Requires a Java-enabled browser (for example, Microsoft Internet Explorer 5.0 or later). The applet requires Java 1.4.1 or higher to run. It will not run on Windows 95 or Mac OS 8 or 9. On a 33K dialup connection, the Java applet will likely require two minutes or more to load. (Once it is loaded you may be able to run it offline.)
Load the model (Java applet) in a new browser window
Created with NetLogo 2.0, a multi-agent simulation program that can be programmed using the Logo language. NetLogo users: view/download model file (13K): hillclimb.nlogo.
This model provides a simple experience of monoculture and diversity, competition and cooperation, and simple navigation -- comparing where you are to where you want to be.
On "Setup," a somewhat random landscape is generated. Each square has an "elevation" with the lightest squares representing the higher elevations, and the darker squares representing the valleys or low spots. The highest spots on the landscape are colored blue.
The round white creatures climb from lower to higher "elevations." Since their vision is limited, they "top out" at the summit of the nearest hill and remain there. Nothing moves, and the simulation appears to stop. The histogram labeled "Fitness" shows the achievements of round white creatures according to "elevation."
Next, advance the "predators" slider to the right. Setup and go again. The black pointed predators pursue the round white creatures, who avoid them while also seeking to gain elevation as before. Notice what happens to the "Fitness" histogram as the model runs.
1. Many "artifical life" systems have spontaneously evolved predation or parasitism. It seems to be an emergent property of complex adaptive systems.
2. Competition and cooperation may be two sides of the same coin.
3. Under the influence of predators, the creatures tend to flock or herd.
4. Simple navigation works. This is like seeking higher elevations, or comparing where you are to where you want to be. But it works better when there is greater diversity, challenge, and cooperation/competition.
The basis of this model was taken from Tutorial 3 in the NetLogo manual. Feel free to alter and distribute this model, but please cite the Managing Wholes simulations page:
Updated 3 April 2004