Cladistics

Cladistics is the hierarchical classification of species based on evolutionary ancestry. Cladistics is distinguished from other taxonomic classification systems because it focuses on evolution (rather than focusing on similarities between species), and because it places heavy emphasis on objective, quantitative analysis. Cladistics generates diagrams called cladograms that represent the evolutionary tree of life. DNA and RNA sequencing data are used in many important cladistic efforts. Computer programs are widely used in cladistics, due to the highly complex nature of cladogram-generation procedures. A major contributor to cladistics was the German entomologist Willi Hennig, who referred to it as phylogenetic systematics.