Biology and life

What is life?

  1. The biological definition of life.

  2. Life from a human perspective.

  3. One life, or many potential lives?
The biological definition of life.
The definition of the word ‘life’ is not as clear-cut as might initially appear.

Plants and animals are certainly living organisms according to any standard scientific definition.

Entities such as viruses are more ambiguous- they can remain locked in a static state indefinitely, then become activated under the right conditions, take over a cell’s machinery, and use the cell’s resources to manufacture copies of themselves.

Even organisms that we typically place squarely in the domain of the living, such as certain insects and crustaceans, can remain in a state of suspended animation, with their biological processes brought to a halt, when their bodies are kept at the right temperatures. In that state, are they considered living or dead, or neither?

When we talk about life in the context of religion, we tend to assume that this refers to human life, from some time post-conception till death. The exact point after conception at which a bunch of cells can be considered a ‘life’ is a widely debated issue, and different groups of people have conflicting opinions about what constitutes human life.

The point at which someone is ‘dead’ is highly contestable as well- in the medical and legal professions, certain vital signs are measured to assess whether someone can officially be considered ‘brain dead.’ Medical staff around the world have arrived at a standardised set of criteria to determine this- however, as one would expect, some arbitrariness is involved in setting those criteria.

We use language to breathe figurative life into all sorts of objects- living, non-living, dead, and any conceivable state in between. We often refer to electronic equipment, for example, as being alive.

In summary, 'life' is a term we use to describe a wide range of disparate phenomena.

These phenomena are typically associated with a copying mechanism (to a higher or lower degree of fidelity, depending on the situation), which results in the propagation of information. That information may take the form of some particular arrangement of proteins, amino acids, or other molecules.
Life from a human perspective.
Human beings are part of this phenomenon, along with all other living creatures. We have a natural respect and appreciation for life- it’s what allows us to exist and be self-aware.

At the same time, it’s important to realise that our human-centred point of view dominates our perspective of the world. ‘Life’ takes on a magnified sense of importance in our minds, because it describes the slice of reality with which we are most familiar and preoccupied.

We place the concept of life on a pedestal and associate it with progress, evolution, and advancement. Rarely, if ever, do we attempt to view things from an alternative standpoint and try to remind ourselves that life is but one particular collection of phenomena, and there are many others.

Many of us see ourselves and other living organisms as brilliantly formed, highly functional showpieces of an intelligent designer. We consider ourselves finished products, equipped to perform whatever task we were meant to serve.

We like to believe that we generally meet our Maker’s basic quality control criteria. The perception that we each serve some pre-ordained purpose arises from our inward-gazing perspective. (Refer to the section on the purpose of life.)

The complex systems of information propagation that we refer to as life have emerged over the course of billions of years, and have been shaped by multitudes of events that have cumulatively led to the particular conditions that surround and govern us today.

The fact that we presently exist in our current form is due to this specific combination of historical events. If circumstances had deviated slightly, they would not have generated quite same state that we see now, but a different version of it.
One life, or many potential lives?
We perceive the body of each living creature as being complex and solid- we tend to think of each organism as essentially indivisible. If a creature lacks some component of its body, it seems incomplete and less than perfect. Again, this perception has emerged because our cumulative, daily experiences give us this impression. It is not, however, the best or the only way of perceiving things.

Take ourselves, for example. Many of us think of each human body as a discrete object, clearly separable from other nearby objects. We could draw an imaginary bounding surface around the human body, making it follow the contours of our skin and hairs closely.

When you consider this exercise in greater detail, problems start to crop up. We realise that it is impossible to draw a precise boundary along our respiratory, digestive and reproductive tracts, for example- our cells are continuously emitting and absorbing chemicals that merge with the ‘external’ environment.

If someone’s nostrils and mouth are open, would we trace the boundary along the inner walls of their mouth, oesophagus, lungs, stomach, and intestines?

Can we consider the air molecules within these tracts part of the person, and thus just draw a connecting line directly between their upper and lower lips, to enclose their mouth, instead of meandering down their throats?

How about the cells that constantly flake off our skin? If they are no longer tethered to our skin surface, but just resting there, ready to fall off at the slightest touch, can we still consider them part of our body?

The list goes on and on. The majority of our cells may stay in the same relative location within our body for days or weeks at a time, but they will eventually be replaced and are constantly turning over. Our bodies engage in a continuous exchange with the environment.

That many of us find it hard to internalise this fact is unsurprising- after all, we have little need to harbour such awareness of our bodies in our daily lives. We do not need to be consciously aware of every event in our body- our cognitive faculties would be thoroughly overwhelmed if so. In fact, the events in our body of which we're aware are a miniscule proportion of the total number of events that occur.

However, these few, carefully-sampled events are the ones that provide us with crucial information, and offer us the opportunity to make a decision and influence our behaviour. The other events, of which we remain blissfully unaware, are largely inconsequential, and can be safely ignored.

We do not generally think of our limbs as having a life of their own.

But the situation is different when it comes to other species. Many plants are able to propagate through cuttings. Bacteria undergo binary fission to create new individuals. Human beings store reproductive cells in their bodies, which, when combined appropriately, give rise to new individuals.

Thus, the idea that our bodies are complete, self-contained units, discrete from the environment, is simply the result of our subjective perspective. Could we say that each of us stores multitudes of ‘half’ lives in our reproductive organs? If we have a million such cells, does that effectively equate to half a million ‘full’ lives?

We may intuitively believe that life is one of the most important and spectacular marvels of the universe. Remember, though, that this belief stems from the fact that once we recognise that a particular phenomenon exerts direct and profound influences on our being, we harbour an exaggeratedly high regard for it.

The notion that bodies and lives correspond in a one is to one ratio is equally contrived and inaccurate. Our working definition of ‘life’ stands us in good steed in the majority of day-to-day situations.

Keep in mind, however, that the true meaning of life more much complicated, and that the scope addressed is far wider than we typically realise.
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