Fig. 3.

Different modes of compartmentalization may have been involved in the evolution of life. Ordered from left to right based on their capacity to limit exchanges with the environment: 2D films, like adsorbed nucleic acids on clay or lipid lamellar phases; organic hydrogels such as those formed by high concentrations of nucleic acids; coacervates that phase separate from the bulk above critical concentrations of charged polymers; hollow coacervates, obtained from the previous assemblies under specific conditions; lipid membranes closed in a spherical shape, such as vesicles or liposomes.