Larry Yaeger's alife simulation running on a Silicon Graphics Iris Workstation is called Poly World. Our description of PolyWorld is based on notes taken during an oral presentation and video demonstration given in the Artificial Life Panel Session of SIGGRAPH '92: In PolyWorld the visual organisms roam on a bounded two dimensional grid. The organisms "brains" are small neural nets enabling the organisms to control their external visual appearance and to perceive the external world by processing pixmaps. The simulation controls for total energy while striving to explore competition and self-organization. Genes present are for size, strength, maximum speed, mutation rate, number of crossover points in the neural net, lifespan, energy to offspring, and ID (a parameter used to enable mimicry). The neural net can make decisions about whether the organism should eat, fight, mate, move, turn, light (effecting the external appearance of the light sensor panel it emits), or focus (gaze at the appearance of others). To see the organisms evolve to different species adopting distinct and atypical strategies and behaviors for survival is most impressive. Words do not do justice to the video animation sequences.
Gary R. Greenfield. Graphical Evolution Experiments in Artificial Life. Technical paper (TR-93-01). Math and Computer Science Technical Report Series. Richmond, Virginia: Department of Mathematics and Computer Science, University of Richmond, February, 1993.