Experimental Models on the Prebiotic Formation of Biopolymer Building Blocks.

The scientific study of the origins of life is a deep pursuit that exists at the intersection of multiple disciplines. Prebiotic chemistry focuses on understanding how biopolymer building blocks such as amino acids, nucleotides, and sugars emerged and how their chemical and structural space evolves toward life (chemical evolution). Simulation experiments have been essential for exploring plausible pathways for the origin of building blocks under early Earth conditions and planetary environments. Key examples include the seminal Miller-Urey experiment and the polymerization of hydrogen cyanide. Research highlights the role of environmental cycles and geochemistry in shaping the prebiotic chemical space. These processes facilitated the condensation and stabilization of biopolymer precursors, particularly in terrestrial or small-pond scenarios. Noncanonical building blocks, including triazines and alternative amino acids, may have contributed to proto-biopolymer formation. This expands our understanding of chemical evolution. Despite significant progress, challenges remain, particularly in understanding nucleoside formation and the transition to modern biopolymers. This review provides a general overview of the prebiotic formation of biopolymer building blocks and examines both classic and seminal experiments and recent experimental approaches. Insights provided by extraterrestrial samples, such as carbonaceous meteorites and asteroids, also contribute to offering a comprehensive perspective on abiogenesis.