Life arises from non-life.
This is a rather a bold statement. But not so challenging. Many researchers
and scientists made great leap to
understand the reason for the wonderful lovely and fabulous play-station of life we have on earth. Not all succeeded, but surely all advanced.
We need to initially make clear the difference between evolution and origin of life. Darwin Theory of Evolution explain how so many variety of organism and species exist. Why do we have so many difference kinds of life-form. Ranging from trees to lion, man to rat, etc. So evolution is not the theory we need to look towards when we want to study how life exactly originated.
Succinctly speaking, evolution is just three things.
Survive, survive and survive. No matter what it take. The unit of evolution is
genes. This is a very important phenomenon and must be understood very keenly.
This unit of survival, the genes, wants it copies to propagate and survive. If
a particular individual fails to reproduce and deliver its offspring, he is so
sure to end his legacy there and there. His genes won’t play in the orchestra
of evolution. We all evolved from same ancestor. We all are cousin. Not me and
you, but you, me, the stray dog, the dolphins, Osama Bin Laden, Tom Cruise and
everyone. We all came from the same root. Such a beautiful reality.
Let me give you brief about the theory as to how life
originated on this planet. This theory is based on a process termed as Abiogenesis.
This process helps us understand how a non-living thing can turn into a living
this. In order to be called life, anything needs to qualify for three criteria
– grow, multiply and mutate. That what all life’s on this planet is all about.
Abiogenesis explains how this might have happen ‘chemically’
and thus forming this fuzzy cream of life. This process is not so complicated,
but rather difficult to explain. But let me push you done this. For life to be
formed we need to understand what it takes to make one. Speaking of protein,
oxygen, DNA would be useless here. All of these are the products of life,
rather than ingredient of life. So we
need to look on other planet and in the vastness of space to find out what all
material was already available. We found that organic material are quite common
everywhere. Secondly, we should accept
the fact that initial life has to be very simple. So no mitochondria, no DNA, no
nucleus, no ribosomes, etc.
Life started with simple fatty acid. The pre-biotic life
contained simple fatty acids. Under the action of pH, and constant cosmic
condition, these fatty acid formed vesicle, or a container. These containers
were permeable(permit able) to small organic molecule. So here we have a
container and some organic material in it (a very minute resemblance to modern
cell). Now when the vesicles, moving
around did encounter any free fatty acid, it used to take it inside itself. So
eventually, the size of vesicle started increasing. This is due to pure
thermodynamic process. It’s quite logical that if I go on increasing the
content, the size/volume would gradually increase. This process can be compared
to modern time eating and growing. Now
when the size of vesicle increased, it started to break apart due to natural
physical forces (winds, water, earthquake, rocks, etc.). Now when the division
occurs, no content of the vesicle are lost. It’s a pure conservative division. So here we have, just using natural process,
something which grows and divide. You can call it life right away, but it’s
better to wait rather some more lines to complete.
There are numerous nucleotides. DNA and RNA are made from nucleotide
(or at least, it plays important role in formation of DNA and RNA). In order to
form a nucleotide, all it takes takes to form one is self-polymerization. This
process of polymerization is chemical process. Monomer can self-replicate. It
is just a covalent hydrogen bond which they need to form. Now the vesicles can
only take-in monomer and not polymer (simply because polymer is bigger is size
than monomer). Once a monomer enters the
vesicle, and start polymerizing, it forms a polymer and now it cannot escape
from the vesicle. This is easy to understand. The entry to the vesicle is
confined by size. If the entry door size is 2*2, we cannot remove a package of
5*5. Now these polymers can be considered to separate itself from each other
(not from the vesicle). As a when more and more polymer enters the vesicle, the
size of vesicle increases. Now the
vesicle with more polymer will now start taking away lipids from the vesicle
having less polymer (again pure thermodynamic). It’s interesting that we have
found out competition among these vesicles. This is the origin of competition. A vesicle which contains monomer which can
replicate faster would grow and divide faster, eventually increasing in
number. Thus aroused (natural) selection.
Now it’s easy to know why Mutation + Natural Selection =
Increased Information. Thus we have
derived a rather beautiful and considerable explanation as to how the early
life originated. Once initial simple
life was created, evolution took the charge of setting up the drama of life of which
you and I are part. In billion and billion years of evolutionary times, some
trait of these polymers would have been selected, some getting rejected, just
to increase in size and number. That is what life is. I used to think this a
radical event. But now researcher claim that if we give enough time to any
planet (with all the resources and condition), life is bound to arise on it. On
some of it, life would have being created like a soap bubble and in a matter of
moment, disappeared never to come back. On some other planet, there might be
earth like habitat believing like we human do; that they are alone is this vast
cosmic arena. On some other planet, which would have been billion and billion
year older than earth, life would have born, survived and perish due to some
internal war, or rather a cosmic fight. We don’t know it yet, we want to know...
