It reminds me of the taxonomy of living things. The 8 levels (Domain, Kingdom, Phylum, ...) are useful at the top, but break down fairly quickly as we've learn

It reminds me of the taxonomy of living things. The 8 levels (Domain, Kingdom, Phylum, ...) are useful at the top, but break down fairly quickly as we've learned how complicated life really is. The last plant I looked up (Wisteria) doesn't really have a useful phylum or class classification, and has 7 non-mappable "clade" groups of which it is a member. They still teach the 8 levels though.