Artificial Life

Also called "A-Life" or "Alife" by practitioners and wannabes.

The construction and study of artificial systems that are engineered so as to capture aspects of biological systems.

In origin, founded in the latter 1980s by ChrisLangton? in part as a rebellion against the foolishness of ArtificialIntelligence, since it relies on BottomUpDesign principles, not TopDownDesign like AI did. Inasmuch as ArtificialLife systems use BottomUpDesign and are MultiAgentSystems, they are often prone to exhibit EmergentBehavior.

In practice, a way of creating pretty and exotic-seeming screensaver things. In terms of potential, a way of both instantiating our current hypotheses about real-world biological systems in order to really test them, and also a way to embrace EmergentDesign.

"Weak Alife" can be defined as building stuff that acts like it was alive. "Strong Alife" can be defined as building living systems.

Cf: http://alife.org and related links for much more information. EvolutionaryAlgorithms are considered a type of Alife, in some circles.

ArtificialLife is sometimes erroneously equated with ArtificialIntelligence, or treated as a sub-field of it. The opposite is more true; areas of ArtificialIntelligence can be considered a branch of ArtificialLife.

If anybody's interested, the AlifeWiki? has just come online at http://news.alife.org/wiki.

: a rebellion against the foolishness of ArtificialIntelligence

I think that's a bit over the top. Also, I don't think many a-lifers seriously try to build an ArtificialIntelligence.

But there certainly are quite a few A-lifers whose work was informed by the problems of the traditional AI approach - the ones that required an AI to "understand" its environment in order to interact with it. The MIT roboticist RodneyBrooks? gives a great talk on how traditional AI-based robots would take a little teeny step, scan their environment, build a model of it, understand the model in light of their goals, take a little teeny step, and so forth. In Rodney's robots, whose SubsumptionArchitecture is quintessentially Alife, each leg just goes along on its own, and there's very little communication between the parts, but the desired behavior ("walking", for instance) just emerges from the collective behavior of the components.

Especially with the Cog project (http://www.ai.mit.edu/projects/cog/), Rodney's group is definitely trying to build ArtificialIntelligence.

(Rodney, by the way, is the one who coined the slogan "FastCheapAndOutOfControl?".) -- BillTozier

A few companies are now starting to get into the ALife game. The old, commonly referenced one is SwarmCorp (see ComplexSystems and NelsonMinar). A new kid on the block is DaliInc. -- JosephKiniry

There also is the Tierra program by Tom Ray (http://www.isd.atr.co.jp/~ray/tierra/) which has evolved small programs that seem (or are really) alive, and the CreaturesSeries? (the subject of CreaturesWiki).

An example of evolving predator/prey flocking ArtificialLife with complex EmergentBehavior can be found at http://www.neocoretechs.com/alife. Hopefully, this is an entertaining and informative example of the GeneticAlgorithm as well -- JonGroff

This was written on Sunday, May 4, 2003, two weeks after the passing on April 18, 2003 of Dr. E. F. Codd ("Ted" Codd), the "Father of the Relational Model" for very large data bases. I would like to dedicate this entry to Dr. Codd and his lovely wife, Sharon. [This entry also appears at the DrCodd entry.]

It was about 1995 and I was on the phone with Dr. Codd, he in Florida at his home, and me in Mission Viejo, CA. I was telling him that Chris Langton would like to meet him. Chris had told me not long before then that Chris, in his research that led to "Artificial Life," had thoroughly digested Ted's doctoral thesis "Cellular Automata" and leveraged Dr. Codd's 8-state self-reproducing cellular automata ("machine" or "pattern") in creating Chris's own "machine." By the way, you can read some of this history in Mitch Waldrop's book "Complexity - The Emerging Science at the Edge of Order and Chaos" on pages 216-222. I related this story of Chris' to Dr. Codd and Ted asked me if I would like to hear the story of how he devised his eight-state cellular automata. I was all ears. So, Ted (if you're listening) and Sharon, here is that true story, as related to me over the phone by Ted.

Dr. Codd related that he and a fellow doctoral student were in a "pub" and the "lad was speaking rather reverently of John Von Neumann's 29-state machine." Ted, not one to let something like this slide by (Sharon, you know this wonderful trait so well), insisted he could beat that! Ted boldly said he could drastically reduce the number of required states and still produce the same results. His buddy replied in the negative. With the quick retort, "Yes, I can, I'll bet you I can!" the challenge demanded some sort of "formality." Dr. Codd said to me, "We were poor graduate students, what did we have of value to bet?" "How about a beer?" Ted chuckled over the phone. And, sure enough, shortly thereafter they returned to the "pub" and Ted presented his eight-state machine (8-state cellular automata).

Ted and I laughed over the fact that a "branch of science," artificial life, was borne from a bet over a beer.

I hope you have enjoyed this true story.

I had the honor of spending time with Dr. Codd and his wife Sharon at the 25th anniversary of the Relational Model in Boston, MA in 1994, where he graciously signed my copy (#242) of his book (edited by Sharon) specially published for that event. Thank you, Dr. Codd, for a life of giving that has made such a difference for just about every human on earth.

-- Gavin Gray (ggray2@earthlink.net), San Diego, CA