The suggested “Zn world” scenario identifies the geological conditions under
which photosynthesizing ZnS edifices of hydrothermal origin could emerge
and persist on primordial Earth, includes a mechanism of the transient storage
and utilization of solar light for the production of diverse organic compounds,
and identifies the driving forces and selective factors that could have
promoted the transition from the first simple, photostable polymers to more
complex living organisms.