1920s that the first cells in early Earth's oceans could be, in essence, coacervate droplets. Haldane used the term primordial soup to refer to the dilute mixture of organic molecules that could have built up as a result of reactions between inorganic building blocks such as ammonia, carbon dioxide and water, in presence of UV light as an energy source. Oparin proposed that simple building blocks with increasing complexity could organize locally, or self-assemble, to form protocells with living properties. He performed experiments based on Bungenberg de Jong's colloidal aggregates (coacervates) to encapsulate proteinoids and enzymes within protocells. Further work by chemists Sidney Fox, Kaoru Harada, Stanley Miller and Harold Urey further strengthened the theory that inorganic building blocks could increase in complexity and give rise to cell-like structures. The Oparin-Haldane hypothesis established the foundations of research on the chemistry of abiogenesis, but the lipid-world and RNA-world scenarios have gained more attention since the 1980s with the work of Morowitz, Luisi and Szostak. However, recently, there has been a rising interest in coacervates as protocells, resonating with current findings that reactions too slow or unlikely in aqueous solutions can be significantly favored in such membraneless compartments. See also Protocell Artificial cell References Colloidal chemistry Polymer chemistry Origin of life