The struggle is evident in all living organisms from the simplest plants and animals to the most complex life form yet to evolve, man. It’s likely that this drive for survival began as simply favorable characteristics of early pre-life molecular species that allowed them to survive a bit longer than most in the hostile conditions existing in the young universe. Anything in the universe resembling an organized structure is subject to ultimate breakdown and dispersion of component particles. This is to achieve maximum entropy according to the third law of thermodynamics and everything is destined to eventually meet this fate. Living things die and decay, mountains are eroded, man made objects crumble and return to dust, stars eventually undergo thermonuclear disintegration and even the universe itself will all, sooner or later, fulfill the third law of thermodynamics.
We can only speculate about what sort of favorable characteristics occurred to endow DNA precursor chemical structures with some rudimentary enhanced survivor ability. In fact there may have been a succession of such occurrences before one took hold and eventually led to DNA. We’ll never really know the story of how DNA came about but it’s likely that it took place very slowly over the course of millions of years. Furthermore, we can only speculate about what further enhancements await this incredible chemistry millions of years in the future.
DNA is truly a miracle in that it has the ability to sidestep the third law of thermodynamics by renewing itself in successive generations. Individuals die out but the DNA code lives on in the progeny of each generation. The chemistry that led to DNA has, through trial and error, led to this ultimate process of survival.
Reproduction is not the only mode of survival being directed by DNA. Rather, survival is, perhaps, the strongest of what we call biologic drives. Nearly all aspects of human behavior can be traced back to the primary directive of DNA, to enhance survival. In the case of early man, obtaining food and shelter were essential for his survival. Today these same needs are expressed in the norms of essentially all cultures and even can be suggested by behavior falling outside the norms. For example, people are generally motivated to earn an ample supply of money. This ensures not only adequate food and shelter for the family but also an enhanced quality of life that, in turn, ought to aid in longevity, i.e. enhanced survival as a result of better medical care, regular exercise and better nutrition. Similarly, unethical, dishonest and outright criminal activities could also have the ultimate goal of enhanced survival in spite of being outside the bounds of accepted behavior. However, we can also look at lower animals and even plants to observe behaviors, instincts, reproductive patterns and tropisms that favor enhanced survival of the particular individual but, more importantly, the DNA.
Surely by now, you’ve picked up on my thought. It’s not the individual or any organism that is of prime importance here, it’s the DNA. DNA is the program (the software) that allows life to exist. For the physicist, life is defined as a biochemical system that is capable of temporarily maintaining itself in a state of negative entropy. DNA is the blueprint that brings about construction of such an organism with this capability. The organism is simply the vehicle that allows the DNA to replicate and be carried forward from one generation to the next. As individuals, we are slaves to our DNA. We will follow our DNA’s instructions, care for it throughout our lives and pass it on to continue its life from one generation to the next. We will die but our DNA lives on.
Understanding this relationship that we all have with our DNA can go a long way in explaining and understanding many aspects of human behavior – an excellent topic for future thoughts.