Section 17.2 Summary – pages 450-459 Phylogenetic Classification: Models The evolutionary history of a species is called its phylogeny (fy LAH juh nee). A classification system that shows the evolutionary history of species is a phylogenetic classification and reveals the evolutionary relationships of species. Section 17.2 Summary – pages 450-459

Section 17.2 Summary – pages 450-459 Cladistics One biological system of classification that is based on phylogeny is cladistics (kla DIHS tiks). Scientists who use cladistics assume that as groups of organisms diverge and evolve from a common ancestral group, they retain some unique inherited characteristics that taxonomists call derived traits. Section 17.2 Summary – pages 450-459

Cladograms

Using a Cladogram branches indicate development of new or significantly different traits groups that are closer together on the cladogram probably share a more recent common ancestor than groups that are farther apart.

Fan Diagrams do not show direct ancestry, just a probable sequence can show time line and numbers of organisms in related groups organisms that are closer in the same colored ray share more characteristics