Entropic Models in Biology: The Next Scientific Revolution?

ENTROPIO MODELS IN BIOLOGY: THE NEXT SCIENTIFIC REVOLUTION?* DANIEL D. JONESt By now, no one would deny that the economy of biological processes ¿s governed by the Entropy Law, not by the laws of mechanics. —Nicholas Georgescu-Roegen, 1971 Man appears to be unique among the animals in his propensity to form mental constructs of phenomena in the world about him. These mental constructs serve many purposes, ranging from the simple ordering of personal experience to the unification of large numbers of people through the collective effect of shared social and cultural views. In science , these mental constructs serve a special purpose which goes beyond the mere collectivization of scientists. For it is through such intellectual constructs that purposeful experiments are chosen from the multitude of possible experiments and that predictions of experimental results are formulated and tested. Above all, these mental constructs serve as starting points for the critical, adversary debate which frequently leads to the generation of new constructs which are judged by the scientific community to be superior to the old. In the history and philosophy of science, these mental constructs of the natural world have been the subject of a diverse and shifting nomenclature. For now, I will use only the term "model" to mean a set of idealized assumptions about the inner structure, composition, or mechanism of an object or system [I]. This general definition will be extended and ramified to more specific forms as required. One of the more successful kinds of model in scientific history has been the mechanical model. These depend for their operation on the coupling of mechanical forces, although, as we shall see later, they have been generalized to mechanistic models incorporating other kinds of forces as well. Mechanical models have a great appeal to the human mind because man has had a sound intuitive appreciation of mechanical *This article was submitted as an entry in the first Perspectives Writing Award competition for authors 35 years old or younger. t7430 Colshire Drive, McLean, Virginia 22101. Perspectives in Biology and Medicine · Winter 1977 | 285 force as a push or a pull since prehistoric times. The physical sensations associated with manipulative limbs and opposable thumbs probably played an important role in the development of this intuitive understanding of force as well as in the development of early toolmaking activities. But this concept of force was spatially localized. With the advent of the Newtonian method and its spectacular successes in celestial mechanics, the idea of physical force acting at a distance became widely manifest. Among the technological spin-offs of Newtonian mechanics was the growing realization that power, or more properly energy, could be transported from one place to another by the coupling of forces through a suitable configuration of levers, pulleys, gears, etc. This realization and its practical applications led to the development of what is called in retrospect the Industrial Revolution. An important philosophical result of the Industrial Revolution was the widespread conception of the universe as a vast clockwork mechanism of interlocking forces. One of the chiefspokesmen ofthis mechanistic philosophy, Ludwig Büchner, wrote, "Science . . . gradually establishes the fact that macrocosmic and microcosmic existence obeys, in its origin, life, and decay, mechanical laws inherent in things themselves. . . . There is no force without matter; no matter without force" [2]. Within this philosophical context, a methodological approach to scientific research was prescribed by William Thomson, Lord Kelvin, who argued that the human mind can comprehend a phenomenon clearly only if it can represent that phenomenon by a mechanical model [3]. The idea of the mechanical coupling of forces and the associated ideas of discrete cause and effect reigned supreme in physics for many decades until they were challenged by developments in thermodynamics, quantum physics, and cosmology. In retrospect, nineteenth-century physics can be seen to have contained within itself the seeds for drastic alteration of the mechanical point of view and the potentiality for its replacement. This challenge came initially from thermodynamics, the science of heat. The laws of classical mechanics had been most successfully applied to reversible phenomena, that is, to processes which could conceivably occur in reverse order to that actually observed. There is no apparent reason, for example, why...