One main use of ALife, is as an aid to natural biology. However, unlike tradional biology, ALife attempts to put together systems that behave like living organisms, rather than taking apart living organisms to see how they work.
Why is this so important? Well, lots of reasons:
1. Another Life Form?
Scientists only have one form of life that they can study - carbon bases life as found on the planet Earth. Computers enable scientists to create model universes which function along different lines to our universe.
2. What If?
Scientists can model part of our world which they find either perplexing, or can set up conditions at the start of something and alter one or more variables, to see what would have happened if...
3. Speed?
The earth took billions of years to evolve, so to make another model and run it, would take, well a really long time. However, a computer can zip through generations faster than you can say that long word from Mary Poppins. This makes it possible to actually study a biosphere relatively quickly, and to be able to restart it with a slightly different initial configuration.
These three aspects belong to the branch of Artificial Life often known as 'Weak A-Life', that is computer programs as useful simulations of real life.
This web site focuses on weak alife, containing two real-life simulations: Conway's Game of Life simulation, modelling simple emergent behaviour, and Craig Reynold's boid simlulation, roughly modelling the behaviour of a flock of birds, or shoal of fish. ( See the separate tutorials for more information on each of these ).
These are both fairly simple simulations, however much more complex ones can be built, for example Sante Fe's Biotopia or Thomas Ray's Tierra which contain many different types of complex evolutionary creatures.
Of course there is also the more flippant view - that Weak ALife is just a game or toy, that may be fun and interesting but ultimately holds little real worth.
There is also a second type of ALife, dubbed 'Strong Alife'. The area of Strong ALife focuses on computer programs that are in some sense actually living. However, this type of ALife goes beyond the scope of this site.