ABSTRACT
Increasing complexity in behavior was related by A. S. Romer primarily to the development of locomotion and concomitant development of the sensory and nervous systems. The matter was treated specifically with regard to brains and behavior by Harry Jerison. Romer’s study dealt implicitly with rates of change but the matter was treated only in a very general sense. Basic to his analysis was the proposition that evolution in general had moved toward increased complexity. General morphology and behavior kept stride in the course of the increase. The relationship between structure and physiology of the nervous system and behavior can be treated definitively only by studies of living animals. Auditory, narial, pineal, and tactile sensory structures have left some evidence of changes, some well documented and others more obscure. The nervous and sensory changes considered together provide a framework within which the course and rates of changes from reptiles to mammals has occurred.
