Complex Adaptive Systems
The flight path of a cannonball and the orbit of a revolving planet can be described by differential equations that do not change over time. Conversely, the movements of a stock market, a system that fluctuates dynamically over time, can not be described by differential equations.

The stock market is an example of how a group of simple systems interact to produce an adaptive, complex system. When a single system governed by its rules interacts with the other systems, they produce sophisticated effects. Artificial Life, Inc. specializes in the use of techniques such as cellular automata and genetic algorithms to simulate these complex systems.

Roaches versus Vacuum Cleaners
This demo simulates the evolution of a cockroach colony as a complex predator-prey system. The vacuum cleaner pursues the roaches. Roaches avoid the vacuum when pursued, eat when hungry, and mate after eating.

The cockroaches are randomly generated and enter from the sides of the window. Cockroaches are sustained by food that periodically appears in the window. Food disappears if not quickly eaten. After a roach eats, it reproduces when it encounters a mate that has also eaten recently. These well-fed roaches change color and reproduce with a clanking sound. Cockroaches die if they go hungry for longer than a pre-specified period. Dead roaches are visually signified as unmoving blobs.

The vacuum cleaner hunts roaches. It only senses a roach within a specified distance. A second vacuum appears when there are over 15 roaches and disappears when there are under 10 roaches.

Conclusion
This demo graphically represents the dynamics of predator versus prey and the availability of resources. The next stage of the project involves the genetic coding of cockroaches with the proclivity to eat and grow. These characteristics would affect a roach’s speed and its chance for survival. When roaches mate, these codes would be passed on to their offspring. Consequently, this natural selection would result in a “super roach" balancing its tendencies to eat, flee, and flourish.