The vertebrate forebrain subdivides into the telencephalon and the which includes the

Brain is a part of the central nervous system together with the spinal cord. It is divided into forebrain, midbrain and the hind brain. Forebrain in vertebrates consists of telencephalon and a posterior diencephalon, while the mid brain is the middle part of the brain that serves primarily the processing of data from the eyes and ears, and the hind brain in vertebrates consists of the metencephalon anteriorly and myelencephalon posteriorly. The main structures of Diencephalon includes the hypothalamus, thalamus, pineal gland and the posterior portion of the pituitary gland.

It is evolution, because we all have some of the same traits like eye color or shape or ears.