The document discusses the classification of organisms into a hierarchical system and the evolution of classification over time. It describes Linnaeus' original system that grouped organisms into seven levels from kingdom to species based on physical similarities. Modern evolutionary classification groups organisms based on evolutionary relationships and common ancestry as shown in cladograms. The three domain system divides all life into Bacteria, Archaea, and Eukarya with Eukarya further divided into kingdoms of Protista, Fungi, Plantae, and Animalia.

1. Classification Chapter 18

2. 18.1 Finding Order In Diversity Why do you think we would need to classify? To study the diversity of life, biologists use a classification system to name organisms and group them in a logical manner.

3. Why Classify? Taxonomy: A discipline where scientists classify organisms and assign each organism a universally accepted name

4. Why Classify? Depending on where you are this animal could be called a mountain lion, puma, cougar or a panther– all of which are common names However the scientific name is Felis concolor

5. Assigning Scientific Names Using scientific names made it easier to give one name to one animal because common names have very different meanings in different areas or they are just different all around.

6. Binomial Nomenclature Carolus Linnaeus A Swedish botanist During the early 18 th Century (1707-1778), he created a 2 word naming system

7. Binomial Nomenclature Each species is assigned a 2-part scientific name Always written in italic First word is capitalized Second word is lower cased Ex: Grizzly Bear is called Ursus arcotos

8. Binomial Nomenclature First part of the name is the genus the animal belongs to Genus: Group of closely related species Second part of name is unique to each species within a genus

9. Linnaeus’ System of Classification Linnaeus’ hierarchical system of classification includes 7 levels From largest to smallest: Kingdom, Phylum, Class, Order, Family, Genus, Species

10. Linnaeus’ System of Classification Taxon: Each level or group of organization into which organisms are classified. Kingdom: Largest taxonomic group. Most inclusive of closely related phyla

11. Linnaeus’ System of Classification Phylum: Several different classes make up a phylum: they are closely related Class: Composed of similar orders, larger categories

12. Linnaeus’ System of Classification Order: Broad taxonomic categories composed of similar families Family: Group of genera that share the same characteristics

13. 18.2 Evolutionary Classification Phylogeny: Evolutionary relationship among organisms Biologists now group organisms into categories that represent lines of evolutionary descent, or phylogeny not just physical similarities.

14. Evolutionary Classification Evolutionary Classification Strategy of grouping organism together based on their evolutionary history The higher the level of taxon, the farther back in time is the common ancestor of all the organisms in the taxon

15. Classification Using Cladograms Derived characters Characteristics that appear in recent parts of a lineage but not in its order members Cladogram Diagram that shows the evolutionary relationships among a group of organisms

16. Characteristics/ Traits Organisms Crab Barnacle Molted External Skeleton Segmentation Limpet Tiny free flowing Larvae Items to the left: organisms has it Items to the right: organism does not have it

17. Similarities in DNA and RNA The gene of many organisms show important similarities at the molecular level. Similarities in DNA can be used to help determine classification and evolutionary relationships.

18. 18.3 Kingdom and Domains 5 Kingdoms Monera, Protista, Fungi, Plantae and Animalia 6 Kingdoms Biologists came to recognize that the Monera were composed of 2 distinct groups

19. Kingdoms and Domains As a result, Monera have been separated into 2 kingdoms: Eubacteria and Archeabacteria Eubacteria, Archeabacteria, Monera, Protista, Fungi, Plantae and Animalia

20. The 3 Domain System Domain: A more inclusive category than any other larger than a kingdom Domain Eukarya is composed of Protista, Fungi, Plantae, and Animalia Domain Bacteria is composed of Eubacteria Domain Archaea is composed of Archaebacteria

21. 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 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 Eukarya

22. Domain Bacteria Unicellular and prokaryotic Cell walls with peptidogylcan

23. Domain Archaea Unicellular and Prokaryotic Cell walls with out peptidogylcan Live in some of the most extreme environments you can imagine

24. Domain Eukarya Consists of all organisms that have a nucleus Protista: Composed of eukaryotic organisms that cannot be classified as animals, plants or fungi Members share great variety

25. Domain Eukarya Fungi: Heterotrophs: most feed on dead or decaying matter They secrete digestive enzymes on food and absorb food molecules

26. Domain Eukarya Plante: Multicellular, photosynthetic autotrophs Cone-bearing and flowering plants, mosses and ferns Cells have cell walls

27. Domain Eukarya Animalia: Multicellular heterotrophs Cell walls have no cell walls They move for part of their lives