Artificial life: stepping closer to reality.

Artificial life: Stepping closer to reality

Creating synthetic life may not require miracles. This week, at the second Artificial Life Conference in Santa Fe, N.M., hundreds of investigators reported on computer, chemical, mathematical and robotic systems that behave somewhat like slime molds, ants, growing plants, sea animals and networks of biochemicals. They say their efforts could spawn insights into natural life, how life began on Earth and even life as we haven't yet known it.

Two unproved assumptions underlie this embryonic field, says physicist and conference organizer Christopher Langton of Los Alamos (N.M.) National Laboratory. One is that "life" refers more to the organization of matter than to any particular kind of matter. The other is that it's possible to create artificial systems that display living behavior by abstracting the operational principles and functional relationships of the parts of living organisms and recapturing these within other media -- even nonbiological systems such as computers or novel sets of chemicals.

Just as computer simulation has opened a new brand of research especially suited for probing complex phenomena such as atmospheric chemistry and human intelligence, artificial life could open up powerful new ways of investigating what makes real living things tick, Langton says.

In a written statement, he and other organizers envision still other far-reaching discoveries: "By extending the empirical foundations upon which biology is based beyond the carbon-chain life that has evolved on Earth, Artificial Life can contribute to theoretical biology by locating life-as-we-know-it within the larger context of life-as-it-could-be."

Many of the studies described at the meeting involve a class of computer programs known as cellular automata. For a sense of how these work, imagine a computer monitor displaying a grid of cells that resembles an unworked crossword puzzle. Then fill in or empty the cells according to rules derived from the states of nearby cells. After repeating this exercise a number of times, sometimes according to rules that change with the evolving patterns of light and dark cells, you begin to see lifelike shapes, movements and interasctions unfolding on the monitor. Researchers admit that even the most sophisticated cellular automata don't qualify as life, but they say these simulations of synthetic life may hold clues to real living things -- and perhaps to some artificial ones that await creation.