This book deals with general quantitative regularities of the alteration of evolutionary and reconstruction (critical) periods of development. An equation and a model of development are introduced which generalize a wide range of commonly accepted models, allowing the analysis of the characteristics of processes occurring on different structural levels of natural system organization. On the basis of this model, a hierarchy of critical constants has been established, applicable to, for example, geological history, cyclicity in the individual development of animals, structures of population and...