2 What is Classification? System to organize ALL living things into groups with biological meaning.Taxonomy: The study of classification.
3 Assigning a NameProblem: Common names can vary among languages. Common name is misleading. Descriptions are too long to be a name.ex: Mountain Lion or Puma or Cougarex: Starfish, dragonflyex:“Oak with deeply divided leaves that have no hairs on their undersides and no teeth around their edges.”Solution: Latinized and Greek words are commonly used to avoid any language issues. Reduce the number of words to a two part name.
4 Carolus Linnaeus Homo sapiens The Linnean system where each species has a 2 part (scientific) name:BIONOMIAL NOMENCLATUREgenusSpecies(Genus is 1st word, species is 2nd)Homo sapiensmeans “wise man”perhaps in a show of hope & optimism
5 Genus groupings Classify organisms into broader groups Species that are closely related are grouped into the same genusLeopard Panthera pardusAfrican lion Panthera leoTiger Panthera tigris
6 Classification System Linnaeus’ hierarchical system:Kingdom generalPhylumClassOrderFamilyGenusSpecies specificTaxons(Kings play chess on fine gold squares)
8 So…, classification sequence is now: Kingdoms and DomainsModern groups are six kingdoms: Eubacteria, Archaebacteria, Protista, Fungi, Plantae, AnimaliaDomains – newest, largest inclusive category developed from comparing r-RNA subunits. Bacteria, Archaea, EukaryaSo…, classification sequence is now:D, K, P, C, O, F, G, S
10 Bacteria & Archaebacteria EukaryoteProkaryoteClassification6 Kingdom systemProkaryotesNo separate organelles in their cellsBacteriaArchaebacteriaEukaryotesSeparate organelles in their cellsProtistsPlantsFungiAnimalsBacteria & Archaebacteria
11 Classification of Living Things Figure Key Characteristics of Kingdoms and DomainsTaxon CharacteristicsSection 18-3Classification of Living ThingsDOMAINKINGDOMCELL TYPECELL STRUCTURESNUMBER OF CELLSMODE OF NUTRITIONEXAMPLESBacteriaEubacteriaProkaryoteCell walls with peptidoglycanUnicellularAutotroph or heterotrophStreptococcus, Escherichia coliArchaeaArchaebacteriaProkaryoteCell walls without peptidoglycanUnicellularAutotroph or heterotrophMethanogens, halophilesProtistaEukaryoteCell walls of cellulose in some; some have chloroplastsMost unicellular; some colonial; some multicellularAutotroph or heterotrophAmoeba, Paramecium, slime molds, giant kelpFungiEukaryoteCell walls of chitinMost multicellular; some unicellularHeterotrophMushrooms, yeastsEukaryaPlantaeEukaryoteCell walls of cellulose; chloroplastsMulticellularAutotrophMosses, ferns, flowering plantsAnimaliaEukaryoteNo cell walls or chloroplastsMulticellularHeterotrophSponges, worms, insects, fishes, mammals
12 Organizing systems Making sense out of the differences Eastern gray squirrelSciurus carolinensis
13 Organizing the world of organsims The Tree of Lifeorganize creatures by structure & functionhow they are builthow they liveorganize them into groups of closely related creatures
14 Modern Classification Just using appearance is not enough.New system uses:1. Fossils2. Dissections/comparative anatomy3. Molecular similarities/DNA/enzymes4. Evolutionary similarities or developmental milestonesEx: amniotic sac, jaws, endothermic
15 CladisticsClassifying organisms according to the order that they diverged from a common ancestor.Ancestral characters – found in all groupsDerived characters – found in some groupsex: backbone is an ancestral trait found in all birds and mammalsex: hair is a derived trait found in only mammals
16 Vertebrate Cladogram What are the Derived Traits in this cladogram? What could the ancestral trait be?Which organisms share the trait of claws/nails?Which organism doesn’t have any of the traits?Which organisms are more closely related?Perch and pigeonPigeon and chimp