Biological Evolution (Oparin)

About biological evolution, Oparin suggested that the giant molecules must have undergone various types of combination forming the complex masses, so called coacervates. The enzymes have developed before the cells. Gradually, the gene aggregates because surrounded by enzymes which formed the cytoplasm. These enzymes could have combined the nitrogen bases, simple sugar and phosphates into the nucleotides. Nucleotides might have combined to form DNA and RNA. The nucleoproteins marked the beginning of life. Some proteins and fatty acids organized around the coacervates to form the surface membrane (Plasma membrane). Some of its proteins differentiated into enzymes. These processes must have culminated in the origin of ever first living cell. Many of the biologists do believe that life originated in sea. The first cell like structure were called Eobionts or Pre cell. Oparin called them 'Protobionts'. These were perhaps similar to Mycoplasma which gave rise to Monerans (cells without a well defined nucleus) and protista (cell without distinct nucleus). The protista gave rise to Eukaryotes that evolved into protozoa, metazoan and metaphyta. Then came up the saprophytes, chemosynthesizers and finally the photosynthesizers. This provided plenty of free oxygen to the primitive atmosphere leading to the evolution of aerobic mode of respiration. It is to be noted that in geological time scale, the term million (106) years ago, appears meaningless to us, because it stands beyond our experience. That is why the geologists have devised a "speeded-up time scale," where 2000 years become equivalent to 1 minute. According to the time scale, it will be easy to remember as if: --The earth came up about 4.5 years ago—The first life on the earth began about 3 years ago—The Paleozoic began about 6.5 months ago—The dinosaurs become extinct about half a day ago—The man's written history began about 2 minutes ago, and Historically, Columbus discovered America about 14 second ago.