How do ontogeny, morphology, and physiology of sensory systems constrain and direct the evolution of amphibians?

The evolutionary success of extant amphibians is accompanied by secondary simplification of sense organs and of the nervous system. Strong morphological reduction is found in the lateral line system and in the auditory and visual systems. There is a close correspondence between the degree of secondary simplification on the one hand and genome size (DNA content) and cell size on the other. This process may be the major cause of the observed secondary simplification. -from Authors