Taxonomy - Classification of Organisms

Aristotle is credited with the first true classification system Aristotle is credited with the first true classification system. He grouped all living things into two basic groups: plant and animal OR

Carolus Linnaeus – father of taxonomy Taxonomy – study of classification Developed system known as binomial nomenclature TWO name system First name is GENUS , second is SPECIES Ex. Humans – Homo sapiens GENUS name SPECIES name

Dog - Canis familiaris Wolf - Canis lupus Same GENUS…different SPECIES Notice the genus is capitalized but the species begins with a lower case letter! Both are italicized or underlined.

Loxosceles reclusa (Brown Recluse) This is the ‘scientific name’ -uses Latin because it is an unchanging language No chance for confusion – no nick names http://www.your-inner-voice.com/brownreclusespider.html Mugil cephalus - scientific name Nicknames - striped mullet, black mullet, sea mullet, flathead mullet, and gray mullet

7 levels of organization In taxonomy there are 7 levels of organization Kingdom BIGGEST Phylum Class Order Family Genus Species smallest King Phillip Came Over For Green Soup MOST GENERAL Can INTERBREED

Grass pickerel & Muskellunge Try this! Which of the organisms in the chart are most closely related? WHY? Grass pickerel & Muskellunge They belong to the same GENUS

Circle the two organisms that are most closely related? Taxon House Cat Mountain Lion Dog Human Kingdom Animalia Phylum Chordata Class Mammalia Order Carnivoria Primates Family Felidae Canidae Hominidae Genus Felis Canis Homo Species domesticus concolor familiaris sapiens

Which level is the most general? The most specific? At what taxonomic level do the dog and human become different? What is the family name of the dog? Which organism is most closely related to the wolf? What is the scientific name of the wolf? A genus is composed of a number of related? A group of related phyla are? Which taxon contains the largest # of organisms?

6 Kingdoms of Life Archaebacteria Eubacteria Protists Fungi Plants Animals

Characteristics of the Six Kingdoms

Dichotomous Keys A tool that uses a series of paired statements and the visible characteristics of the organism.

1. Always start at statement 1 (or the beginning point) 2. Decide which path best describes the organism (Statement A or Statement B) 3. Follow that path to find the next choice (Go to …) 4. When you can go no further, you will find the name!

Practice

1. 4. 2. 5. 3.

Taxonomic Diagrams Phylogenetic Tree Cladogram Taxonomic Diagrams Mammals Turtles Lizards and Snakes Crocodiles Birds Mammals Turtles Lizards and Snakes Crocodiles Birds Taxonomic Diagrams Sometimes, biologists group organisms into categories that represent common ancestries, not just physical similarities. Early naturalists used physical characteristics and later, fossil data, attempting to represent evolutionary relationships among organisms. Today, modern classification systems use fossil data, physical characteristics and DNA/RNA information to draw increasingly more accurate branching diagrams. Phylogenetic trees, or phylogenies, represent hypothesized evolutionary relationships among organisms and may include extinct as well as modern species. Cladograms are based only on characteristics observable in existing species. The branching patterns in a cladogram are defined by the presence of unique, evolving innovations (derived characteristics) shared by all members of the group. References Campbell, Neil E. and Reece, Jane B. 2002. Biology, Sixth Edition. Benjamin Cummings. Judd, W.S., Campbell, C.S., Kellogg, E.S., Stevens, P.F., Monoghue, M.J. 2002. Plant Systematics: A Phylogenetic Approach, Second Edition. Sinauer Assoicates, Inc. Image References: Buffalo (Jack Dykinga), Alligator (USDA), Turkey (Scott Bauer) http://www.ars.usda.gov/is/index.html From USDA Agricultural Research Service Turtle, Snake Art Explosion, Volume 2 Clip Art Phylogenetic Tree Cladogram

Cladograms A cladogram is a branching diagram that shows the relationships of organism Pg 467 MiniLab

Cladogram Practice F C A G E D B H