Résumé
We propose a dynamic scenario for the emergence and evolution of peptides on the primitive Earth, through a molecular engine (the primary pump), which works at ambient temperature and continuously generates, elongates and complexifies sequential peptides. This new scenario is based on a cyclic chemical reaction sequence that could have taken place on tidal beaches; it requires a buffered ocean, emerged land and a nitrosating atmosphere. We show that the primitive Earth during the Hadean may have satisfied all of these requirements. This scenario is not necessarily what actually happened, but it represents a global approach of peptide prebiotic synthesis, and most of its parts are accessible to experiment. As it develops, it may open up a gateway to the emergence of homochirality and the catalytic activities of peptides.