"Evolution" is cellular automaton that produces "order from chaos", in which random random chaotic origins evolve into pretty ordered patterns over time.
Rules: In Evolution, each cell is in one of N states. These states are often colored using consecutive colors around the rainbow color wheel. (Unlike Conway's "game of Life", there are no live or dead cells, and all cells are equally active.) When producing the next generation, if cell in state X is next to a cell in state X+1, then cell X+1 becomes X. In other words, each color flows into the subsequent color if possible. Cell states wrap around, such that cell 0 flows into 1, cell 1 flows into cell 2, and cell N-1 flows back into cell 0. One way of visualizing this process is in terms of combat, in which each color is struggling for dominance, and is able to defeat the next color, but is in turn defeated by the previous color, in a rock-paper-scissors scenario. Another way of visualizing this process is in terms of evolution, in which each color naturally evolves into the next color, in a circle of life.Environment: Evolution takes place on a rectangular X by Y cell board. The edges of the board wrap around to each other, like the surface of a torus. Alternate topologies such as hexagonal cells could be done too. Similarly, one could make the edges not wrap, but doing so would prevent certain types of outcomes, such as the "Wave".
Variables: Evolution works best when N is a moderate number. The examples on this page have N=17. Too high and the board will tend to freeze and nothing will get started, and too low and the entire board will churn too quickly like soup in a blender. Effects are also good with X and Y being moderate. The examples on this page have X=240 and Y=135.
The program Daedalus can display the Evolution cellular automaton. In the Daedalus "Demos" script (which can be invoked from the "File / Run Script / Demos" menu command) press "F9" to display an Evolution starting from a random initial state, which will animate until it ends or stabilizes.
When Evolution rules are applied to a board, what eventually happens? Starting from a random board, initially small "lakes" of solid color will appear within the random cells. These lakes will grow and merge with each other, until they become "seas". The remaining areas of random cells will be eroded away, until the "continents" become small "islands". Eventually the last islands will disappear, and what remains determines the outcome of the original board. There are two types of outcomes: (1) The board eventually stops at a particular state, at which point future generations won't produce any additional change. (2) The board continuously animates forever through a repeating pattern.
Freeze: This is a "stop" outcome in which the board freezes up early, and most cells will remain random. This "failure to launch" situation should never happen unless N is too high.
Conquer: This is a "stop" outcome in which one color takes over the board, effectively "conquering" all the others. Sometimes there are a few extraneous cells of other colors that weren't wiped out by the previous color, before all instances of that previous color got removed.
Wave: This is a "continuous" outcome in which a wave of the N colors flows across the board between left and right, or between top and bottom. Usually each color appears in a band that's one or more cells wide, however it's possible to have each color appear multiple times within the wave.
Vortex: This is a "continuous" outcome in which a wave of the N colors forms a circle. This circle will quickly tighten around the middle like a tornado, producing a spiral vortex pattern radiating out all colors. Because of the tightening effect, each color within a vortex will always be one cell wide. A vortex will always exist, and can never be penetrated or removed by outside cell effects. In other words, once a vortex (or vortexes) get started, they will continually expand until they cover the entire board.
Example Evolution ending in "Conquer":
Example Evolution ending in "Wave":
Example Evolution ending in "Vortex":
