Awareness-First Hypothesis
Dear Wellwisher, Your “energy stream analogy” is very interesting. But if we follow your analogy only, the life processes must come to a stand-still after sometime, because thermodynamics allows only one-way pass. This is because, you have showed only one direction in this stream in the case of metabolism; the reverse direction is that of an anabolic reaction (which decreases entropy) that always occurs in a living cell. This combination of anabolism and catabolism forms a “repetitive energy stream” as you put it. For the catabolism (cellular respiration) to run eternally there must be anabolism also. This means that, anabolism forms macromolecules to provide ‘fuel’ to run catabolism (to break sugars into CO2 and H2O). But, For the macromolecules to form is not in strict accordance with the principles of thermodynamics. Nature does not allow a decrease in entropy, at least without allowing a compensatory increase in the entropy somewhere else in the universe. Life processes trick the nature to do this job. The trick is simple – for decreasing the entropy of molecules and to build macromolecules, life takes-in the surrounding energy. In plants, for example, to produce energy-containing sugars (decrease in entropy) through photosynthesis, nature has to undergo some sort of change so that finally entropy in the surroundings has to increase, and this is done by breaking water (H2O is a source of electrons, as you know, in oxygenic phototrophs) and liberating oxygen (this increases entropy). This is the simple reason why plants need sun light and we need our daily ration to keep life going.
Now the question of templates. Sure, to join one unit with other to build macromolecules of nucleic acids or proteins using codes also needs thermodynamic principles. To run the above metabolic show, it needs a direction (in the form of codes) to direct the chain of reactions one succeeding the other. This is accomplished by proteins (enzymes) which, in turn, are coded by DNA.
The complex metabolic processes cannot run without a direction (codes) – but at the same time, a coding system cannot evolve without an existing metabolism – the dilemma is whether ‘replication-first’ or metabolism-first’?? The answer may be that both of them are complimentary – one cannot exist without the other. It follows that they developed together. But we must ask a question here – what is the whole purpose of this duel mechanism? The answer again is - To harness incoming energy and supply it to the living cell where it is needed. Energy is needed to do work – there are 4 kinds of work a cell has to perform to live – Synthetic, Mechanical, Electrical and Regulatory. Synthetic and regulatory are anabolic works; whereas mechanical and electrical are catabolic. If you think correctly, mechanical movements are also achieved by means of electrical work. Electrical work is done almost entirely at the level of membranes, by the way of ionic transfer. Thus, catabolic work is chiefly represented by electrical activity around the membranes. In other words all the metabolic cycles occurring in a cell assist in upholding the electrical acticity around the membranes. How is this electrical energy utilized at the membranes? This is converted to membrane potentials across the membrane – why – again, this is to ‘do work’.
The conclusion is simple: The purpose of all activity occurring in a cell is to sustain the membrane potentials across the membranes.
What is this electrical activity doing at the membranes – it is ‘creating awareness’ of its surroundings. Why is this awareness essential? Because it is only the way by which a cell can ‘know’ of its presence in its surrounding milieu. But then what is this ‘know’? That is life. The ‘know’ had orchestrated the development of all these sequences of metabolism and replication.
Why, lastly, is reproduction? Life, somehow, ‘knew’ that it cannot sustain for long, and death is inevitable. Reproduction is a life’s ploy to win over death.
Hence my “Awareness-First” hypothesis.