Evolution, Thermodynamics and Information

Prefaces bear much weight on their small shoulders. Written last, they must be retrospective; coming first, they must invite reading further.

This book synthesizes a decade of my own work in extending the Darwinian program. The sense of this extension is recognizing uncompromisingly that life, and its evolution, are truly parts of nature. Given this, the task is to make connections. In this book, I try to broaden the scientific base of evolutionary theory through science of connection. As the science of progress, thermodynamics is essential to this enterprise. As the science of structure and meaning, information theory is essential as well. (p. v)

Thermodynamics is above all the science of spontaneous process, the “go” of things. Approaching evolution thermodynamically allows us to bring the “lifeness” of life into the legitimacy of physical process. (p. 5)

Random variation and natural selection are more words for mechanisms than mechanisms themselves. As other life sciences have deepened their casual structures through incorporation of physical dynamics, evolution --- which, if anything, should provide a bridge linking the physical and the living --- has remained oddly aloof from the assimilation. (p. 6)

The Importance of Language

As a result of its independent lines of development in thermodynamics and communication theory, there are in science today two “entropies.” This is one too many. It is not science’s habit to affix the same name to different concepts. Shared names suggest shared meanings, and the connotative field of the old tends inevitably to intrude on the denotative terrain of the new.

“Entropy” was not a term that Shannon had himself decided on by simple virtue of the formal similarity of his equation to Boltzmann’s. As Denbigh (1982) discusses, he did so at the urging of von Neumann for very practical reasons. Entropy was an established concept that his theory could draw on for salability to the scientific community. Science was the loser for the choice.

Wittgenstein (1973) once defined the job of philosophy as the “battle against the bewitchment of our intelligence by means of language.” The casual usage of such terms as “disorder” and “disorganization” to provide pictorial clarity to the concept of entropy has served primarily to obscure its meaning. To the case at hand: there is an inevitable tendency for connotations to flow from the established to the new, and the Shannon entropy began from the beginning to take on colorations of thermodynamic entropy. In his introductory chapter, Weaver revealingly quotes Eddington that “ the law that entropy always increase --- the second law of thermodynamics --- holds, I think, supreme position among the laws of Nature.” And “Thus when one meets the concept of entropy in communication theory, he has the right to be excited --- a right to expect that one has hold of something that may turn out to be basic and important.” (p. 24)