Sunday, 24 July 2011

Evolution - Are we there yet!



         The earth is estimated to be 4.5 billion years old. The planet was a very different place from the one we know today. The atmosphere was too hot for oxygen, nitrogen and other elements to exist separately as they do today. These elements combined to form methane, ammonia, water vapor, hydrogen molecules, etc. According to Alexander Oparin (1894-1980), a Russian biochemist, these were the raw materials for the evolution of life. As there was no oxygen to form the ozone layer, the earths surface was exposed to the harsh ultra-violet radiation waves of the sun. Furthermore, incredibly violent electrical storms pervaded the atmosphere, unlike anything seen today.
         Under these early conditions, the first organic molecules were created, the most important of which were amino acids. These amino acids were the building blocks of life. After these compounds had been forged on early earth during a period of intense volcanic activity and an electromagnetic atmosphere, the earth began to cool down. The water vapors condensed, creating the oceans, lakes and rivers, in which simple organic molecules began to accumulate for millions of years, producing an "organic soup" of sorts. This mixture washed up on the clay and rocky shores (some of which are known to be off the Canadian and western Australian coastline), where water evaporated leaving behind concentrated organic compounds in high heat.
       



         Although not clear, it is believed that a group of organic molecules formed into droplets, or bubble like structures, which would eventually evolve into the first true cell. These primordial cells would have been autotrophs, which are organisms which produce their own energy, usually from sunlight. Some of these cells would evolve into heterotrophs (organisms which ingest organic material as a nutrient source). We would not be here today were it not for this important evolutionary episode. In this sense, each person is a supreme individual endowed with those qualities, that distinguished the human being from the slime from which he emerged.


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