Origin of life on earth and Shannon's theory of communication.

Abstract

The genetic information system is segregated, linear and digital. It is astonishing that the technology of information theory and coding theory has been in place in biology for at least 3.850 billion years (Mojzsis, S.J., Kishnamurthy, Arrhenius, G., 1998. Before RNA and after: geological and geochemical constraints on molecular evolution 1-47. In: Gesteland, R.F. (Ed.), The RNA World: The Nature of Modern RNA Suggests a Prebiotic RNA, second ed. Cold Spring Harbor Laboratory Press, Boca Raton, FL). The genetic code performs a mapping between the sequences of the four nucleotides in mRNA to the sequences of the 20 amino acids in protein. It is highly relevant to the origin of life that the genetic code is constructed to confront and solve the problems of communication and recording by the same principles found both in the genetic information system and in modern computer and communication codes. There is nothing in the physico-chemical world that remotely resembles reactions being determined by a sequence and codes between sequences. The existence of a genome and the genetic code divides living organisms from non-living matter. If the historic process of the origin and evolution of life could be followed, it would prove to be a purely chemical process (Wächtershäuser, G., 1997. The origin of life and its methodological challenge. J. Theor. Biol. 187, 483-694). The question is whether this historic process or any reasonable part of it is available to human experiment and reasoning; there is no requirement that Nature's laws be plausible or even known to mankind. Bohr (Bohr, N., 1933. Light and life. Nature 308, 421-423, 456-459) argued that life is consistent with but undecidable by human reasoning from physics and chemistry. Perhaps scientists will come closer and closer to the riddle of how life emerged on Earth, but, like Zeno's Achilles, never achieve a complete solution.