How prebiotic complexity increases through Darwinian evolution

Present-day life is amazingly diverse and complex owing to Darwinian evolution. Despite the simplicity of the principle of Darwinian evolution, the process and its outcomes are largely unpredictable. Evolutionary simulation and experiments are useful methods for gaining insights into the process and outcomes of Darwinian evolution. In this short review, we discuss recent progress in theoretical and experimental approaches to understanding the possible evolutionary processes of prebiotic self-replicators. We especially focus on research addressing how a prebiotic self-replicator increases complexity through evolution, including our recent experiments, in which a complex replication network consisting of multiple self-replicating molecules spontaneously evolved from a single replicating RNA.