1. Classification

2. 18-1 Finding Order in Diversity Life on Earth Life on Earth Changing for >3.5 billion years 1.5 million species named 2-100 million species yet to be discovered!

3. Classification Why Classify? Why Classify? Taxonomy Taxonomy Organize living things into groups that have biological meaning Discipline of classifying organisms and assigning each one universally accepted name Taxonomy: Life’s Filing System

4. Assigning Scientific Names One Scientific Name One Scientific Name Common names can be confusing and vary (languages or regions) Ex: cougar, mountain lion, panther, puma = all same animal Ex: buzzard: hawk? Vulture? Scientists have agreed to a single name for each species Use Latin & Greek

5. Scientific Names Binomial Nomenclature Binomial Nomenclature Classification system created by Carolus Linnaeus Swedish botanist, 1700s Each species assigned 2-part scientific name written in italics or underlined 1 st word capitalized ( Genus ) 2 nd word lower case ( species )

6. Scientific Names Genus Genus Species Species What are some examples? What are some examples? Group of closely related species Unique to each species in genus Often a description of some trait of the organism or an indicator of where it lives Brown bear: Ursus arctos Polar bear: Ursus maritimus

8. Linnaeus System of Classification Hierarchical Hierarchical Classification Levels Classification Levels Consists of levels 7 levels Smallest to largest: species, genus, family, order, class, phylum, kingdom Each level called a taxon

10. From Species to Kingdom Species Camelus bactrianus Genus Camelus Family Camelidae Order Artiodactyla Class Mammalia Phylum Chordata Kingdom Animalia Bactrian Dromedary Llama Giraffe Albert’s Coral Sea star camel camel squirrel snake

11. Humans Kingdom Kingdom Phylum Phylum Class Class Order Order Family Family Genus Genus Species Species Animalia Chordata Mammalia Primates Hominidae Homo sapiens

12. Evolutionary Relationships Common Ancestors Common Ancestors The higher the level of taxon, the farther back in time you’ll find the common ancestor of all the organisms in the taxon.

13. Grouping Organisms Phylogeny Phylogeny Historical Grouping Historical Grouping Current Grouping: Evolutionary Classification Current Grouping: Evolutionary Classification Study of evolutionary relationships among organisms Organisms grouped by physical similarities Organisms grouped into categories that represent lines of evolutionary descent (phylogeny), not just physical similarities

14. New Discoveries Change Classifications Limpets Barnacles Crab

16. Showing Evolutionary Relationships Cladogram Cladogram Diagram that shows evolutionary relationships among a group of organisms

18. Modern Taxonomy Phylogenetics Phylogenetics Cladistics (Cladistic analysis) Cladistics (Cladistic analysis) Groups species into larger categories Reflects lines of evolutionary descent Based on characters (traits)

19. Cladistics Clade Clade Group of organisms that includes a common ancestor & all descendants of that ancestor (monophyletic)

20. Building a Cladogram Derived characters Derived characters Molecular Analysis Molecular Analysis trait that appears in most recent common ancestors and was passed on to its descendants Similarities in DNA More similar DNA sequences indicates more recent common ancestor

21. Derived Characters Hair Four limbs Retractable claws Specialized shearing teeth

22. Cladograms 1 2 3

23. Interpreting a Cladogram Clade Tetrapoda Clade Amniota Clade Mammalia Clade Carnivora Clade Felidae Amphibians Reptiles Marsupials Dogs/Relatives Cats Four limbs Retractable claws Amniotic egg Hair Specialized shearing teeth

24. 18-3 Kingdoms & Domains Domain Domain Most inclusive Larger than a kingdom 3 Domains: Bacteria, Archaea, and Eukarya

25. 18-3 Kingdoms & Domains Kingdom Kingdom 6 Kingdoms

26. Kingdoms Eubacteria Eubacteria Unicellular Prokaryotic Autotroph or heterotroph Cell walls w/peptidoglycan Ex: E. coli, Streptococcus, Staph

27. Kingdoms Archaebacteria Archaebacteria Unicellular Prokaryotic Autotroph or heterotroph Cell walls no peptidoglycan “Extremophiles” – live in extreme environments (volcanic hot springs, acidic pools, anoxic mud )

28. Kingdoms “Protista” “Protista” Most unicellular, some multi Eukaryotic Photosynthetic or heterotrophic Greatest variety Ex: kelp, amoebas, slime mold, paramecium, euglena

29. Kingdoms Fungi Fungi Most multi-cellular, some uni Eukaryotic Heterotrophs Feed on dead or decaying organic matter Secrete digestive enzymes Cell walls of chitin Ex: mushroom, yeast

30. Kingdoms Plantae Plantae Multi-cellular Eukaryotic Photosynthetic autotrophs Cell walls of cellulose

31. Kingdoms Animalia Animalia Multi-cellular Eukaryotic Heterotrophic No cell walls

32. Dichotomous Key Dichotomous Key Dichotomous Key Tool that allows user to identify items in the natural world (trees, flowers, mammals, rocks, fish, etc.) Consists of series of choices that lead the user to correct name of a given item Dichotomous – “divided into to parts” Gives 2 choices in each step