LIFESCI 1 Lecture Notes - Lecture 7: Paraphyly, Ingroups And Outgroups, Synapomorphy
Document Summary
As speciation occurs, evolutionary relationships unfold like a tree: on a phylogenetic tree: present day species = tips, last common ancestors = nodes. Phylogenetics: the study of evolutionary and genetic relationships among organisms, taxonomy (classification of organisms) Goal is to recognize and name groups of individuals as species. Group closely related species into more inclusive taxonomic groups. Kingdom phylum class order family genus species. Mnemonic: king phillip came over for good spaghetti: phylogenetics = discover pattern of evolutionary relatedness by comparing features. Features can be anatomy or molecular (called characters ) Phylogenetic tree = a hypothesis about evolutionary history. Sister groups = closest relatives if they share a common ancestor not shared by any other species or group. Closeness of relationship is determined by looking to see how recently 2 groups share a common ancestor. Main goal of phylogenetics = determining what sets of organisms are considered monophyletic groups.
