Clocks and Clouds

STUART KAUFFMAN
Director, The Institute for Biocomplexity and Informatics at The University of Calgary writes about reductionism.

"The evolution of the biosphere, the economy, our human culture and perhaps aspects of the abiotic world, stand partially free of physical law and are not entailed by fundamental physics. The universe is open.

Many physicists now doubt the adequacy of reductionism, including Philip Anderson, and Robert Laughlin. Laughlin argues for laws of organization that need not derive from the fundamental laws of physics. I give one example. Consider a sufficiently diverse collection of molecular species, such as peptides, RNA, or small molecules, that can undergo reactions and are also candidates to catalyze those very reactions. It can be shown analytically that at a sufficient diversity of molecular species and reactions, so many of these reactions are expected to be catalyzed by members of the system that a giant catalyzed reaction network arises that is collectively autocatalytic. It reproduces itself.

The central point about the autocatalytic set theory is that it is a mathematical theory, not reducible to the laws of physics, even if any specific instantiation of it requires actual physical "stuff". It is a law of organization that may play a role in the origin of life.

Consider next the number of proteins with 200 amino acids: 20 to the 200th power. Were the 10 to the 80th particles in the known universe doing nothing but making proteins length 200 on the Planck time scale, and the universe is some 10 to the 17th seconds old, it would require 10 to the 39th lifetimes of the universe to make all possible proteins length 200 just once. But this means that, above the level of atoms, the universe is on a unique trajectory. It is vastly non-ergodic. Then we will never make all complex molecules, organs, organisms, or social systems.

In this second sense, the universe is indefinitely open "upward" in complexity.

Consider the human heart, which evolved in the non-ergodic universe. I claim the physicist can neither deduce nor simulate the evolutionary becoming of the heart. Simulation, given all the quantum throws of the dice, for example cosmic rays from somewhere mutating genes, seems out of the question. And were such infinitely or vastly many simulations carried out there would be no way to confirm which one captured the evolution of this biosphere.

Suppose we asked Darwin the function of the heart. "Pumping blood" is his brief reply. But there is more. Darwin noted that features of an organism of no selective use in the current environment might be selected in a different environment. These are called Darwinian "preadaptations" or "exaptations". Here is an example: Some fish have swim bladders, partially filled with air and partially with water, that adjust neutral bouyancy in the water column. They arose from lung fish. Water got into the lungs of some fish, and now there was a sac partially filled with air, partially filled with water, poised to become a swim bladder. Three questions arise: Did a new function arise in the biosphere? Yes, neutral bouyancy in the water column. Did it have cascading consequences for the evolution of the biosphere? Yes, new species, proteins and so forth.

Now comes the essential third question: Do you think you could say ahead of time all the possible Darwinian preadaptations of all organisms alive now, or just for humans? We all seem to agree that the answer is a clear "No". Pause. We cannot say ahead of time what the possible preadaptations are. As in the first paragraph, we really do not know what will happen. Part of the problem seems to be that we cannot prespecify all possible selective environments. How would we know we had succeeded? Nor can we prespecify the feature(s) of one or several organisms that might become preadaptations.

Then we can make no probability statement about such preadaptations: We do not know the space of possibilities, the sample space, so can construct no probability measure."

In other words, it is impossible to determine the cause of anything of complexity, because the system from which we live is open, and infinite. Perhaps it is possible to describe features of the system, which facilitates our awareness of a larger part of it.

Jonah Lehrer intercedes:

"Karl Popper famously distinguished between two types of scientific problems: clocks and clouds. Clocks are neat, orderly systems that can be elegantly solved through reduction. (Think, for instance, of planetary orbits, which can be explained with gravitational equations.) A cloud, on the other hand, is an epistemic mess; as Popper put it, they are "highly irregular, disorderly, and more or less unpredictable." After all, clouds are carried and crafted by an infinity of currents; they seethe and tumble in the air, and are a little different with every moment in time.

The question, of course, is whether the universe (and all the life contained therein) is a clock or a cloud. The methodology of modern science is predicated on the assumption that everything is a clock, a wonderfully complex timepiece to be sure, but still a clock. But what if reality is a cloud? Is reductionism still valid? Or are clouds best solved through simple observation, induction and ad hoc theorizing? Of course, that's how science was done in the 19th century (eg, Darwin), but maybe that's our future?"