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Primates. Objectives. Discuss physical characteristics shared by all primates Compare similarities and differences between the major primate groups Video: Survey of the Primates. Characteristics of primates. Generalized limb structure Prehensile hand and feet Nails instead of claws
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Primates ANA 215 Primates
Objectives • Discuss physical characteristics shared by all primates • Compare similarities and differences between the major primate groups • Video: Survey of the Primates ANA 215 Primates
Characteristics of primates • Generalized limb structure • Prehensile hand and feet • Nails instead of claws • Omnivorous/generalized dentition • Colour vision • Depth perception ANA 215 Primates
Characteristics of primates • Decreased reliance on smell • Increase in brain complexity • Decrease in the number of offspring • Increase in learned behavior/increase in parental care • Diurnal (mostly) • Social groups ANA 215 Primates
Anatomy - cranium • Brain case • Post-orbital bar • Post-orbital plate • Auditory bulla • Orbits • Flexion of the cranium ANA 215 Primates
Theory • Arboreal hypothesis • Jerison 1973 • Visual predation hypothesis • Cartmill 1992 • Flower and fruit hypothesis • Sussman 1991 ANA 215 Primates
Distribution of primates • New World : tropical and sub – tropical areas including Mexico • Old World : Africa, India, SE Asia and Japan • Habitats: Arboreal and Woodland ANA 215 Primates
Dental formula Most prosimians and NWM 2:1:3:3 2:1:3:3 X 4 = 34 OWM, Apes and Humans 2:1:2:3 2:1:2:3 x 4 = 32 ANA 215 Primates
Mode of locomotion • Intermembral Index = Length of humerus + length of radius Length of femur + length of tibia X 100 • Vertical clinging & leaping: 50 – 67 • Quadrapedalism: 68 – 105 • Brachiation : 106 – 150 • Humans: 72 (spectrum 53 – 150) ANA 215 Primates
Classification changes • DNA hybridization: 98.4% similarity between chimpanzees and humans. Homo troglodytes? • Tarsiers • Strepshirhini (wet nosed Prosmii) • Haplorhini (dry nosed tarsiers and anthropoids). ANA 215 Primates
Prosimian (Strepsirhini) • Increase reliance on smell • Shorter gestation and maturation • Eyes are more laterally placed • Dental comb ANA 215 Primates
Prosimians (Strepsirhini) ANA 215 Primates
Tarsier (Haplorhini) ANA 215 Primates
Anthropoids • Larger brain/body size • Reduced reliance on smell • Increased reliance on vision & colour vision • Postorbital plate ANA 215 Primates
Anthropoids • Fused mandible • Longer gestation and maturation • Increased parental care ANA 215 Primates
Platyrrhini vs Catarrhini ANA 215 Primates
Evolution of monkeys • OWM and NWM • 30 – 50 mya derived from a common monkey ancestor • Floating islands • Homoplasy ANA 215 Primates
Hominoids • Larger than anthropoids • No tail • Shorter trunk • Increase in complexity in brain, behavior and cognition • Increased period of infant dependency ANA 215 Primates
Extinction of primates • Habitat destruction • Bush meat (hunted for food) • Capture for export or trade ANA 215 Primates
Primate Maze Practical • NW 1 Computer Lab: 20/02/06 • Read Chapter 6 of Jurmain et al. (2005) ANA 215 Primates