Reference:Tenth International Conference on the Simulation and Synthesis of Living Systems (ALIFE X), Bloomington, Indiana, USA, 03 Jun 2006 - 07 Jun 2006. Editors: Rocha LM, Yaeger LS, Bedau MA, Floreano D, Goldstone RL, Vespignani A. Artificial Life X. MIT Press, Cambridge, MA. 152-157. 2006