Wednesday, July 19, 2017

A short history of life on earth: 

I. From atom to cell.

Long ago, after the origin of our planet, atoms decided to collaborate, because they were aware that alone is just alone and together they could reach more than alone. So they became unified in molecules. For the same reason, molecules decided to cooperate together and they were unified in macromolecules.
Amino acids e.g. did form societies, billions of years later called proteins by men. Nucleotides did form societies called nucleic acids by the same strange men, who called themselves biologists by the way. But let us return to ca. four billions of years earlier.
The macromolecules became larger and larger and at a certain moment, they decided to investigate whether they could find a way to replicate themselves, in order to avoid the continuous need to start again as atoms and to prevent the long inefficient and boring way to become unified in macromolecules. They became subsequently aware that collaboration between different types of macromolecules would be a necessary step on the way to attain this goal, since it was clear that specialisation and collaboration of differently specialised molecules would offer an extreme efficient approach on the way to progress. This was the beginning of life on earth.

Of course, you could ask: “Why do you talk about atoms and molecules in relation to awareness, deciding and thinking?” The answer is quite simple: “We - men - are constructed from atoms and molecules during evolution. Although thinking became gradually more important during evolution of life and the improved efficiency as a consequence of specialization and collaboration was obvious, there is no reason to draw artificial boundaries.
Actually - looking ahead to our time again - collaboration between atoms and molecules were the first steps on the way to globalization, a form of world wide collaboration between men, as it is nowadays called by both its advocates and its opponents.
Just as the history of life on earth, globalization in the world of men can only be stopped by other and stronger natural powers, simply because it is also part of nature. 
Also ca. 4 billions of years ago, there will have been a lot of atoms and molecules trying to disturb the inevitable collaborations by temporary interruptions of the most obvious processes. The forming of proteins by collaborating amino acids could be temporary hindered by small molecules interrupting the progress of their formation. But just as in case of globalisation in the present time, natural developments can never be stopped completely.
Returning to ca. 4 billions of years ago, the origin of life on our planet has not been unraveled up to now. Not surprising, if we realize that none of us was present in that period, in order to prepare a meticulous description what exactly did successively happen.
Theoretical questions, as those about the origin of life, are a hobby of men, dating from the time that they did no longer need to spend all of their time on collecting of food and fighting to become the fittest. However, as a consequence, they have to find out the past by themselves, based on palaeontology and experiments in laboratories.

What exactly was the first form of life on earth? This is a major issue for biologists to spend their time.
Viruses e.g. though they are relatively simple macromolecular constructs, are not able to replicate without the help of the cells in which they penetrate as parasites. 

Up to now, a unicellular structure is generally considered as the first form of life on earth. Attempts are being made to investigate whether such a structure might arise from molecules brought together under conditions that did exist on earth in the period of the origin of life. But up to now, no unicellular structure was found and certainly no people were found in a test tube.

Such a cell, maybe an amoeba, was at best only the beginning of life. A long evolutionary tree of life did finally produce a large number of successful species. Men are only one of these.

In the next blog, evolution of life on earth will be followed.

No comments:

Post a Comment