In evolution thermodynamics, Ronald Fisher Aylmer (1890-1962) was an English statistical evolutionary biologist noted for his 1930 book The Genetical Theory of Natural Selection, in which he postulated that the second law of thermodynamics, in the form of “entropy tends to increase”, and his fundamental theorem of natural selection, in the form of “the rate of increase of fitness of any organism at any time is equal to its genetic variance in fitness at that time”, may ultimately be subsumed under a more general principle or law. [1]

(a) The system’s considered in thermodynamics are permanent; species on the contrary are liable to extinction, although biological improvement must be expected to occur up to the end of their existence.

(b) Fitness, although measured by a uniform method, is qualitatively different for every organism, whereas entropy, like temperature, is taken to have the same meaning for all physical systems.

(c) Fitness may be increased or decreased by changes in the environment, without reacting quantitatively upon that environment.
(d) Entropy changes are exceptional in the physical world in being irreversible, while irreversible evolutionary changes form no exception among biological phenomena.

(e) Entropy changes lead to a progressive disorganization of the physical world, at least from the human standpoint of the utilization of energy, while evolutionary changes are generally recognized as producing progressively higher organization in the organic world.