Part I, Chapter 7
Too Much, Not Enough: Cycles

Professor Bill Early of the chemistry department at the Jesuit college Georgetown University tells of the time that he was traveling in an elevator, returning from a chemistry lecture on Belousov-Zhabotinsky periodic chemical reactions. Two Jesuit priests joined him on the elevator. As the priests watched, a section of a Belousov-Zhabotinsky reaction changed color in striking fashion. Then it changed again.

"Are those alive?" one priest wanted to know. There was a pause as Early reflected.

"They are like you, Father," he said after a moment. "They metabolize but do not reproduce."

Professor Bill Early

Found in 1799, it was a mere rock. But the chunk of black basalt bore inscriptions in three different forms—hieroglyphics, demotic characters, and Greek. It was called the Rosetta stone, and it led to the first breakthrough in the deciphering of Egyptian hieroglyphics. Cycles—leaving traces of history not in rock but in cells—may be the Rosetta stone of the new thermodynamics. Cycles are found in the wind patterns of hurricanes and tornadoes, in water whirlpools and in nonliving chemical reactions. Cycles in open systems are arguably behind growth, complexity, change, and, ultimately, evolution by reproduction of variants…..

What are cycles, and how do they differ in life and nonlife? Many of the most basic cycles, such as between day and night, seem at least in part gravity-based. Simple cycles include those made by a forced pendulum in a clock, night-day cycles by the rotating Earth, and the seasons. Another type of cycle, which need not be living, is the autocatalytic set of reactions described by Lotka, where A produces B, which produces C, D, and so forth, which feeds back to the production of A. Such an autocatalytic system can begin when a photon, causing chemical excitement, produces an increase in A, which leads to increases in intermediary compounds, thus producing more A. A more subtle but just as real cycle would be the action in an equilibrium system where a minute fluctuation momentarily lifts a particle to a higher energy level before it falls back to its equilibrium state.

In Wicken's world the Second Law powers life. To this developing pantheon of nonequilibrium thinkers, we must now add Wicken (1987), who dares to claim that it is only because of the second law of thermodynamics that life exists at all.

The late Jeffrey Wicken completed some of Lotka's and Schrödinger's unfinished thoughts on the thermodynamic nature of life. Wicken persuasively argued that the second law is not just compatible with life but instrumental in its origins and evolution.

Wicken unveils the connections between autocatalysis—linked, self-perpetuating networks—and thermodynamics, showing them to be woven from a single cloth, the same tapestry whose embroidery includes the origins of life, the reproduction and maintenance of species, the emergence of ecosystems, and the evolution of life. Wicken defines life as "informed autocatalytic organizations"—AOs. Wicken sees AOs at all levels of life, from RNA sequences to the energetics of ecosystems. Specific kinetic configurations manifest the generalized form of life itself—semi-autonomous systems inextricably connected to local energy flows. "The establishment of AOs in the biosphere," Wicken writes (1987, 121), "required thermodynamic potential and the molecular complexity to tap it."

Wicken's thesis is straightforward: thermodynamics infuses biology at all levels. Its second law, combined with imposed gradients, provides the "go" of life, giving life its direction and reason for being. From life's origin to ecosystem processes to the biosphere with its adjunct of human technoscience, life is a second law–driven process. Understanding the philosophical nuances of teleology and its historical abandonment with the rise of the modern scientific method, as well as the mathematical differences between information theory and thermodynamic interpretations of entropy, Wicken challenges us to break the taboo against asking the question, from a scientific perspective, "Why does life exist?"

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