Decussatio pyramid and optical chiasm evolutionary process

From evolutive pattern of invertebrates and vertebrates some interesting peculiarities can be easily Observed and some change in environmental world colonized produced strange anatomic configurations.In example decussatio piramidy in motors system and the cervical vertebres tract .This kind of evolutionary process can be responsible of a sort of intrinsic weakness of a system to be Deeply investigate to produce new hypotesis in some spinal cord conditions.