discuss briefly the origin and evolution of life in the earth.
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Scientists estimate that our planet, Earth, formed around 4600 million years ago. There are six major theories that have been put forward to explain the evolution of life and these are Special creation, spontaneous generation, catastrphism, cosmozoic, steady- state and chemical theory.
The most widely is chemical theory also called as modern theory. According to this theory Life originated from inanimate matter- This was first proposed by Alexander Oparin & J.B.S Haldane. According to Oparin & Haldane postulates- Some volcanic eruptions took place on primitive earth resulting in formation of water bodies with some reducing substances like hydrogen, ammonia, methane, water vapour etc at their bottom surface. These reducing substances favored the formation of some organic compounds known as coacervates. Coacervates are spherical droplets surrounded by tight skin of water molecule. They posses ability of adsorption & undergo chemical reactions by gaining energy from lightening /u-v radiation to form large sized organic compounds. These organic compounds become the possible precursors of cells. This Oparin -Haldane hypothesis was proved by Urey- Miller in 1953. They conducted an experiment in which they created an atmosphere containing CH4 , H2, H2O, and NH3 in a reaction vessel. Next, they ran a continuous electric current through the system, to simulate lightning, resulting in the production of several small organic molecules including urea, hydrogen cyanide, acetic acid and amino acids. These amino acids are the building blocks of proteins in living cells.
Hence, this shows that life originated from inanimate matter.
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The most widely is chemical theory also called as modern theory. According to this theory Life originated from inanimate matter- This was first proposed by Alexander Oparin & J.B.S Haldane. According to Oparin & Haldane postulates- Some volcanic eruptions took place on primitive earth resulting in formation of water bodies with some reducing substances like hydrogen, ammonia, methane, water vapour etc at their bottom surface. These reducing substances favored the formation of some organic compounds known as coacervates. Coacervates are spherical droplets surrounded by tight skin of water molecule. They posses ability of adsorption & undergo chemical reactions by gaining energy from lightening /u-v radiation to form large sized organic compounds. These organic compounds become the possible precursors of cells. This Oparin -Haldane hypothesis was proved by Urey- Miller in 1953. They conducted an experiment in which they created an atmosphere containing CH4 , H2, H2O, and NH3 in a reaction vessel. Next, they ran a continuous electric current through the system, to simulate lightning, resulting in the production of several small organic molecules including urea, hydrogen cyanide, acetic acid and amino acids. These amino acids are the building blocks of proteins in living cells.
Hence, this shows that life originated from inanimate matter.
HOPE THIS WILL HELP U ✌️ ✌️
♥️ PLEASE MARK AS BRAINLIST ♥️
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