6. Earth History

Introduction

The last chapter discerned four rules on which a productive balance on the Earth depends. This chapter puts their operation in the context of Earth history. Balance, it will be seen, is the exception rather than the rule. Also, as will be demonstrated, the Earth’s complex adaptive systems have, over the whole of their four billion years, continued to learn. Over that time it has been imbalance that has been the more normal. It can, however, have truly catastrophic effect.

The Dynamics of Imbalance

In universal terms the concept of balance is problematic. When the universe began there was, according to science, a finite, if huge, amount of concentrated energy. It has subsequently been spreading out to become ever more diffuse. This process, as a persistent flow of higher-exergy to lower-exergy energy is intrinsically unbalanced.

That said, in pockets throughout the universe, a potential for a dynamic balance does exist. This occurs when the flow of concentrated energy into such systems, and the flow of less concentrated energy out, maintains their structures and maintains their productivity at a relatively steady rate. The Earth is such a pocket.

Within such systems, two inherent pressures serve to subvert the balance. One is growth, driven in living systems by reproductive fecundity and by newly emerging complexity. The other is the finite limits of the inorganic environment. The latter fluctuate due to both internal and external causes.

These are the pressures that complex adaptive systems are perpetually seeking to reconcile. The Earth’s evolutionary history is a chronicle of their trial and error learning.

Earth Life History

Scientists continue to debate how and where life on Earth began. What is known is that, whenever and wherever this was, it first required atoms to join together with atoms to form simple molecules, with these increasing in complexity as more atoms joined with them.

Once four specific molecules became available, being lipids, proteins, amino acids and nucleic acids, when they came together, a cell that could live would be formed.

These cooperative processes, says Antonio Damasio, are the basis for all life:

The body…. [is] made up of cooperative systems, which are made up of cooperative organs, which are made up of cooperative cells, which are made up of cooperative molecules, which are made up of cooperative atoms built from cooperative particles. One of the most distinctive features of organisms is, in fact, the extraordinary degree of cooperation exhibited by the constituent elements, along with the resulting extraordinary complexity.1

The “attraction” that underlies these processes is provided by sub-atomic, atomic and molecular bonds. They are made possible through the application of the “useful work” that the spreading of concentrated energy, described in chapter 4 provides.

That work fixes exergetic energy with its a capacity to do useful work, within bond structures, while the entropy created in doing so, is vented out into the wider atmosphere.

This enables the pulling together effect of exergy to be located and stored within the bonds, while the pulling apart consequences of entropic decay are dispersed. Locally, therefore, where the effects of exergy prevail, the balance will favour pressures pulling together.

Living was, nevertheless, a very big jump. The molecules forming the first cell would, presumably, have had no self-awareness, and no sense of purpose. They were just molecules and the atoms that formed them just atoms.

Once they came together, however, they became something else. Despite being tiny, about one tenth the diameter of a human hair, they became interactive and proactive. They actively sought energy and nutrients, they developed the means of excreting their waste, and they acquired a means of reproducing themselves.

They had, that is, acquired an instinct for living. This, as an emergent property of nature’s complex adaptive systems, is the “magic” that these systems, with a surfeit of exergetic energy, can produce. This “magic” is normalised and trivialised for us in the words evolution and emergence.

Slow Beginnings

The first cells are perceived to have resided by ocean vents. Their emergent property of chemosynthesis, enabled them to obtain the energy they need to live from the vents’ chemical emissions.

Eventually, although localised, a balance seems to have existed between these resources and the cells’ fecundity. By later oxygen-facilitated standards chemosynthesis was, however, inefficient. Evolution, as a result, progressed very slowly and life remained localised and single-celled.

Eventually, having lived in this way for 600 million years, some cells acquired a capacity for photosynthesis, the ability to gain energy from sunlight, giving these cells greater mobility.

The process was, however, still anoxygenic. It did not emit oxygen. Respiration remained, as a result, inefficient, and the pace of evolution remained slow. Life continued to be single-celled for a further one billion years.

Then, as if by magic, about 2.5 billion years ago, oxygenic photosynthesis, photosynthesis that did produce oxygen, emerged.

In the Earth’s atmosphere, the oxygen migrating from the oceans reacted naturally with methane, a powerful global warming gas, reducing the latter’s atmospheric concentration.

At a time when the sun’s warmth was not as strong as it is now, the effect was to reduce global temperatures, and precipitate two or more “snowball Earths”.2

This effect, although seemingly major, may not have been of great significance for the oxygenic cyanobacteria producing the oxygen in the oceans, nor on the anaerobic bacteria also living there. A second effect would, however, be profound.

Previously, anaerobic cells in the oceans, had been the only form of life on Earth. Not only did they not need oxygen to live, it was, to them, a poison. The oxygen the cyanobacteria produced had, however, little initial impact upon them.

This was made possible by the presence of dissolved compounds in the water with which the oxygen combined, leaving the water largely oxygen free. A productive balance was, by this means, temporarily maintained.

Once the supplies of dissolved chemicals were exhausted, however, disaster ensued. Oxygen levels now rose rapidly and anaerobic bacteria died in vast numbers.

In adaptive cycle terms this was the phase of release, that is followed by the exploration and experimentation of the reorganisation phase. With free oxygen and free resources now available, this, it is envisaged, is when multi-celled aerobic cells, including eukaryotes, would have emerged. Eukaryotes are the forerunners of all plant and animal life.2

However, while seeming to be progress, it contained the seeds for further disaster. Beginning slowly, but eventually developing rapidly, and with few if any constraints, numbers of aerobic multi-celled organisms surged in a classic illustration of boom and bust.

By two billion years ago the nutrients on which that expansion depended are perceived to have been exhausted, and again vast numbers died.3 Oxygen levels, both in the oceans and in the atmosphere, fell back towards their previous low levels.

Subsequently not a lot happened. Conditions seem to have favoured anoxygenic photosynthesising bacteria, reduced efficiency and little evolutionary change.4 In the one billion years that followed, experimentation and magic ground, seemingly, almost to a halt.

Production and Balance

About nine hundred million years ago, aided, it is perceived, by flows of nutrients into the oceans, the pace quickened. The oxygenic cyanobacteria and aerobic eukaryote cells that had survived the adverse conditions became more active, more complex and more productive.

The art of balance remained, however, elusive. As a result, with increased levels of oxygen in the atmosphere, and with volcanic activity increasing, a series of self-reinforcing events causing the Earth to cool, were again set in train.

The snowball Earth this time resulting, lasted nearly sixty million years. During it conditions under the ice favoured anaerobic life, and oxygen breathing life struggled. A large proportion is again believed to have died.5

The reorganisation phase that followed enabled green planktonic algae to emerge,6 and, perhaps, the first early ancestors of animals.7 They, however, could not prevent a repeat snowball Earth, lasting this time, about 12 million years. It again resulted in large scale extinction.

It was followed by the emergence of macroscopic seaweed and, by 635 Ma, the first fossil evidence of animal sponges.

Animals were a major innovation in nature’s search for biological balance. In breathing oxygen and emitting carbon dioxide, they offered a greater potential for control over the balance between oxygen and global warming gases in the atmosphere.

This gave greater ability for increasing the Earth’s level of sustainable productivity.

That said, the significant extinction events of 542,8 488,9 444, and 37210 Ma still exhibit characteristics of biological stress, indicative of biological imbalance.

Each was, however, followed by increased interaction, interdependence, and relationship complexity between animals and plants. They range from the parasitic and predatory relationships of constraint, to commensal and mutualistic relationships of growth.

There was, as a result a large increase in biological productivity indicative of a favourable, pulling-together balance.11

However, and interestingly, after 372 Ma all the major extinction events occurring had non-biological causes such as asteroid impacts and major magma events. This suggests that global growth after 372 Ma had been successfully constrained within the Earth’s limits. Natures complex adaptive systems had, it seemed, learned.

Lessons Learned?

Nature’s complex adaptive systems had learned, that is, to live within the rules.

Those rules encouraged increased productivity through reproduction and greater complexity. Complexity increased efficiency through, for instance oxygenic photosynthesis, but it also produced diverse species able to occupy a range of niches.

Productivity was also increased through cooperation. This is most strikingly observed in our own human bodies. They are comprised of about 36 trillion aerobic cells and about 40 trillion single-celled bacteria, a large proportion of which are anaerobic. Overarching productivity, this shows, entails cooperation even from polar opposites.

But productivity has also been constrained. Perhaps the most notable example is that of the Cambrian explosion seen in the last chapter. Primed by the differing complexities of species across trophic levels, predation was seen to power the transfer of resources between these levels so increasing productivity, but also, by limiting population size, to constrain it.

Lastly, the venting of excesses has been observed in the multiple, and massively destructive, extinction events that a failure of balance has induced.

Seen in this light, complex systems that seek sustainably balanced high productivity will undoubtedly view some self-denial and some self-sacrifice, as productive. This, it seems, is the role that parasites, viruses, famines, climate change and floods, emerged to fulfil.

By comparison we humans, at huge cost to other species and to the planet, have greatly increased our energy consumption, we have placed ourselves in competition, and even at war,12 with nature, and we have neutered many of its regulatory constraints. In doing so we have set ourselves strongly, and seemingly deliberately, on the path of boom and bust.

But why?