Evolutionary cephalization

Question

With the examples of invertebrate nervous systems, how process of the evolutionary cephalization can be explained?

Answer 1

Taking the example of invertebrates it is generally observed that the evolution increases the complexity of organisms to be accompanied through the convergence of nervous cells to the special structures in order to control and command: the ganglia and the brain. Within the simple invertebrates, such as cnidarians, the nervous cells are generally not concentrated however, they are found dispersed within the body. In the platyhelminthes beginning of the cephalization with anterior ganglion concentrating neurons is previously verified. Within the arthropods and annelids existence of the cerebral ganglion is palpable. In the cephalopod molluscs, the cephalization is greater and the brain controls the nervous system.