The idea of playing god on computers took off 30 years ago, when mathematician John Conway invented the Game of Life, in which colored cells in a grid vie for survival. By now, applications of artificial life (Alife) are becoming commonplace: Social scientists use "evolutionary" algorithms to explore social interactions, for example, while biologists harness the equations for studying protein folding and lining up DNA sequences.
Try your hand at the creation and destruction of life at Zooland , a site where animals mate and compete, armies battle, landscapes bloom, and whimsical creatures learn to walk or swim. The site is targeted "somewhere between newbie/layman and die-hard expert," says Zooland mastermind Jörg Heitkötter, head of research at the Internet provider UUNET's subsidiary in Germany. After boning up on the subject with The Hitchhiker's Guide to Evolutionary Computation, co-authored by Heitkötter, you'll be ready to jump to Alife software programs for Macs, PCs, and UNIX. For instance, The Iterated Prisoner's Dilemma looks at trade-offs between cooperation and defection; in Sugarscape, civilizations evolve as tribes trade and bicker over stores of sugar (Science, 1 November 1996, p. 727 ); and in yet another game, lions stalk gazelles on a virtual savanna.