In my own lifetime I've seen the pendulum of scientific opinion swinging over wide ranges. I remember that some years back, each man was advised to drink over a two litres of water a day. Just recently I read the results of a scientific investigation that cautioned against excessive ingestion of water, and that the body automatically seeks water by feeling thirst whenever water is needed. The study also observed that the needs of water vary from person to person and there is no standardised rule that every person must compulsorily drink a specified quantity of water. Likewise some years ago coconut was considered to be quite a dangerous commodity to consume due to its cholestrol content and my nephew and neice scrupulously avoided it. Again I read recently that coconut is not in fact dangerous, and can be safely eaten. Well ! Scientific opinion can vary over wide ranges.
The situation can however become somewhat dangerous when the Weltanschauung (world view) of a majority of people is guided by opinions that may or may not be fully grounded in reality. The opinions of a majority of 'well-informed' people, who have their world view well grounded in modern science, dismiss the view that there is 'Intelligence' behind the workings of the cosmos. It is generally regarded by most people that all scientists base their opinions on cold logic brewed with healthy empirical evidences and that they do not have personal predelictions to bias their views one way or the other. As I have shown in the previous blogs there have been recorded instances to suggest that this assumption is without basis.
Most educated men have their world view derived mainly from what they have heard of Charles Darwin's 'Theory of Evolution'. While I too strongly affirm the overwhelming evidences in favour of the evolutionary theory which, in addition to biological evidences, drew a lot of strength from a host of geological evidences that were strongly promoted by Charles Lyell, I would also like to bring into people's consideration some of the problems in both the geological record and in the biological evidences.
Firstly, let me put forth evidences in support of evolution of life:
1. If there is a vertical stack of books, it is obvious that (in normal circumstances) the book at the bottom most level must have been placed the earliest and the succeding ones later and later till at the very top the latest book would have been kept. There could be exceptions of course and it could happen that a book could be inserted later somewhere in the middle, bu this is rather exceptional. A similar thing happens when beds of sedimentary rocks are laid down and this establishes a rule of the 'Order of Superposition' where the oldest beds in a normal sequence are the bottom most. In actuality in the field complications can arise due to folding and fracturing of rocks (faulting) when It can happen that an older bed may be found to overlie a younger bed, and in such cases the beds are reversed.
2. It is generally observed that the oldest rocks (established as older both by Order of Superposition and other evidences like radiometric dating) are generally without evidences of life. As one goes up in the geological stack one sees a progression from 'simple life forms' like single celled animals like bacteria, algae, and unicellular organisms and as one goes higher and higher he first finds invertebrates, and later vertebrates. The oldest vertebrates encountered are the fishes and later the amphibians and thence the reptiles and later the birds and lastly the mammals.
3. As of today (February 22nd 2012) no mammalian fossils have been found in, say, the rocks of the Devonian Period. And as of today, no human fossils have been found in the rocks of, say, the Eocene.
4. The Geologic Column constructed out of a combination of various evidences that include palaeontological (fossils), radiometric dating, structural evidences and petrological (study of rocks) is so compelling that to my mind there seems to be scarce possibilities of doubt.
To be continued ...
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