Origin of Life: Can A Liability Be Turned Into an Asset?
Most of us know the Second Law of Thermodynamics (2TD) as the law of decay and disorder, and would tend to assume it would constitute a major obstacle to theories of the origin of life by chemical evolution (see online book); certainly creationists Duane Gish and Henry Morris frequently employed the 2TD skilfully in their debates with evolutionists. Surprisingly, Eric Schneider and Dorian Sagan (Carl Sagan’s son by his first wife, the Gaia theorist Lynn Margulis) praised the 2TD as a life-giving principle in their new book, Into the Cool: Energy Flow, Thermodynamics and Life. “Cool is not enough” remarked J. Doyne Farmer (Santa Fe Institute) in his review of the book in Nature.1 Unimpressed with the concept, he smirked, “There’s more to life than the second law of thermodynamics.”
How could Schneider and Dorian Sagan turn a liability like 2TD into an asset? Farmer gives their thesis a two-paragraph synopsis:
The authors’ central thesis is that the broad principle needed to understand self-organization is already implicit in the second law of thermodynamics, and so has been right under our noses for a century and a half. Although the second law is a statement about increasing disorder, they argue that recent generalizations in non-equilibrium thermodynamics make it clear that it also plays a central role in creating order. The catchphrase they use to summarize this idea is “nature abhors a gradient”. Being out of equilibrium automatically implies a gradient in the flow of energy from free energy to heat. For example, an organism takes in food, which provides the free energy needed to do work to perform its activities, maintain its form and reproduce. The conversion of free energy to entropy goes hand in hand with the maintenance of organization in living systems.
The twist is to claim that the need to reduce energy gradients drives a tendency towards increasing complexity in both living and non-living systems. In their words: “Even before natural selection, the second law ‘selects’, from the kinetic, thermodynamic, and chemical options available, those systems best able to reduce gradients under given constraints.” For example, they argue that the reason a climax forest replaces an earlier transition forest is that it is more efficient at fixing energy from the Sun, which also reduces the temperature gradient. They claim that the competition to reduce gradients introduces a force for selection, in which less effective mechanisms to reduce gradients are replaced by more effective ones. They argue that this is the fundamental reason why both living and non-living systems tend to display higher levels of organization over time. (Emphasis added in all quotes.)
Interesting, Farmer mumbles, but uh-uh. “This is an intriguing idea but I am not convinced that it makes sense.” He proceeds to criticize their vagueness of the “selection” process or why things should tend to increase in complexity. Yes, the 2TD is important for understanding the operation of complex systems, but “the authors’ claim that non-equilibrium thermodynamics explains just about everything falls flat,” he contends. For example, “consider a computer.” A computer has a power supply, but “the need for power tells us nothing about what makes a laptop different from a washing machine.” At this point, things get interesting. Farmer starts arguing intelligent design; is this J. Doyne Farmer speaking, or Stephen Meyer?
To understand how a computer works, and what it can and cannot do, requires the theory of computation, which is a logical theory that is disconnected from thermodynamics. The power supply can be designed by the same person who designs them for washing machines.
The key point is that, although the second law is necessary for the emergence of complex order, it is far from sufficient. Life is inherently an out-of-equilibrium phenomenon, but then so is an explosion. Something other than nonequilibrium thermodynamics is needed to explain why these are fundamentally different. Life relies on the ability of matter to store information and to implement functional relationships, which allow organisms to maintain their form and execute purposeful behaviours that enhance their survival. Such complex order depends on the rules by which matter interacts. It may well be that many of the details are not important, and that there are general principles that might allow us to determine when the result will be organization and when it will be chaos. But this cannot be understood in terms of thermodynamics alone.
With this, Farmer left the origin of life as an unsolved problem. “Understanding the logical and physical principles that provide sufficient conditions for life is a fascinating and difficult problem that should keep scientists busy for at least a millennium,” he wrote. Thermodynamics is just one of many actors in the play, and not even the principal one; “The others remain unknown.”
1J. Doyne Farmer, “Cool is not enough,” Nature 436, 627-628 (4 August 2005) | doi: 10.1038/436627a.
They’re not unknown; they’re right in your hotel room drawer. This review was interesting because Farmer invoked arguments similar to those used by creationists and intelligent design theorists. Since it is highly doubtful that Farmer’s review was religiously motivated, this supports the contention that arguments against chemical evolution arise from the facts, not the motivation.
Contrary to the habits of their opponents, Morris and Gish always stuck to the scientific principles and observational facts, not theological arguments, in their famous debates on college campuses with leading evolutionists. Like Farmer, they stressed that energy is necessary, but not sufficient, for life or for any other directed process that uses energy to accomplish work. They argued that two other principles always need to be applied: (1) an energy conversion mechanism, and (2) a program to direct the energy toward the desired end. In an automobile, for instance, the chemical energy of the gasoline is converted into kinetic energy of the drive shaft by channeling the “explosion” of the fuel in the piston according to a programmed sequence of events: inlet, spark, explosion against the moveable piston, outlet for the waste gases and heat, etc. In a plant leaf, the energy of sunlight is directed into very complex conversion mechanisms of photosynthesis to direct it into metabolic processes.
Gish always emphasized that the application of raw energy is even more harmful than none at all: pouring gas on the car and lighting a match does not help it drive uphill, and holding a dead stick up to the sunlight will not make it sprout and grow fruit. Only when the far-from-equilibrium energy is channeled by intelligent design will the tendency toward disorder be overcome, and that only locally and temporarily. The downhill effects of the Second Law of Thermodynamics are inexorable; all real processes must obey the law of entropy. In this book review, Farmer admitted as much, and even made the case stronger by pointing to computers. A laptop computer channels electrical energy into complex programmed pathways that we all know are the result of intelligent design. Software engineers may be far from equilibrium, but there’s more to the story than that!
That Schneider and Dorian Sagan would try to turn the Second Law into a driving force for evolution is almost comical. The Big Science establishment treats Gaia theory, even its most naturalistic incarnations, with nearly the same disdain as it does creationism. Nature would not let this book get by with any more than faint praise for some aspects, but that they would let the reviewer employ implicit ID/creationist reasoning to debunk its primary thesis is instructive.