It's anaerobic heterotrophic. According to the experiment and the evidence of primitive stratigraphic fossils, the "biological precursors" in the chemical evolution stage-spheres and microsomes-can survive only by directly absorbing organic matter. The most primitive prokaryotes also survive by devouring organic matter in the surrounding environment. The earliest autotrophs-photosynthetic bacteria, chemosynthetic bacteria and cyanobacteria-are all advanced prokaryotes and late species.