Squirm3 > EvSelfReps > Exp2

Evolvable Self-Replicating Molecules in an
Artificial Chemistry

Experiment 2: Evolution - adaptation to the environment

Below the experiment is running as a java applet - if you don't see anything then you either need to change your browser settings to enable java, or use a different browser.

You can control how fast the applet runs by using the slowdown controls, if enabled they cause a delay of so many milliseconds per timestep. Remember to hit 'update applet' after changing the value.

The flood controls let you specify whether you want the flood to occur and, if so, how often. The default value of 2000 timesteps was the one reported in the paper. The flood clears out one half of the area and replenishes it with more 'raw material' - atoms of random type with state 0. Use 'update applet' after changing the values.

If you want maximum speed then there are controls that let you draw only every 100 timesteps, for example. If you really want maximum speed then take a look at the C++ version on the development page.

The 'pause/run' button is a toggle switch that lets you stop and start the applet.

When you hover over the atoms with the mouse their type and state are displayed. This works best when the applet is paused.

To reset the applet, use your browser's Refresh button.

Slowdown: milliseconds
Flood every: timesteps (alternates left and right)
Draw only every: time steps


In this experiment we show how the molecules evolve over time. Molecules that are shorter are able to replicate faster and are thus 'fitter' since they can capture the raw materials quicker than their longer competitors. After ten thousand time steps or fewer the only remaining form of replicator is the shortest possible one, the e8-f1 pair.

The java source for this applet is here: sq3.zip (13k) - for instructions on building the source see the development page.