The Algae and Their (Imperfect!) Classifications

The classification of algae—historically based on pigments, food reserve materials, and morphology under light microscopy—has long been in a state of debate and flux. Scientific classifications are highly technical and precise, and at the same time very messy. Taxonomists frequently recategorize species based on new knowledge—especially so now that more and more molecular data are being amassed. By getting a sense of the relationships between, and differences among, major taxonomic groups, the hope is that it may be easier to understand how physiological responses of these different groups relate.