Russian biochemist who developed one of the first modern theories about the origin of life on Earth.

Aleksandr Ivanovich Oparin studied plant physiology at Moscow State University and became a professor there in 1929. In 1935 he co-founded the Bakh Institute of Biochemistry in Moscow and was appointed its director in 1946.

The theory which in 1924 made Oparin famous concerns abiogenesis, the spontaneous generation of life from non-living chemical substances. Oparin believed that conditions on primitive Earth were different to those of the present. He suggested that the ancient seas were like a 'primeval soup' which contained many organic compounds. These were created when sunlight, a virtually limitless source of energy, reacted with chemicals in the water. These organic compounds formed the basis of life. They combined, becoming increasingly complex, until living cells were formed.

Oparin also conducted researched into enzymes and did much to provide a technical basis for industrial biochemistry in the USSR. His published works include The Origin of Life on Earth (1936).