Alexandr Oparin and the origin of life on Earth

In the long essay here examined, the Soviet biochemist A. Oparin elaborated and proposed in a coherent and exhaustive way the three main historical phases characterising the origin of life on Earth from an entirely inorganic environment: i) formation of simple organic molecules; ii) appearance of macromolecules interacting with an aqueous substrate so as to form primitively organised microstructures; iii) constitution of metabolically active protocells working as thermodynamically open system. On the whole, Oparin described a biochemical adventure marked by chemico-physics and natural selection, this latter working on microstructure. Oparin worked according to the canons of dialectic materialism applied to Nature by Friedrich Engels and did not give anything to divine and fantastic. He treated all questions biochemically and neglected Morgan's genetics: mitosis, chromosomes and genes were for Oparin conceptual, and then questionable, elements that he set up against the firm bases of biochemico-physics. In such context, proteins and enzymes were the dominant substances of life owing to their manifold activities. Oparin's book was translated into about fifty languages and was a decisive factor for the successive development of detailed experimental research. Even though dated, this book still shows interesting topics on which the specialists are working at the best of the current technology.