Chapter 2:  Biology -- The Rules for Life

Rules that govern the physical world are wondrous, complex, and forever beyond our complete comprehension. Add to that the mysterious property we recognize as life-force, and the level of complexity increases many-fold. From the smallest observable subatomic particles, to the outer reaches of the Cosmos, every aspect is controlled by a predetermined, hierarchical set of rules. At the lower level, subatomic particles follow their own set of rules which allow them to form atoms of various kinds. Another set of rules dictates how atoms might combine to create molecules, possibly of great complexity. One of the most intriguing structures to be built from these molecules is DNA, an essential component of all living things. And again, DNA chains or chromosomes have a unique set of rules that govern their behaviour. Chromosomes exist within cells, and embryonic cells can continually divide to create the many and various forms of life we recognize.

Every living cell must be driven by a common set of rules. It makes no difference if the cell is destined to become a dog or a dinosaur, it must still obey the same rules. So, if all cells behave according to the same set of rules, what determines dog or dinosaur? The obvious answer must be that a cell also contains its own unique information, which in turn influences outcomes from the generic rules. A truly remarkable feature of the life-cycle is the mechanism of reproduction that allows accumulated relevant life experiences to be passed to future generations. This information is stored in DNA sequences. Here we are trying to make the important distinction between Rules that apply equally to all entities of the same type, and Properties or characteristics that only influence outcomes for specific entities.

Every living organism is the product of both the rules that govern life, and many of the properties inherited from the single cell that continually divided to create the organism. Any condition or state that makes a particular entity significantly different from its peers, is considered a Property of that entity. It is not always easy to distinguish between what might be considered a Rule, and what constitutes a Property. Information programmed into DNA chains relates to both individual characteristics and species specifics. As an example, consider a frog born with some psychological abnormality that sets him apart from his peers. DNA instructions have determined that he was going to grow to be a frog. Embedded elsewhere in those instructions could be some indication of psychological problems occurring somewhere along the cell-division process.

Over the last 50 years, biologists have cleverly and convincingly shown how characteristics of various species adapt to their circumstances, and pass on the information to benefit future generations. The way DNA replicates and stores information is central to the whole mechanism of evolution. However, there may be additional ways of passing information from parent to progeny rather than direct inheritance or teaching by example. Perhaps we have assumed there can be no information transfer from mother to child at or before birth, just because we have no explanation of how such a process might work. Instinct is something that many animals, including humans, appear to possess at birth. Is instinct a pattern of behaviour that belongs to a species as a whole, or does it result from collective wisdom passed down from previous generations? It is not clear we currently know the answer to that.

To be consistent with the premise that all things ultimately result from immutable rules, we need to identify which rules apply equally to all forms of life. One of the most obvious influences on life, is death. Even though end-of-life is often a sad experience in the human context, death is an essential part of life. The approximate end-game for each individual of a species, is just as carefully orchestrated as the start of life. One of the most challenging questions for biological science, is why we age, and what are the mechanisms causing us to wear out. Recent biological advances have given some insight into the way DNA chains are continually shortened at each replication ( Telomeres & Immortality ). There is some randomness associated with this shortening process, and obviously some lifespans are longer than others. There are environmental factors that influence this, but there seems to be an underlying constant built into the genes of every living organism that ultimately dictates a certain natural life-expectancy. It is unlikely we will be able to manipulate the rule that drives this shortening process. However, what we do have is the ability to medically interfere with the natural telomere mechanism, and thereby potentially influence life-expectancy.

So why is programmed mortality important in the survival of the species? The obvious answer is that there must be a sustainable balance between the creation of new life, and the phased extinction at the end of each life. In addition, there could also be a more subtle explanation for the phenomena. A requirement for Evolution, with its dependence on Natural Selection, is that there must be a selection available. This selection results from chance mutations that propagate through a species. Mutation also occurs as cells replicate within an organism throughout its lifetime. This mutation is a double-edged sword, and often produces very undesirable outcomes. As a direct consequence of mutation, various forms of cancer can develop as an individual ages. With programmed mortality, and less likelihood of participating in procreation late in life, there is a safety mechanism that reduces the risk of genetic flaws flowing through to the next generation.

There is another mechanism capable of keeping the population of specific species within the bounds of sustainability – Regeneration. This process is rarely found in either plants or animals. Studies of a particular species of jellyfish, Turritopsis Dohrnii, have demonstrated that they have the most amazing ability to return from adulthood to an infant state, under the right conditions ( Turritopsis Dohrnii ). However, if regeneration was common throughout all lifeforms, it would seriously impede the evolution process by limiting the cross-pollination of gametes. We might interpret the curious behaviour for this particular type of jellyfish as an aberration that is allowed within the rules that govern all life.

The notion of immutable rules mentioned in the previous chapter, seems to have more relevance to the rules of physics, than to the rules of life. However, this does beg the question as to whether the rules regarding life might also be immutable. The possible outcomes from applying the rules for life seem endless. When we apply the rules of physics, it appears as though the results range from a clearly defined set of atomic structures, through to relatively predictable behaviour at a cosmic level. What is sometimes obscured in our macro view of the world, is that even the laws-of-physics can produce many different outcomes from the application of a single rule. Every rule has an associated probability that a certain outcome will result from certain input conditions. When we drill down below the atomic level into the strange realms of quantum mechanics, there is no requirement that any particular particle has to be either black or white – it could in fact be black AND white at the same time.

We can identify the chemicals and molecules that are essential to life. What we have more difficulty with is deciding where and when the rules associated with life come into effect. At some point after the creation of our Universe, atoms combined to create complex molecules containing the blueprint for life – DNA. The cells containing DNA had acquired a momentous property in the evolutionary scheme. We know approximately when this happened, about 3.5 billion years ago, and are coming closer to understanding how. As regards rules, atomic structures that had been governed purely by the laws-of-physics, now in some mysterious way obey an additional set of rules that belong to the branch of science we term “Biology”.

Delving deeper for an understanding about which rules might be associated with which entities, we are faced with the same dilemma as when deciding at what point a collection of atoms might eventually become living matter. Stem-cells, almost spontaneously, begin to follow rules related to the role required of them in a specific environment. They seem to develop and grow entirely in response to their situation. It's interesting to examine the mechanisms involved where they follow both the rules that apply to all stem-cells, and also obey an independent set of rules specifying a group dynamic. Indications are that new cells receive instructions in the form of chemical signals from surrounding cells, encouraging them to perform in a role that will be of benefit to the group as a whole ( Stem-Cell Niche ).

At the moment our Universe was born, most scientists agree that visible matter consisted mainly of simple atoms like hydrogen and helium. Complex atomic structures were formed at a later time during the life-cycle of stars and galaxies. It is extremely unlikely that any complex molecules existed at the time of the Big Bang, and it must be assumed the material defining life has been incubated elsewhere at a later time. Even though the rules pertaining to life existed at the time of the Big Bang, the environment conducive to life was a long way off.

To try to understand this idea of rules pre-existing any circumstances where they might be applied, let's consider a hypothetical analogy. Imagine millions of Lego blocks were poured into a giant mixer. Left for long enough, the plasma of bricks could fall into place and form Lego-Land. It is easy to dismiss this outcome as absurd. And yet, we readily accept the idea that planet Earth and all human civilization has resulted from exploding stars spewing particles into the galactic mixer. When the first Lego bricks were created, the designer could not have envisaged all possibilities resulting from their use. Similarly, the guys who built the giant mixer in our analogy, could not have imagined the device being used to organize Lego bricks into meaningful structures. So if Lego-Land was the result of this experiment, there must have been extra input besides just the bricks and mixer. This extra input must be quite independent of the building blocks or the environment.

Continuing with this analogy, let's contemplate what makes the Lego-Land result so unbelievable. Comparing the experiment with the functioning of our Universe is grossly unfair for three basic reasons. Atomic particles are closely integrated with the laws-of-physics, almost as if they were originally part of the same design specification. Anything involving Lego bricks must rely on a tiny subset from the laws-of-physics, without benefit of co-working with these laws. Secondly, the experiment is seriously disadvantaged by the fact that it is only being run once, and thus there is no opportunity to modify the original design to cope with unanticipated situations. And thirdly, formation of Lego-Land requires something not accessible from an environment composed solely of plastic blocks – Intelligent Life. In engineering terms, there is something magnificent about any design that stands the test of time, and behaves predictably in every possible future scenario. From a human perspective, this is impossible to achieve. Because the laws-of-physics and the atomic building blocks have remained unchanged for 14 billion years, one could be led to the conclusion that our Universe is not the first where these rules have been trialled. Alternatively, maybe the rules existed unchanged for eternity.

Returning to reality, it is hard to build a model for our existence that does not require input from some unseen and unknown source. Our understanding of atomic structures that are fundamental to everything in our physical world, is expanding at an incredible pace. It must be remembered that humans can never extend their role beyond that of observers. We can conduct some pretty amazing experiments within the existing laws-of-physics and Nature, but with the best will in the world, we can never create a giant mixer that 'knows' how to construct Lego-Land. Admittedly, some exceedingly convoluted engineering might do the trick, but that would still require physical implementation. In keeping with the theme of this book, we have categorized the mysterious inputs as the Rules for Eternity.

Interplay between the rules for life and the broader set of immutable rules, creates some interesting possibilities as to what form life might take in extreme alien environments. What if the rules-for-life themselves are far more flexible than we currently understand them to be, and any limitations are imposed solely by mechanical constraints and the laws of physical science? Taking examples from our home planet, it does appear that over a very broad range of environmental parameters, life will attempt to establish a foothold. Because we are surrounded by carbon-based life on Earth, is it valid to assume that this must be the only formula for life? Possibly not. Examining the constraints of physics on the life we are familiar with, usually provides a logical explanation for the way a particular life-form is implemented. For giant trees, the tallest living things, gravitational forces dictate that their centre-of-gravity must be situated close to the centreline. Any serious deviation that creates an imbalance will cause the tree to topple.

As another example of how the laws-of-physics greatly influence what form life can take, consider how huge some species of dinosaur had become during their reign. Limitations were imposed on size, not just by how much food there was to eat, but also how much of it they could eat. If they were purely eating machines, surrounded by food, survival would not be driven by how fast they could travel – a small coefficient-of-drag did not play significantly in their design. These massive objects were seriously hampered by inertia. Perhaps they might have been able to grow even larger but were prevented from doing so purely on the grounds of logistics. Their huge bulk could have made them so lethargic that they became increasingly reluctant to make the effort to drag themselves far enough to find a mate – a fatal mistake in the plan for survival of any species. On a different planet, with quite different gravity, dinosaurs could have evolved to be similar shapes, but radically different dimensions.

Of particular interest to us humans is consideration of what might be limiting factors on the survival of our own species. All animals, with the notable exception of man, surrender gracefully to the dictates of nature that have been designed to ultimately benefit the whole planet and all forms of life. Outcomes might seem harsh on an individual basis, and entire species can become extinct to be replaced by new players. However, that is the broader cycle of life that we have been born to, and must accept. Humans have judged themselves to be positioned at the top of the intellectual tree on planet Earth. Note that other species might assess human intelligence somewhat differently, and could have made a collective decision not to openly challenge the claim. With unmatched ability to influence the planet on a large scale, it is understandable that humans might be tempted to believe they can operate outside the laws of nature. As mentioned previously, this is well demonstrated by the human population explosion over the past century. Population density, distribution, and diversity have grown beyond the point where outcomes could be controlled by a handful of powerful leaders. There is now a degree of inevitability associated with the fate of humankind, and it certainly incorporates many undesirable components. One rather pessimistic interpretation might be that human civilization has run its course, and now faces extinction according to the same rules that apply to all species.

Thanks to careful observation over many generations, guidelines for the good health of both individuals and planet Earth have been established. In recent times, science and medicine greatly sped up the trial-and-error learning process. One recurring theme relates to what we eat. Looking back as best we can over thousands of years, it seems dietary patterns of old might have produced more healthy individuals than is frequently the case in some pampered Western societies of today. There should be no surprise here, and the explanation relates to the slow rate of evolution of the human animal. Back when our cave-dwelling ancestors were evolving to suit the food available to them, the basic bio-mechanisms were established. Because changes in lifestyle were extremely slow, there was time for evolution to keep pace with mild environmental changes. In modern times, diets are changing rapidly and dramatically, and not always for the best. The bio-mechanisms in place today have not really had a chance to adjust, and research often indicates the benefits of returning to dietary habits of the past. One of the most serious threats to human civilization is the fact that the environment is changing more rapidly than we can adjust via evolution.

It is almost impossible to distinguish between effects from the fundamental rules of life, and those that result from environmental conditions or influences from other life-forms. Various species might compete in the same territory for the same resources; others might be complementary and provide support and new opportunities. There is one function that does appear common to all forms of life – Optimization. Natural selection that plays a role in evolution is one of the more obvious forms of optimization. Once the basic requirements for life are met, as they are here on Earth, there seems to be no restriction on where and when a new species can be created. The form it takes is designed to fit exactly within the resources available. That surely must be the perfect example of optimization at its best. Virtually every property of plants and animals is subject to optimization.

As an example, consider what factors influence the average height of humans. Over the last century, average height has increased a little in response to improved nutrition. There were noticeable dips in height related to both world wars, possibly resulting from short-term poorer dietary conditions. Studies have shown that the average height of humans today is slightly less than it was around 150,000 years ago ( Human Evolution ). The rate of increase today is slowing, suggesting there might be an inbuilt limit for the optimal height of man, and that limit was set when Homo sapiens first appeared. It is logical that early humans were optimized as hunters, and being tall meant they were able to run fast. The idea that there might be age-old inbuilt constraints on humans has quite interesting implications.

Enhanced capabilities for collecting and analysing huge volumes of data have helped identify the subtle statistical adjustments brought about in the process of optimization. As we are discovering with ever-increasing clarity, anything we can observe, measure, and interpret as a fundamental rule of nature is most likely an encapsulation of various other rules. Consider the rules that human science has ascribed to the whole spectrum of molecular chemical processes. They may seem to be relatively independent, deserving of classification as fundamental rules. However, all chemical processes and interactions are ultimately dependent upon the basic properties of atoms. Once again we are confronted with the mind-blowing realization that atoms were originally contrived in such a way as to enable the beauty, complexity, and vastness of existence.