Artificial life: Encyclopedia II - Artificial life - Nature of the field

Artificial life - Nature of the field

Although the study of artificial life does have some significant overlap with the study of artificial intelligence (AI), the two fields are very distinct in their history and approach. Organized AI research began early in the history of digital computers, and was often characterized in those years by a "top-down" approach based on complicated networks of rules. Students of alife did not have an organized field at all until the 1980s, and often worked in isolation, unaware of others doing similar work. Where they concerned themselves with intelligence at all, researchers tended to focus on the "bottom-up" nature of emergent behaviors.

Artificial life researchers have often been divided into two main groups (although other groupings are possible):

• The strong alife position states that "life is a process which can be abstracted away from any particular medium". (John Von Neumann). Notably, Tom Ray declared that his program Tierra was not simulating life in a computer, but was synthesizing it.
• The weak alife position denies the possibility of generating a "living process" outside of a carbon-based chemical solution. Its researchers try instead to mimic life processes to understand the appearance of single phenomena. The usual way is through an agent based model, which usually gives a minimal possible solution. That is: "we don't know what in nature generates this phenomenon, but it could be something as simple as..."

The field is characterized by the extensive use of computer programs and computer simulations which include evolutionary computation (evolutionary algorithms (EA), genetic algorithms (GA), genetic programming (GP), swarm intelligence (SI), ant colony optimization (ACO)) artificial chemistries (AC), agent-based models, and cellular automata (CA). Often those techniques are seen as subfields of alife. With technical papers on the subjects being included and accepted in artificial life conferences until their field has grown enough to hold their own conferences. As such, over the years, artificial life has also worked as a temporary umbrella term for different techniques that would not be accepted in other fields.

Artificial life is a meeting point for people from many other more traditional fields such as linguistics, physics, mathematics, philosophy, computer science, biology, anthropology and sociology in which unusual computational and theoretical approaches that would be controversial within their home discipline can be discussed. As a field, it has had a controversial history; John Maynard Smith criticized certain artificial life work in 1995 as "fact-free science", and it has not generally received much attention from biologists. However, the recent publication of artificial life articles in widely read journals such as Science and Nature is evidence that artificial life techniques are becoming more accepted in the mainstream, at least as a method of studying evolution.

Adapted from the Wikipedia article "Nature of the field", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki