  The original hypothesis about Three-stage origin of life (TOL) on the Earth
is developed and discussed. The role of the temperature factor in life origin
is considered. It is supposed, that three stages of abiogenesis (DNA world, RNA
world and the Protein world) consistently followed each other during Darwinian
evolution. At the same time, the natural directional selection of the most
stable macromolecules and effective catalytic reactions took place. The
direction of this selection is related to action of the principle of
{\guillemotleft}Increasing Independence from the Environment{\guillemotright}
(IIE) and is caused by temperature evolution of the atmosphere of the Earth.
The direction of Anagenesis and inevitability of occurrence of genetic
mechanisms is discussed.
