Abstract
CAMPBELL'S expressed aim1 is “to describe the entropy pump whereby the species of living matter not only prevent a drop into a position of greater positive entropy at each generation, but may in fact acquire more negentropy as their reproduction continues”. This is attempted by recourse to the example of a codfish laying a million eggs the entropy content of whose genomes shows a normal distribution about a mean value in accordance with the second law of thermodynamics. On one tail of this distribution curve will be a small percentage of eggs with an entropy content equal to or less than that of the parents. There follows the crucial sentence: “These remarkable ones are most likely to grow up and repeat the reproductive process”. What follows in Campbell's communication is unexceptionable provided that this sentence is true. But what is the evidence that those eggs which are “most likely to grow and repeat the reproductive process” are those whose genomes have a lower entropy content than those of the parents ? It is at this point that the author merely evades one of the most important questions at issue in the earlier correspondence2–4. The genome may be regarded as a series of DNA molecules functioning as templates. The thermodynamic entropy content of these molecules is a function of the arrangement of the atoms, conventionally expressed as k. log D where k is the Boltzmann constant and D is a measure of the atomic disorder. A single alteration in the relative positions of adjacent nucleotide bases could convert a crucial part of the genome code to nonsense so that its capacity to support development was lost, but this could occur without an increase, indeed even with a decrease, in the thermodynamic entropy content of the genome molecules5. Stated in a more general way, this is the problem of the relationship between the amount of developmentally meaningful organization in the genome (we will call this the information content) and its entropy content. There are two problems here: first, the definition and quantization of the information content of the genome and, second, the nature of its relationship to the thermodynamic entropy content. One avenue of enquiry which offers hope in this situation would seem to be the information theory analogy.
Similar content being viewed by others
Article PDF
References
Campbell, B., Nature, 215, 1308 (1967).
Popper, K. R., Nature, 213, 320 (1967).
Buchel, W., Nature, 213, 319 (1967).
Woolhouse, H. W., Nature, 213, 952 (1967).
Lwoff, A., Biological Order (MIT Press, 1960).
Szilard, L., Z. Physik., 53, 840 (1929).
Shannon, C. E., and Weaver, W., The Mathematical Theory of Communication (University of Illinois Press, 1949).
Brillouin, L., Science and Information Theory (Academic Press, New York, 1956).
Brillouin, L., Science and Information Theory, second ed. (Academic Press, New York, 1962).
Carnap, R., and Bar-Hillel, Y., Brit. J. Phil. Sci., 4, 147 (1953).
Linschitz, H., in Essays on the Use of Information Theory in Biology (University of Illinois Press, 1953).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
WOOLHOUSE, H. Entropy and Evolution. Nature 216, 200 (1967). https://doi.org/10.1038/216200a0
Received:
Issue Date:
DOI: https://doi.org/10.1038/216200a0
This article is cited by
-
Increasing Entropy of Biological Systems
Nature (1968)
-
Entropy, Evolution and Living Systems
Nature (1968)
-
Entropy, not Negentropy
Nature (1968)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.