電気化学で拓く宇宙における生命の起源

抄録

How and where did life on Earth originate? Did the life’s origin happen from a combination of a huge number of geological events that were specially and temporally separated from each other, or did it occur within a local environment through a series of chemical processes that were compatible with the conditions prevailing within the setting? One of the key sites to resolve these questions is deep-sea hydrothermal systems, where the emergence of protometabolism through sulfides-promoted abiotic CO₂ fixation has long been suggested to be the most plausible initial process toward the origin of life. However, geochemical mechanisms to harness the reductive power provided by hydrothermal systems remain to be elucidated. Here, this review introduces “geoelectrochemistry” as a general potent means to realize protometabolism at the vent–seawater interface in early ocean hydrothermal systems. Based on the relevant field, laboratory, and theoretical investigations of these systems, together with the latest astronomical observations of extraterrestrial planets/satellites, the fundamental nature of driver for life are discussed as a base to consider the ubiquity and similarity of life in Universe.