The previous page shows four heatsinks evolved by the system. The designs were defined to be symmetrical about the planes x=0 and z=0 and were evolved from an initial population of entirely random shapes (on the top of a base of pre-defined size).
The desired function of a heatsink was defined by four reusable 'evaluation modules'. These specified that a heatsink should be a certain size, should have a certain mass, be unfragmented (i.e., no part should be unconnected and 'float free' of the design), and have a very high surface area (the higher the surface area, the better a heatsink can radiate heat away from a CPU chip).
The four designs show the variety of designs the computer created. The top-left resembles a conventional heatsink design, using a row of upright 'slats' to increase the surface area. The others show the more typical sort of heatsink desing evolved by the system. These designs increase the surface area by creating heatsinks with detailed, uneven surfaces (in the same sort of way that nature increases the surface area of coral). [To achieve this, the system 'decided to' add large numbers of primitive shapes to the designs. This in turn increased the number of parameters that the system needed to evolve. In other words, the system evolved the dimensions of the hyperspace it was searching in, while at the same time evolving the shape of the designs.]