TAXONOMY SBI3U A Good Classification 1. It groups together all things that are similar. 2. It excludes all things that are dissimilar. 3. It serves a function. TAXONOMY IS… the science of discovering naming describing classifying organisms DISCOVERING Danionella dracula Discovered in Burma Documented 2009 © Ralf Britz | Natural History Museum, London The discovery of new organisms is the first step of taxonomy. Every year, new discoveries are made throughout the world, as taxonomists explore new areas, or new tools become avail- able for analyzing specimens. TA X O N O M Y IS Electrolux addisoni (Compagno & Heemstra, 2007) Not your average vacuum cleaner! What’s in a name? A scientific name is the passport by which all organisms are known. NAMING TA X O N O M Y Photo: Phil Heemstra | Wikimedia Commons DESCRIBING Part of this process involves the comparison to related organisms to confirm if the species is new. TA X O N O M Y IS CLASSIFYING X O N O M Y IS LINNAEUS If you do not know the names of things, the knowledge of them is useless Critica Botanica 1737 Carl von Linné (or Linnaeus), the “father of taxonomy”, laid the foundations for the modern scheme of nomenclature - the discipline of naming species. N A M ES M A TT ER Linnaeus gave classification the consistency and precision we need when we describe bio- diversity, trade commodities, buy seeds for farming, manage pests, or deal with any other of the many areas in which humans need taxonomic knowledge. Carl von Linné, 1707-1778 Drawing: AMNH Library Carolus Linnaeus • Described organisms with two word names • Developed binomial nomenclature • First word = genus name • Second word = species name Modern classification is based on the 18th century work of Carolus Linneaus • Organisms are assigned to groups called “taxa” (sing. “taxon”) • Taxa are hierarchically arranged • Each subsequent taxon contains fewer species than the preceding taxon • Only members of “species”, the smallest taxon, are able to produce fertile offspring Why binomial nomenclature? • Much easier than a 10+ word name under old “polynomial system” • Same name no maFer where you go • Less confusion • Binomial = SCIENTIFIC NAME What is a species anyway? • Biological species concept –A group of actually or potenLally breeding natural groups that are reproducLvely isolated from other groups. » Ernst Mayr, 1924 ScienLfic Names You May be familiar with • Homo sapiens • Canis lupus • Felis domes0cus All organisms classified in a hierarchy • Kingdom (broadest) • Phylum • Class • Order • Family • Genus • Species (most specific) ↓KINGDOM ↓ PHYLUM ↓ CLASS ↓ ORDER ↓ FAMILY ↓ GENUS ↓ SPECIES ↓ ANIMALIA ↓ CHORDATA ↓ MAMMALIA ↓ CARNIVORA ↓ ODOBENIDAE ↓ ODOBENUS ↓ Dichotomous Key… ØBiological key ØA series of branching two-part statements used to identify organisms (or objects) ØEach step offers two mutually exclusive options designed to divide one group of organisms into two smaller groups ØCan be used to identify organisms using visual information alone Characteristics – organized either: A)Spider Key à similar to a tree diagram List Structure