The Nature, Origin and Evolution of Life: Part I The Fundamental Logic and Organization of Life

“An organism’s astonishing gift of concentrating a ‘stream of order’ on itself and thus escaping the decay into atomic chaos seems to connect with…chromosome molecules, which doubtless represent the highest degree of well ordered atomic association we know of…. To the physicist the state of affairs is not only not plausible, but most exciting, because it is unprecedented.”

- Erwin Schrödinger

“Living matter, while not eluding the ‘laws of physics’…is likely to involve ‘other laws of physics’, hitherto unknown, which, however, once they have ben revealed, will form just as integral a part of this science as the former”

- Erwin Schrödinger

“Life seems to be orderly and lawful behavior of matter, not based exclusively on its tendency to go over from order to disorder, but based partly on existing order that is kept up.”

- Erwin Schrödinger

Introduction

Somewhere between the firm, immutable and highly ordered world of solids illustrated by rocks and crystals held together by strong London-Heitler forces and the amorphous, disorderly and statistical/probabilistic world of gases, lies the vibrant and mutable yet highly regulated and orderly world of living matter capable of evolution, development, metabolism, and reproduction (1) Although the precise molecular basis of heredity and replication were not fully elucidated at the time, Schrödinger expressed his prophetic statement above. The fundamental concept and structure of heredity and life outlined by him not only was largely confirmed in the years to come but actually served as an inspiration for the ground breaking work of J.B.S. Haldane, Francis Crick, James Watson, Rosalind Franklin and others in establishing the precise molecules and processes involved in the replication and hereditary mechanisms of life (2). In the end, Schrödinger acknowledges that an understanding of the complexity and yet orderliness of life does not require laws outside of the natural laws of physics but “hinges upon the aperiodic crystal forming the hereditary substance, largely withdrawn from the disorder of heat motion”. However, he finds the highly organized actions of this group of atoms is unprecedented and unknown anywhere in nature other than in the living substance. The most striking fact, he notes, is that this intricate and finally tuned mechanism of life and heredity is not of human origin but is the “finest masterpiece ever achieved along the lines of the Lord’s quantum mechanics” (1).

Classification, memory. heredity, and measurement

While the molecular biological processes of heredity and the role of variation and natural selection have largely been established as noted above, the logical and physical basis of cellular biology and heredity have been largely ignored. As noted by Pattee and others, the important logical issue is that the inheritance and replication of a trait must involve a classification or code and not simply the action of the classical physical description of the action of motion on the initial conditions (3). Such laws ignore the concepts of classification, coding and memory. As Pattee notes, “the biological aspect of hereditary evolution is that the process of natural selection operates on the actual traits or phenotypes and not on the description of the phenotype in the memory storage which is called the gene. This is essential because it allows the internal description or memory to be a kind of virtual state which is isolated for a finite time from the direct interactions which the phenotype must continuously face.” (3) When there is no coding process connecting the description from that described, there cannot be a process such as evolution by natural selection. The fundamental logic of evolution was described and illustrated by Von Neumann in his proposed self-replicating automaton which had the same logical processes as subsequently found in cellular systems (3, 4). As Pattee notes, von Neumann knew that replication alone would be insufficient from a logical and evolutionary sense and a living hereditary process must allow for increasing complexity of the organism. From Schrödinger we understand that such a hereditary process requires a memory or storage of hereditary information in cells which requires a high degree of stability among the relatively limited number of atoms/molecules which we now know are present in deoxyribonucleic acid (DNA) rather than the statistical properties of a very large number of atoms as in classical physics (1, 3).

One may recall that the process of classification or conceptualization involves focusing on specific characteristics while ignoring or blurring irrelevant ones. Thus, the interaction selects for important aspects related to the overall goal while constraining the effects of irrelevant details (5, 6). In the measurement or memory process by a classical system consisting of many atoms, the reversible number of possible states, like the reduction of the wave function, results in an irreversible classification or simplification of the underlying dynamics. We cannot explain the exceptional permanence of the genetic information nor the reliability of the transcription and translation at the cellular level by considering only statistical averages of large numbers of correlated molecules since we know clearly that the specific molecular processes involve relatively small numbers of atoms (3). As Pattee notes, such permanence and reliability at the molecular level are only conceivable with the description of measurement in a quantum mechanical system (3).

Molecules and enzymes

The measurement process in classical physics is undertaken by measurement devices consisting of manmade machines constituted from a very large number of atoms. When considering life, naturally constructed molecules generally consist of large numbers of atoms or macromolecules that behave in a classical manner. Therefore, Pattee and others have asked what is the simplest molecular configuration exhibiting hereditary traits which could have arisen naturally on the primordial earth (3). He has made the argument that the activation energy and entropy determine the biological reactions that are energetically possible linking classification or heredity with the control of rates of specific reactions generally associated with enzymes. In fact, the flexible structure and needed fit associated with enzymes and likely including nucleic acids clearly impose constraints on the underlying atomic dynamics thus representing molecular measurement devices (3).

All of these considerations become most apparent when noting that a complete and thorough understanding of life, including heredity and the transmission of genetic information, require an understanding of the origin of life and the evolution of life toward more complex living matter. It would appear that the origin and evolution requirements must relate to the interaction of a quantum mechanical system of heredity and a classically described measurement device with the former controlling the underlying molecular dynamics. As a result, one can anticipate the remarkable reliability of biologic heredity including the exceedingly low mutation rate at the quantum level.

Molecules and messages

Pattee has also argued that a molecule becomes a message only in the context of a larger system of constraints similar to a language. Dependence on the structure of symbols and global language constraints is reflected in the objective separation of the simplified symbolic description (genotype) of life from its detailed physical reactions (phenotype). This distinction represents the essence of life allowing for evolution and distinguishing living from nonliving matter (7). It is not the actual atomic structure of molecules that represents the basis of life but the internal representation of their structure as symbols.

Constraints of life

As noted above, in living matter, constraints have some form of material structure such as molecules and membranes. These ultimately obey the laws of nature as well as constrain the underlying dynamics and represent an alternative description or classification of the underlying system ‘simplifying’ its detailed behavior forming a new level of organization. Importantly, the alternative description represents the entire system taken as a functional whole. Pattee has noted that all measurement, recording, classification, decision-making and informational processes when alternative states on one level of description are reduced as a result at some higher level of description makes alternative states more likely and, in a sense, catalyzing certain events. It appears that hierarchical controls providing alternative descriptions are fundamental and necessary in all complex integrated systems from logical propositions to the development and evolution of biological systems arising spontaneously in nature (7). In the end, the continuing challenge to the understanding of the objective basis of the separation of object and symbol emerges in consideration of the origin and evolution of life where the separation of genotype and phenotype appears in its simplest and most fundamental form.

Conclusions

While unavoidably incomplete, we have summarized many of basic logical features and requirements for matter to assume the characteristics and behavior associated with life. Living cells have been characterized as encapsulated systems of polymers that utilize nutrients and energy from the environment by engaging in enzyme-catalyzed metabolism, growth by catalyzed polymerization, growth guidance by genetic information, division into daughter cells, and reproduction of genetic information, while remaining vulnerable to mutation of stored genetic information enabling evolution over time through natural selection (8). In subsequent commentaries, we will expand on these issues and address our current understanding of the origin of life, cellular development and growth, organization and development of multicellular organisms, increasing complexity and evolution of living organisms and the occasional disorganization of living cells resulting in conditions such as cancer. Each of these will provide further clues and a deeper understanding of the fundamental nature, origin, and evolution of life.

Declaration of Interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.

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Funding

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