Devil Cat Ghost Cat Mountain Lion Screaming Cat Puma Florida Panther Cougar There are at least 50 common names for the animal shown on the previous 7 slides. Common names vary according to region. Soooowhy use a scientific name? Why are some kinds similar and others NOT similar? Question to be answered later? How can we make sense of (explain) this diversity? How can we organize what we know about these organisms? Early Efforts at Naming Organisms The first attempts at standard scientific names often described the physical characteristics of a species in great detail. Results in long names Difficult to standardize the names of organisms Different scientists described different characteristics. Answer: CLASSIFY! Similar types (species) grouped together, separated from other species. Then, group similar groups together, etc. The science of classifying organisms is called taxonomy. The father of modern taxonomy was Carolus Linnaeus (Carl von Linn). Why Do We Classify Organisms? Biologists group organisms to represent similarities and proposed relationships. Classification systems change with expanding knowledge about new and well-known organisms. Tacitus bellus Classification system organizes biological knowledge. Classification itself is HYPOTHESIS about relationships, similarity because of common ancestry. Leucaena leucocephala Lead tree Classification Binomial Nomenclature Two part name (Genus, species) Hierarchical Classification Seven Taxonomic Catagroies Systematics Study of the evolution of biological diversity Hierarchical Classification Taxonomic categories KingdomKing PhylumPhilip ClassCame OrderOver FamilyFor GenusGreen SpeciesSoup CLASSIFICATION = Sequence of levels. Linnaean system, from Carolus Linnaeus, 1740's Kingdom Phylum Class Order Family Genus Species King Phil called old fat George stupid. CLASSIFICATION = Linnaean system The 7 taxonomic categories Species - a group of organisms that breed with one another and produce fertile offspring. Genus - a group of closely related species. Family - genera that share many characteristics. Order - is a broad taxonomic category composed of similar families. Class - is composed of similar orders. Phylum- several different classes that share important characteristics. Kingdom - largest taxonomic group, consisting of closely related phyla CLASSIFICATION Whittakers Five Kingdoms, 1965 Kingdom Monera (Bacteria) Kingdom Protista Kingdom Fungi Kingdom Plantae Kingdom Animalia Woese, 1985 Prokaryotic organisms are far more diverse than thought previously. Domain Eubacteria (prokaryotic true bacteria) Domain Archaea (prokaryotic archaeans) Domain Eukarya (eukaryotic organisms) BacteriaArchaeaEukarya BacteriaArchaeaProtistaPlantaeFungiAnimalia MoneraProtistaPlantaeFungiAnimalia The three-domain system The six-kingdom system The traditional five-kingdom system Prokaryotic organisms are far more diverse than thought previously. Domain Eubacteria (prokaryotic true bacteria) Kingdom Gram-positive bacteria Kingdom Gram-negative bacteria Kingdom Mycoplasmas Kingdom Rickettsias Kingdom purple-sulfur bacteria and more Domain Archaea (prokaryotic archaeans) Domain Eukarya (eukaryotic organisms) Domain Eubacteria Prokaryotic organisms are far more diverse than thought previously. Domain Eubacteria ( prokaryotic true bacteria ) Domain Archaea ( prokaryotic archaeans ) Kingdom Thermophiles Kingdom Halophiles Kingdom Methanogens Kingdom ARMANS (Archeal Richmond Mine Acidophilic Nanoorganism Science vol 314, 22 Dec ) Domain Eukarya ( eukaryotic organisms ) Domain Archaea Prokaryotic organisms are far more diverse than thought previously. Domain Eubacteria ( prokaryotic true bacteria ) Domain Archaea ( prokaryotic archaeans ) Domain Eukarya ( eukaryotic organisms ) Kingdom Protista Kingdom Fungi Kingdom Plantae Kingdom Animalia Domain Eukarya Kingdom Protista Amoeba ParameciumGiardia Water MoldSlime Mold Euglena Dinoflagellates Diatom Brown AlgaeGreen Algae Kingdom Fungi Kingdom Plantae Bryophyte (Moss) Pteridophyte( Fern) Coniferophytes (Pine Trees) Angiosperm; Dicot Angiosperm; Monocot Kingdom Animalia DOMAIN KINGDOM CELL TYPE CELL STRUCTURES NUMBER OF CELLS MODE OF NUTRITION EXAMPLES Bacteria Eubacteria Prokaryote Cell walls with peptidoglycan Unicellular Autotroph or heterotroph Streptococcus, Escherichia coli Archaea Archaebacteria Prokaryote Cell walls without peptidoglycan Unicellular Autotroph or heterotroph Methanogens, halophiles Protista Eukaryote Cell walls of cellulose in some; some have chloroplasts Most unicellular; some colonial; some multicellular Autotroph or heterotroph Amoeba, Paramecium, slime molds, giant kelp Fungi Eukaryote Cell walls of chitin Most multicellular; some unicellular Heterotroph Mushrooms, yeasts Plantae Eukaryote Cell walls of cellulose; chloroplasts Multicellular Autotroph Mosses, ferns, flowering plants Animalia Eukaryote No cell walls or chloroplasts Multicellular Heterotroph Sponges, worms, insects, fishes, mammals Eukarya Classification of Living Things Key Characteristics of Kingdoms and Domains Go to Section: Section 18-3 are characterized by such as and differing which place them in which coincides with which place them in which is subdivided into Living Things Kingdom Eubacteria Kingdom Archaebacteria Eukaryotic cells Prokaryotic cells Important characteristics Cell wall structures Domain Eukarya Domain Bacteria Domain Archaea Kingdom Plantae Kingdom Protista Kingdom Fungi Kingdom Animalia Go to Section: Eubacteria Archaebacteria Protista Plantae Fungi Animalia Kingdoms Domain Kingdom Phylum Class Order Family Genus Species Did King Phil call old fat George stupid ? Carolus von Linnaeus ( ) Swedish scientist who laid the foundation for modern taxonomy Binomial Nomenclature Carolus von Linnaeus Two-word naming system Genus Noun, Capitalized, Underlined or Italicized Species Descriptive, Lower Case, Underlined or Italicized Ursus americanus American Black Bear Binomial Nomenclature: a two-name system First part of name: genus first letter always capitalized Second part of name: species first letter always lowercase Entire name is underlined and italicized Names must be submitted for acceptance by original discoverer, and are generally Latin or Latinized Canis domesticus Canis lupus Names are generally closely related organisms are often in the same genus, also giving clues about their names. Some names are given for the discoverer, or the discovery location, or even a Latinized descriptive term in English. Often Latin names contain clues about the type of organism being described. Systematics: Evolutionary Classification of Organisms Systematics is the study of the evolution of biological diversity, and combines data from the following areas. Fossil record Comparative homologies Cladistics Comparative sequencing of DNA/RNA among organisms Molecular clocks MammalsTurtlesLizards and Snakes CrocodilesBirdsMammalsTurtlesLizards and Snakes CrocodilesBirds CladogramPhylogenetic Tree Taxonomic Diagrams A phylogenetic tree is a family tree that shows a hypothesis about the evolutionary relationships thought to exist among groups of organisms. It does not show the actual evolutionary history of organisms. Why a hypothesis? Phylogenetic trees are usually based on a combination of these lines of evidence: Fossil record Morphology Embryological patterns of development Chromosomes and DNA Taxa show unique combinations of characteristics. For example, birds have feathers, beaks, and wings, and lay eggs, while mammals have hair, teeth, and give live birth. Cladistics - is a relatively new system of phylogenetics classification that uses shared derived characters to establish evolutionary relationships. A derived character is a feature that apparently evolved only within the group under consideration. Diagrams called cladograms are used to represent the phylogeny of organisms. A phylogenetic tree based on a cladistic analysis is called a cladogram. What derived character is shared by all the animals on the cladogram on the next slide? There are three basic assumptions in cladistics: 1.Organisms within a group are descended from a common ancestor. 2.There is a bifurcating pattern of cladogenesis. 3.Change in characteristics occurs in lineages over time. Cats are more similar to dogs than they are to frogs, because they share a more recent common ancestor with dogs TRADITIONAL CLASSIFICATION CLADOGRAM AppendagesConical Shells Crab Barnacle Limpet Crab Barnacle Limpet CrustaceansGastropod Molted exoskeleton Segmentation Tiny free-swimming larva Traditional Classification Versus Cladogram Birds Mammals Reptile Amphibian Fish Four Limbs Amniotic Egg Endothermic Fur Feathers Vertebrae Fish Amphibians Reptiles Birds Mammals Possible evolution of the Kingdom Animalia Modern Evolutionary Classification Molecular Clocks Comparisons of DNA can also be used to mark the passage of evolutionary time. A model known as a molecular clock uses DNA comparisons to estimate the length of time that two species have been evolving independently. Comparison reveals more DNA in common, the more recent the common ancestor Dichotomous Keys Identify Organisms Dichotomous keys versus evolutionary classification Dichotomous keys contain pairs of contrasting descriptions. After each description, the key directs the user to another pair of descriptions or identifies the organism. Example: 1.a) Is the leaf simple? Go to 2 b) Is the leaf compound? Go to 3 2.a) Are margins of the leaf jagged? Go to 4 b) Are margins of the leaf smooth? Go to 5