The Origin of Life: A Perspective on Exchange-Based Self-Maintaining Systems
The birth of life on Earth is one of the great mysteries that science is exploring. We humans are also creatures, as are other animals, plants, bacteria, and microbes — all of which are considered living beings.
It is well known that living beings are born from parental organisms and that the diverse species of life have evolved from original species. However, the first life form, and consequently the first species, must have emerged without a preceding life form or species. The question of how the first life and species appeared in an inanimate environment constitutes the enigma of the origin of life.
As part of my personal research, I am contemplating the mystery of the origin of life. Although I am not an expert in biology or chemistry, from the perspective of a systems engineer, I aim to bring a new viewpoint to this mystery by considering life as a system.
I have written several articles on this theme. In this article, I delve deeper into my thoughts from the perspective of life maintenance, a focus that has been central to my previous attention.
This article introduces new concepts such as the expansion of maintenance mechanisms enabling growth and evolution, analysis of the maintenance function from the dual aspects of organisms and species, and the characteristic of maintenance in living beings as an exchange-based process. These additions have illuminated the essential significance of the self-maintenance system perspective in the quest to unravel the origin of life.
Let’s take a closer look below.
Maintenance of Life in Organisms
Organisms perform chemical reactions using resources ingested into their bodies, thereby maintaining their structural integrity and resources.
Maintaining structural integrity requires regular maintenance against aging, recovery from sudden damages, damage detection, avoidance actions to prevent hazards leading to damage, and identification of dangers.
For chemical reactions, the body needs stored resources, including chemical substances and energy. These are replenished from the external environment and excesses are expelled, signifying the maintenance of resources.
To maintain the stock of resources, regular maintenance and emergency responses to sudden shortages or excesses are necessary. This also involves detecting shortages or excesses, avoiding actions leading to anomalies, and identifying abnormalities.
Organisms possess processing mechanisms for maintaining their body structure and resources. These mechanisms are programmed within the body’s structure and are executed based on the progression of time, the state of the body’s structure and resources, and external conditions. Processes are realized through combinations of structural changes in the body, movement of resources, and sequences of chemical reactions.
Growth and Aging
Many organisms grow during the first half of their lifespan.
This involves increasing the size and complexity of the body’s structure and resources, and improving precision. Similarly, the variety and complexity of processing mechanisms are enhanced.
Aging represents the reverse process.
Maintenance of Species
A species is the collective of individuals belonging to that species.
Species also maintain themselves. Focusing on a single generation, the maintenance of each individual ensures the preservation of the species.
Over multiple generations, the reproduction and demise of individuals reveal the maintenance of the species. This is analogous to the maintenance of body structure and resources in a single organism.
Growth and Aging of Species
Species increase or decrease their numbers, akin to growth and aging.
They also diversify or homogenize individual traits, which is similar to growth and aging.
Diversification can lead to the emergence of new species, comparable to reproduction in organisms. Similarly, the extinction of species is analogous to the death of organisms.
Exchange-Based Maintenance
The targets of maintenance for living beings include body structure, quantity of resources, and processing systems.
The fundamental difference between many artificial objects and living beings lies in their methods of maintenance. In the case of artificial objects, whether buildings, inventories, or machines, the aim is to keep the same material in the same place over time. When degradation, consumption, or wear occurs, repairs or replacements are made to restore the original state.
In contrast, in living beings, the substances composing the body structure, resources, and processing systems are continuously replaced, even during and after their formation.
Substances at each location are consumed, discarded, and replaced with new materials, a process occurring everywhere. This can be termed exchange-based maintenance.
Exchange-based maintenance is similar to the rotation of positions and personnel within a company’s organization. Over time, as people change, even if all individuals differ from the original staff, the organization retains its structure and functions. Living beings maintain their body structure, resources, and processing systems using the same methodology.
This allows the system to constantly renew itself, making it less prone to degradation and obsolescence.
This methodology is also applicable to the maintenance of species. As older individuals die, new ones are born, keeping the overall freshness of the species constant.
This method may seem less efficient than the common maintenance approach seen in many artificial objects, which involves replacement upon aging or degradation. However, without needing a highly intelligent mechanism to recognize and process aging or undeteriorated parts, this method effectively maintains overall newness.
Utilizing Exchange-Based Maintenance for Growth and Aging
The targets for growth in life include body structure, resources, and processing systems. Increasing their size, capacity, and variety constitutes growth, while reduction signifies deterioration.
Many artificial objects do not manage growth and aging well. Once constructed, their size, capacity, and precision are fixed, and when maintenance is no longer feasible, the entire object is typically discarded. While artificial objects can age and deteriorate, indicating a loss of strength, their size, capacity, and variety usually remain unchanged. This suggests that the concept of aging in artificial objects differs from aging in living organisms.
The ability of living beings to increase or decrease the size, capacity, and variety of their body structure, resources, and processing systems is due to the features of exchange-based maintenance. The structure, resources, and processing systems of living beings, maintained through continuous replacement of materials, can grow by increasing the materials added at the replacement sites compared to those consumed or discarded.
Conversely, by increasing the materials consumed or discarded compared to those newly placed, aging can be induced. The same methodology applies to the growth and aging of species.
System Architecture of Life
Both organisms and species possess mechanisms for the maintenance, growth, and aging of their structure, resources, and processing systems.
Responding to time, internal states, and external conditions, these mechanisms are realized through combinations of structural changes, resource movements, and processing system operations.
This represents the overarching system architecture of life.
When contemplating the origin of life, this system architecture of life provides a significant foothold. Extensive research on the origin of life has revealed that the chemical substances constituting organisms, as well as structures like cell membranes and cytoskeletons, can be produced even in inanimate environments.
Without such structures and resources, life on Earth would not be possible. However, structures and resources alone do not constitute life. The mechanisms for maintenance, growth, and aging of both organisms and species are necessary.
Conversely, if it can be demonstrated that these mechanisms could emerge from inanimate environments, one explanation for the origin of life becomes possible.
This underscores the significance of clarifying the comprehensive system architecture of life in understanding the origin of life.
Autonomous Self-Maintaining Systems
If the structure, resources, and processing systems can continue to maintain themselves, an autonomous self-maintaining system is formed.
Imagine a planet where sunlight is abundant, and diverse material resources are readily available.
Suppose there is a device A capable of generating and storing energy from sunlight. Device A can also collect and store material resources from its surroundings.
Additionally, device B uses the energy and resources stored in device A to maintain itself, device A, and device C. Device C incorporates a mechanism that periodically instructs device B to perform maintenance activities.
This system of devices A, B, and C, arranged in a space and interacting with each other, becomes an autonomous self-maintaining system.
Evolution of Autonomous Self-Maintaining Systems
Suppose device B can apply its maintenance function to create devices A, B, and C. Then, this group of systems can be viewed as a macro system that maintains itself.
If device B can introduce slight variations when maintaining or creating devices A, B, and C, these devices have the potential to evolve. Devices that are easier to maintain will increase in number due to natural selection, as others decrease.
Furthermore, if devices A, B, and C are contained within a single package, with maintenance and creation occurring at this unit level, it becomes the unit of evolution.
Origin of Autonomous Self-Maintaining Systems
Let’s trace back to before the appearance of devices A, B, C, and their package.
Consider a scenario without devices A and C and the package.
In this case, maintenance instructions for device B could have been replaced by stimuli from the external environment. The energy and resources used by device B could also have been supplied by the external environment. The location where device B accumulates energy and resources could have been prepared by the external environment.
If the conditions of this convenient external environment are met, device B can maintain itself.
If device B undergoes changes while continuing to maintain itself, it could potentially die, degenerate, or evolve.
If a large number of such device Bs are generated on a planet over a long period and placed in a convenient external environment, some could steadily evolve through death and degeneration.
If the gears of evolution for device B start turning smoothly, eventually device B might be able to create itself. Then, a large number of self-replicating device Bs could exist within the planet’s convenient environment.
Further, if device B evolves to produce devices A and C, the supply of energy and resources and processing instructions to device B, previously reliant on the external environment, could be replaced by devices A and C.
At this point, even away from the convenient external environment, a system capable of self-maintenance is formed.
A Hypothesis on the Flow of the Origin of Life
If devices A, B, and C are
made of chemical substances constituting organisms, and their processing is the same as that performed by organisms, the process from the evolution of device B to the formation of a self-maintaining system could be one hypothesis for the flow of the origin of life.
If devices A, B, and C can further encapsulate their combination within a membrane, it becomes a cell.
Implementation of Devices by Amino Acid Polymers
I believe these devices are primarily made of amino acid polymers. A polymer is a substance where multiple chemical substances are linked together like a chain. A long chain of amino acid polymers is a protein.
These devices require complex chemical processing. Since proteins mainly perform scientific processing among the chemical substances constituting organisms, it is natural to assume that these devices are realized by proteins or shorter amino acid polymers.
Information Retention by DNA or RNA
To increase the precision of self-maintenance and device creation, information equivalent to design blueprints or work instructions is necessary.
Although some level of maintenance is possible without such information, as devices composed of amino acid polymers evolve, they become longer and more complex. Maintaining the same state becomes increasingly difficult for long and complex amino acid polymers. Therefore, without blueprints or instructions, evolving beyond a certain stage becomes challenging.
DNA or RNA is needed as a medium to accurately record this information. In organisms, DNA and RNA indeed serve the roles of design blueprints and work instructions.
During the evolution of amino acid polymers, utilizing DNA or RNA to retain information equivalent to blueprints and instructions made it possible to realize devices of longer and more complex amino acid polymers, facilitating further evolution.
Packaging by Cell Membranes
Before the appearance of cell membranes, I believe pools, ponds, and lakes on Earth were where amino acid polymers, DNA, RNA, and their chemical precursors accumulated.
The interior of a cell is a liquid rich in water, suitable for chemical reactions involving chemical substances. The sea is too vast for the accumulation of chemical substances or devices like amino acid polymers, DNA, and RNA, making moderately sized water bodies more appropriate. Moreover, pools, ponds, and lakes are numerous on Earth, each accumulating different types and amounts of chemical substances and varying in energy supply. This increases the probability of suitable devices for evolution appearing.
We have only observed self-maintaining systems composed of proteins, DNA, and RNA operating within cell membranes. Therefore, it is easy to overlook that, before the advent of cell membranes, exposed proteins, DNA, and RNA could have existed in pools, ponds, and lakes, forming systems that cooperatively self-maintain.
Viruses provide evidence of this. Viruses, with exposed or membrane-enclosed DNA or RNA, infect cells of living organisms to replicate. The much simpler structure of viruses suggests they originated before cells. Even without cells, similar systems could have existed in pools, ponds, and lakes, allowing viruses to replicate.
It is conceivable that systems with only proteins enclosed by membranes or both DNA/RNA and proteins enclosed by membranes, but not yet capable of complete self-maintenance like cells, also existed. Eventually, these systems evolved with cell membranes for packaging, leading to the emergence of fully self-maintaining cells.
Origin of Organisms and Species
Life on Earth can be categorized into organisms and species, as discussed.
If we consider the hypothesis that self-maintaining systems functioned in pools, ponds, and lakes before the birth of cells, distinguishing between organisms and species becomes challenging.
Here, mechanisms for self-maintenance similar to those of organisms exist alongside mechanisms for replicating DNA like species.
This perspective allows us to see the concepts of organisms and species coexisting without separation. The introduction of cell-enclosed organisms then clearly differentiated organisms and species.
Origin of Exchange-Based Maintenance
Considering a system of self-maintenance established in pools, ponds, and lakes without membranes, maintenance occurred in a literally fluid environment undergoing constant change.
New substances were supplied from upstream, existing substances flowed downstream, and internal movement of water constantly altered the location of substances. Chemical substances also gradually decomposed.
If self-maintenance was realized in this context, continuously generating and incorporating new parts to compensate for parts flowing out or decomposing would have been suitable, leading to exchange-based maintenance.
Utilizing the characteristics of exchange-based maintenance, the self-maintaining system could grow and evolve by increasing the number and diversity of devices like proteins, DNA, and RNA.
Conclusion
This article’s analysis has made it clearer that the perspective of self-maintaining systems is fundamentally important for understanding life and its origin.
Focusing on the maintenance of life shifts the viewpoint from the origin of cellular life to the exploration of the origin of self-maintaining systems. As discussed, chemical substance-based self-maintaining systems could have formed on Earth before the appearance of cellular life.
This changes the image of the origin of life. Traditionally, the synthesis of chemical substances like proteins, RNA, and DNA in an inanimate environment, eventually combining to form cellular life, has been a common narrative.
However, from the perspective of life maintenance, even before cellular life, self-maintaining systems composed of proteins, RNA, and DNA could have emerged in an inanimate environment, spreading and evolving globally. This process eventually led to the birth of cellular life, overturning the traditional image of distinct systems before and after the appearance of cellular life. It suggests that cellular life is merely a milestone in the continuous evolution of self-maintaining systems.
Cellular life is an incredibly advanced and complex system, and imagining it assembling suddenly can make the origin of life seem miraculous and enigmatic.
However, the perspective of emerging and evolving self-maintaining systems implies that life’s origin could start from much simpler systems. This allows for the explanation that cellular life evolved from a complex system through the repeated accumulation of minor chances over time. This shifts the perception of life’s origin from miraculous coincidence to a series of inevitable, small chances, offering a new way to comprehend the genesis of life.
