As readers of RNCSE are undoubtedly all too aware, a familiar creationist argument runs as follows: since the Second Law of Thermodynamics says that disorder is increasing, how can evolution, which involves an increase in complexity, possibly have occurred? The answer has been repeated before almost every school board in the country, and in more than a few courtrooms: first, the Second Law of Thermodynamics addresses an increase in the total entropy of a system, but does not in any way preclude local decreases, and, second, there are other driving forces aside from the Second Law of Thermodynamics, as the last few decades of research on self-organization in complex systems have amply shown. How those other “organizing” forces actually drive evolution, self-organization, and complexity, however, remains a wide-open question and a very active area of interdisciplinary research.
Eric D Schneider and Dorion Sagan weigh in on the argument with their new book Into the Cool: Energy Flow, Thermo-dynamics and Life. Their central thesis is contained in the striking catchphrase “nature abhors a gradient”; they propose that it is the flow of energy down gradients that is the central driving force that balances the Second Law’s drive toward disorder. It is a striking and provocative thesis and certain to inspire new ways of thinking in many scientists studying complexity in biological systems. Unfortunately, the catchphrase is unlikely to provide as sweeping a solution as the authors propose, and it is packaged in a book that suffers from a number of flaws likely to put off many readers. The book may aim for the sharp clarity of Richard Dawkins, or the charm and scintillating wit of Stephen Jay Gould (the flyleaf even makes a comparison to Darwin!). But, plagued by overblown hyperbole and intellectual sloppiness, it falls far short.
The book begins with a clichéd review of the history of science. Newton enters, straight out of central casting, accompanied by his faithful “clockwork universe”, and endless references to apples. A wince-inducing chapter subheading reads: “Clunk Goes the Clockwork Cosmos”. The section begins with a description of Robert Boyle’s work in the “twilight of thermodynamics”. One would think that authors who show a deep concern for time’s arrow (“Thermodynamics had released the arrow of time,” they write on page 36. “It went quivering into Newton’s shiny smooth apple, generating heat as friction.”) would appreciate the distinction between twilight (end of the day) and dawn (beginning), which is, historically, where Boyle was in relation to the history of thermodynamics. One might be struck by the quivering-arrow metaphor, but the metaphors fall too thick and fast to be taken seriously. “The wake-up call [of thermodynamics] is still reverberating in the collective scientific mind, still groggy from Newton’s dreams.” “Classical thermodynamics upset the Newtonian applecart.” You get the idea.
The authors set up a false dichotomy between the “celestial clockwork” and thermodynamics, which “messed all that up. It measured loss, and implied that — despite the magnificent motions of the planets — time moves in only one direction. The direction of burning.” But Newton was familiar with burning: he was an alchemist, whose mystical views strongly influenced his science. Neither scholars nor the readers of a popular science book (and Into the Cool, published by a university press, appears to aim to be more than that) should be treated to such a cartoon version of the history of science.
Having dispensed with Newton and Boyle, we enter the history of thermodynamics. Following a discussion of irreversibility, the authors’ attempt at metaphor turns ugly as they refer to Ludwig Boltzmann’s suicide as “an irreversible act”. If this is an attempt at humor, it is unnecessary and cruel.
Into the Cool becomes equally problematic when it moves toward the exposition of the authors’ “grand theory” that thermodynamic gradients drive evolution. This exposition, to the reader’s great frustration, is approached, but never consummated. The mechanism by which a system’s motion down a gradient leads to complexity remains unexplained, unless one can infer that this occurs simply because competition for more efficient methods of exploiting gradients drives evolution. The authors do make this point, but they constantly imply that more is going on than this — but what that “more” is, they never clearly articulate.
The authors replace clear exposition of a scientific idea by the use of sweeping metaphors that hold little substance. “Separate from the world, we are yet inextricably connected to it.” (How are we separate from the world?) A paragraph later: “Metastable processes underlie the selves we mistake for things.” And finally, one which had this reviewer’s metastable self reaching for the unstable equilibrium of a stiff drink, “… the cyclical pendulum of scientific overreaction has perhaps reached its apex, coming to just that point where the potential energy of its historical emphasis is ready to give way to the kinetic energy of physics as a factor in macroevolutionary explanation” (p 152).
Excessive tendency toward metaphor and cliché could be forgiven, were it balanced by clear exposition of a strong idea. The idea of the central role of gradients in the organization of life is tantalizing, intriguing, and definitely worth pondering. But the authors never settle down to a clear exposition of how gradients lead to increased complexity. They skitter from one subheading (“Mousetraps and Dynamite”, “Toward a Science of Creative Destruction”, and so on) to another, never staying in one place long enough to build a coherent argument. The book is also frustratingly filled with scientific inaccuracies: bifurcation is confused with bistability (Figure 6.1), hysteresis is mistakenly defined as “retardation or lagging” (p 129), population biology is confused with population genetics (p 145), and on the same page we are told that “Darwin connected all living beings through time to a single origin.” Did he?
More frustrating than the inaccuracies, and the arguments that begin but are never completed, are the arguments that simply make no sense. The authors decry algorithmic models of complexity, inexplicably conflating such models with the idea that the laws of physics change, and condemning both “inevitable casualt[ies] of a thoroughgoing evolutionary world-view.” How does the emergence of complex structures from simple algorithmic rules relate to the notion of the gradual changing of fundamental constants of nature? If there is a connection, it is far from obvious, and it is certainly not explained.
Despite its inaccuracies and hyperbolic atmosphere, Into the Cool raises provocative questions as to the role of thermodynamic gradients in the origin of complexity and in evolution. It is a shame that Schneider and Sagan develop these ideas neither clearly nor fully, and fail to set them in the context of other well-studied influences on the development of complexity in living organisms. Had they done so, the authors might have made a much stronger case for the primacy of gradients.