Prispevek obravnava biodiverziteto kot zgodovinski pojav in produkt evolucije. Zavzema se za dosledno filogenetsko obravnavo pestrosti življenja na Zemlji. Opozarja, da marsikje še vedno prevladuje pojmovanje življenja v obliki premočrtnega niza od primitivnih do bolj popolnih oblik, in da pravilnejša alternativa – evolucijska zgodovina kot razvejeno drevo – še ni dobila svojega mesta v biološkem izobraževanju. Podane so osnove filogenetske sistematike in argumenti v prid uporabi naravnih skupin pri pedagoški in znanstveni obravnavi biodiverzitete.

In this paper, biodiversity is considered as a historical phenomenon and the result of evolutionary processes. It is argued that as such the diversity of life on Earth should always be analyzed in a consistently phylogenetic perspective. Further, the problem of persistent ladder-thinking in several biodiversity-related fields including biological education, is discussed. In order to facilitate tree-thinking, fundamentals of phylogenetic systematics are laid out. Based on examples from well-known taxonomic groups, the advantages of monophyletic over artificial groupings in both educational and scientific aspects of biodiversity are discussed.