What are the main provisions of the natural science theory of the origin of life of the biochemist A.I. Oparin?

According to this theory, life arose in the specific conditions of the ancient Earth, and is considered by Oparin as a natural result of the chemical evolution of carbon compounds in the Universe. According to Oparin, the process that led to the emergence of life on Earth can be divided into three stages:
1 the emergence of organic substances, the formation of biopolymers from simpler organic substances (proteins, nucleic acids, polysaccharides, lipids, etc.);
3 the emergence of primitive self-reproducing organisms (protobionts) 2, 3, 1 chemical stage – abiogenic synthesis of organic monomers.
2 prebiological appearance of protobiopolymers (coacervates) capable of metabolism and self-reproduction.