Squirm3 > EvSelfReps > Exp1

Evolvable Self-Replicating Molecules in an
Artificial Chemistry

Experiment 1: Repeated self-replication and simple evolvability

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.

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
Draw only every: time steps


When the applet starts there is a single e8-a1-b1-c1-f1 molecule in a random soup. The world is 50x50, there are 500 extra atoms as well as the molecule. The molecule quickly replicates using the reactions as detailed in the paper, soon there are lots of copies of the molecule.

After a few thousand timesteps the 50x50 world has been taken over by the replicators, all of the useful raw material has been used up and so replication is no longer possible. Of the remaining atoms, most of them are d0's (dark blue) since these were never used.

If you look at the replicators that are present after a few thousand timesteps you will notice that they are not all exact copies of the original. Many of them are shorter, some may be longer. Replicators that are the shortest possible with these reactions (e8-f1 pairs) may be visible.

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