Semi-involuntary interactive evolution of tiny populations of Voronoi patterns

The Applet

The following applet is a minimalistic point-and-click game: just click on the colored balls before they fade away - the more you keep ``alive'', the higher your score. Before reading further, give it a try!


The pattern of every colored ball is the Voronoi diagram associated to a given set of points (for a given sequence of colors). These points and colors correspond to the genetic code of the balls, whose reproductive success depends on their fitness.

There are two (non-distinguishable from the user's perspective, and non-interreproducing) species of balls:

  • Shy ones (avoiders), that prefer not to interact with the user (the less they are clicked, the higher their fitness);

  • Gregarious ones (seekers), that prefer to interact with the user (the more they are clicked, the higher their fitness).

The question that this project explores is the following: does the fact that two families of balls are subject to opposite evolutionary pressure lead to their aspect to diverge after a number of generations? And if so, how?


Apparently counter-intuitively, avoiders evolve to develop bright colors, whereas seekers evolve towards drab colors.

The reason, in hindsight, is clear enough: the human player will prioritize clicking on balls that seem on the cusp of disappearing, and thus the ones that whose default colors are already faded-looking will tend to be clicked more often than the ones that look brighter.

As they say, it is the squeaky wheel that gets the oil!

Details and code

For more information about the simulation, you can look at the pdf file.

You can also download the code from github and play around with it.