Introduction to the Problem of Prebiosis - the Origin of Life

A basic summary of the origin of the earth and the conditions found there during prebiosis, the formation of life, volcanic activity, UV exposure, high temperature and storms. The nature of evolution and the inadequacy of the gene theory of evolution in the prebiotic situation. The need for a new form of evolutionary theory based on data not genes. Bioepistemic evolution and its application to prebiosis.

The Conditions for Prebiosis and the Origin of Life

Introduction

Introduction
Copyright Statement

1 Introduction

Scientists think the earth is about 4.6 billion years (Ga) old and that it was formed from many smaller objects, then orbiting our newly formed sun, which gathered together under gravity to create a planet. Much energy would have been released during the earth's formation, making it very hot. It would have remained hot for about a billion years, partly because bodies as large as a planet cool very slowly and partly because orbiting objects would have continued falling onto its surface, delivering further energy as they did so. Hence, for a billion years or so, the earth would have been biologically dead, too warm for the chemistry of life to be relevant and too unstable from collisions and volcanic eruptions for evolution to gain a toehold.

Eventually, the earth did cool and, following a "prebiotic" phase, life seems to have emerged between 3 and 3.5 Ga ago. "Prebiotic" is a word, an adjective, that applies to the period just before the emergence of life as we would now recognize it. The phrase "prebiotic evolution" names the very first processes and mechanisms that led to the evolutionary emergence of life-like entities from the carbon containing chemicals of the early earth, the first chemical steps in evolution. Those events actually happened and real processes did create life on earth; unless our scientific ideas are entirely wrong, the fact of our own existence, and that of the myriad other creatures sharing our planet, is evidence of that. Even so, "prebiotic evolution" does not name a generally agreed scientific theory to describe those processes or point to any very plausible mechanisms for how they occurred. This article will advance some new ideas and review others but readers should not expect them soon to become received wisdom. This is the "origin of life" question which is, by any standards, a difficult problem. In truth, we may never know with any certainty how prebiotic evolution happened. We may never be able to convincingly model processes that lasted for hundreds of million of years or gather credible observational evidence for events that occurred before fossils were laid down, before developed organisms even existed.
The prebiotic earth seems to have been, by current standards, an inhospitable place. Although the sun was less bright, the earth would have been hotter than today beneath a very different atmosphere, so the climate would have been stormier. In addition, earth spun on its axis more quickly than it does now and days would have been shorter, producing higher winds speeds which would again have made storms more severe and lightning much more common. The land would have experienced higher levels of volcanic activity, producing acidic seas, and there would have been more water in the oceans. Prebiotic evolution occurred in this environment.

At that time, genetics would have been irrelevant since neither nucleic acids nor proteins would have evolved. As a result, no ancient fossils, archaic organisms or DNA sequences will ever confirm or refute ideas about processes occurring at that time. Some observers might find it unwise to intrude upon a field where knowledge is so limited, hard facts and evidence so hard to find and speculation so rife. They might find such studies pointless, but this author disagrees. Surprisingly, it is exactly the irrelevance of genetics that motivates this essay. Yes, to be sure, prebiotic evolution necessarily occurred in the absence of genes but that circumstance creates the freedom, even the necessity, to discuss evolution in a gene-free manner and that is the point. This author is a critic of the genetic foundations of modern evolutionary theory and argues that it is data not genes that should be the basis for that theory. Hence, it is exactly the freedom to discuss evolution without the straightjacket imposed by genetics that the author desires and which leads him to believe that interesting results can emerge from the arguments to be presented.

Genetics is an empirical science that arises from, and is applicable to, breeding experiments and biology. Genetics grew from biology and scientists normally describe biological evolution in terms of statistical or population genetics, the classic study being R. A. Fisher's Genetic Theory of Natural Selection, published in 1930. There is no reason to dispute the technical correctness of Fisher's studies - applied within their range they seem valid. Population genetics can link macroscopic theories of biological evolution with individual observations from breeding experiments. Nonetheless, the genetic theory of evolution is an incomplete theory.

Three major problems are -

• The concept of "gene" was undefined even in Fisher's time; he treated the gene simply as an atom of evolution. Today, despite our vastly increased understanding of molecular biology and genetic mechanisms, the gene still lacks any adequate and generally accepted definition. Nonetheless, Fisher's work has grown in reputation to the point where it is hailed as the theoretical foundation for evolutionary theory. That state of affairs in unsatisfactory; it is a weak science that cannot define its most fundamental term.
• There remain some aspects of evolution, even of biological evolution, that cannot be described in terms of population genetics. For example, while genes can be regarded as formatting some of the data on DNA, genes behave differently depending on their chromosomal location. Hence, some of the data on the chromosome, including data about the chromosomal location of genes, is extra-genetic so that genes cannot be treated simply as "atoms of evolution." Doing so leads to an incomplete theory of biological evolution.
• Even if our understanding of biological evolution were complete, we could not claim a general understanding of evolution since evolutionary thought is applied to several other fields besides biology. It is, for example, applied to the social sciences, epistemology, neurobiology, immunology and in the use of evolutionary algorithms in information technology (IT.) Among all these fields, only biology uses genes to transfer data from generation to generation and it follows that all those other fields fall outside the observational data set from which population genetics grew. In other words, population genetic arguments cannot be properly applied to any of them. Not surprisingly, attempts to shoehorn such fields into a genetic mould have met with limited success.

It is in response to this situation this author has, in recent years, developed bioepistemic evolution, a form of evolutionary theory based on the concept of "data" rather than genes. Bioepistemic evolution can be a general form of evolutionary theory because all evolutionary fields, including those listed above, necessarily transfer data from generation to generation. Hence, while a general theory of evolution based on genes must fail, it should be possible to construct a general theory based on data and that is the aim of bioepistemic evolution.

In principle, bioepistemic evolution, as a general theory of evolution, will apply wherever evolution occurs and will inform all its aspects, including those that are not amenable to genetic analysis. The author has already used bioepistemic evolution to obtain new insights into human nature, for example into the origins of human social organization, sexuality and humour. The aim of this essay is to apply bioepistemic evolution in the entirely different context of the chemical events to be expected in the environment thought to have existed just after the earth had cooled and become stable enough for evolution to occur.

Copyright Statement

© John A Hewitt MA PhD (Cantab.)
The work described here was performed as an independent investigation by John A Hewitt who asserts the right to be recognized as its author and as the originator of the novel ideas presented here. The topics to which this claim applies include, but are not limited to, the application of bioepistemic evolution to the prebiotic situation, the discussion of the sun as a data and power source for prebiotic evolving systems, the recognition of sun-induced chemical oscillations as information carriers subject to evolutionary selection and to the theories for the origin of biochemical pathways and self-oscillatory, allosteric and cyclic biochemistry that result.
This study is a greatly extended version of a poster originally presented at the Royal Society meeting on conditions for the emergence of life on the early earth, London, February 13 & 14, 2006.