Organizing Life’s Diversity Taxonomy (Classification) Chap 17

Classification We all classify things in our everyday life based on their similarities –Cars, music, books, electronics, shoes Biology Taxonomy –Branch of biology that classifies and names organisms –Based on similar and different characteristics

Taxonomy is based mainly on: Anatomy (looks like) Behavior (acts and lives like) Fossil record Comparing DNA, RNA, Proteins –Taxonomic system changes as technology changes Lesser Red Panda Giant Panda

3 Domains of Life Everything can be classified into the three main DOMAINS each with it’s own kingdoms –Distributed among the domains are 6 Kingdoms Domain Eukaryota Kingdoms Animals Plants Fungus Protists Domain Archaea Kingdom Archaebacteria Domain Bacteria Kingdom Eubacteria Made of Prokaryotic cells Made of Eukaryotic cells

Taxonomy Systems Aristotle first attempted to classify organisms but Carolus Linneaus came up with the first real useful taxonomic system: It was based on physical and structural similarities –Example: In order to be the class Mammalia: organisms needs to have hair, produce milk, have live young, and be warm-blooded. Carolus Linnaeus Swedish Botanist ( )

Binomial Nomenclature Two-word naming system for a species –Genus name and specific epithet Note capitalization and italics Canis lupus Felis catus Tyrannosaurus rex T. rex Homo sapien

Linnaean Taxonomy Eight major divisions or taxa (singular: taxon) where each level is more specific than the one above Name of taxonDescription Domain (3)Largest number of organisms Kingdoms (6)Made up of similar phylums PhylumMade up of similar classes ClassMade up of similar orders OrderMade up of similar families FamilyMade up of similar genuses GenusMade up of similar species SpeciesSmallest (interbreeding populations)

Mnemonic for Remembering Linnaean Taxonomy Dear Kate, Please Come Over For Good Soup. Domain, Kingdom, Phylum, Class, order, family, genus, species.

Example: Wolves and Dogs Animalia Chordata Mammalia Canidae Carnivora lupus Canus Kingdom Class Phylum Family Order Genus species Animalia Chordata Mammalia Canidae Carnivora familaris Canus

Cladograms - Evolutionary Family Trees Relationships based on derived characteristics –More derived characteristics shared the more closely related 2 organisms. Vertebrate chordates cladogram

Cladograms continued

Dichotomous Keys Keys used to identify or classify an organism based on its characteristics Ocean Invertebrate Taxonomic Key Cnidaria Porifera Arthropoda