Chemoton

The chemoton is the minimal chemical model of an autopoietic system, proposed by the Hungarian theoretical biologist Tibor Gánti in 1971. It consists of three coupled subsystems: a metabolic cycle that produces the components of the system, a membrane boundary that separates the system from its environment, and an informational polymer that templates the reproduction of the metabolic cycle. The chemoton is not a claim about what actually existed on early Earth; it is a logical proof that life — understood as organizational closure — requires at minimum three mutually supporting cycles, not one.

The significance of the chemoton for origin of life research is that it reframes the question from 'which molecule came first?' to 'which organizational regime came first?'. The chemoton predicts that the transition from chemistry to life was not the invention of a single molecule but the coupling of three already-existing processes. This has direct implications for prebiotic chemistry: the search for life's origin should focus not on isolated reactions but on environments where metabolic, boundary, and templating chemistry could co-localize and co-evolve — such as submarine alkaline hydrothermal vents or mineral-rich tidal pools.