Artificial Life is the study of man-made systems that exhibit behaviors characteristic of natural living systems, such as self-organization, reproduction, development, and even evolution. It complements the traditional biological sciences concerned with the analysis of living organisms by attempting to synthesize and study life-like behaviors within computers or other ”alternative” media. By extending the empirical foundation upon which biology rests beyond the carbon-chain based life that has evolved on Earth, Artificial Life can contribute to the theoretical biology by locating ”life-as-we-know-it” within the larger context of ”life-as-it-could-be,” in any of its possible physical incarnations.