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Stewart Dean's Guide to Artificial Life

Artificial Life - an Introduction.

Artificial Life is a the name for a collection of various disciplines. It is about the study of non organic organisms, of life like behaviour beyond the creation of nature. In the quest of behavioural biologists to understand the behaviours of nature and computer scientists to create new and better programs, paths increasingly crossed. Research of different kinds can, in many cases, lead to unifying knowledge. Later on I will be looking at some of the people involved with artificial life and the work they have done.

Artificial Life, increasingly called aLife by its disciples, is about the emergent properties. An emergent property is created when something becomes more than the sum of its parts. The most extreme example of an emergent property we know of is life on this planet. We are morethan the sum of our parts. Half a human does not work without the other half, but as a whole we are capable of very complex behaviour. Artificial Life is an attempt to explain existing life as well as creating something new. It should not be confused with Artificial Intelligence; the two fields have only a few topics in common.

To best describe the field it is first important to understand, or at least attempt to classify, what real life actual is. My handy Oxford dictionary defines life as:

Life n. (pl. lives. pr. ~vz.) State of functional activity and continual change peculiar to animals and plants before death, animate existence.

Life can also be classified as something capable of reproducing its self, capable of adapting to an environment and also capable of independent actions not decided by some exterior agent. We are carbon based life, as is most of nature. We are the complicated application of organic chemistry that centers around the combination of commonly found atoms. This is despite being true but is also a gross simplification. How these atoms combine depend on many different variables such as entropy and evolution. To combine atoms to create life is a very improbable event, but given the right range of variables in an environment* and enough time life on Earth was a very probable thing. Natural creations, such as DNA, the brain, and the eye, are all complex items but are, in terms of Chaos theory and strange attractors. Given one set of events they become inevitable, almost unavoidable. The knock on effect is that their creation makes other steps inevitable, except if major environmental changes happen.

We must also remember that we are probably only one combination of atoms that leads to life. Having never met alien life that does not share the same environment and source we only know life in the incantation we know. The single example can become indistinguishable from thephenomena. Nature could be said to be one application of the rules of life. In the past the two were inseparable as there were no other examples. With alife the phenomena can be seen in isolation to nature, the rules and complexities can be seen to be borrowed by nature, just as maths is borrowed by physics. It has no monopoly.

Alife is only artificial in the sense that is it man made. In Alife the environment is originally created by humans inside a computer. The rules of life are fairly universal and apply even out of a natural setting. The waiting for useful combinations of atoms to form is replaced by creating a set of rules for creatures or cells to follow. If these creatures are capable of reproduction and some form of mutation and they are complex enough the creatures will evolve or the cell pattern will change into new forms. The result is either the population dies out or a solution to survival in the environment is found. The environment may be a programming problem like counting people on a tube platform or solving a mathematical problem, or it may be an area of memory shared by other similar creatures.

There is no stipulation that an environment must mirror real life, after all by creating a-life we are also looking for benefits for us as humans. Alife could solve many of the problems that are currently to complex to solve by hand. Alife is used in synthetic chemistry to model new compounds and in engineering to design aircraft. Alife can be used to digest information, creating information agents and automate events that change so cannot be easily programmed.

This is only an introduction to the field. Further understanding can be gained by exploring the links in this text. Explore at will. I have tried to include not only internal links but links to external sources.

Please send any corrections, comments or additions to: alife(at)stewdean(dot)com

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