The new science that models the processes and forms of biological life on computers, is one of the most exciting areas of current scientific work. Bringing together researchers from genetics, computer science, artificial intelligence, cybernetics and chaos theory, "Artificial Life" challenges the very notion of what "life" is - whether evolving and reproducing forms, be they mechanical or based in a computer, can be said to be alive. Both our understanding of biological life forms and evolution, and the concept of life itself, are being radically extended by this work.