March 1993By Richard J. Lanham
Richard J. Lanham teaches in the Department of Medicine at the State University of New York at Buffalo.
Artificial Life. By Steven Levy. Pantheon. 390 pages. $25.
Artificial Life is an account of the efforts of scientists to build on the ideas of John von Neumann about how "living" processes might be created. Von Neumann (1903-1957) was a Hungarian mathematician who worked on the atom bomb and was a contemporary of Einstein's at the Institute for Advanced Study in Princeton. It is said that other professors at the Institute who knew both men considered von Neumann the bright one. Von Neumann was born Jewish and died Catholic.
Besides his work on atomic reactions, von Neumann had several other interests. One of these was the analysis of what "living" meant. He set about creating an automaton (by means of a computer program) that would "reproduce," "migrate," "mutate," "respond to its environment," and "evolve" -- in a word, would emulate "aliveness."
Later other workers in diverse fields extended von Neumann's work. A few of the processes of the automata are now not only on computer screens but have been incorporated into the mechanisms of robots. One of these workers, Charles G. Langton, convened an "Interdisciplinary Workshop on the Synthesis and Simulation of Living Systems" in 1987 and again in 1990 at the Santa Fe Institute for Studies in the Sciences of Complexity. On the basis of the published proceedings, other publications, and numerous interviews, Levy wrote his popular account.
Artificial Life has nothing to do with Artificial Intelligence. The latter is an attempt to simulate the thinking of an expert and apply that thinking to a problem the expert would normally be expected to solve. Chess playing is the well-known example. Artificial Intelligence seeks to impose a complex solution "down" on a problem.
To understand the basic idea of Artificial Life one need only contemplate an ant colony. There, if an ant finds itself outside the anthill next to a crumb of bread, it will carry the food back to the hill. The animal is responding to an instruction inherent in its nervous system to BRING FOOD HOME. If another ant in the hill happens upon a dead mate, the live ant buries the dead one, responding to the instruction, BURY ANY DEAD ANT FOUND IN THE ANTHILL. If a third ant discovers damage to the hill, it immediately begins repairs, responding to the instruction, REPAIR ANY BREACH IN THE RAMPARTS. In the ant colony, there is no "overall plan" or "overall planner" directing what the functioning community is to be. But when the actions of all ants are aggregated, colony "life" emerges. Such life is a complicated, unpredictable system made up of simple, individual, and programmed actions.
And this is exactly how the basic systems of Artificial Life are constructed. The systems are largely -- but not exclusively -- computer programs. They start with primitive "organisms" (blips on the screen corresponding to the ants) which follow simple "rules" (the ants' instructions inherent in their nervous system) in regard to their initial "state" (whether the ant is outside or inside the hill), and to their "environment" (whether there is a bread crumb or a dead ant or a crumbling wall nearby). Out of the random interactions of all these "organisms" a "group behavior" emerges, which emulates "life."
Thus Artificial Life is in a sense the opposite of Artificial Intelligence. If Artificial Intelligence seeks to impose a complex solution "down" on a problem, Artificial Life seeks to impose simple behaviors "up" toward a complex result -- which is not only complex, but strange. For what is happening here is unpremeditated ordering of random events. This is an apparent violation of the Second Law of Thermodynamics, which holds that disorder (the technical term is "entropy") is always increasing, everywhere. Here disorder seems to be decreasing, at least in spots. Eerie. It's like clocks starting to run backward.
There is more to systems of Artificial Life. Random mutations and rearrangements of the "rules" are planned for. This simulates DNA changes in genes, allowing for "evolution." Part of a "rule" of one "organism" can join with a portion of a "rule" from a second "organism" forming a third "organism." This simulates sexual reproduction. An "organism" can be "rewarded" by being allowed more "offspring" if it "responds well" to its "environment," just as an animal in a desert that can tolerate dry heat will produce more progeny than an animal that cannot. "Diseased organisms" can "heal" themselves. "Parasites" develop (one blip without enough "rules" to "survive" uses the "rules" of another blip to get by). "Organisms" change as they evolve. They "learn" (to follow a particular path in a grid on a computer screen, for example). Some changed "organisms" become extinct rapidly. Others flourish until their "environment" changes and then perish. "Populations" rise and fall.
You will notice that no mention is made in this account of particular materials out of which "life" must be made. These scientists are not talking about life as we know it on earth, but "life" as it might be constructed anywhere. "Life" to them is not skin and bones, but processes that a variety of materials might engage in. When I realized this, I began to feel that I was not learning so much about biology as I was glimpsing into the workings of God's mind.
This book is understandable by anyone with a general education. Levy's prose is clear and elegant. The minds of the scientists he describes are divergent and demand contemplation. The picture of how science actually operates is grimy and thrilling. And the subject is serious. Artificial Life is to biology what the Big Bang theory is to astrophysics. If the science continues as it has begun, its promise for good and harm to mankind will be greater than that of atomic fission and fusion. There are urgent ethical problems in this discipline that need to be addressed.
There are special reasons why Levy's book should be read by religious traditionalists. This new science will, no doubt, be cited as "proof" for the nonexistence of God. It is nothing of the kind. But if those who will make this argument set the agenda for the discussion of Artificial Life, I am afraid of a reaction akin to that to the thought of Galileo, Newton, and Darwin, in which science was held to conflict with religion. This would be unfortunate.
This book describes for the lay reader a topic so fascinating that even a moderate antipathy to reading about science can be overcome. The work reported on, and the book itself, are beautiful, powerful, and profound. The work deserves the highest prize in science -- and the book the highest prize in literature.