Chapter 18 Classification 18 1 Finding Order in

Chapter 18 Classification

18. 1 Finding Order in Diversity I. Assigning Scientific Names □ Common names confusing=varies w/lang & location □ Scientific name (latin) same worldwide The many names of Boletus edulis France: Cepe Puma Cougar Panther German y: Steinpilz United States: King Bolete England : Penny Bun Common names for a mountain lion: Poland: Borowik Finland: Herkkut atti Italy: Porcini Sweden: Stensop p Spanish : Rodelló n

□ Dichotomous key: guide to ID unknown org Ø Uses paired statements with alternate choices

A. Binomial Nomenclature: 1. Linneaus (Swedish botanist) developed 2. 2 -word naming system □ Genus species or Genus species □ Genus=type or group; species=unique description This poison arrow frog's scientific name, Dendrobates azureus, means blue tree-walker! B. Classifying species into larger groups The king vulture Sarcorhamphus papa has a scientific name that means "father or leader with a fleshy, curved beak. " 1. Systematics: organizing life into meaningful groups 2. Taxa: biological groupings

II. Linnaean Classification System A. Uses 7 hierarchical, ordered ranks-taxa 1. Largest to smallest: Kingdom, phylum, class, order, family, genus, species

B. Problems with Traditional Classification 1. Used visible similarities/differences (barnacles look like limpets but are more like crabs) 2. Today: use evolutionary relationships Barnacle: crustacea Crab: Crustacea Limpet: gastropod mollusk

18. 2 Modern Evolutionary Classification I. Evolutionary Classification □ Phylogeny: species grouped by evolutionary descent A. Common Ancestors: taxa groupings show relationships 1. Larger, more diverse taxa=more ancient common ancestor B. Clades-a monophyletic group: single common ancestor and all descendants (living & extinct)

II. Cladogram q Cladistic analysis shows specific traits branch from comm ancestor q Links groups showing evolutionary relationships A. Building Cladograms: branches (nodes) represent ancestral species splitting in 2 1. 2. Each node=last point species above line shared com ancestor Root of node=common ancestor of those more recent

B. C. D. E. Derived Characters: trait arising in most recent ancestor of lineage Losing Traits: tetrapods (4 limbs) include reptiles; snake still reptile Interpreting Cladogram: character positions reflects order they arose Clade vs Traditional grps: evol. links more accurate=clades connects all species back to original ancestor (dinosaurs/ birds/reptile)

III. DNA in Classfication A. Genes as Derived Characteristics 1. Gene homologies (similarities) determine evolutionry relationshps 2. Mutations=derived characteristisc 3. More recent commn ancestors = ↓ diffs in genes (more mutations in common) =>closer related

B. New Evolutionary Trees 1. DNA=more accurate evolutionary tree 2. American vulture looks like African vulture yet DNA & behavior more similar to stork (more recent comm ancestor) 3. Giant panda DNA more like bears; Red panda DNA more like racoons (Pandas now in different clades) African Vulture Amercan Vulture Giant Panda Raccoons Stork Red pandas Giant pandas Common Ancestor Bears Red Panda

18. 3 Kingdoms (6) & Domains(3) I. Changing Ideas about Kingdoms A. W/diversity of life: science moved from Linnaeus’s 2 kingdms to 5 B. Genetic data= bacteria Kingdom Monera divided into 2 C. Genome data=new taxonomic division: Domain (larger than kingdom); now have 3 □ “Protista”: so diverse, > than 1 comm ancestr=not true clade

II. The Tree of Life

A. Domain Bacteria 1. Kingdom Eubacteria 2. Characteristics: a) Unicellular b) Prokaryotic c) Thick Cell Wall □ Peptidoglycan d) Diverse (majority)

B. Domain Archaea 1. Kingdom Archaebacteria 2. Characteristics: a) b) c) d) Unicellular & anaerobic Prokaryotic Cell membranes contain unique lipids Extreme Env’t

C. Domain Eukarya w/4 Kingdoms 1. Kingdom Protista a) b) c) d) Paraphyletic group (more than 1 com ancestor) Plant-like, fungus-like, animal-like members Now at least 5 clades Most single celled 2. Kingdom Fungi a) b) c) d) Feed on dead/decaying org. Cell walls contain chitin Digest externally Most multicellular

3. Kingdom Plantae a) Autotrophic=Photosynthesis b) Cell Wall (cellulose) c) All plants are sister group to red algae (protist) 4. Kingdom Animalia a) Multicellular/hetero b) No Cell Wall/Motile