Chapter 6

1. Chapter 6 A Survey of the Living Primates

2. Chapter Outline • Primates Characteristics • Primate Adaptations • Geographical Distribution and Habitats • Diet and Teeth

3. Chapter Outline • Locomotion • Primate Classification • A Survey of the Living Primates • Endangered Primates

4. Primates As Mammals • There are approximately 190 species of nonhuman primates • Primates belong to: • Vertebrate class - Mammalia • Subgroup of placental mammals.

5. Prosimians • Members of a suborder of Primates, the Prosimii. • Traditionally, the suborder includes lemurs, lorises, and tarsiers.

6. Primates • Members of the order of mammals Primates, which includes prosimians, monkeys, apes, and humans.

7. Anthropoids • Members of a suborder of Primates, the Anthropoidea. • Traditionally, the suborder includes monkeys, apes, and humans.

8. Primates Characteristics • Fur (body hair) • Long gestation followed by live birth • Homeothermy, the ability to maintain a constant body temperature • Increased brain size • Capacity for learning and behavioral flexibility.

9. Primate Limbs • A tendency towards erect posture. • Hands and feet possess grasping ability. • Features of the hands and feet: • 5 digits on hand and feet • Opposable thumb • partially opposable great toe • Tactile pads enriched with sensory nerve fibers at the ends of digits

10. Primate Limbs • A horse’s front foot, homologous with a human hand, has undergone reduction from 5 digits to one.

11. Primate Limbs • Raccoons are capable of considerable manual dexterity and can readily pick up small objects with one hand, they have no opposable thumb.

12. Primate Limbs • Many monkeys are able to grasp objects with an opposable thumb, while others have very reduced thumbs.

13. Primate Limbs • Humans are capable of a “precision grip.”

14. Primate Limbs • Chimpanzees with their reduced thumbs are capable of a precision grip but frequently use a modified form.

15. Primate Senses and the Brain • Color vision is a characteristic of all diurnal primates, nocturnal primates lack color vision. • Depth perception is made possible by eyes positioned forward on the front of the face. • Decreased reliance on the sense of smell. • The brain has expanded in size and become increasingly complex.

16. Binocular Vision in Primates

17. Primate Maturation • Longer periods of gestation • Reduced numbers of offspring • Delayed maturation • Extension of the entire life span.

18. Primate Learning and Behavior • Have a greater dependence on flexible, learned behavior. • Tend to live in social groups. • Males are permanent members of many primate social groups, a situation unusual among mammals.

19. Base of an Adolescent Chimpanzee Skull • In an adult animal, the bones of the skull would be fused together and would not appear as separate elements as shown here.

20. Question • Which of the following is not a primate characteristic? • stereoscopic vision • highly developed sense of smell • orthograde or upright posture • prehensility

21. Answer: b • A highly developed sense of smell is not a primate characteristic.

22. Question • Binocular vision in primates contributes to • color vision. • lateral vision. • panoramic vision. • stereoscopic vision.

23. Answer: d • Binocular vision in primates contributes to stereoscopic vision.

24. Primate Adaptation • Primate anatomical traits evolved as adaptations to environmental circumstances. • Arboreal Hypothesis • Visual Predation Hypothesis • Angiosperm Radiation Hypothesis

25. Arboreal Hypothesis • Arboreal living was the most important factor in the evolution of primates. • Prehensile hand is adapted to climbing in the trees. • A variety of foods led to the omnivorous diet and generalized dentition.

26. Visual Predation Hypothesis • Primates may have first adapted to shrubby forest undergrowth and the lowest tiers of the forest canopy. • Forward facing eyes enabled primates to judge distance when grabbing for insects. • Flowering plants may have influenced primate evolution.

27. Angiosperm Radiation Hypothesis • Suggests the basic primate traits were developed in conjunction with the rise of the angiosperms (flowering plants) that began around 140 mya. • Flowering plants provide numerous resources for primates, including nectar, seeds, and fruits.

28. Geographical Distribution of Living Nonhuman Primates

29. Geographical Distribution of Living Nonhuman Primates

30. Primate Habitats • Most live in tropical or semitropical areas of the new and old worlds. • Most are arboreal, living in forest or woodland habitats. • No nonhuman primate is adapted to a fully terrestrial environment; all spend some time in the trees.

31. Primate Diet and Teeth • Generally omnivorous, reflected in their generalized dentition. • Most eat a combination of fruits, leaves, and insects. • Most have four types of teeth: incisors, canines, premolars and molars.

32. Dental Formula • The human maxilla (a) illustrates a dental formula characteristic of Old World monkeys, apes, and humans. The Cebus maxilla (b) shows the dental formula typical of most New World monkeys.

33. Primate Locomotion • Most are quadrupedal, using all four limbs in their locomotion. • Arm swinging is found among the apes. • Prehensile tails, found only among the new world monkeys, are used as an aid to locomotion.

34. Differences in Anatomy and Limb Proportions and Locomotor Patterns

35. Differences in Anatomy and Limb Proportions and Locomotor Patterns

36. Differences in Anatomy and Limb Proportions and Locomotor Patterns

37. Differences in Anatomy and Limb Proportions and Locomotor Patterns

39. Human Chromosome 2 • Human chromosome 2 has banding patterns that correspond to those of chimpanzee chromosomes 12 and 13. • These similarities suggest that human chromosome 2 resulted from the fusion of these two ape chromosomes during the course of hominid evolution.

40. Revised Partial Classification of the Primates • The terms Prosimii and Anthropoidea have been replaced by Strepsirhini and Haplorhini.The tarsier is included in the suborder with monkeys.

41. Prosimians • The most primitive of the primates. • Characteristics: • Reliance on olfaction • Laterally placed eyes • Shorter gestation and maturation periods • Dental specialization called the "dental comb”

42. Rhinarium • This cat’s rhinarium enhances his sense of smell.

43. Dental Comb • Prosimian dental comb, formed by forward projecting incisors and canines.

44. Lemurs • Found on the island of Madagascar and other islands off the coast of Africa. • Extinct elsewhere in the world. • Characteristics: • Larger lemurs are diurnal and eat vegetable foods: fruit, leaves, buds, and bark. • Smaller lemurs are nocturnal and insectivorous (insect -feeding).

45. Geographical Distribution of Modern Lemurs

46. Ring Tailed Lemur

47. Sifakas in Their Native Habitat in Madagascar

48. Slow Loris

49. Galago or “Bush Baby”

50. Lorises • Found in tropical forests and woodlands of India, Sri Lanka, southeast Asia, and Africa. • Characteristics: • Use a climbing quadrupedalism. • Some are insectivorous; others supplement their diet with fruit, leaves, gums, and slugs. • Females frequently form associations for foraging or in sharing the same sleeping nest.