Various endogenous and environmental challenges of homoiostasis have resulted in the evolution of apparently quite different mechanisms for the same or similar functions in individual representatives of the animal kingdom. One of the prominent achievements of comparative physiology over the last few decades has been the description of regula- tory features common to many studied species beyond the extreme diversity of their morphological forms. Delineation offunctional princi- ples universally applicable to the physiology and biochemistry of living systems became often possible through...