There is considerable variation in the application of names to this group and the vaious subgroups in the literature. There is still not full agreement as to how the chromist taxa are interrelated.
The Chromista appear to represent an independent evolutionary line that diverged from the same common ancestor as plants, fungi, and animals. It was for this reason that the new kingdom Chromista was proposed. The precise relationship of the chromists to the other eukaryotes is not yet known, but they appear to be part of the so-called "crown eukaryotes", which includes not only plants, animals, and fungi, but also Alveolates and possibly the red algae. There is some evidence that the Haptophyta may not belong to the Chromista. They lack several of the morphological and molecular characters common to this group, but we have included them here since no alternative relationships have been suggested.