Is Entropy the driving force behind Life?

We all would be familiar with the second Law of Thermodynamics which simply put states that entropy of the system always increases with time. Entropy means the disorder in the system. Thus with the passage of time a system tends to loose its order and tends to go haywire. This is widely accepted and one of the laws of the universe and thus cannot be violated. Well one cannot violate the laws but can always bend it a bit to one's own advantage. Don't believe me, ask a lawyer. But I am not here to talk about lawyers. I talk about life.

One fine night, I walked on the roads of Bangalore, watching the traffic whiz by, in contemplative mood wondering how people were going about their lives in a hurry always wanting to go some place, always on the move and soon with passage of time they will die and fade away and new people will take their place and may be the hurry would be even more as technology would have advanced even more, we would be knowing more, would be living in better conditions and the pace of life would have become even faster. And as my thought process went on I realized life always ended, yet it always began and it always persisted. One word came to my mind, Entropy! How come Entropy is never able to catch up with life?

Consider an organism (be it unicellular or multi-cellular) as a unit of life. Now, organism as a whole be it unicellular or multi-cellular is a system having definite regulated boundary separating it from the environment. It exchanges energy and matter with the environment. As per the second law of thermodynamics, the system is suppose to disintegrate with time. That happens in case of an organism, the phenomenon we call aging (aging also has a relation with entropy as arrow of time which we will discuss later) and when the entropy is too high that it does not allow the normal life processes to function properly, the organism dies. So, the law of the universe prevails and everybody does not live happily ever after. But..

But before the organism dies it carries out an important process. It replicates (or reproduces in case of multi-cellular organisms). For maintaining simplicity of the explanation, we will consider only single cellular organism. So an organism divides into two. This division process happens after a certain period of time (ageing) and when the entropy of the cell has reached a certain level. The process of division reduces the entropy. Thus, one system with high entropy divides and gives rise to two systems with less entropy. So, the organism may "die" but the Life as a process goes on ad continuum. And this brings us to Evolution.

Evolution is nothing but a way or a method of Life to continue despite the changing environment. Remember, Life after all is nothing but a chemical system. And evolution happens by reproduction (or division of cells or whatever you want to call it that gives rise to new Life). So, to sum up Life continues by evolution and evolution happens by reproduction. So, we can safely assume that reproduction is a means of lowering entropy. But, at the same time reproduction is a means by which evolution happens. So, to put it together, evolution is a means of lowering entropy.

Come to think of it, evolution leads to a higher order in the life system (be it a cell or organism) i.e. it increases the efficiency of the system (cell or life). This in turn means lowering of randomness or entropy of the system. Hence, evolution leads to lowering of entropy, in other words evolution leads to survival. As discussed before, Life escapes from this second law of thermodynamics to 'SURVIVE', otherwise Life as any other chemical system will perish with time. Hence, for Life to survive means lowering of the entropy at a certain minimal level and reproducing is a means by which Life achieves this feat.

Now, entropy is also called the arrow of time because it is unidirectional in other words, irreversible. So, is Evolution as a recent study by University of Oregon researchers have found (appeared in Sep. 24, 2009 issue of Nature). Well, all of this shows that Entropy rather indirectly plays a very important role in Evolution and in other words continuation of Life. To put it spectacularly, Entropy is a force that drives Life although in an indirect way.

Well looks impossible isn't it? But all of this adds up. We need to take a look at the entropy level of a cell at various points thus establishing an entropy cycle of a cell. Well it is difficult at this point to calculate entropy of a whole cell but if found out can certainly give us key insight of functioning of Life.