One of the biggest questions in science is how life first emerged on Earth. Researchers generally agree that the appearance of the first biopolymers and their building blocks marked a critical step in the origin of life (OoL). However, scientists still do not know exactly how a collection of prehistoric inert chemicals (gases) transformed into the first living systems.
The mystery remains difficult to solve because the full sequence of events that led to life is impossible to observe directly and extremely challenging to recreate. Over the past century, scientists have proposed numerous hypotheses, most of them centered on chemical evolution occurring either on Earth or in space. Yet each explanation has limitations, often relying on specific experimental findings and/or theoretical assumptions.
Several well known models have attempted to explain the (terrestrial) chemical OoL, including the Metabolism-first world (FeS world), Zinc world, Thioester world, RNA world, and Lipid world. While each provides valuable insights, none offers a complete explanation of how life emerged from nonliving matter. No single theory has successfully integrated all aspects of the process into a unified and convincing scenario.
