Introduction to Zoology & Classification

1. Introduction to Zoology & Classification

2. SCIENTIFIC WORDS / IDEAS

3. Scientific Terminology • Hypothesis: A prediction of the outcome of an experiment • Written: If______________, then _____________, because____________.

4. Testing Hypotheses • Observation • Something you take in with your senses • Experiment • Perform CONTROLLED experiments to test repeated observations • If continued to be accepted………….

5. Scientific Theory • Principle • Tested many times • Explains many different phenomena • Makes predictions • Falsifiable – people are constantly trying to prove wrong and correct “bad”’ science

6. Theory vrs Scientific Theory • Theory (as used outside of science) • Guess • Speculation • Has not been tested

7. Law vrs Theory • Law • Observation that has been repeated numerous times • Law of gravity • Does not explain the observation • Theory • Explains why or how something in nature happens

8. Which is most important to a scientist? • Fact • Hypothesis • Law • Theory

9. Theory is the most important • Theory • Explains laws, hypotheses and facts • Law • States what happens • Hypothesis • Untested theory • Fact • Observation

10. Major Scientific Theories • Germ Theory of Disease • Germs cause infectious disease • Atomic Theory • Matter is made if tiny atoms • Gene Theory (Chromosomal Theory) • Genes on chromosomes determine heredity • Cell Theory • All living things are made of cells

11. Theory of Evolution • Populations of organisms change over time • Changes result in new species that share a common ancestor.

12. Evolution is both a fact and a theory • Fact • Evolution is documented in the fossil record and has been observed in our lifetime. • Theory • How evolution happens

13. Theory of Evolution • Scientists no longer ask if evolution occurs. They study how evolution occurs. • Evolution is the major theory that guides research in Zoology

14. CLASSIFICATION REVIEW

15. Aristotle 384 BC • Classified organisms as either plants or animals

16. Carolus Linnaeus 1707-1778 • Swedish Botanist • Systema Naturae, 10ed • 1758 • Classification system • Taxonomic groups of related organisms • Binomial nomenclature • two names • Genus + species • Capitalized, Italics

17. Taxonomic Groups

19. Species • “Species are groups of actually or potentially interbreeding populations, which are reproductively isolated from other such groups.” • When they reproduce, create FERTILE offspring Ernst Mayr

21. * * Archaea

23. Kingdom Monera or Eubacteria • Single celled • Prokaryotic • Make or absorb food • Cell wall • peptidoglycan

24. Kingdom Archaea • Single celled • Prokaryotic • Make or absorb food • DNA • Similar to Eukaryotic • Cell wall • Pseudopeptidoglycan or protein only

25. Kingdom Protista • Single celled • Eukaryotic • Ingest or produce food • Kind of the “junk drawer” of classification

26. Kingdom Fungi • Multicellular • Eukaryotic • Cell wall • Chitin • Absorb food

27. Kingdom Plantae • Multicellular • Eukaryotic • Cell wall • Cellulose • Produce food • photosynthesis

28. Kingdom Animalia • Multicellular • Eukaryotic • No cell wall • Ingest food • Motile

29. Terminology • Classification • Assigning organisms to different catagories based on their relationship • Taxonomy • The science of naming organisms • Systematics • Determining evolutionary relationships of organisms

30. Cladogram • Evolutionary relationship of a group of organisms • Each clad (group) share something in common • Ancestral traits are the oldest • Derived traits evolved later • Nested hierarchially

31. Cladogram for Transportation • Wheels are the most ancestral • Wings are the most derived

32. MAKE A CLADOGRAM

33. Characteristics for Constructing Cladogram • Tail is the most ancestral • Four limbs is the oldest derived trait • Fur is a later derived trait • Loss of tail is the most derived trait

34. Gorilla Chimpanzee Tail Lost Fur Four Limbs Tiger Lizard Fish

35. Synapomorphy • A derived character shared by two or more groups. • Fur is a synapomorphy for the various groups of mammals. • Synapomorphies are used to determine evolutionary relationships

36. Symplesiomorphy • Character shared by a number of groups • Inherited from ancestors older than the last common ancestor. • Symplesiomorphies are not helpful in determining evolutionary relationships

38. Birds Mammals Reptile Feathers Amphibian Fur Fish Endothermic Amniotic Egg Four Limbs Vertebrae Accepted Cladogram for Animals

39. Homologous Characters • Similarity in features of different groups because of their descent from a common ancestor

40. Analagous Characters • Similarity in characteristics in different groups caused by factors OTHER THAN their distant common ancestry

41. Monophyletic • A group of all the descendants of a common ancestor • The common ancestor is in the group • Example: Mammalia • Ancestor was a mammal like reptile

42. Paraphyletic • A group of descendants of a common ancestor • Common ancestor is in the group • Not all descendants are included • Example: Reptiles • Does not include birds and mammals

43. Polyphyletic • A group that has some similarities • Common ancestor is in not in the group • Not all descendants are included • Example: Flying vertebrates

44. Asymmetry • No Lines of symmetry • Most protists & many sponges • Do not develop complex communication, sensory or locomotor function

45. Radial Symmetry • Multiple lines of symmetry • Not as simple communication, sensory or locomotor function; but still not as complex

46. Bilateral Symmetry • One line of symmetry • Usually longitudinal, dividing animals into right and left mirror images • Characteristic of active, motile, crawling or swimming animals • Usually move in one direction – so the end that faces the world is normally where complex sensory, nervous and feeding structures evolve and develop. (Cephalization)