Rajinder ... I have read your article in depth. In this case I must agree with Lloyd but please don't think I am being negative. The article you cite reads from the late seventies, early eighties. These were genuine expressed thoughts of that time.
Much has changed in the understanding of DNA ... and in particular the more primitive RNA.
My opinion is as follows.
If we look at the timeline of the Earth for the last 4,550 million years it quickly becomes apparent that for 90% of that time life consisted of
slime.
The
fossil record shows (in the main part) compelling evidence that, we, and all other living things have evolved from slime. Further, that this has occured in the last 543 million years. There is no question of the odds against a monkey typing a shakespherian sonnet. It happened. When the odds are extremely high it is no longer true to conclude that it will NOT happen, but simply when, because it will happen.
If the odds are billions to one against, then after billions of attempts the right combination
WILL occur. For Slime, each cell living only for a moment with a unique 'fingerprint' of DNA, it took 4,000 million years before the first noticeable change occured. If you take the time to think of
how many cells lived and died and mutated in that period before a beneficial (natural positive selection) change occured then you will realise that even a monkey typing the bible would have been a quicker and better bet.
So now our question becomes much simpler. We no longer have to explain the complexity of life as we know it, all we have to do is ask how did slime occur ?
In effect the question becomes, could RNA (
http://en.wikipedia.org/wiki/RNA ), a sugar protein, become DNA, a sugar protein capable of supporting and sustaining a carbon and water based life form.
I believe it did and I could supply many proofs here but would not necessarily convince you and would make the post overlong.
The following is an extract from
http://www.pbs.org/wgbh/evolution/ch...bandwidth.html
Life's origins (3,850 mya)
Evidence preserved in rock layers in present-day Greenland tells us that life existed at least 3,850 million years ago (mya). While this helps us understand when life began, it doesn't explain how life began.
Scientists agree that certain conditions were needed for living cells to evolve from the gases and water thought to be present on the early Earth. These include a concentrated supply of organic chemicals, the most important of which was cyanide; energy to fuel reactions between these chemicals; protection from extreme heat; and some sort of biological catalysts to encourage the building of proteins and assist in reproduction.
One of the more compelling hypotheses offered to explain how living cells formed describes an "RNA world." It holds that chemical reactions sparked by the introduction of energy produced RNA (ribonucleic acid) sequences called ribozymes. Some of these ribozymes helped assemble proteins -- the workhorses of living cells. Other ribozymes helped RNA replicate itself. The primitive cells of this "RNA world," like cells today, probably had water-repellent outer membranes to hold together and protect their contents.
If life evolved near the planet's surface, ultraviolet radiation or lightning could have provided the vital spark. But if, as many scientists now think, it evolved underwater, heat generated by Earth itself -- like that found today in hydrothermal vents along volcanic ridges in the deep sea -- probably supplied the energy.
cool bananas ... greg