Comparative Vertebrate Neuroanatomy: Evolution and Adaptation

The evolution and elaboration of the nervous system has been a major factor in the success and diversification of backboned (vertebrate) animals and the potential for fastmoving large-brained predators is highlighted.

Abstract

The evolution and elaboration of the nervous system has been a major factor in the success and diversification of backboned (vertebrate) animals. An anthropocentric view focuses on increased cephalisation, important as it was to human evolution; but this is only one aspect of a multifacetted subject. Neural crest and ectodermal placodes are unique to vertebrates, and were crucial to the development of specialized sense organs. With the evolution of jaws and, roughly simultaneously, paired fins came the potential for fastmoving large-brained predators and the need for close integration of sensory information and motor-control mechanisms (for example, cerebellar development). In tetrapodal land animals, we see an elaboration in somatosensory, visual and auditory pathways to cope with the wider range of sensory information, as well as improved corticospinal pathways and integrative control areas (for example, the reticular formation).