Evolution is driven by the desire to reproduce. Thus, sex desire is the most powerful desire in a living being
Right from birth, our experience journey starts. All living beings and entities take birth to gain experience. This collective experience and knowledge then help in the evolutionary process of life in the universe.
Presently the highest form of life on this planet earth is a human being. Its experience episode starts from the moment the brain starts forming -- that happens in the womb even before birth.
Brain is an autonomous nervous system. The neurons need to be activated so that they can form neural pathways which leads to thought and memory formation. Thus, electrical and chemical signal needs to be flowing through them continuously for their survival; otherwise the neurons will get petrified and die. The electrical signal is triggered by the inputs from sense organs.
Neural pathways form memories and with time and constant repetition the memories become strong. This is the genesis of psychological knots.
These knots reduce the processing power of the brain. Therefore, a smaller number of memories allow increased availability of neurons so that the information processing is very fast and extensive.
This need for neurons to have continuous inputs gives rise to curiosity, experience episode and knowledge gain; if there is a desire in a being for experience, evolution will take place.
Thus, knowledge or gaining knowledge leads to evolution. This knowledge makes us do things and produce innovations for betterment of life. By soaking up information from sense organs we increase our knowledge. The primacy of sense organs therefore is supreme in life experience and hence evolution.
As we age, the memories and memory knots increase and thus the processing memory of the brain is reduced. Besides, the sensory organs also become less efficient so that the quality of information to the brain is reduced. This reduces the curiosity and the desire to gain new experience and leads to mental lethargy in old age.
With processing power of brain being reduced, the internal churning of memories does not produce new insights which could give joy and happiness.
With desire for learning becoming less, the desire to live is also reduced. That is the sign of depression and hallucination in old age. The interest can, however, be raised with immediate inputs received from sense organs. Thus, a change in scenery and other inputs like reminder of happy times keep the brain momentarily active.
So, what should be done? Obviously the most important thing is to keep the brain free from powerful memory knots so that its processing power is high. This can be done by thinking deeply on any thought for a long time or practicing Sanyam as Patanjali has stated. And this process must start when one is young and with less memory knots. By practicing Sanyam, the nimbleness of the brain is maintained throughout life since it has the ability to dissolve the memory knots.
In old age Sanyam can also be practised by thinking about pleasant thoughts or recalling happy memories. Thus, meeting friends, thinking about children, looking at old photographs can bring in happy memories back. With continuously dwelling on happy thoughts the psychological knots can be reduced.
Unfortunately, it is much easier to remember unhappy episodes than the happy ones because evolutionary process makes our brains to be ever ready for any eventualities and survival. Somehow traumatic events and their memories help us to do so.
But the big question remains. Why is there a desire to reproduce?
Darwin and scriptures
Evolution is driven by the desire to reproduce. Thus, sex desire is the most powerful desire in a living being. Darwin gave a beautiful theory of evolution and the forces driving it. But was silent on why there is a desire to reproduce.
Similarly, our ancient scriptures are also not clear about this. Though Patanjali states in his sutras that the desire to live is in us since time immemorial and that the object of getting experience is to serve the purpose of Atman.
Thus, a possible reason for evolution could be to increase knowledge. A thinking brain has the capability of acquiring knowledge and a large number of brains (billions and billions of them) increase the knowledge of universe and hence evolution. This knowledge remains in physical form and in knowledge space (KS).
However, I think a better reason for evolution could come from the big bang evolutionary theory. A small portion of our universe is visible; the rest is dark matter. It can be conjectured that the evolution will continue till all the dark matter is converted into the visible world.
This will need living beings to populate the new worlds and hence the desire to procreate and, in the process, increase the knowledge of the universe.
(The writer, an IIT and US-educated engineer, and a 2022 Padma Shri award winner, is Director, Nimbkar Agricultural Research Institute, Phaltan, Maharashtra. Views are personal. He can be reached at firstname.lastname@example.org)