Abstract:Primitive cells consisting of a self-replicating nucleic acid genome encapsulated within a self-replicating membrane would have depended upon a rich, complex and variable environment to drive their reproduction. I will describe simple and robust pathways for the coupled growth and division of primitive cell membranes composed of fatty acids and related single-chain amphiphiles. I will also discuss recent progress towards the efficient and accurate chemical replication of RNA. Chemical template-copying generally proceeds best at low temperatures, but strand separation requires transient exposure to high temperatures, which would also facilitate the entry of nutrients into primitive cells. Taken together, these chemical and physical considerations favor an origin of life scenario involving ponds or lakes in a geothermally active environment.