Classification of Organisms

1. Classification of Organisms

2. Classification of Organisms • The study of the kinds and diversity of organisms and their evolutionary relationships is called systematics or taxonomy • Taxonomy is the work involved in the original description of a species. • Systematics is the assigning of species into evolutionary groups.

3. Father of Modern Classification • The modern classification system originated with the work of Carolus Linnaeus • he recognized the different species could be grouped into broader categories based on shared characteristics • any grouping of animals that shares a particular set of characteristics forms an assemblage called a taxon

4. Classification.ppt CLASSIFICATION • OBSERVATION: • Many kinds of organisms: • Some similar to each other. • wood frog, • leopard frog, • bull frog

5. CLASSIFICATION Classification.ppt • Others less similar • fish, • frogs, • snakes

6. Classification.ppt CLASSIFICATION • Others very dissimilar • people, • pine trees, • protozoans

7. Classification.ppt CLASSIFICATION • Why are some kinds similar and others NOT similar? • Question to be answered later? • How can we make sense of (explain) this diversity? • How can we organize what we know about these organisms?

8. Classification.ppt Answer: CLASSIFY • Similar “types” (species) grouped together, separated from other species. • Then, group similar groups together, • etc.

9. Classification.ppt CLASSIFICATION • Species = kind of organism • fundamental unit in evolution and ecology • more precise definition soon

10. Classification.ppt CLASSIFICATION • Necessary? YES !! ~ 1 million species of plants, 5-10 million species of animals + fungi, protists, bacteria no good estimates of numbers of species • Human mind needs to organize information.

11. Classification.ppt CLASSIFICATION • Classification system organizes biological knowledge. • Classification itself is HYPOTHESIS about relationships, similarity because of common ancestry.

12. Classification.ppt HYPOTHESIS of relationship

13. Modern taxonomists use 7 taxa: • kingdom, phylum, class, order, family, genus and species • as taxa increase organisms get more specific

14. Classification.ppt CLASSIFICATION = Sequence of levels.Linnaean system, from Carolus Linnaeus, 1740's Kingdom Phylum Class Order Family Genus Species King Phil called old fat George stupid.

15. Kingdoms and Domains The three-domain system Bacteria Archaea Eukarya The six-kingdom system Bacteria Archaea Protista Plantae Fungi Animalia The traditional five-kingdom system Monera Protista Plantae Fungi Animalia

16. Classification.ppt CLASSIFICATIONWoese, 1985 Domain Kingdom Phylum Class Order Family Genus Species Did King Phil call old fat George stupid ?

17. Kingdoms of Life • In 1969, Robert H. Whitaker classified kingdoms based on cellular organization and mode of nutrition • this lead to the formation of the 5 kingdoms

18. 5 Kingdoms of Classification: Monera: comprised of bacteria and cyanobacteria • distinguished by being single cell prokaryotes Protista: comprised of Amoeba, Paramecium etc…. • distinguished by being single celled eukaryotes Plantae: multi-cellular photosynthetic eukaryotes • plants have cell walls and are non-motile

19. 5 Kingdoms of Classification: Fungi: multi-cellular heterotrophic eukaryotes • fungi have cell walls and usually non-motile • digest organic matter extra-cellularly (outside of cell) and absorb the breakdown products Animalia: multi-cellular heterotrophic eukaryotes • animal cells lack a cell wall and usually motile • feed by ingesting other organisms or parts of other organisms

20. Monera prokaryote single-cell Protista eukaryote multi-cell Plantae eukaryote multi-cell autotrophic Fungi eukaryote multi-cell heterotrophic, external digestion Animalia eukaryote multi-cell heterotrophic, internal digestion

21. DOMAINS??? • Many taxonomists have pushed the idea that the five kingdom system isn’t enough • they feel that organisms share too much similarities and need to be grouped otherwise • the push has led to the addition of 3 domains

22. 3 Domains • Archae: bacteria that live in extreme conditions • Eubacteria: “true bacteria” • Eukarya: all eukaryotic organisms

24. BioEd Online Taxonomic Diagrams Mammals Turtles Lizards and Snakes Crocodiles Birds Mammals Turtles Lizards and Snakes Crocodiles Birds PhylogeneticTree Cladogram

25. Binomial Nomenclature: • when a species is talked about only the genus and species names are used • this is called thescientific name • unique to each type of organism • Required by the International Code of Zoological Nomenclature

26. Writing Scientific Names • the genus names is always capitalized • both names are either italicized or underlined • leave a space in the underline between names ex. Homo sapien Felis leo Quercusrubra

27. Ursus americanus American Black Bear

28. Often Latin names contain clues about the type of organism being described. Canisdomesticus :And closely related organisms are often in the same genus, also giving clues about their names Canislupus: Some names are given after the discoverer, or the discovery location, or even a Latinized descriptive term in English

29. Conclusion The classification system for organisms have been around for a long time. It has endured several changes and is quite complex. Without it modern biology could not exist, much in the same way that a grocery store would go out of business if it did not have a classification system.