Classification CHAPTER 18 Why Classify Whats in a

Classification CHAPTER 18

Why Classify? What’s in a name? � In order to name and group organisms in a logical manner we must arrange them according to similarities and differences. Usually from physical characteristics or DNA/Protein sequencing. � Taxonomy- classifying organisms and assigning each a name – according to their characteristics, physical traits. �Scientists that classify living organisms are called Taxonomists.

Do you organize? � Think of your house: �Is there a logical set up? Is it organized? �Your clothes? Do you have them arranged by season? By color? By style? �School work, do you organize it by subject? A day or B day? � All of us organize in some way. Choosing the arrangement by our personal needs and aesthetics.

Assigning Scientific Names � Early Efforts- described physical characteristics � Carolus Linnaeus – Botanist and Naturalist � Developed the current 7 category naming system we use today. � Did not agree with Darwin’s Theory of Evolution through natural Descent, but understood that similar organisms shared similar traits. � Binomial Nomenclature: � two word naming system, the Genus and species ○ Genus – capitalized, ○ species – never capitalized � Abbreviated to – G. spp. � Always typed in italics � Underlined when written Genus species ○ Homo sapien – modern humans � H. sapien

Linnaeus’s System (7 categories) Broad characteristics � � � � Kingdom Phylum Class Order Family Genus Species (unique & grouped) to Narrow characteristics (Specific & individual)

K Kingdom Ph Phylum C class O order F Family G Genus S species

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

Ursus maritimus Ursus arctos When written or typed the genus is always capitalized and the species is not

Evolutionary Classification � Phylogeny- study of evolutionary relationships among organisms � Biologists classify organisms by grouping them according to evolutionary descent, not physical characteristics.

Cladograms � Uses derived characteristics to show evolutionary relationships among a group of organisms

Molecular Clock

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

Kingdoms and Domains All Living Organisms Eukaryotes Prokaryotes Eukarya Protista Fungi Plantae Animalia Bacteria Archaea Eubacteria Archaebacteria

Kingdoms and Domains pg 459 Classification of Living Things DOMAIN Bacteria Archaea KINGDOM Eubacteria Archaebacteria CELL TYPE Eukarya Protista Fungi Plantae Animalia Prokaryote Eukaryote Cell walls with peptidoglycan Cell walls without peptidoglycan Cell walls of cellulose in some; some have chloroplasts Cell walls of chitin Cell walls of cellulose; chloroplasts No cell walls or chloroplasts Unicellular Most unicellular; some colonial; some multicellular Most multicellular; some unicellular Multicellular MODE OF NUTRITION Autotroph or heterotroph Heterotroph Autotroph Heterotroph EXAMPLES Streptococcus, Escherichia coli Methanogens, halophiles Amoeba, Paramecium, slime molds, giant kelp Mushrooms, yeasts Mosses, ferns, flowering plants Sponges, worms, insects, fishes, mammals CELL STRUCTURES NUMBER OF CELLS

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

3 Domain System

Identify through Dichotomous Key � Used to identify organisms based on physical characteristics. � A series of paired statements are used to separate characteristics of different organisms. � From the simple: To the complex: Texas Wildlife – Turtles Texas Plants – NRCS Interactive

Identify through images:

Endosymbiotic Theory