1. Historical Geology Lecture 25 The Pleistocene Epoch and Human Origins

2. Historical Geology Outline IPleistocene Timeline A.Nebraskan B.Kansan C.Illinoisan D.Wisconsin 1.Extent 2.Great Lakes 3.Lake Bonneville 4.Lake Missoula a.Channeled Scablands IIClimate Controls A.Geography B.Albedo C.Milankovitch Cycles IIIGlacial Cycles and Sea Level IVThe Origin of Humans

3. Historical Geology The Quaternary Pleistocene Ice Ages Wisconsin 75,000 – 10,000 Illinoian 265,000 - 125,000 Kansan 435,000 - 300,000 Nebraskan 1,800,000 - 500,000

4. Historical Geology The Quaternary Last Glacial Maximum

5. Historical Geology The Quaternary Ice Ages - Wisconsin

6. Historical Geology The Quaternary Ice Age Geology Glacial Subsidence Loess Deposits Pluvial Lakes Lake Agassiz Great Lakes Lake Bonneville Lake Missoula Scablands Drainage System

7. Historical Geology The Quaternary Ice Age Geology - Pluvial Lakes

8. Historical Geology The Quaternary Ice Ages – Lake Agassiz

9. Historical Geology The Quaternary Ice Ages – The Great Lakes

10. Historical Geology The Quaternary Ice Ages – Lake Bonneville

11. Historical Geology The Quaternary Ice Ages – Lake Missoula

12. Historical Geology The Quaternary Ice Ages – Lake Missoula

13. Historical Geology The Quaternary Ice Ages - Wisconsin BeforeAfter Before the ice age rivers drained predominanly to the northeast, but due to the presence of a large continental ice sheet new rivers to the sea were formed.

14. Historical Geology Geography Ocean Currents Albedo Earth's Orbit Climate Controls

15. Historical Geology Eccentricity Obliquity Precession Climate Controls Orbital Forcing

16. Historical Geology Climate Controls Orbital Forcing - Eccentricity

17. Historical Geology Climate Controls Orbital Forcing - Obliquity

18. Historical Geology Climate Controls Orbital Forcing - Precession

19. Historical Geology Climate Controls Orbital Forcing - Cumulative Effect

20. Historical Geology The Cenozoic Era Sea Level and Glacial Cycles

21. Historical Geology 10 20 30 40 50 60 CENOZOIC Millions of years ago Present loss of tree- dwelling existence binocular vision opposable digits tree-dwelling existence TREE SHREWS PROSIMIANS NEW WORLD MONKEY OLD WORLD MONKEY ORANGUTANS GORILLAS HUMANS CHIMPANZEES Primate Evolution

22. Historical Geology

23. Timeline of Human Evolution Australopithecus afarensis

24. Historical Geology Timeline of Human Evolution Homo erectus

25. Historical Geology Timeline of Human Evolution Homo neanderthalis

26. Historical Geology Brain Size Erect Posture and Bi-pedalism Hands Face and Eyes Teeth and Jaws Throat and Larynx Sexual Dimorphism Neoteny Human Characteristics

27. Historical Geology Brain Size L to R:A. afarensis H. erectus H. sapiens sapiens Human Characteristics

28. Historical Geology Human Characteristics Bipedalism

29. Historical Geology Human Characteristics Bipedalism

30. Historical Geology Hands Face and Eyes Teeth and Jaws Throat and Larynx Human Characteristics

31. Historical Geology Sexual Dimorphism Neoteny Human Characteristics Femur A. afarensis 3.5 mya Skull A. robustus Skull H. habilis 2 mya

32. Historical Geology Humans Populate the World