1. Primate Evolution 5 November, 2007

2. Time, time, time…. Earth’s origin Origin of life

3. Themes Bush analogy (vs. ladder) “Extinction is the rule” Incompleteness of the fossil record “Once we were not alone” The nature of the evidence Fossils Fossils Molecular- protein/DNA Molecular- protein/DNA

4. Class- Mammalia Derived from a branch of the reptiles- the therapsids ~200 M ybp

5. Class- Mammalia Characteristics Hair Hair Mammary Glands (w/ or w/o nipples) Mammary Glands (w/ or w/o nipples) “Warm blooded” “Warm blooded” Egg layers- earliest form= “monotremes” Egg layers- earliest form= “monotremes” Lots of unique anatomical features (1 aorta, 3 middle ear bones, one jaw bone (dentary), etc…) Lots of unique anatomical features (1 aorta, 3 middle ear bones, one jaw bone (dentary), etc…)

6. Mammals, continued… Anatomy Anatomy One jaw bone 3 middle ear bones Specific arterial structures structures Initially small, rat-like, nocturnal insect eaters

8. Earliest Mammals Modern descendents- platypus (of Australia) & echidna (of New Zealand)

9. “Advanced” Mammals- the “Placentals” ~ 100 M ybp- “Age of the Dinosaurs” (Cretaceous era) (older fossil?- ~ 130 M ybp, 1 meter in length) “Live bearing mammals” Internal development Internal development Some form of connection between mother and fetus= “placenta” Some form of connection between mother and fetus= “placenta”

10. Two parallel lineages: Marsupial mammals- kangaroo, wallaby, opossum Young “born” only partially developed Young “born” only partially developed No eggs- internal (initial) development- rudimentary placenta No eggs- internal (initial) development- rudimentary placenta Well-developed nipples- young attach to complete development Well-developed nipples- young attach to complete development

11. Live bearing Mammals “Eutheria” True placenta True placenta Offspring spend longer developing in mother Offspring spend longer developing in mother

12. The reality of the situation at ~ 65 M ybp Mammals (monotremes, marsupials & eutherians) were all a very small part of animal diversity Eutherians represented by a very small number of small, nocturnal, shrew-like animals The “K/T Boundary” (cretaceous/tertiary)

13. The reality of the situation at ~ 65 M ybp The “K/T Boundary” (cretaceous/tertiary)- one of many historical “Mass extinctions” (many living groups, including the dinosaurs)

14. Mammalian diversification Explosive diversity of mammalian types in “vacuum” of rapid dinosaur extinctions- especially eutherians

15. ~60 M ybp Primates (taxonomic Order) Tree-dwelling Tree-dwelling Omnivorous Omnivorous Branchiate- swing by arms Branchiate- swing by arms Dexterous hands Dexterous hands Claws replaced by nails Claws replaced by nails Opposable thumb Opposable thumb Forward-facing eyes, binocular vision Forward-facing eyes, binocular vision Parental care Parental care

16. ~ 58 M ybp Ancestral Primate “Wet-nosed” primates Mostly nocturnal Tree-dwelling Lemurs “Dry-nosed” primates Mostly diurnal Specialized hands and feet for grasping Tarsiers + Monkeys & Apes (a.k.a. “Simians”) First- cat-sized and arboreal

17. ~ 40 M ybp Ancestral Simian New-World Monkeys N/S America Long prehensile tail Flat nose Tree-dwelling Mostly nocturnal Capuchin, Marmosets, Howler monkey Old-World Monkeys + others Africa & Asia Simple, no tail Narrow nose Tree-dwelling Mostly diurnal Flat fingernails Baboon, Macaque, Great Apes Atlantic Ocean

18. ~ 25 M ybp Ancestral Old World Monkeys, et al Old-World Monkeys Baboon, Macaque, Proboscis Monkey (Apes) “Hominoids” Mostly arboreal Africa, Asia Other anatomical features Gibbon, Great Apes

19. ~ 18 M ybp Ancestral Hominoids “Lesser Apes” Tree-dwelling Strong brachiating Gibbons The “Hominidae” Humans +Great Apes

20. The “Hominidae”

21. Orangutans Asia ~ 14 M ybp Sivapithecus (Ramipethecus)- fossil ~ 14 M ybp Initially thought to be an early “homininae” The “Homininae” Evolved in Africa: Gorilla, Chimp, Pygmy Chimp, Human

22. The “Homininae” ~ 7 M ybp Gorillas 2 (4?) species Knuckle-walk Intelligent Western & Eastern species (w/ subspecies) The “Hominini” Humans, Chimpanzee, Pygmy Chimpanzee (Bonobo)

23. The “Hominini” 6- 7 M ybp Molecular evidence- “Molecular clocks” Antibody specificity DNA hybridization Chimpanzee Larger, stockier More aggressive Male-dominated social groups Bonobo Gracile More cooperative, more sexual Female-dominated Social groups The “Hominids” Humans + fossils leading to modern humans

24. The “Hominids” Bipedal Large brain Small canine teeth teethLater: Tool production Tool production Language Language Art Art

25. BREAK TIME

27. D F G E B A

28. Raymond Dart- 1924 Australopithecus africanus

29. Donald Johansen Australopithecus afarensis

30. 1994- East Africa & Chad

31. Importance of A. afarensis “Robust” lineages “Gracile” lineages

32. “Once we were not alone”

34. ChimpGorilla CD G B E

35. Homo sapiens as the “wanderer” The “out of Africa” theory Years before present (byp)