  The concept of the evolutionary sequence of jetted active galactic nuclei
(AGNs) has been challenged in the last few decades since AGN subclasses are
considered to be different due to their viewing angle. In this paper, we
collected a sample of 1108 blazars (472 flat-spectrum radio quasars, FSRQs and
636 BL Lacertae objects, BL Lacs) and 120 Seyfert galaxies (SGs) with available
redshifts and spectral properties in radio, optical, X-ray, and gamma-ray bands
in order to compare the properties of SGs and the blazar subclasses and also
explore their possible unification through evolution. It is found that the
ratio of the relative difference of SGs and the blazar subclasses are
approximately the same implying that they have an evolutionary relationship. We
discovered from the results of a two-dimensional Kolmogorov-Smirnov (K.S.)
test, that the probabilities (p) for the composite spectral indices:
optical-X-ray radio-X-ray radio-optical and X-ray-gamma-ray to come from the
same parent population is p, less than 0.05, implying that the null hypothesis
cannot be rejected, thus, supports SGs-BL Lacs-FSRQs evolutionary
sequence................. These results agree with the prediction that SGs have
an evolutionary relationship with the blazar subclasses.
