[The thermodynamic direction of biological evolution. The model and the reality]

A macrothermodynamic model of evolution of the supramolecular structures and chemical composition of living objects during ontogenesis and at long-term stages of general biological evolution is presented. A study of quasiclosed (thermodynamically and kinetically) systems, phases of the biomass supramolecular structures, enables a conclusion on the thermodynamic direction of biological evolution to be made. In correspondence with the second principle, this direction leads to variations in the chemical composition and structure of the living systems during their development. Indirect and direct evidence of the trend to a minimal Gibbs specific function of formation of the supramolecular structures in animal tissues during ontogenesis are presented. The conclusion that thermodynamics is the "driving force" of evolution of the biological world is confirmed.