Artificial life: sustainable self-replicating systems

Nature has found one method of organizing living matter, but maybe other options exist — not yet discovered — on how to create life. To study the life “as it could be” is the objective of an interdisciplinary field called Artificial Life (commonly abbreviated as ALife) [1, 2, 3]. The word “artificial” refers to the fact that humans are involved in the creation process. The artificial life forms might be completely unlike natural forms of life, with different chemical compositions, and even computer programs exhibiting life-like behaviours. ALife was established at the first “Interdisciplinary Workshop on the Synthesis and Simulation of Living Systems” in Los Alamos in 1987 by Christopher G. Langton [4]. ALife is a radically interdisciplinary field that contains biologists, computer scientists, physicists, physicians, chemists, engineers, roboticists, philosophers, artists, and representatives from many other disciplines. There are several approaches to defining ALife research. One can discriminate between soft, hard and wet ALife (Figure 1). “Soft” ALife is aiming to create simulations or other purely digital constructions exhibiting life-like behaviour. “Hard” ALife is related to robotics and implements life-like systems in hardware made mainly from silicon, steel and plastic. “Wet” ALife uses all kinds of chemicals to synthesize life-like systems in the laboratory. Bedau et al. [5] proposed 14 open problems in ALife in the year 2000, but none of them have been solved yet. Aguilar et al. [3] summarized the ALife research challenges and divided them into thirteen themes: origins of life, autonomy, selforganization, adaptation (evolution, development, and learning), ecology, artificial societies, behaviour, computational biology, artificial chemistries, information, living technology, art, and philosophy.