Basics of Biology

Biology and Life

What was the Oparin-Haldane hypothesis?

In the 1920s, while working independently, Russian biochemist Aleksandr Oparin (1894–1980) and British geneticist and biochemist John Burdon Sanderson Haldane (1892–1964) both proposed scenarios for the “prebiotic” conditions on Earth (the conditions that would have allowed organic life to evolve). Although they differed on details, both models described an early Earth with an atmosphere containing ammonia and water vapor. Both also surmised that the assemblage of organic molecules began in the atmosphere and then moved into the seas. The Oparin-Haldane model includes the idea that organic molecules—including amino acids and nucleotides—were synthesized without living cells (or abiotically); then the organic building blocks in the prebiotic soup were assembled into polymers of proteins and nucleic acids; and finally, the biological polymers were assembled into self-replicating organisms that fed on the existing organic molecules. (For more about nucleic acids, see the chapter “DNA, RNA, Chromosomes, and Genes.”)


This is a web preview of the "The Handy Biology Answer Book" app. Many features only work on your mobile device. If you like what you see, we hope you will consider buying. Get the App