American Theoretical Biologist and Complex Systems Researcher who studies the origin of the Earth
Stuart Kauffman, fully Stuart Alan Kauffman
American Theoretical Biologist and Complex Systems Researcher who studies the origin of the Earth
Biospheres maximize the average secular construction of the diversity of autonomous agents and the ways those agents can make a living to propagate further.
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.
Consider a bacterium swimming upstream in a glucose gradient. We readily say that the bacterium is going to get food, that is, the bacterium is acting on its own behalf in an environment. Call a system able to act on its own behalf in an environment an ?autonomous agent? [as are] all free-living cells and organisms.
To state my hypothesis abruptly and without preamble, I think an autonomous agent is a self-reproducing system able to perform at least one thermodynamic work cycle.
Evolution is not just "chance caught on the wing". It is not just a tinkering of the ad hoc, of bricolage, of contraption. It is emergent order honored and honed by selection.
Work is more than force acting through distance; it is, in fact, the constrained release of energy, the release of energy into a small number of degrees of freedom. It is the constraints themselves ? with as Phil Andersons point out, a kind of rigidity ? that largely constitute the organization process. But ? and here will be the hook ? in many cases it takes work to construct the constraints themselves. So we come to a terribly important circle, work is the constrained release of energy, but it often takes work to construct the constraints.
Francisco Varela is amazingly inventive, freewheeling, and creative. There's a lot of depth in what he and Humberto Maturana have said. Conversely, from the point of view of a tied-down molecular biologist, this is all airy-fairy, flaky stuff. Thus there's the mixed response. That part of me that's tough-minded and critical is questioning, but the other part of me has cottoned on to the recent stuff he's doing on self- representation in immune networks. I love it.
You cannot do a work cycle at equilibrium, meaning that the concept of an autonomous agent is inherently a non-equilibrium concept. A second is that once this concept is developed it's only going to be a matter of perhaps 10, 15, or 20 years until, somewhere in the marriage between biology and nanotechnology, we will make autonomous agents that will create chemical systems that reproduce themselves and do work cycles. This means that we have a technological revolution on our hands, because autonomous agents don't just sit and talk and pass information around. They can actually build things. The third thing is that this may be an adequate definition of life. In the next 30 to 50 years we are either going to make a novel life form or we will find one?on Mars, Titan, or somewhere else. I hope that what we find is radically different than life on Earth because it will open up two major questions. First, what would it be like to have a general biology, a biology free from the constraints of terrestrial biology? And second, are there laws that govern biospheres anywhere in the universe? I'd like to think that there are such laws. Of course, we don't know that there are?we don't even know that there are such laws for the Earth's biosphere?but I have three or four candidate laws that I struggle with.
I believe there is a fourth law of thermodynamics, or some cousin of it, concerning self-constructing nonequilibrium systems, such as biospheres, in the cosmos [but cannot prove it].
In his famous book, What is Life?, Erwin Schr”dinger 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. For the better part of a year and a half, I've been keeping a notebook about what I call autonomous agents. An autonomous agent is something that can act on its own behalf in an environment. Indeed, all free-living organisms are autonomous agents. Normally, when we think about a bacterium swimming upstream in a glucose gradient we say that the bacterium is going to get food. That is to say, we talk about the bacterium teleologically, as if it were acting on its own behalf in an environment. It is stunning that the universe has brought about things that can act in this way. How in the world has that happened?
Let's turn to the biosphere. If a random mutation happens by which some organism can detect and utilize some new source of free energy, and it's advantageous for the organism, natural selection will select it. The whole biosphere is a vast, linked web of work done to build things so that, stunningly enough, sunlight falls and redwood trees get built and become the homes of things that live in their bark. The complex web of the biosphere is a linked set of work tasks, constraint construction, and so on. Operating according to natural selection, the biosphere is able to do what Maxwell's demon can't do by himself. The biosphere is one of the most complex things we know in the universe, necessitating a theory of organization that describes what the biosphere is busy doing, how it is organized, how work is propagated, how constraints are built, and how new sources of free energy are detected. Currently we have no theory of it?none at all.
Living systems exist in the solid regime near the edge of chaos, and natural selection achieves and sustains such a poised state.
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 co-evolutionary 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.
Our world, and probably the universe, is a place of unending creativity, from the most basic chemistry in interstellar clouds to human culture. It cannot be understood reductionistically, but is a self-organizing creative force that does not violate the laws of physics, but is not controlled by them. Agency, value, and creativity are as fundamental to our world as the insights of physicists.
Put briefly ? and Schrodinger did not say so guessing his intuition is up to us ? I think his intuition was that an aperiodic crystal breaks a lot of symmetries, therefore contains a lot of (micro) constraints that can enable an enormous diversity of real and organized processes to happen physically. This idea of organized processes seems to be hinted at in his statement that the aperiodic crystal would contain a microcode for (generating) the organism. I have inserted ?generating?, and this is the set of specific processes aspect of information that I think we need to incorporate into our idea of what information IS. I think Schrodinger is telling us both a deeper meaning of what information ?is?, and part of how the universe got complex ? by repeatedly breaking symmetries that enabled organized processes to happen that both provided new sources of free energy and enabled the breaking of further symmetries.
Alone, each molecular species is dead. Jointly, once catalytic closure among them is achieved, the collective system of molecules is alive.
Stephen Jay Gould is extremely bright, inventive. He thoroughly understands paleontology; he thoroughly understands evolutionary biology. He has performed an enormous service in getting people to think about punctuated equilibrium, because you see the process of stasis/sudden change, which is a puzzle. It's the cessation of change for long periods of time. Since you always have mutations, why don't things continue changing? You either have to say that the particular form is highly adapted, optimal, and exists in a stable environment, or you have to be very puzzled. Steve has been enormously important in that sense. Talking with Steve, or listening to him give a talk, is a bit like playing tennis with someone who's better than you are. It makes you play a better game than you can play. For years, Steve has wanted to find, in effect, what accounts for the order in biology, without having to appeal to selection to explain everything?that is, to the evolutionary "just-so stories." You can come up with some cockamamie account about why anything you look at was formed in evolution because it was useful for something. There is no way of checking such things. We're natural allies, because I'm trying to find sources of that natural order without appealing to selection, and yet we all know that selection is important.
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.
The famous physicist Wolfgang Pauli is said to have remarked that the deepest pleasure in science comes from finding an instantiation, a home, for some deeply felt, deeply held image.
Anyone who tells you that he or she know the how life started is a fool or a knave.
The life cycle of a cell is simply amazing. It does work to construct constraints on the release of energy, which does work to construct more constraints on the release of energy, which does work to construct even more constraints on the release of energy, and other kinds of work as well. It builds structure. Cells don't just carry information. They actually build things until something astonishing happens: a cell completes a closed nexus of work tasks, and builds a copy of itself. Although he didn't know about cells, Kant spoke about this 230 years ago when he said that an organized being possesses a self-organizing propagating whole that is able to make more of itself. But although cells can do this, that fact is nowhere in our physics. It's not in our notion of matter, it's not in our notion of energy, it's not in our notion of information, and it's not in our notion of entropy. It's something else. It has to do with organization, propagation of organization, work, and constraint construction. All of this has to be incorporated into some new theory of organization.
As a threshold of diversity is crossed, a giant web of catalyzed reactions crystallizes in a phase transition. A critical diversity of molecules must be reached for the system to catch fire, for catalytic closure to be attained.
The onset of evolutionism brought with it the concept of branching phylogenies. The branching image, so clear and succinct, has come to underlie all our thinking about organisms and evolution.
As I thought about this, I noted that the bacterium is just a physical system; it's just a bunch of molecules that hang together and do things to one another. So, I wondered, what characteristics are necessary for a physical system to be an autonomous agent? After thinking about this for a number of months I came up with a tentative definition. My definition is that 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.
The strange thing about the theory of evolution is that everyone thinks he understands it. But we do not. A biosphere, or an econosphere, self-consistently co-constructs itself according to principles we do not yet fathom.