The Phylogenetic Evolution of the Nervous System: A Brief Review

Knowledge about the evolution of the nervous system is quite limited, because it is a tissue that is rarely preserved in fossil records. What is known about its evolution is based on the interpretation of the anatomy and molecular genetics of more recent groups. However, this interpretation is limited, given that today's animals are more derived. The aim of this study was to describe the evolution of the nervous system in terms of complexity. A bibliographical review of books and periodicals was carried out. It emerged that organisms from the earliest times onwards must constantly adjust to their environment in order to survive, and their neuronal communications called synapses are the basis of complex processes such as movement and learning. During evolution, the main changes in the level of complexity of the nervous system have been related to the number of neurons. More complex organisms, such as humans, have a greater number of neurons.