Unit 4 continued Primates and primate behavior

Transcription

1 Unit 4 continued Primates and primate behavior 1

2 Primates Traits found across the primate order *Tendency towards erect posture *Highly prehensile hands and feet *Generalized dentition *Reliance on complex behavior What accounts for these traits? Why did such adaptive features emerge in the first place? 2

3 Arboreal hypothesis Cluster of primate traits are the result of living in the trees. Evidence for: -highly prehensile hands and feet -generalized diet fits with the niche 3

4 Arboreal hypothesis Cluster of primate traits are the result of living in the trees. Evidence for: -highly prehensile hands and feet -generalized diet fits with the niche Evidence against: -other mammals live in the trees but lack primate characteristics 4

5 Visual adaptation hypothesis Cluster of primate traits are the result of the visual emphasis of insect predation Evidence for: -accurate, 3-D vision -grasping hands and feet Evidence against: -primates are characterized by a generalized diet and dentition 5

6 Angiosperm radiation hypothesis Cluster of primate traits are adaptive responses to the radiation of flowering plants Evidence for: -diverse set of foods make generalized diet more likely -explains emergence of color vision Evidence against: -Angiosperms appeared millions of years before primates 6

7 Strepsirhini Groups: Lemurs and lorises Compared to the haplorhines -more ancestral -more reliance on olfaction -less reliance on complex behavior -faster maturation rates 7

8 Haplorhines - monkeys, apes, and humans Platyrrhines New world monkeys -prehensile tails, found in South America 8

9 Haplorhines - monkeys, apes, and humans Catarrhines (Africa and Asia) Old world monkeys, apes, and humans Cercopithecoids Old world monkeys 9

10 Haplorhines - monkeys, apes, and humans Catarrhines (Africa and Asia) Old world monkeys, apes, and humans Cercopithecoids Old world monkeys Cercopithecines (baboons, macaques, etc) 1. Ischial callosities - sitting pad composed of callused skin 2. Estrus - period of female sexual receptivity (correlated with ovulation) Colobines (leaf-eating monkeys) Tarsiers (some traits from both subfamilies) Hominoids (apes and humans) - see rest of the ppt 10

11 Hominoids - the apes and humans Compared to the other haplorhines, hominoids: Location: Asia and Africa -larger body size -lack a tail -shoulders adapted for suspensory behavior -more complex behavior -increased period of infant dependency 11

12 Gibbons and Siamangs Location: Asia Morphology: traits reflecting adaptation to brachiation Behavior: territorial; social unit = adult male and female and their offspring 12

13 Orangutans Location: Islands of Sumatra and Borneo Morphology: sexual dimorphism between male/female body size Diet: frugivorous Behavior: mostly solitary 13

14 Gorillas Location: West/east equatorial Africa Morphology: largest living primates; also sexual dimorphism between male/female body size Diet: vegetarian Behavior: Groups with one or two adult silver back males, several females and offspring 14

15 Chimpanzees Location: equatorial Africa Morphology: smaller body size; less pronounced sexual dimorphism Diet: varied diet (fruits, leaves, and hunting small animals) Behavior: live in large communities; complex social interactions emphasizing male-male bonds 15

16 Bonobos Location: Near Zaire River Morphology: similar body size to chimpanzees Diet: varied diet Behavior: fluid communities; complex social interactions emphasizing male-female bonds; copulate throughout female estrous cycle 16

17 17

18 Humans Location: Everywhere Morphology:adaptations of the pelvis, leg, and foot enable habitual bipedalism Diet: generally omnivorous Behavior: Completely dependent on culture 18