1. 32-1 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Chapter 32: Evolving earth

2. 32-2 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University History of life on earth Fossils provide information about past life –preserved remains or indications of organisms Whole organisms or parts of organisms –shells, bones, leaves, pollen Tracks and traces –footprints, burrows Chemical fossils –organic compounds

3. 32-3 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Fossils Organisms are preserved when they are protected from decay –buried in sediment –encased in resin Compaction and chemical changes turn sediments into rock Depending on type of rock, fossils may –retain their shape –be flattened –be carbonised (soft parts preserved as a carbon film) –be filled in with minerals –dissolve out, leaving an empty mould –be replaced with other material, such as silica (opal)

4. 32-4 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Time scales Rock layers (strata) contain characteristic sets (suites) of fossils –rocks with the same suite of fossils are of the same age Fossils are used to divide the geological time scale into eras and periods Ages of rocks and fossils are determined using radiometric dating

5. 32-5 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Fig. 32.5: Modern geologic time scale (based on the 2000 edition of the International Stratigraphic Chart) (cont.)

6. 32-6 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Fig. 32.5: Modern geologic time scale (cont.) (based on the 2000 edition of the International Stratigraphic Chart) Copyright © T Itoh & R M Brown Jr, Planta Journal, vol. 160, pp. 372–81. Springer-Verlag, 1984

7. 32-7 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Eras Major divisions of geologic time –Precambrian (4500–545 m.y.a.) –Palaeozoic (545–250 m.y.a.) –Mesozoic (250–65 m.y.a.) –Cenozoic (65–0 m.y.a.) Divided into periods

8. 32-8 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Precambrian era Archean eon (4500–2500 m.y.a.) Proterozoic eon (2500–545 m.y.a.) Oldest fossils 3500–3300 m.y.a. –prokaryotes: cyanobacteria (including stromatolites) Photosynthesis released oxygen into atmosphere –changed composition of atmosphere –2300–1800 m.y.a.

9. 32-9 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Eukaryotes Prokaryotes only form of life for 2100 m.y. Oldest eukaryote fossils 1400 m.y.a. –single-celled protists with chloroplasts Multicelled organisms –metaphytes (red algae) 1260–950 m.y.a. –animals 680–640 m.y.a.

10. 32-10 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Ediacaran fauna Fossils of soft-bodied animals –impressions –tracks and burrows –no hard exo- or endoskeletons Difficult to classify some fossils –do not resemble living phyla Fossils first recorded from Ediacara Hills, South Australia –fauna on all continents

11. 32-11 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Palaeozoic era ‘Ancient life’ (545–250 m.y.a.) Aquatic groups –trilobites –brachiopods –nautiloids, ammonoids (cephalopod molluscs) –jawless and jawed fish (‘Age of Fish’)

12. Fig. 32.11: Trilobite 32-12 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University

13. 32-13 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Palaeozoic era (cont.) Life moves onto land in Silurian period –arthropods –amphibians –reptiles –land plants Ended with mass extinction –Permian period (250 m.y.a.) –trilobites, many invertebrate groups

14. 32-14 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Mesozoic era ‘Middle life’ (250–65 m.y.a.) Plants and invertebrates –ferns, conifers, cycads –flowering plants –bivalves, predatory gastropods –ammonoids –reef-building corals

15. 32-15 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Mesozoic era (cont.) Vertebrates –mammal-like reptiles, dinosaurs, marine reptiles, flying reptiles (‘Age of Reptiles’) –birds –mammals Ended with mass extinction –K–T boundary –ammonites (shelled cephalopods), many large reptiles

16. Fig. 32.18: Archaeopteryx 32-16 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University

17. Question1: Why was Archaeopteryx such an important find in the fossil record? 32-17 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University

18. 32-18 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Cenozoic era ‘Modern life’ (65–0 m.y.a.) Major groups –mammals diversify (‘Age of Mammals’) –hominids –modern forms of most organisms

19. 32-19 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Biogeographic regions Areas of the earth occupied by characteristic biota TerrestrialMarine PalaearcticArctic/Antarctic OrientalCool temperate EthiopianWarm temperate AustralianTropical Nearctic Neotropical

20. 32-20 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Fig. 32.20: Biogeographic regions

21. 32-21 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University ‘New World’ regions Nearctic –North America, Greenland –examples:  kangaroo rat  pronghorn  turkey Neotropical –South America, Central America –examples:  New World monkeys  sloth  rhea

22. 32-22 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University ‘Old World’ regions Palaearctic –Europe, Asia –examples:  desman  saiga Ethiopian –Africa, Madagascar, Arabia –examples:  hippopotamus  giraffe and okapi  lemurs (Madagascar)

23. 32-23 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University ‘Old World’ regions (cont.) Oriental –India, South-East Asia –examples:  tree shrew  gibbon  leafbird Australian –Australia and adjacent areas –examples:  echidna, platypus  kangaroo  emu

24. Question 2: What defines a mammal? a) endothermic b) mammary glands c) internal fertilisation d) scales 32-24 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University

25. 32-25 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Australian region More than Australia –New Zealand, islands of Western Pacific, New Guinea, eastern Indonesia archipelago –biota determined by history and proximity Wallace’s Line –boundary between Australian and Oriental biogeographic regions  Oriental biota dominates to west, Australian biota to east –approximates collision zone between tectonic plates

26. 32-26 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Fig. B32.6: Wallace’s Line

27. 32-27 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Plate tectonics Earth’s surface formed from mobile plates –tectonic plates Move relative to one another –plate tectonics –continental drift Configuration of land masses has changed over geologic time –still changing

28. 32-28 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Fig. 32.6: Distribution of plates

29. 32-29 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Sea-floor spreading Plate movement driven by sea-floor spreading Lava rises from mantle to surface at oceanic ridges –forms new oceanic crust on either side Continents pushed away from oceanic ridges –example: Indian–Antarctic ridge in Southern Ocean separating Australian and Antarctic plates

30. 32-30 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Subduction zones Where edges of plates meet One plate slides beneath the other into mantle –subduction zone –deep-water trenches –examples: Marianas Trench, Java Trench Plates slide past each other –major fault zones –example: San Andreas Fault

31. 32-31 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Fig. 32.7: Cross-section of lithosphere and asthenosphere

32. 32-32 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University Ancient earth Movement of continents over geologic time Land masses accreted into different configurations at different times –Gondwana: southern masses –Laurasia: northern masses –Pangea: southern + northern land masses

33. F ig. 32.8: Position of the world’s land masses 32-33 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University

34. Summary Fossils provide a record of past organisms and their ages Geologic eras mark major events in the evolution of life The evolution of life has been influenced by the history of the earth Changes in earth’s atmospheric composition and the position of its continents have influenced the evolution and distribution of organisms Biogeographic regions of the world are characterised by unique biotas 32-34 Copyright  2010 McGraw-Hill Australia Pty Ltd PowerPoint slides to accompany Biology: An Australian focus 4e by Knox, Ladiges, Evans and Saint Slides prepared by Karen Burke da Silva, Flinders University