Oil and gas generation is a basic problem of geology and natural sciences, which is associated with energy resources as well as with the origination of life on the Earth. The evolution of hydrocarbons is controlled by the evolution of the biosphere and is an issue of phylogeny. Organic matter (OM) buried in sediments since the Early Precambrian consists mostly of phytoplankton, the main carrier of lipids producing hydrocarbons. Organic matter accumulates in marine sediments according to the law of periodicity. Middle Paleozoic fossilized OM is largely composed of zooplankton. Zooplanktonic OM, classified as sapropelites, had interfered with the process of oil and gas generation since its origin, e.g., tentaculites of the Domanik formation increased oil content. The inception of low-lipid macrophytes gave rise to introduction of humic OM into water bodies and formation of mixed-type OM. The larger the humic component in OM, the higher its gas potential. However, instead of replacing oil generation, enhanced gas generation had come on the scene since the Mesozoic, and their scales were approximately equal. The actual oil/gas ratio in sedimentary basins depends both on phylogenetic factors and on the evolution of each separate basin.