Classification/Taxonomy

1. Classification/Taxonomy Chapter 18

2. Why Classify? To study the diversity of life, biologists use a classification system to name organisms, group them in a logical manner, and study evolutionary relationships.

3. Taxonomy Defined: Discipline of classifying organisms and assigning each organism a universally accepted name. In other words, naming things.

4. Why common names don’t work Common names vary among different languages. Cat Arabic: quttah Czech: kocka French: chat German: katze Japanese: neko Russian: kotchka Spanish: gato

5. Why common names don’t work Common names vary among different countries. Example: United Kingdom – Buzzard refers to a hawk United States – Buzzard refers to a vulture Red-tailed Hawk Honey Buzzard Turkey Vulture

6. Why common names don’t work Many species have several common names. Sand tiger shark Sand shark Gray nurse shark

7. Why common names don’t work Same common name used for different species Dolphin Dolphin Mahi mahi Turciops truncatus

8. First Attempt to Classify Aristole (Greek Philosopher) * About 300 BC * Classified based on method of reproduction * Used the words like “genera” and “species” * Grouped animals between those with blood and those without blood * He had many errors in his classification system, but it was used until the 1700s

9. Carolus Linnaeus • (1707 – 1778) • Created the system of naming we use today. • In taxonomy, a group or level of organization is called a taxonomic category or taxon.

10. Binomial Nomenclature • “Bi” means 2 • “nomial” means naming • Nomenclature means “the system of” Defined: In Binomial Nomenclature, each species is assigned a two-part scientific name. (genus & species)

11. Example of Binomial Nomenclature • Polar Bear is Ursus maritimus • Ursus: genus Ursus contains 5 other kinds of bears • maritimus: species The Latin word, maritimus, refers to the sea. Polar bears often live on pack ice that floats in the sea.

12. Here We Go…Polar Bear *Do NOT have to write* Species: maritimus Genus: Ursus Family: Ursidae Order: Carnivora Class: Mammalia Phylum: Chordata Kingdom: Animilia What do these mean?...lets see

13. What they mean Species: maritimus (lives in marine environment) Genus: Ursus (kind of bear) Family: Ursidae (larger category of bears) Order: Carnivora (meat-eating animals) Class: Mammalia (warm-blooded, hair, & milk) Phylum: Chordata (vertebrates) Kingdom: Animilia (there are 6 kingdoms) *Do NOT have to write*

14. How to remember: DaKing Phillip Came Over For Green Salad Domain Kingdom Phylum Class Order Family Genus Species

15. Phylum Chordata Class Mammalia Order Carnivora Family Ursidae Genus Ursus Species maritimus

16. Rules of the Game Uniqueness: Every name has to be unique. Universality: Zoologists have adopted, by International Code of Zoological Nomenclature, a set of rules for naming animals. A single language is to be used on a worldwide basis. All animals are given a generic name (common name) and specific name in Latin &/or Greek (scientific name). These names are in italics when TYPED or are underlined when HAND WRITTEN. Human: Homo sapiens Lion: Panthera leo

17. Taxonomy Video

18. Genus species If these three species belong to the same genus, they are descended from a common ancestor. Felis domestica domestica Domestic Cat Felis Felis negripes negripes Black Footed Cat Felis margarita margarita Sand cat`

19. A Problem with Traditional Classification • Traditional classification systems relied on body structure comparisons only (not DNA) • Due to convergent evolution, organisms that are quite different from each other evolve similar body structures. Convergent Evolution: Process by which unrelated organisms independently evolve similarities when adapting to similar environments. Sugar Glider… Live in Australia Look similar, but totally unrelated! Flying Squirrel… Live in the US (GA)

20. Another Problem with Traditional Classification Example: The Crab, The barnacle, & The limpet • The barnacle and the limpet have similarly shaped shells & look alike • The crab has a very different body form • Based on anatomy, the barnacle & limpet could be classified together and the crab in a different group.

21. Related This incorrect because crabs and barnacles are actually related

22. Modern Principles of Classification • Modern classification system has its roots in the system of Linnaeus • Modern classification has been revised to reflect Darwinian Principle of common descent • Most recently, molecular systematics (DNA) has driven the most recent revisions in classification

23. Crustaceans Gastropods Molted Exoskeleton Even though they do not look a like, crabs & barnacles are actually related Segmentation Free swimming Larva

24. Evolutionary Classification/Systematics • Biologists now group organisms into categories that represent lines of evolutionary descent, not just physical similarities Evolution Classification (Systematics): Is the strategy of grouping organisms together based on their evolutionary history.

25. Animal Systematics • Phylogeny: Phylogenetic tree (also known as evolutionary tree). Based on the study of characters that vary among species. • Character: anything that has a genetic basis and can be measured. Systematics First Used ONLY Morphology Morphologyis a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features.

26. Classification Using Cladograms Cladogram: A diagram that shows the evolutionary relationships among a group of organisms.

27. Crustaceans Gastropods Not in Notes…Follow Along! Molted Exoskeleton Using Cladograms, you can see that crabs and barnacles share similar characteristics because they both molt & are segmented Segmentation Free swimming Larva

28. Crustaceans Gastropods Molted Exoskeleton You can also see that ALL have a free swimming larva stage Segmentation Free swimming Larva

29. The Three-Domain System • In 1990, a new taxonomic level called Domain was introduced and changed how bacteria were classified. • Domain Archaea • Domain Bacteria • Domain Eukarya • There are 6 Kingdoms total: 1. Eubacteria 2. Archaebacteria 3. Protista 4. Fungi 5. Plantae 6. Animalia Both are Bacteria Everything else (Except viruses)

30. 6 Kingdoms Prokaryote Prokaryote Eukaryote Eukaryote Eukaryote Eukaryote Eubacteria Archaebacteria Protista Fungi Plantae Animalia Autotroph or heterotroph Autotroph or heterotroph Autotroph/ heterotroph Heterotroph Autotroph Heterotroph Includes Algae Don’t belong in other euk No cell wall No chloroplasts Multicellular “Ancient Bacteria” Release enzymes to digest food Most common bacteria Cell walls & Chloroplasts Live in very hot places E. ecoli Pyrococcus furiosus Paramecium H. coccinea Fern frod Homo sapiens

31. Systematics First Used Morphology…Now also use other methods too! • Molecular Evidence- is the analysis of hereditary molecular differences, mainly in DNA sequences, to gain information on an organism's evolutionary relationships.

32. Systematics First Used Morphology…Now use other methods too! • Biochemical Evidence – is the analysis of similar chemical makeups of organisms to compare evolutionary relationships.

33. Systematics First Used Morphology…Now use other methods too!Click HEREfor video • Embryonic Evidence – is the analysis of the early development of embryos an comparing them to other animals.

34. Other Patterns of Organization • Unicellular Level of Organization • Protista- one-celled organisms • Diploblastic Organization Body parts organized into layers derived from two tissue layers • Ectoderm – gives rise to epidermis (outer layer) • Endoderm – gives rise to gastrodermis , the tissue that lines the gut cavity Examples: Jellyfish & Hydra Amoeba Hydra

35. Other Patterns of Organization • Triploblastic Animals • Tissues derived from three embryonic layers • Ectoderm • Mesoderm – found in middle. Gives rise to supportive, contractile, and blood cells. • Endoderm

36. Other Patterns of Organization • Triploblastic Animals (continued) • Organized based on the presence or absence of body cavity • Body Cavity – fluid-filled space in which internal organs can be suspended and separated from body wall. A true body cavity is known as a coelom.

37. Advantages of a Body Cavity • Provide more room for organ development • Provide more surface area for diffusion of gases, nutrients, & wastes into & out of organs • Provide an area for storage • Often act as hydrostatic skeletons (as in earthworm) • Provide a vehicle for eliminating wastes & reproductive products from the body • Facilitate increased body size

38. More Symmetry Terms to KnowWrite these down on paper!(not in notes) • Inferior– Below a point of reference • Superior– Above a point of reference • Terminal– Middle or center point of reference

39. Phyla To Know Porifera: Sponges Cnidaria: Jellyfish, Sea Anemones, Corals Echinodermata: Sea Urchin, Starfish, Sand Dollars Mollusca: Snails, Clams, Octopus Arthropoda: Insects, Crustaceans, Spiders Chordata: Vertebrates

40. The End.