I’ve always found Stuart Kauffman fascinating, although his thinking can be hard to grasp (for me). Here’s one old attempt to get hold of it. He hasn’t published at book length since, but he’s still thinking about these things, as in this recent piece. Re-reading, I am reminded of a more recent thinker about origins and life who reckons energy is the key, Nick Lane. Maybe there’s a slogan which is the biological equivalent of “follow the money” for sociopolitical investigation: “follow the energy”?
How did everything get to be so complicated? For most people, a rueful exclamation; for Stuart Kauffman, the most interesting question about the universe. And although Darwin gave a pretty convincing answer a century and a half ago, it doesn’t meet Kauffman’s demands. He badly wants a more general account of how complex creatures can emerge from much simpler origins – and not only endure but give rise to yet more complex ones. Investigations is his ambitious, idiosyncratic but fascinating record of where he has got to.
One necessary trick is to channel energy in ways that help build more elaborate structures. Most of the light and heat from the sun that beats down on the Earth’s surface bounces back into space, or gets re-radiated as low-grade heat. If that were all that happened, though, it would make for a pretty dull planet. More interesting things begin when molecules arise that can trap this energy, and use it to drive chemical cycles which build cells. Plants grow. Animals prowl. Neurons fire. Eyes and brains decode text.
Kauffman’s approach to explaining how such things can be is unconventional. A philosopher turned doctor turned theoretical biologist, he works out of the Santa Fe Institute in New Mexico, where the house style is computer simulation of just about anything. In his last book, At Home in the Universe , he outlined the power of self-organisation, arguing that there are laws that can generate order where we don’t expect it. In Kauffman’s computer-generated universe, stable structures appeared where intuition predicted a mess. Wherever he looked – in networks of interacting genes, in vats of chemicals or in the patterns of decision that tie producers to consumers in the marketplace – he saw “order for free”.
In Investigations , one puzzle he wants to cast in a new light is how to read the energy exchanges that underpin all these processes. In his earlier probing of the origins of life, for instance, he claimed that if you put enough chemicals of the right kind together and some react to generate products that can catalyse further reactions, then stable self-catalysing networks emerge of their own accord. Now he is worrying over the fact that such networks won’t do anything more than cycle drearily on unless something gives them a shove. At the most general level, he wants to explain the existence of what he calls autonomous agents – defined as “an autocatalytic system carrying out one or more work cycles”.
“Work” is one of the ideas Kauffman badly wants to reinvent. It is a physicist’s word that cloaks some of the deep problems of biology. A work cycle is a constrained release of energy: you make a series of them happen every time your car engine turns over. The constraints on the release of energy that enable organisms to do things have to be contrived very precisely to fit their purposes.
Intriguingly, this view challenges the assumptions of biology for the last half century. After decades teasing out the biochemical details of energy transfers in cells, the ascent of DNA signified that information stood for all that was interesting about the inner workings of life – hence the headline hype about the human genome project. Now, in pursuit of new ways of understanding the meaning of organisation, Kauffman wants to bring energy back in. He is not giving up on information, but he wants a more complete picture of how it is used. DNA is information on the inside, but a bacterium swimming in the direction of a stronger sugar concentration, for example, is using information from outside to direct its motion in pursuit of more energy.
The ultimate goal is a biology that would describe the conditions for creating a biosphere, in all its teeming variety, anywhere in the universe. At the moment, Darwinism is the nearest biology gets to a theory of everything. But it is not nearly enough. “I hope there may be general principles governing the self-consistent construction of any biosphere,” says Kauffman. It is not clear yet exactly what these are, but that is part of the fun.
As he ponders the connections between energy, information, organisation, reproduction and evolution of new constraints, he spells out his own intuitions while admitting: “I find it delightful that we hardly have the concepts to state these issues.” Even more delightfully, his ideas about the evolution of complexity may also turn out to apply to the economics of technology and even to cosmology, as he outlines in closing chapters.
Reading about concepts that are not yet quite developed produces fun and frustration in roughly equal measure. The book is undeniably heavy going in places. Some of the chapters take for granted science that another writer would explain at length. Although there are plenty of concrete examples, much of the core argument keeps trying to turn back into mathematics. Yet Kauffman’s obsessive probing of the limits of understanding is pretty gripping, in its way. The book may be science. It may be, as he suggests hopefully, proto-science. It is certainly a crash course in how to think like Stuart Kauffman, which is a great way to see blind spots in the science that already exists. (2001)
Stuart Kauffman. Investigations. Oxford U.P.