Before shedding light on how life originated on Earth, it is important to know exactly, how ancient humans viewed nature. If we think a little deeper, we will see that the human beings at that time used to look at any worldly phenomenon with extreme amazement and what seems to be a common natural phenomenon to us today, that time, it seemed to be an uncommon miracle. That is, the tendency to believe in miracles or super-naturalism has been ingrained in human nature since ancient times. As a result, over centuries, the issue of the origin of first life on earth has never become a major question for a larger section of human society.
Then, as it turned out, that we lost a lot of valuable time and finally, began to start thinking about the emergence of the first life on earth between the seventeenth and eighteenth centuries, but there also, had to face a great deal of opposition from most powerful group of theists, due to their specific belief of supernatural creator & vitalism etc.
Not that, no one at that time thought of anything new, but rather, some wonderful theories or hypotheses, and inventions, inspiring people to search for the source of life, to replace the alternative perspectives of conventional supernatural thinking. So, in the interval of that time, we saw the simultaneous discovery of the first microscope in the seventeenth century, as well as the discovery of animal cells, which, of course, had to wait until the nineteenth century to be recognized. Then at the same time, one by one, scientists discovered the presence of urea in the urine of human body, and Shortly afterwards, in 1828, the scientist Frederick Wohler synthesized urea of human urine, using common inorganic substance found in nature, which, unfolded the actual truth, before us, that, common inorganic elements in nature are the only main source of all the essential organic compounds suitable for the creation of life.
Thus, one thing became clear like water, that the first life on earth was not created miraculously by a supernatural creator, rather, it could be termed as a strange natural process cycle, which, being, started on earth at about 3.5 billion years ago, through several mutual chemical reactions amongst ordinary inorganic elements, in an extraordinary environment of nature.
By that period, in 1859 Charles Darwin’s Evolution theory “On the origin of species”, presented a new concept, that, how after origination of first life on earth from last primordial common ancestor, the species evolved themseleves through the principle of natural selection, by reproducing grdually from generation to generation, and afterwards in 1865, Gregor Johann Mendel also made an another brekthrough in biology, by presenting his famous principle of inheritance. Thus in due course, it became a big subject of inspiration to other rationalists also.
Within a short period of time, a tremendous conceptual flow propagated throughout the whole world and since, entire 19th to 20th century, we saw one by one, Halden & Operin's hypothesis, about how first cell took birth in primordial soup, concept of genetic materials inside tiny cell , DNA, RNA & its replication procedure and so on.
Finally, till the year 2016, all research results altogether gave authentic logical evidence through laboratory verification and ultimately, we at least came to know that, life on earth descended out of one primordial organism cell and they were our last universal common ancestor, bacterium.
In my above discussion, I basically explained the innumerable struggle of scientists against most powerful orthodox theists of those days, only to establish their findings about the origin of life on earth. However, at last we have seen the victory of rationalism and discovered the almighty nature in a new perspective, of a source of all creations throughout entire universe.
In the next page, I will try to focus on little bit idea of microbes, blood cells, our immunity etc. and their direct as well as indirect role in human health.
