Complexity and the Emergence of life

Complexity and the Emergence of life

Complexity has also unexpectedly thrown some light on the possible explanation for the origin of life itself. While scientists were conducting their research into complexity, they came across certain chemical processes which provided the basis for profound insight into the concepts of chaos and complexity. Eventually, it led to Ilya Prigogine's formulation of his Theory on Dissipative Systems which earned him the Nobel Prize in Chemistry in 1977. His paper on Nonequilibrium Thermodynamics threw new light on the Second Law of Thermodynamics and reconciled the differences between the apparently opposite views implied by physics and biology on the Second Law whereby a century old dispute was resolved. It will be recalled that the Second Law dictates that everything must become more disorderly over time while the growth in complexity of living organisms appears to be exempt from this destiny.

Prigogine proved that irreversibility is the key to understanding the apparent conflict between physical and biological laws as far as the Second Law of Thermodynamics is concerned. In classical thermodynamics, irreversibility leads to waste and loss of energy while in biological systems irreversibility gives rise to higher order and complexity which are indispensable conditions for the emergence of life. However, this growth in complexity and more orderliness is achieved at the expense of the organism's environment. He demonstrated in a particular chemical process that with the system's own catalyst feed-back loops it creates the instability through repeated self-amplifying feedbacks that leads to the formation of new complex structures on successively higher levels after each round of reactions which are multilateral. Such automatic feedback, self- sustaining and amplifying multilateral reactions will occur once the “ Bifurcation Point “ ( defined as a point or threshold beyond which chaotic behaviour will be exhibited in a dynamic system as explained above ) is reached thus setting in motion the irreversible engine of Chaos. Therefore, Prigogine concluded that :- “ Irreversibility is the mechanism that brings order out of chaos.”

It would seem that Prigogine had resolved the enigma of the apparent immunity of living organisms from the Second Law of Thermodynamics by viewing the puzzle through the proper perspective. For physical systems with no feedback loops and devoid of nonlinearity, the Second Law does lead to greater disorder in the total perspective of the closed system such as the universe as a whole. In other words, the whole universe is heading towards a heat death when all the differentials in energy levels in every part of the universe have been equalized. When such a stage is reached no further activities including mechanical and biological can be carried out. 

On the other hand, biological systems are open systems that will become more and more orderly in the opposite direction at the expense of their environment with which they interact. When living organisms grow, they consume fuel in the form of food and create wastes in the process. Even for plants that undergo photosynthesis, they draw their energy from the sun's nuclear furnace. When the sun's energy runs out all biological systems will die out as well. In the meantime, the irreversibility in biochemical reactions prevent the complex structures in living organisms from reverting back to their original primitive states. Thus, irreversibility “ brings order out of chaos “ that characterise the nature of the original randomly arranged atoms before complexity sets in and before the emergence of life which is composed of atoms. There is, in fact, no paradox between life and the Second Law. As Bertrand Russell once said :- “Paradox is truth standing on its head vying for attention.” 

Through Prigogine's insights scientists have acquired a better grasp of the principles governing the emergence of life. Since the publication of Prigogine's Theory on Dissipative Systems, other scientists have resorted to mathematical modelling to simulate the conditions necessary for life to develop spontaneously. Although no definitive conclusion can be reached to solve the enigma of life's origin yet mathematical models have been able to provide some theoretical basis for testing different likely candidate theories for the origin of life. With the aid of ever improving computer technology, more input factors can be fed into the various models as initial conditions so that the results will be more realistic and sophisticated. Even more advanced nonlinear models with more feedback loops do not pose any challenge to ever increasing computer power.