An autonomous agent is something that can both reproduce itself and do at least one thermodynamic work cycle. It turns out that this is true of all free-living cells, excepting weird special cases. They all do work cycles, just like the bacterium spinning its flagellum as it swims up the glucose gradient. The cells in your body are busy doing work cycles all the time.
Stuart Kauffman is a theoretical biologist who studies the origin of life and the origins of molecular organization. Thirty- five years ago, he developed the Kauffman models, which are random networks exhibiting a kind of self-organization that he terms "order for free." Kauffman is not easy. His models are rigorous, mathematical, and, to many of his colleagues, somewhat difficult to understand. A key to his worldview is the notion that convergent rather than divergent flow plays the deciding role in the evolution of life. He believes that the complex systems best able to adapt are those poised on the border between chaos and disorder.
Kauffman asks a question that goes beyond those asked by other evolutionary theorists: if selection is operating all the time, how do we build a theory that combines self-organization (order for free) and selection? The answer lies in a "new" biology, somewhat similar to that proposed by Brian Goodwin, in which natural selection is married to structuralism.
Kauffman says that he has been "hamstrung by the fact that
I don't see how you can see ahead of time what the variables
begin science by stating the configuration space. You know
the variables, you know the laws, you know the forces, and
the whole question is, how does the thing work in that space?
If you can't see ahead of time what the variables are, the
microscopic variables for example for the biosphere, how do
you get started on the job of an integrated theory? I don't
know how to do that. I understand what the paleontologists
do, but they're dealing with the past. How do we get started
on something where we could talk about the future of a biosphere?"
STUART A. KAUFFMAN, a theoretical biologist, is emeritus professor of biochemistry at the University of Pennsylvania, a MacArthur Fellow and an external professor at the Santa Fe Institute. Dr. Kauffman was the founding general partner and chief scientific officer of The Bios Group, a company (acquired in 2003 by NuTech Solutions) that applies the science of complexity to business management problems. He is the author of The Origins of Order, Investigations, and At Home in the Universe: The Search for the Laws of Self-Organization.
"THE ADJACENT POSSIBLE"
KAUFFMAN): In his famous book, What is Life?, Erwin Schrödinger
asks, "What is the source of the order in biology?" He
arrives at the idea that it depends upon quantum mechanics and a
microcode carried in some sort of aperiodic crystal—which
turned out to be DNA and RNA—so he is brilliantly right. But
if you ask if he got to the essence of what makes something alive,
it's clear that he didn't. Although today we know bits and pieces
about the machinery of cells, we don't know what makes them living
things. However, it is possible that I've stumbled upon a definition
of what it means for something to be alive.
Right now I'm busy thinking about this incredibly important problem. The frustration I'm facing is that it's not clear how to build mathematical theories, so I have to talk about what Darwin called adaptations and then what he called pre-adaptations.
You might look at a heart and ask, what is its function? Darwin would answer that the function of the heart is to pump blood, and that's true—it's the cause for which the heart was selected. However, your heart also makes sounds, which is not the function of your heart. This leads us to the easy but puzzling conclusion that the function of a part of an organism is a subset of its causal consequences, meaning that to analyze the function of a part of an organism you need to know the whole organism and its environment. That's the easy part; there's an inalienable holism about organisms.
But here's the strange part: Darwin talked about pre-adaptations, by which he meant a causal consequence of a part of an organism that might turn out to be useful in some funny environment and therefore be selected. The story of Gertrude the flying squirrel illustrates this: About 63 million years ago there was an incredibly ugly squirrel that had flaps of skin connecting her wrists to her ankles. She was so ugly that none of her squirrel colleagues would play or mate with her, so one day she was eating lunch all alone in a magnolia tree. There was an owl named Bertha in the neighboring pine tree, and Bertha took a look at Gertrude and thought, "Lunch!" and came flashing down out of the sunlight with her claws extended. Gertrude was very scared and she jumped out of the magnolia tree and, surprised, she flew! She escaped from the befuddled Bertha, landed, and became a heroine to her clan. She was married in a civil ceremony a month later to a very handsome squirrel, and because the gene for the flaps of skin was Mendelian dominant, all of their kids had the same flaps. That's roughly why we now have flying squirrels.
The question is, could one have said ahead of time that Gertrude's flaps could function as wings? Well, maybe. Could we say that some molecular mutation in a bacterium that allows it to pick up calcium currents, thereby allowing it to detect a paramecium in its vicinity and to escape the paramecium, could function as a paramecium-detector? No. Knowing what a Darwinian pre adaptation is, do you think that we could say ahead of time, what all possible Darwinian pre adaptations are? No, we can't. That means that we don't know what the configuration space of the biosphere is.
It is important to note how strange this is. In statistical mechanics we start with the famous liter volume of gas, and the molecules are bouncing back and forth, and it takes six numbers to specify the position and momentum of each particle. It's essential to begin by describing the set of all possible configurations and momenta of the gas, giving you a 6N dimensional phase space. You then divide it up into little 6N dimensional boxes and do statistical mechanics. But you begin by being able to say what the configuration space is. Can we do that for the biosphere?
I'm going to try two answers. Answer one is No. We don't know what Darwinian pre adaptations are going to be, which supplies an arrow of time. The same thing is true in the economy; we can't say ahead of time what technological innovations are going to happen. Nobody was thinking of the Web 300 years ago. The Romans were using things to lob heavy rocks, but they certainly didn't have the idea of cruise missiles. So I don't think we can do it for the biosphere either, or for the econosphere.
You might say that it's just a classical phase space—leaving quantum mechanics out—and I suppose you can push me. You could say we can state the configuration space, since it's simply a classical, 6N-dimensional phase space. But we can't say what the macroscopic variables are, like wings, paramecium detectors, big brains, ears, hearing and flight, and all of the things that have come to exist in the biosphere.
All of this says to me that my tentative definition of an autonomous agent is a fruitful one, because it's led to all of these questions. I think I'm opening new scientific doors. The question of how the universe got complex is buried in this question about Maxwell's demon, for example, and how the biosphere got complex is buried in everything that I've said. We don't have any answers to these questions; I'm not sure how to get answers. This leaves me appalled by my efforts, but the fact that I'm asking what I think are fruitful questions is why I'm happy with what I'm doing.
I can begin to imagine making models of how the universe gets more complex, but at the same time I'm hamstrung by the fact that I don't see how you can see ahead of time what the variables will be. You begin science by stating the configuration space. You know the variables, you know the laws, you know the forces, and the whole question is, how does the thing work in that space? If you can't see ahead of time what the variables are, the microscopic variables for example for the biosphere, how do you get started on the job of an integrated theory? I don't know how to do that. I understand what the paleontologists do, but they're dealing with the past. How do we get started on something where we could talk about the future of a biosphere?
There is a chance that there are general laws. I've thought about four of them. One of them says that autonomous agents have to live the most complex game that they can. The second has to do with the construction of ecosystems. The third has to do with Per Bak's self-organized criticality in ecosystems. And the fourth concerns the idea of the adjacent possible. It just may be the case that biospheres on average keep expanding into the adjacent possible. By doing so they increase the diversity of what can happen next. It may be that biospheres, as a secular trend, maximize the rate of exploration of the adjacent possible. If they did it too fast, they would destroy their own internal organization, so there may be internal gating mechanisms. This is why I call this an average secular trend, since they explore the adjacent possible as fast as they can get away with it. There's a lot of neat science to be done to unpack that, and I'm thinking about it.
One other problem concerns what I call the conditions of co-evolutionary assembly. Why should co-evolution work at all? Why doesn't it just wind up killing everything as everything juggles with everything and disrupts the ways of making a living that organisms have by the adaptiveness of other organisms? The same question applies to the economy. How can human beings assemble this increasing diversity and complexity of ways of making a living? Why does it work in the common law? Why does the common law stay a living body of law? There must be some very general conditions about co-evolutionary assembly. Notice that nobody is in charge of the evolution of the common law, the evolution of the biosphere, or the evolution of the econosphere. Somehow, systems get themselves to a position where they can carry out coevolutionary assembly. That question isn't even on the books, but it's a profound question; it's not obvious that it should work at all. So I'm stuck.