The origin and spread of a cooperative replicase in a prebiotic chemical system

摘要: The origin of life requires the emergence a system autocatalytic polymers such as RNA. We consider trans-acting replicase that catalyses replication template (either copy itself or another sequence). Our model includes alternating plus/minus strand where only plus is catalyst. Prebiotic chemistry generates random sequences and allows for non-catalysed, template-directed synthesis new strands. These chemical reactions are insufficient to sustain replication, but they provide background in which first can arise. In well-mixed case, minimum value catalytic rate parameter k stable replicating state survives scales 1/f, f fraction catalysts. When catalysts rare (f→0), not any finite because replicases overrun by parasitic templates already present prebiotic system, additional parasites created mutation contrast, 2d spatial simulations, moderate with appropriate values local diffusion constant. calculate probability spread from single isolated This occurs range narrower than existing replicators stable. uses 'Two׳s Company' rules, two molecules on site may replicate, crowding when three one site. A mean-field theory presented predicts most important results model. emphasize spatially-localized stochastic transition between 'dead' controlled 'living' replication.