Clocks Running Backwards

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.