatifs.fun — Free interactive games, experiments & simulations