Procedure of evolutionary cephalization

Question

Using illustrations of invertebrate nervous systems how can the procedure of evolutionary cephalization be explained?

Answer 1

Considering the illustration of invertebrates it is examined that evolution makes the raising of the complexity of organisms to be accompanied by the convergence of nervous cells to special structures for commanding and controlling: the ganglia and brain. In simple invertebrates, such as cnidarians, the nervous cells are not concentrated however they are found scattered in the body. In platyhelminthes a starting of cephalization with the anterior ganglion concentrating neurons is already confirmed. In annelids and arthropods the presence of a cerebral ganglion is evident. In cephalopod molluscs the cephalization is even bigger and the brain commands the nervous system.