The theory for the origin of life that emerges from bioepistemic evolution is further developed on the author's newer site - Evolution and Origin
In its rank0 section, that site includes all the origin of life work given here and also extends it to describe chemical, evolutionary mechanisms for the emergence of "bacterial protocells;" although lacking genetics, such protocells would otherwise have resembled bacteria, both chemically and morphologically.
Bioepistemic Interpretation of the Theory of Prebiotic Oscillations
Bioepistemic evolution as a guide to the theory of prebiotic oscillations. Identification of crucial stages in prebiosis - origin of biochemical pathways, coevolution of enzymes with lipid vesicles, oscillating biochemistry, allostery and the emergence of cells. Separation of data and power sources as evidence of prior design, either adaptive or intelligent.
Bioepistemic Evolution and the Theory Prebiotic Oscillations
8.1 Primordial Soup as a Data Processing Device
8.1.1 The Systems Approach to Prebiosis
8.1.2 Data from the Sun and the Resulting Data Processes
8.1.3 Origin of Cell Membranes
8.1.4 Self-Oscillation and the Separation of Power and Data Sources
It is generally recognized that evolution depends on inputs of free energy that come mostly from the sun. Less widely recognized, but emphasized in bioepistemic evolution and here, is the importance of data in evolution and, in particular, the need for a data input into prebiotic evolution. This work argues that prebiotic evolution was initiated because the sun acted as a high-powered, repeating data source that effectively made the organic chemistry of the prebiotic earth into a mixture of "evolving systems," a mixture of data systems. Like any other data systems, the evolving systems of the prebiotic earth can be described in terms of their data inputs, their data processes and their data outputs.
From an IT point of view, how a data process is implemented is unimportant - IT is not concerned with the mechanism whereby data processes are achieved, only with data, data systems and data processes. In short, for IT, what matters is the data itself and its fate but, by way of contrast, scientists emphasize mechanism and want to know how all such processes work. This article has attempted to understand prebiotic evolution by fusing these two approaches. It began by examining the chemical mechanisms whereby a primordial soup might process prebiotic data from the sun and it then looked at prebiotic evolution and how, given the underlying chemistry, these prebiotic evolving systems might be expected to develop.
Bioepistemic evolution argues that a data system becomes an evolving system, when three distinct stages are present. These stages and the associated data processes are essential to all evolving systems and are :-
- The previous generation of an evolving system will have created a knowledge output, encoded as data. This data ouput will become the data input for the current generation. This input data will be, or will have been, subject to the data process of replication with variation.
- The evolving system will contain a process that interprets the data into information. These different interpretations will be separately identifiable. That is to say, an interpretation will be in some way bounded, separate from and distinguishable from other interpretations.
- This separateness enables the third data process, that of selection from among the available interpretations. The selected interpretation then becomes knowledge which is encoded as data to become the data input for the succeeding generation.
The systems approach does not identify how these processes worked in prebiosis, one can only form hypotheses for that. On the other hand, it does tell us, with certainty, that prebiotic evolution required a power source and a data source. Again, one can only hypothesize as to the nature of those sources but we can be sure that they existed.
Commercial data processing devices are designed with separate data and power sources, the mechanism being such that input from the data source controls the actions of the power source. Usually, the power source is used to amplify the signal from the data source but no undesigned data processing device could operate by such a mechanism. Therefore, no undesigned data processing device could utilize a low powered data source and a scientific view of prebiosis requires that its data sources must be high powered. The simplest assumption is that a prebiotic evolving system will have a single, high powered, input that is modulated and so able to deliver both data and power.
The challenge for understanding prebiosis arises because
- The need for a data input into prebiotic evolution has not been generally recognized. Neither has it been recognized that this data input is likely to be unified with the power input.
- No previously evolved or designed logic device or process can be invoked during the early stages of prebiosis. Hence, none of the electronic design concepts of IT can be applied to early prebiotic evolution. The data replication, interpretation and selection processes of early prebiotic evolution must be such as to depend on uncontrolled chemistry and physics and on nothing else.
The theory of prebiotic oscillations is unusual among theories of evolution in that it does not propose that the initial stages of prebiosis require an evolving system to replicate its data content. Instead it is proposed that the sun provides the powerful, repeating data input needed to "replicate" these early oscillations in chemical composition. This means that the theory of prebiotic oscillations requires no "primordial replicators" and does not regard replicators as fundamental to evolution. Indeed, in this theory, it is data, and the inherently replicative nature of the sun's data input, that emerges as fundamental to prebiotic evolution.
The sun provides a steady output of available free energy, which is available to power prebiotic evolution, while the spin of the earth means that the sun's power is switched on and off once per day. In other words, at any point on earth's surface, the energy flow from the sun is modulated to carry a data signal, day-night, on-off or 0,1 which simply, steadily repeats day after day.
The data input of prebiotic evolution was quite boring, just a steady, repeating input of 0,1,0,1,0,1,0,1 …. etc. and the dead, primordial earth would have received this signal with passive indifference. However, the sun delivers a very powerful signal which even passive receivers can interpret. Every rock, cloud, puddle and particle of sand on the earth's surface would have interpreted this data signal into oscillations of temperature and other environmental variables but, for the most part, those interpretations would have led to no evolutionary processes because they are not bounded and can never be selected.
Prebiotic oscillations, on the other hand, are bounded, albeit that the bounding is in chemical, rather than three dimensional, space. Prebiotic oscillations can be selected. Many individual oscillations would offer their interpretation of the sun's input data signal over many millions of years but it is the oscillations themselves, resulting from shifts in chemical equilibria, that pick up this data flow and are subject to evolution. Individual chemicals do not pick up the sun's data flow or become subject to evolution - apparent selection of chemicals arises from selection of the oscillations that have those chemicals as components. Evolution is about data, or pattern and sun induced oscillations of concentration are repeating patterns that contain the data signal that generated them. Evolution applies to these patterns.
Each prebiotic oscillation is a separate evolving system. Each oscillation interprets the same data input in its own, discrete way to produce separate pieces of information. Each oscillation is a separate interpretation of the same input data.
Selection could arise in the prebiotic soup partly because the different prebiotic oscillation were bounded, separable from one another in chemical space, and partly because high energy processes existed that could make the necessary selections. The different oscillations would have proved fit or unfit depending on their exposure to high energy events. Fit oscillations would have accumulated carbon content in the form of their component compounds, while unfit oscillations would have lost carbon content and the corresponding compounds would have declined in concentration. The resulting shifts in intensity, or amplitude, of the different oscillations would have represented the first accumulation of knowledge on the earth, which would have been sustained through succeeding generations or, which is the same thing, succeeding days.
As chemical compositions changed, or new compounds were synthesized by random, high energy events, new equilibria and new oscillations became possible. The replicating, input data remained the same, but the interpretations evolved and varied and were passed on to the next generation. Thus, the theory of prebiotic oscillations incorporates replication with variation. Variation in early prebiosis consists of variation in the interpretations of the same data.
A major step in prebiotic occurred when protoenzymes began to catalyze prebiotic oscillations. Such catalyzed oscillations must have taken place within an environment bounded in three dimensional space, otherwise the various components would have diffused apart from one another. An abundant, bounded environment on the prebiotic earth is likely to have been oil droplets, which are bounded both in their volume, which cold accommodate hydrophobic compounds, and in their outer surface, which could accommodate amphiphiles. The latter chemicals would have stabilized such droplets, because of their emulsifier properties. This means that oscillations involving amphiphiles would have been self-bounding in the sense that they would have at least helped to generate the boundary they needed in order to become an evolving system. Self-bounding is a requirement for selection and, therefore, it is likely that the first catalyzed oscillations to be selected were those involving amphiphilic chemicals, catalyzed by an amphiphilic catalyst, which was itself formed in some other oscillation. The result is that some emulsifying amphiphiles would have increased in their concentration, along with that of the catalysts that speed up the oscillations in which they are involved. This would have been an example of a coevolution between two oscillators, both dependant on one another.
Some of those amphiphiles would have been not just emulsifiers but, in their pure state, they would have been capable of forming vesicles in the absence of any oil droplets. Such vesicles could have better fulfilled the bounding role because they possess an inner hydrophobic layer as well as inner and outer boundaries where amphipathic and hydrophobic oscillations could develop. Most importantly, vesicles contain a volume of aqueous medium and any hydrophilic chemicals dissolved in this region will be bounded by the outer bilayer. Hence vesicles can come to replace oil droplets altogether for any coevolutions that make use of hydrophilic components. Such protocellular vesicles would not have been common under early prebiotic conditions but selection would have increased their population. They, and the protolipids that formed them, would have been the first products of adaptive design and controlled chemistry, the first objects to manifest the level0 knowledge beginning to accumulate on earth.
A second major step in evolution arises when self-driven oscillations become important. If the emergent cell oscillates with a time period of one day, then the sun need no longer provide a data input - that role can be filled by the self-oscillating chemical pathway. The sun must remain the ultimate power source that fuels the oscillation but, even in the pitch dark, a self-oscillating reaction can continue to oscillate, deliver data and drive the interpretations and selections associated with it, for as long as it has fuel. Evolutionary advantage can be gained from this change because, free of the solar timekeeper, self-oscillating reactions can vary in their time period, providing a new parameter to be optimized by adaptive variation.
With the emergence of such a self-oscillating reaction, the processes of evolution have done what the designers of commercial data systems do, they have created a data processing system with separate data and power inputs, with the power input used to amplify the data input. The selection of self-oscillating chemical reactions displays the work of adaptive design at its earliest stages. The emergent phenomena of biochemistry and biology have freed themselves of the sun as a data source. Self-oscillating chemical reactions have become able to provide the data inputs required by succeeding generation. By this time, evolution can best proceed by phasing out the sun's role as a data input while increasing the contribution made by the inherited knowledge that has accumulated over the generations. The biosphere will remain forever dependent on the sun as its ultimate power source but, from the point of view of data, self-oscillating chemical pathways can become independent. The long journey that will become the evolution of earthly life has begun.
© 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, 13 & 14 February, 2006. This internet version was made available on 6 September, 2006. Comments and criticism are solicited - see the "contact & copyright" link for contact details.