Classification 1 Species of Organisms •There are 13 billion known species of organisms •This is only 5% of all organisms that ever lived!!!!! •New organisms are still being found and identified 2 What is Classification? Classification is the arrangement of organisms into orderly groups based on their similarities Classification is also known as taxonomy Taxonomists are scientists that identify & name organisms 3 Benefits of Classifying •organisms Accurately & uniformly names •starfish Prevents misnomers such as & jellyfish that aren't really fish Uses same language (Latin or some Greek) for all names • Sea”horse”?? 4 Confusion in Using Different Languages for Names 5 Latin Names are Understood by all Taxonomists 6 Early Taxonomists •2000 years ago, Aristotle was the first taxonomist Aristotle divided organisms into plants & animals He subdivided them by their habitat ---land, sea, or air dwellers • • 7 Early Taxonomists •John Ray, a botanist, was the first to use Latin for naming His names were very long descriptions telling everything about the plant • 8 Carolus Linnaeus 1707 – 1778 • 18th century taxonomist • Classified • organisms by their structure Developed naming system still used today 9 Carolus Linnaeus •Called the “Father of Taxonomy” •Developed the modern system of naming known as binomial nomenclature Two-word name (Genus & species) • 10 Standardized Naming •Binomial nomenclature used •Genus species •Latin or Greek •Italicized in print •Capitalize genus, but NOT species •Underline when Turdus migratorius writing American Robin 11 Binomial Nomenclature Which TWO are more closely related? 12 Rules for Naming Organisms • The International Code for • • Binomial Nomenclature contains the rules for naming organisms All names must be approved by International Naming Congresses (International Zoological Congress) This prevents duplicated names 13 Classification Groups • Taxon ( taxa-plural) is a • • category into which related organisms are placed There is a hierarchy of groups (taxa) from broadest to most specific Domain, Kingdom, Phylum, Class, Order, Family, Genus, species 14 Hierarchy-Taxonomic Groups BROADEST TAXON Domain Kingdom Phylum (Division – used for plants) Class Order Family Genus Species Most Specific 15 Dumb King Phillip Came Over For Gooseberry Soup! 16 Domains • Broadest, most inclusive taxon • Three domains • Archaea and Bacteria are • unicellular prokaryotes (no nucleus or membrane-bound organelles) Eukarya are more complex and have a nucleus and membranebound organelles 17 ARCHAEA • Kingdom - ARCHAEBACTERIA • Probably the 1 cells to evolve • Live in HARSH environments • Found in: –Sewage Treatment Plants (Methanogens) –Thermal or Volcanic Vents (Thermophiles) –Hot Springs or Geysers that are acid –Very salty water (Dead Sea; st Great Salt Lake) - Halophiles 18 ARCHAEAN 19 BACTERIA • Kingdom - EUBACTERIA • Some may cause DISEASE • Found in ALL HABITATS except harsh ones • Important decomposers for environment • Commercially important in making cottage cheese, yogurt, buttermilk, etc. 20 Live in the intestines of animals 21 Domain Eukarya is Divided into Kingdoms •Protista (protozoans, algae…) •Fungi (mushrooms, yeasts …) •Plantae (multicellular plants) •Animalia (multicellular animals) 22 Protista •Most are unicellular •Some are multicellular •Some are autotrophic, while others are heterotrophic Aquatic Ex: Amoebas, paramecium, Euglena and Diatoms • • 23 • Multicellular, except yeast • Absorptive • • Fungi heterotrophs (digest food outside their body & then absorb it) Cell walls made of chitin Ex: mushrooms, yeast, black bread mold. 24 Plantae •Multicellular •Autotrophic •Absorb sunlight to make glucose – Photosynthesis Cell walls made of cellulose • 25 • Multicellular • Ingestive • • Animalia heterotrophs (consume food & digest it inside their bodies) Feed on plants or animals Ex; Reptiles, Amphibians, Aves, Mammals, Fish 26 Characteristics of Animals •Fish There is a great deal of diversity among the animals we call fish, but they all share certain things in common. All fish: -live in water -have fins -breathe through gills. •Amphibians Amphibians include the frogs, toads and salamanders. Amphibians: -have smooth or bumpy skin -are dependent on water for reproduction -can breathe with lungs or gills depending on the species, but all -an breathe through their skin. •Reptiles Reptiles include lizards, snakes, turtles and crocodilians (alligators, crocodiles and a couple others). They are characterized by: -having tough, dry, scaly skin -breathing with lungs -having eggs with a leathery eggshell that does not have to be laid -in water to survive (though some reptiles do not lay eggs and instead have -live births) -being ectothermic (cold-blooded). • Birds Birds have some fairly obvious common characteristics: -feathers -beaks -wings as well as some not so obvious characteristics, such as: -remarkably lightweight bones -being endothermic (warm-blooded). •Mammals Mammals are the group of vertebrates that includes humans, river otters and dolphins. The characteristics of mammals are they: -are endothermic (warm-blooded) -have hair -breathe air with lungs -give live births -produce milk 27 28 Taxons •Most genera contain a number of similar species •The genus Homo is an exception (only contains modern humans) Classification is based on evolutionary relationships • 29 30 Basis for Modern Taxonomy •Homologous structures (same structure, different function) Similar embryo development Molecular Similarity in DNA, RNA, or amino acid sequence of Proteins • • 31 Homologous Structures (BONES in the FORELIMBS) shows Similarities in mammals. 32 Similarities in Vertebrate Embryos 33 Cladogram Diagram showing how organisms are related based on shared, derived characteristics such as feathers, hair, or scales 34 Primate Cladogram 35 How are cladograms constructed? Organisms are grouped together based on their shared derived characteristics (trait modified from the ancestral trait). Cladogram construction Given a table of derived characters (traits), create a cladogram Step 1 – Create a Venn Diagram How many organisms are you comparing? This number will equal the number of circles in your Venn diagram. Now count the number of characters each organism has. This will be the order that you place the organisms in the Venn Diagram. Venn Diagram Placenta:Human Mammary glands: Kangaroo & Human Two pairs of limbs: Bullfrog, kangaroo & Human Vertebrae: Shark, bullfrog, kangaroo & humans Step Two – Convert the Venn Diagram into a Cladogram Kangaroo Bullfrog Shark Human Placenta Mammary Glands Two pairs of limbs Vertebrae Convert the Venn Diagram into a Cladogram Lizard Trout Human Earthworm Hair Legs Vertebrae copyright cmassengale 42 copyright cmassengale 43 Must do Data Table First Then VENN DIAGRAM and last construct CLADOGRAM copyright cmassengale 44 copyright cmassengale 45 Independent Practice Problems: copyright cmassengale 47 Dichotomous Keying •Used to identify organisms •Characteristics given in pairs •Read both characteristics and either go to another set of characteristics OR identify the organism 49 Example of Dichotomous Key 1a 1b 2a 2b 3a 3b 4a 4b Tentacles present – Go to 2 Tentacles absent – Go to 3 Eight Tentacles – Octopus More than 8 tentacles – 3 Tentacles hang down – go to 4 Tentacles upright–Sea Anemone Balloon-shaped body–Jellyfish Body NOT balloon-shaped - 5 50