The evolutionary unified scheme (Vagnetti et al., 1991; Vagnetti and Spera, 1994) is the first attempt to describe the radio source populations accounting at the same time for their cosmic evolution and their anisotropic phenomena. It achieves an interconnection between anisotropy and evolution through a changing balance between two optical components, an isotropic “thermal” one and a relativistic beam. It predicts an evolution of the radio-optical ratio, interpreted as a slow increase of the Lorentz factor with the cosmic time (Vagnetti et al., 1991). It also predicts a link between the high and low-power unified schemes, and in particular between high and low-redshift blazars, and between high and low-redshift radio galaxies.