Thompson designed an electric circuit to perform a tone-discrimination task â it listens to a sound, and can tell you which of two expected tones it has heard. Thompson then The critical part: the evolved circuit was selected not as a simulation, but by making a physical version and - experimentally - measuring how well it performed. This line in the abstract is far too modest: a greater respect for the natural properties of the implementation medium than is usual â because what happens is - excuse my French - BATSHIT INSANE. Jumping to The evolved circuit is a mess. So, of that tangle: