Classification aka Taxonomy

Taxonomy = names & groups of organisms according to their characteristics & evolutionary history. Why classify? To study the diversity of life, scientists use classification to group organisms in a logical way to make sense.

Order From Chaos When you need a new pair of shoes, what do you do? You probably walk confidently into a shoe store, past the tens or hundreds of pairs of shoes you don’t want and straight to the kind you do want. How do you find them? Shoes are organized in the store in categories. People organize objects by grouping similar objects together.

Early Systems of Classification Aristotle: 1. Animals by land, water, or air 2. Plants by stems 3. Common names used; varied from place to place. 4. Long Latin descriptions; difficult to remember (up to 12 words long!) European Honey Bee: Apis pubescens thorace subgriseo abdomine fusco pedibus posticis glabis unttinque margine cilatus

Carolus Linnaeus Binomial nomenclature: Two word Latin name for organism He used the organisms morphology (form & structure). Levels of classification – 7 from largest (or most diverse) to smallest (or most alike): *Kingdom, Phylum, Class, Order, Family, Genus, Species.*

Linnaeus’s System of Classification Kingdom Phylum Class Order Family Genus Species

Giant panda Abert squirrel Grizzly bear Black bear Red fox Coral snake Sea star KINGDOM Animalia PHYLUM Chordata CLASS Mammalia ORDER Carnivora FAMILY Ursidae GENUS Ursus SPECIES Ursus arctos

Binomial Nomenclature Scientific Name = genus & species The genus part is first & capitalized The species part is second & lower case Both are in italics or underlined. They are Latin so an organism has the same name all over the world. Sometimes the species is split into: varieties – slightly different subspecies – in different geographical areas

Robin?

Robin? Great Britain Robin: Erithacus rubicula North American Robin: Turdus migratorius

Panther, Puma, Mountain Lion, Cougar: Puma concolor

Phylogeny – evolutionary history Organisms now classified by evolutionary history as well as similarities. Phylogenetic Tree = the ancient ancesters are at the bottom (trunk) & newer species are the branches. Based on: Fossil record Morphology Embryological development Similarity of chromosomes

Cladistics A Cladogram shows evolutionary relationships from shared derived traits. For example: Feathers – birds; amniotic egg – reptiles & birds

Cladograms

CLASSIFICATION BASED ON VISIBLE SIMILARITIES Appendages Conical Shells Crustaceans Gastropod Crab Barnacle Limpet Crab Barnacle Limpet Molted exoskeleton Segmentation Tiny free-swimming larva CLASSIFICATION BASED ON VISIBLE SIMILARITIES CLADOGRAM

CLASSIFICATION BASED ON VISIBLE SIMILARITIES Traditional Classification Versus Cladogram Section 18-2 Appendages Conical Shells Crustaceans Gastropod Crab Barnacle Limpet Crab Barnacle Limpet Molted exoskeleton Segmentation Tiny free-swimming larva CLASSIFICATION BASED ON VISIBLE SIMILARITIES CLADOGRAM

Similarities in DNA & RNA Even the genes of diverse organisms show many similarities. The more similar the more recently the two organisms shared a common ancester

Modern Systems Six Kingdom System 1. Archaebacteria – unicellular, prokaryotes, autotrophic (chemosynthesis). Live in harsh environments. Waste products may include methane. Reproduce asexually – binary fission. 2. Eubacteria – unicellular, prokaryotes, most use oxygen, reproduce – binary fission

Six Kingdom System cont. 3. Protista – eukaryotes (membrane bound organelles); most unicellular, no specialized tissues; - Euglena, Amoeba. Multicellular may look like plants - algae 4. Fungi – heterotrophic, absorb nutrients; unicellular & multicellular 5. Plantae – multicellular, autotrophic (photosynthetic); except for a few parasitic forms 6. Animalia – multicellular, heterotrophs

5 Kingdom System 1. Monera = Archaebacteria & eubacteria 2. Protista 3. Fungi 4. Plantae 5. Animalia

Difference

3 Domain System 1. Domain Archea = archaebacteria 2. Domain Bacteria = eubacteria 3. Domain Eukarya = protista, fungi, plantae, animalia (all have true nucleus & membrane bound organelles)

Living Things Eukaryotic cells Prokaryotic cells are characterized by Important characteristics and differing which place them in Domain Eukarya Cell wall structures such as which is subdivided into which place them in Kingdom Plantae Kingdom Protista Kingdom Fungi Kingdom Animalia Domain Bacteria Domain Archaea which coincides with which coincides with Kingdom Eubacteria Kingdom Archaebacteria

Classification of Living Things 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 Eukarya 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

DOMAIN ARCHAEA DOMAIN EUKARYA DOMAIN BACTERIA Kingdoms Eubacteria Archaebacteria Protista Plantae Fungi Animalia DOMAIN BACTERIA

Click the image to play the video segment. Panthera leo?, Part 1 Click the image to play the video segment. Video 1

Click the image to play the video segment. Panthera leo?, Part 2 Click the image to play the video segment. Video 2

Classification Of Humans Domain Eukarya Kingdom Animalia Phylum Chordata Subphylum Vertebrata Class Mammalia Order Primates Family Hominidae Genus Homo Species sapien sapiens