Origins of Life: The Garakuta World

Abstract

Since the 1920s, a large number of studies have been conducted, and most monomers found in proteins and nucleic acids have been synthesized abiotically and/or detected in extraterrestrial bodies. However, the question of how the first life arose from non-living matter remains controversial. One popular theory is the RNA world hypothesis, but it still faces challenges in explaining how the first functional oligonucleotide formed abiotically. Alternative hypotheses propose that life may have arisen from simpler, less sophisticated molecules rather than complex ones like proteins or RNA. For instance, when a mixture of simple molecules (e.g., CO, N₂, and H₂O) is irradiated with high-energy particles, macromolecular organic compounds can form. These compounds, though containing some amino acid moieties, are largely uncharacterizable and have been referred to as "Garakuta molecules." Interestingly, Garakuta molecules exhibit some functional properties, such as esterase activity. This has led to the proposal of the Garakuta world hypothesis, suggesting that life could have emerged from these Garakuta molecules.