ABSTRACT
The scientific goal of reconstructing a possible scenario that could have led to the first living systems on Earth still eludes researchers. They are nevertheless convinced that the transition from chemical compounds on the primordial Earth to life was an evolutionary process. This chapter aims to show the crucial role played by the evolutionary hypothesis of the origin of life in pursuit of a solution. This evolutionary hypothesis maintains that prebiotic evolution constituted in highly constrained physical and chemical processes that led to the emergence of infrastructural entities capable of gradually engaging in Darwinian evolution. A few theoretical and empirical representative case studies discussed here demonstrate the heuristic, fruitful value of the evolutionary hypothesis in origin-of-life research. The differences between the evaluation of an early and a late onset of natural selection and between possible evolutionary processes in these case studies are pointed out. Significantly, despite these differences, gene-first, metabolism-first, protometabolism as preparation for RNA, co-evolution of genes and metabolism, and system-first scenarios, all rely on prebiotic inorganic and organic catalysts and on physico-chemical selection processes in channeling the emergence of evolvable infrastructures and in their gradual evolution.
