Advancement of the TI concept: defining the origin-of-life stages based on the succession of a bacterial cell exit from anabiosis

Abstract

<abstract> <p>Now there is a huge variety of scenarios of prebiotic chemical evolution, culminating in the emergence of life on Earth, which demonstrates the obvious insufficiency of existing criteria for a reliable consideration of this process. This article develops the concept of thermodynamic inversion (TI concept) according to which the real succession of the formation of metabolism during the origin of life is fixed in the stages of the exit of a resting bacterial cell from anabiosis (suspended animation), just as the succession of events of phylogenesis is fixed in ontogenesis. The deepest phase of anabiosis considers by us as an intermediate state of a microorganism between non-life and life: it is no longer able to counteract the increase in entropy, but retains structural memory of the previous living state. According to the TI concept, the intermediate state between non-life and life thermodynamically corresponds to the approximate equality of the total contributions of entropy and free energy in prebiotic systems (S<sub>c</sub> ≈ FE<sub>c</sub>). Considering such intermediate state in prebiotic systems and microorganisms as a starting point, the authors use the experimentally recorded stages of restoring the metabolic process when a resting (dormant) bacterial cell emerges from anabiosis as a guideline for identifying the sequence of metabolism origin in prebiotic systems. According to the TI concept, life originated in a pulsating updraft of hydrothermal fluid. It included four stages. 1) Self-assembly of a cluster of organic microsystems (complex liposomes). 2) Activation (formation of protocells): appearance in the microsystems a weak energy-giving process of respiration due to redox reactions; local watering in the membrane. 3) Initiation (formation of living subcells): formation of a non-enzymatic antioxidant system; dawning of the protein-synthesizing apparatus. 4) Growth (formation of living cells—progenotes): arising of the growth cell cycle; formation of the genetic apparatus.</p> </abstract>