Use the noun phylogeny to describe the branch of biology that focuses on evolution and the differences between species.
You're most likely to come across the word phylogeny in a biology class. It's another term for "phylogenetics," the study of evolution, diversity, and the way different organisms and species are related to each other. The German biologist Ernst Heinrich Haeckel was the first to use the word phylogeny, in 1866, and Darwin used it soon after. It combines the Greek phylos, "race," with geneia, "origin."