In a Swiss laboratory, a group of ten robots is competing for food. Prowling around a small arena, the machines are part of an innovative study looking at the evolution of communication, from engineers Sara Mitri and Dario Floreano and evolutionary biologist Laurent Keller.
They programmed robots with the task of finding a “food source” indicated by a light-coloured ring at one end of the arena, which they could “see” at close range with downward-facing sensors. The other end of the arena, labelled with a darker ring was “poisoned”. The bots get points based on how much time they spend near food or poison, which indicates how successful they are at their artificial lives.
They can also talk to one another. Each can produce a blue light that others can detect with cameras and that can give away the position of the food because of the flashing robots congregating nearby. In short, the blue light carries information, and after a few generations, the robots quickly evolved the ability to conceal that information and deceive one another.
Their evolution was made possible because each one was powered by an artificial neural network controlled by a binary “genome”. The network consisted of 11 neurons that were connected to the robot’s sensors and 3 that controlled its two tracks and its blue light. The neurons were linked via 33 connections – synpases – and the strength of these connections was each controlled by a single 8-bit gene. In total, each robot’s 264-bit genome determines how it reacts to information gleaned from its senses.
In the experiment, each round consisted of 100 groups of 10 robots, each competing for food in a separate arena. The 200 robots with the highest scores – the fittest of the population – “survived” to the next round. Their 33 genes were randomly mutated (with a 1 in 100 chance that any bit with change) and the robots were “mated” with each other to shuffle their genomes. The result was a new generation of robots, whose behaviour was inherited from the most successful representatives of the previous cohort.