A depiction of “peneplains”, from cartographer Erwin Raisz’s “Table of Physiographic Symbols” (1931) (Ѻ); which Harold Blum, in his “chemical peneplanation” model (1934), suggests that non-chanced based, theologically-free thermodynamic potential based evolution landscapes (see: Gibbs landscapes) would look similar to, akin, e.g., to Maxwell's thermodynamic surface.

A [Lewis] + B [Henderson] = C [Gibbs-based evolution]

“Practically since its first definite formulation by Darwin the concept of chance variation and natural selection has dominated the study of evolution, although frequent attempts have been made to replace or modify it.”

“Probably most such attempts are provoked by a vaguely defined awareness of an insufficiency in the natural selection hypothesis, and the recognition of a directive factor in evolutionary processes which persists through successive generations. The latter concept which is commonly known as ‘orthogenesis’, is supported a by considerable amount of evidence (Leo Berg, 1926), but at present is not widely accepted among biologists. The general reason for abandoning or neglecting this concept has been the failure, thus far, to demonstrate the existence of the necessary directing factor outside of the theological doctrine; and one may suspect that fear of leaning too closely to such doctrine has caused most biologists to ‘shy off’ from orthogenesis. It will be the aim of the writer to indicate the actual existence of a directing factor in evolutionary processes, while at the same time avoiding all necessity of invoking theological concepts.”

Harold Blum’s 1934 “A Consideration of Evolution from a Thermodynamic Viewpoint”, wherein he adds Lawrence Henderson (1918) to Gilbert Lewis (1923) to outline a chemical potential model of directive evolution, i.e. “chemical peneplanation” as he calls it, a sort of Gibbs landscape peneplain, so to say; which he explicitly says is theologically-free (see: year god was disabused from science). [2]

“A possible directive factor would seem to be provided by the second law of thermodynamics. The principle of irreversibility involved in this concept supplies the necessary irreversibility which has been shown to be required for the evolutionary process, the direction of development being such as would always be accompanied by an increase of entropy, the return over the same pathway being prohibited by the fact that it would involve a decrease in entropy.

We may examine this hypothesis more fully: For our study we may consider the earth as an isolated system and for such a system we may safely assume that the second law of thermodynamics holds, i.e. that the entropy of the earth tends always to increase toward a maximum. The modification of the earth toward its present state must then have taken place with an increase of entropy which may be regarded as the directive agent for this change. Let us consider the evolution of the inorganic chemical compounds on the earth, assuming that this process commenced from a more or less homogeneous mixture of a given number of elements. The chemical reactions possible would be limited to those taking place with a decrease in free energy, and thus an increase in entropy.”

“Those not acquainted with the terminology of thermodynamics may, for the purpose of this paper, simply regard free energy and entropy as quantities with opposite signs but not as equivalent; free energy represents chemical potential. For a discussion of the principles of chemical thermo­dynamics see Lewis and Randall (1923).”

“The primary tendency would be to eliminate those reactions taking place with the greatest decrease in free energy, which would tend to go almost to completion. Thus we must find that most of the existing chemical compounds are the result of reactions which have taken place with a considerable decrease of free energy the probability of whose reversal would be small.”

“The formation of NH3, like H20, takes place with a consider­able decrease of free energy-about 3,000 calories per mol; and, since N2, H2 and 02 should all have been pres­ent in large quantities in the early history of our earth, it should have been possible for large quantities of both these substances to be formed. However, the rate of formation of NHs from its elements is extremely slow as compared to that of H20, so that the formation of the latter compound would have taken precedence.”

“We might speculate to the possibility of the development of life along an ammonia environment, in another solar system lacking in H2O; for NH3 is not impossible as an environment, as Henderson seems to intimate, but prohibitively improbable in our solar system, since elementary oxygen must have been present at one time or another in all the offspring of our sun so that H20 rather than NH3 must have been formed.”

Physical chemist Gunther Lauth (2014) talking (V|2:48) about Maxwell’s thermodynamic surface (1875) and or Gibbs thermodynamic surfaces (1873), with thread commentary by Ronald Kriz (2015); which visually is what Harold Blum (1934) seems to be grasping at in his chemical peneplanation model of evolution.

“We may introduce at this point a useful analogy: a large mound of earth were allowed to be eroded away by a constant flow of water over its surface, the water being applied just at the top of the mound, the force producing erosion would be proportional to the potential energy represented by the difference in level between the top of the mound and its base. Assuming purely mechanical factors, the rate of erosion would be proportional to this force.

This potential may for our purposes considered as analogous to chemical potential represented by free energy, although like all analogies this one is not exact but only useful in illustrating the general concept involved.

As the mound decreased in height the potential energy would decrease in proportion and consequently the rate of erosion would proceed more and more slowly; the geologist will recognize in this analogy the principle of peneplanation.

If we accept the concept that the entropy of the earth is and has been increasing, we must assume that, certainly so far as concerns chemi­cal reactions, the rate of increase of entropy is decreas­ing, since those reactions taking place with the greatest decrease in free energy must have been eliminated first in this process of chemical peneplanation.

It might be objected that this analogy is false in that, as previously mentioned, rates of chemical reactions are not proportional to the free energies of the reactions concerned. However, given a great period of time such as has undoubtedly elapsed since the formation of our earth, most reactions would have had time to occur, given the proximity of reacting substances and the proper conditions. Thus, although the particular reactions occurring may have been selected according to their rates, the general tendency would be to eliminate first those reactions taking place with the greatest decrease in free energy.”

Some visuals (Ѻ) of peneplain surfaces in geological terms.

“Given sufficient time for the action of denuding forces on a mass of land standing fixed with reference to a constant base-level, and it must be worn down so low and so smooth, that it would fully deserve the name of a plain. But it is very unusual for a mass of land to maintain a fixed position as long as is here assumed. I have therefore elsewhere suggested that an old region, nearly base-levelled, should be called an almost-plain; that is a peneplain.”

— William David (c.1900) [3]