1. Long gestation. Reduced numbers of offspring/pregnancy. Extended period of time to reach reproductive maturity Greater dependence on flexible, learned behaviors

2. Tendency to live in social groups.

3. Menstrual and estrus cycles

4. Centers of gravity and pelvis shape Bipedalism

7. Chimpanzee: wrong pelvis for sustained bipedalism

9. In solidified volcanic ash – dated at 3.6 mya) Australopithecus afarensis: Laetoli, Tanzania, Africa

10. Sounds and language

12. Brain size

14. c. 55 mya Modern primates

15. Primate diversity Madagascar

16. Prosimians Primitive Southeast Asia, Africa, Indonesia, Madagascar Snout with moist, fleshy nose-pad Madagascan radiation: formerly 44 species of lemurs. Size range. Humans arrived c. 2,000 ybp Therefore, many species exterminated

17. Specialized features Aye-aye Madagascar

18. Lemurs Madagascar Lemurs: e.g., Ring-tailed--mostly terrestrial e.g., Sifakas--arboreal

19. Lorises Gabon, Central Africa Different niches

20. Tarsier SE Asia

23. Arboreal Some with prehensile tails New World monkeys

25. Almost exclusively arboreal Most quadrupedal Left: 7 species different niches

27. Old World monkeys Tails not prehensile Most arboreal and quadrupedal Colobus monkey

28. Exception: baboons: mainly terrestrial

29. What’s wrong? Humans share a common ancestor with great apes

31. Gibbons & Siamangs On a evolutionary branch separated from all other primates Relatively small ‘lesser’ apes 13-25 lbs. 9 species SE Asia

32. A gibbon Most have extremely long arms Permanently curved fingers Short thumbs

33. Orangutan Indonesian Islands: Java & Borneo On an evolutionary branch separated from other great apes and humans Pronounced sexual dimorphism males: 200+ lbs females: 100 lbs Slow, cautious climbers “four-handed” Almost exclusively arboreal Largely solitary

34. ♂ ♀ Pronounced sexual dimorphism

35. Orangutan (juvenile) Quadrupedal Bears weight on sides of hands and feet

36. Gorillas Largest living primates On an evolutionary branch separated from humans, chimpanzees, and bonobos Western and eastern equatorial Africa Pronounced sexual dimorphism –males: 400 lbs. –females: 150-200 lbs. Primarily terrestrial

37. 2 Species:Western (Lowland gorillas) and Eastern (Mountain gorillas)

38. Young gorilla Quadrupedal knuckle walking

39. Chimpanzees: most closely related to bonobos (same genus: Pan) Moderate sexual dimorphism: males: 100+ lbs; females: 80 lbs Some populations use tools; may engage in group hunting for meat

40. Chimpanzee Bonobo Not a “pygmy chimpanzee” Separate species

41. Bonobo Democratic Republic of the Congo Has attracted attention because of a full repertoire of sexual activities used extensively in its social interactions More linear body than chimpanzees Longer legs relative to arms Relatively smaller head Brief bouts of bipedalism: mostly quadrupedal

42. Threatened species Bonobo future? Rocky Mountain News: March 6, 2006 1984: Est. 100,000 2005: Est. 5,000 Why the drop in density? Killed and sold (ca. $200/bonobo) Prized as food. Sold to local markets and urban restaurants