Gunpreet, Subject Matter Expert at Edumarz
Answer: There are various theories regarding the evolution of life on earth such as Darwin’s theory of evolution and Mendel’s experiments. But no one can explain how life began on earth in the first place.
J.B.S. Haldane, a British scientist (in 1929) suggested the origin of life from simple inorganic molecules which were present on the primitive earth. According to him, these simple molecules could have given rise to more complex organic molecules and the first primitive organisms would arise from chemical synthesis. But this was speculation.
The evidence for the origin of life from inanimate matter was provided by Stanley L. Miller and Harold C. Urey with the help of an experiment, conducted in 1953.
They created an atmosphere similar to the primitive earth that consisted of molecules like ammonia, methane, and hydrogen sulphide, but no oxygen, over water. They maintained this environment at a temperature just below 100°C and sparks were passed through the mixture of gases to simulate lightning. After one week, 15% of the carbon from methane got converted to simple compounds of carbon including amino acids which are the basic unit of protein molecules. Protein molecules support life in basic form, thus it provides evidence of the origin of life from inanimate matter.
Miller and Urey Experiment