Answer 1

 The theory of origin of life on earth was given by J.B.S. Haldane in 1929. He suggested that life must have evolved from the simple inorganic molecules such as ammonia, methane and hydrogen sulphide that were present on earth when it was formed. He said that conditions on earth at that time could have converted simple inorganic molecules into complex organic molecules necessary for life. These complex organic molecules must have combined together to form the first living organisms.