On what basis "new systematics" differ from classical systematics?

New systematics differs from classical systematics in:
(a) Morphological definition of species has given way
to biological cytology, physiology, biochemistry and ecology etc.
(b) Species are not fixed or static but highly dynamic.
© Species no longer occupy the central position in the
work of systematics, instead emphasis has shifted over sub-species and populations.
(d) Experimental variability is introduced to measure various parameters. Statistical data is compiled to know the scale of primitiveness, inter-relationships and advancements.