Natural Selection Simulator
Watch fur colour evolve in a bunny population as predators hunt and the environment changes.
Watch bunnies hop, breed and get hunted by hawks. Camouflaged bunnies survive longer. Change the ground or the season and watch the fur colours evolve. Click any bunny to see its genes.
About the Natural Selection Simulator
Free natural selection simulation. Bunnies with white or brown fur face predators on snow or grass. Change the environment, predation and mutation rate and watch the population evolve. Built for biology, the natural selection simulator runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Watch fur colour evolve in a bunny population as predators hunt and the environment changes. Use it to explore biology ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Natural Selection Simulator
- Use the controls to change Ground, Hawks (predator pressure), Food supply (max population), Mutation rate, Speed, and more. The simulation reacts instantly.
- Pick an option such as Snow, Forest floor, Auto seasons to switch modes or load an example.
- Press "Send a hawk", "Pause", "Reset" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Switch the ground and watch the population shift.
- Raise predator pressure to 90%.
- Turn the mutation rate up and watch variety appear.
- Run 20 generations with Auto-run.
Key ideas you can learn
- Individuals whose traits match the environment survive and reproduce more.
- Change the environment and the favoured trait changes with it.
- Mutation adds new variation, and chance (genetic drift) matters most in small populations.
Where this is used in the real world
Natural selection explains antibiotic-resistant bacteria, pesticide-resistant insects and how species adapt to new habitats. Conservation biologists use it to understand survival.
Who is this simulation for?
Biology students and teachers who want to explore living systems, populations and genetics interactively and safely.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
What is natural selection?
The process where organisms with traits that suit their environment are more likely to survive and pass those traits on, so the population changes over generations.
Why do the results differ each time I run it?
Survival and mutation are random, so each run varies. Selection pushes the average in one direction, but chance adds noise, especially with small populations.
Is the Natural Selection Simulator free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Natural Selection Simulator work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.