Contents:– Historical Background, Environment and Its Inhabitants, Grading Natural World, Life History Adaptation, Competition and Coexistence, Coevolution, Mutualism and Commensalism, Para-sitism, Predation, Herbivory, Evolutionary Adaptation, Environmental Variability, Sex and Adaptation, Molecular Ecosystem, Flow of Energy, Elemental Cycles, Regenerative Processes, Molecular Regulation, Molecular Evolution of Society.