Classification

1. Classification How and why are organisms classified? What tools do we use to classify organisms?

2. Why do we classify? Definition: Taxonomy: the branch of biology that deals with the naming and classifying of organisms. • Current system based on phylogeny (evolutionary ancestry) • History A. Early classification did not classify organisms by ancestry b/c it was not believed organisms evolved.

3. History continued B. Aristotle: Greek philosopher who more than 2000 years ago divided organisms into 2 groups 1. Plants: classified by type of stem 2. Animals: divided by environment. (Land, water, or air) According to Aristotle which of these 3 animals would be classified more closely?

4. History continued C. Carolus Linnaeus: Swedish botanist who, in the 18th century, developed a framework for organisms to be named and classified. • His system was based on structural similarities.

5. Example of Phylogeny • According to this phylogenetic tree who are humans most closely related to?

6. II. Linnaeus’ System • Binomial nomenclature: Two name system that is unique to every type of organism 1. Names are Italicized or underlined 2. Genus • first name and is capitalized 3. Species • second name, lower case and descriptive 4. All names are in Latin Why use Latin and not common names? Common names vary from language to language but Latin is universal

7. Examples of names • Genus and species • Homo sapiens • Musca domesticus • Quercus alba • Quercus rubra Common name • Humans • Housefly • White Oak tree • Red Oak tree

8. III. Levels of Classification What is the relationship among the levels? • Do • Kings • Play • Chess • On • Friday • Generally • Speaking? • Domain • Kingdom • Phylum • Class • Order • Family • Genus • species More closely related species share more levels of classification From Domain down to species, each level has a new set of criteria that each organism must share

9. Dolphin and Human • How many levels of classification do we share with Dolphins?

10. 3 Domains • Archaea*: oldest group of prokaryotes • Eubacteria*: evolved from Archaea • Eukaryota: cells with a nucleus • *prokaryotes

11. Domain: Archaea - prokaryotes that live in extreme environments: hydrothermal vents, salty or acidic environments.

12. Domain: Eubacteria – prokaryotic, very diverse, heterotrophic or autotrophic, free-living or pathogenic cyanobacteria Staphylococcus

13. 5 Kingdoms • When using the 5 kingdom system, • Eubacteria + Archaea = Monera

14. Domain: Eukaryota • All are eukaryotic (cells have a nucleus) 1. Kingdom Protista: mostly unicellular organisms that are plant-like, animal-like, or fungus-like Amoeba Euglena Paramecium Diatoms

15. 2. Kingdom Fungi: all types of fungus (mushrooms) Multicellular heterotrophs with cell walls of chitin ( yeast – unicellular) Digest food outside the organism and then absorb nutrients

16. 3. Kingdom Plantae: Multicellular autotrophs with cells walls of cellulose • land based plants, trees, grasses, moss, and shrubs • photosynthetic

17. 4. Kingdom Animalia: multicellular heterotrophs without cell walls. • divided into invertebrates and …………..

18. ………. vertebrates