Once the model starts, you should see a school of male guppies swimming in the habitat. These male guppies are randomized in terms of appearance, age, and size at the beginning. Neither female guppies nor predators are included in the model.

Five rules are applied to the male guppies, including—swimming, growing and death, surviving, reproducing, and overpopulation.

1. Swimming—Every guppy swims in the habitat.

2. Growing and death—Guppies get bigger, older, and then eventually die.

3. Surviving— The more different is a guppy’s color from the background, the more likely is it preyed on by a predator.

4. Reproducing— The brighter guppies have a higher chance to reproduce offspring than the drabber ones. A small portion of the male offspring guppies is either slightly brighter or drabber than the father guppy. The range of mutation is controlled by.

5. Overpopulation—Once the number of males reach to the defined carrying capacity, every guppy has a 50% chance to die regardless of its age, size, or color.

1. Explore male coloration distribution in different habitats.

2. Explore if the distribution patterns hold in different settings, e.g., carrying capacity, color ratio, mutation rate, etc.

3. Switch the habitat while the model is running, and explore the results.