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'Artificial Life', (commonly 'Alife' or 'alife') is a field of study and associated art form which examine systems related to life, its processes and its evolution through simulations using computer models, robotics, and biochemistry^[1]. There are three main kinds of alife: ''soft'' from software, ''hard'' from hardware, and ''wet'' from biochemistry approaches respectively^[2]. Artificial life imitates traditional biology by trying to ''recreate'' biological phenomena.^[3] The term "Artificial Life" is often used to specifically refer to soft alife.

Contents

Overview

Philosophy

Techniques

Related subjects

History

Criticism

Notable simulators

See also

References

External links

Overview

Artificial Life studies the evolution of agents, or populations of computer simulated life forms in artificial environments. The goal is to study phenomena found in real life evolution in a controlled manner, hopefully to eliminate some of the inherent limitations of evolutionary studies using live bacteria or mice. The simulated nature of the organisms and environments also allows for unorthodox and previously impossible experiments (such as a comparison of Lamarckian evolution and natural selection).
Also sometimes included in the umbrella term "artificial life" are other agent based emergent properties, such as the development of economies or societies. The common thread between all "artificial life" is the concept of an iterative population approach: generations of agents which can mutate and become fitter over time.

Philosophy

At present the definition of life commonly accepted does not allow for any alife simulations to be considered "alive". However, different opinions about artificial life's potential have arisen:

★ The ''strong alife'' (cf. Strong AI) 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 is not simulating life in a computer, but synthesizing it.

★ The ''weak alife'' position denies the possibility of generating a "living process" outside of a chemical solution. Its researchers try instead to mimic life processes to understand the underlying mechanics of phenomena. That is: "we don't know what in nature generates this phenomenon, but it could be something as simple as..."

Techniques

★ Cellular automata are often used, especially in the history of artificial life, due to the ease of scalability and parallelization. Alife and cellular automata share a closely tied history.

★ Neural networks are sometimes used to model the brain of agents. Although traditionally more of an artificial intelligence technique, neural nets can be important for simulating population dynamics of higher organisms that can ''learn''. The symbiosis between learning and evolution is central to theories about the development of instincts in higher organisms, for instance, as in the Baldwin effect.

Related subjects

#Artificial intelligence has traditionally used a top down approach while alife generally works from the bottom up.
#Artificial chemistry started as a method within the alife community to abstract the processes of chemical reactions.
#Evolutionary algorithms applied to optimization problems are strongly related to weak alife, yet are sometimes dismissed as 'not ''real'' artificial life'. Many optimization algorithms have been crafted which borrow from or closely mirror alife techniques. The primary difference lies in explicitly defining the fitness of an agent by its ability to solve a problem, instead of its ability to find food, reproduce, or avoid death. The following is a list of evolutionary algorithms closely related to, and used in alife:
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★ Ant colony optimization
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★ Evolutionary algorithm
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★ Genetic algorithm
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★ Genetic programming
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★ Swarm intelligence
#Evolutionary art uses techniques and methods from artificial life to create new forms of art.
#Evolutionary music uses similar techniques, but applied to music instead of visual art.

History

Criticism

ALife has had a controversial history; John Maynard Smith criticized certain artificial life work in 1994 as "fact-free science". However, the recent publication^[4] 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.
Generally the lack of biologists and abundance of computer scientists in the field has hurt the field's credibility within mainstream biology. There is also scepticism of the field within the computer science community.

Notable simulators

See also

★ Autonomous foraging

★ Complex adaptive system

★ Social simulation

★ Synthetic life

References

1. Dictionary.com definition
2. Artificial life: organization, adaptation and complexity from the bottom up Mark A. Bedau
3. What is Artificial Life? Christopher Langton
4. Evolution experiments with digital organisms

External links

★ International Society for Artificial Life (ISAL)

★ Artificial Life (journal)

★ Biota.org Online Magazine and Podcast

★ Grey Thumb Artificial Life Blog

★ Biota Interview with Jay Lemmon on this Wikipedia entry (MP3)

★ 9th European Conference on Artificial Life (ECAL 2007)

★ [irc://irc.freenode.net#alife Freenode #alife IRC chat room]