Abstract
Evolution proceeds in phases, alternatingly convergent and divergent. During the divergent phases, many variants of an evolutionary system arise, and in the convergent phases, these are brought together in a new, higher unity, which in turn varies, and so on. Thus the mechanism of evolution is trialistic, proceeding according to the Hegelian principle (in the widest sense) of thesis, antithesis and synthesis. This mechanism is at the same time mirrored in the structure of the evolving systems, being most clearly expressed in the derivation of periodic systems of the individual levels of evolution. These relationships will be discussed using examples from symbiosis research, population dynamics and biogenesis.