COMPARATIVE PHYLOGENY. “It is a truism that the study of evolution requires a comparative approach. If we want to reconstruct and learn about extinct common ancestors, the study of one extant relative is not nearly enough. Evolutionary principles emerge only when we look at a plethora of forms in phylogenetic context.”
http://extavourlab.com/pdfs/papers/2016_Extavour_CurrOpGenetDev.pdf