A Simulated Ecosystem with Three Species

In the simulation below, there are three species of organisms: stars, plusses, and pentagons. Their behavior is controlled by parameters that you can control with the sliders below. For each species, there are three parameters that determine how quickly it moves away from (negative values) or towards (positive values) each of the species, including itself. In addition, each organism has a little bit of randomness added to its movement. There are three other parameters that control the overall amount of movement of the organisms, how much organisms tend to move in the same direction they have been moving (inertia), and how rapidly the influence of other organisms falls off as the organisms get further away. You can also pick up, move, and "throw" individual organisms by clicking on or touching them. There are some preset configurations that you can explore. If you come up with an interesting pattern, please share the parameter values with me.

Movement of Plusses:

Movement of Stars:

Movement of Pentagons:

Toward Plusses

Toward Stars

Toward Pentagons

Movement Amount:


Falloff of Influence with Distance:


This simulated ecosystem shows a number of very common phenomena associated with systems. As you explore it, some general system phenomena to look for are:
Designed and programmed by Robert Goldstone (rgoldsto@indiana.edu). Visit our Percepts and Concepts Laboratory