The above theory could be tested by recreating in the laboratory on a small scale, the conditions which must have existed when life originated on the earth.
Miller, an American biologist subjected a gaseous mixture of methane, ammonia, water vapour and hydrogen in a closed flask at 80°C to electric sparking, foa week. This mixture, with its temperature, and electric discharge through it, represented a situation that might have prevailed on the earth before life came into existence. When the contents of the flask were examined a week later, theywere found to have amino acids which are essential for the formation of proteins. As we have said before, proteins are the essential building blocks for living organisms. With the making, in the laboratory, of molecules related to life, the credibility of the Oparin-Haldane theory of chemical evolution greatly increased. Many amino acids have been obtained, since by this method. So also some sugars and nitrogenous bases which are otherwise found in the nucleus of a cell, which is a unit of living organisms. Similar experiments have led to the production of various compounds which form many kinds of fats and important natural pigments. Miller's experiment thus forms a turning point in our approach to the problem of the origin of life. The evidence, we get from Miller's experiment, is supported by evidence of similar chemical reactions occurring in space even today. Chemical analysis of a meteorite which fell near Murchi Murchison in Australia, in 1969, shqwed the presence of organmolecules. The types and relative proportions of these molecules were very similar to the products formed in Miller's experiment. The presence of organic molecules like methane, ethane, formaldehyde, acetyle'ne etc. has been shown in interstellar space by radioastronomy also.