THE PRIMATES

1. THE PRIMATES Year 13 Biology Achievement standard 3.7

2. Terms • Arboreal – Tree-dwelling • BinocularVision – ability to see 3D, depth perception and colour • Prehensile – ability to grasp (hands, feet, tail) • Quadrapedalism – walking on all four limbs • Brachiation – use of arms to suspend body during feeding and to move the body by arm-swinging • Bipedalism – walking on two legs (habitual) • Hominid – Humans and their ancestors • Hominoid – Group containing humans and apes

3. Primate Groups • Prosimians • Arboreal or tree living • Grasping hands and feet • Long, mobile limbs • Quadrapedal • Binocular vision • Upright sitting position • Nails instead of claws • Use scent marking to communicate – wet nose

4. Primate Groups • New World Monkeys (Americas) • Prehensile or grasping tail – used as a 5th limb • Quadrapedal • Arboreal or tree living • Nostrils wide apart • E.g. spider monkey

5. Primate Groups • Old world monkeys (Africa and Asia) • Tail not prehensile • Quadrapedal • Some are ground living • Nostrils close together – reduced sense of smell • E.g. Baboon

6. Primate Groups • Great Apes • Some brachiating • Mostly ground dwelling • Quadrapedal • Flattened nose • Bony eye ridges • E.g. Gibbon, Gorilla, chimp, Orangutan

7. Primate Groups • Hominids • Bipedal • Reduced canines and outer teeth • Large cerebral cortex (forebrain) • Eye ridges reduced, chin and nose protrude • Very sensitive skin • Reduced body hair • Very complex social behaviour

8. Evolution of Apes and Human (Hominoids)

9. Primate Skull Features Cranial Vault Sagittal Crest Nuchal Crest Brow Ridge Heavy Malar Zygomatic Arch Diastema Foramen Magnum Protruding Muzzle Massive Jaw Large Canines Massive Molars

10. General Ape Characteristics • No tail • Y-5 Pattern on teeth. • Quadrupedal • Semi or fully-erect posture • Arms long in comparison with hind limbs • Rib cage flattened from front to back • Larger brains • Upper lip free from gums • Powerful canine teeth and large incisors

11. Differences between Humans and Apes • Main physical differences between quadrupedalism and bipedalism • The Skull • Teeth and Jaw • The legs • The feet • The chest

12. Physical differences between Apes and Humans

13. Physical differences between Apes and Humans – The Skull

14. Physical differences between Apes and Humans – The Skull

15. Physical differences between Apes and Humans – The Skull

16. Physical differences between Apes and Humans – The teeth and jaw.

17. Physical differences between Apes and Humans – The teeth and jaw.

18. Physical differences between Apes and Humans – The pelvis and backbone

19. Physical differences between Apes and Humans – The pelvis and backbone

20. Physical differences between Apes and Humans – The legs

21. Physical differences between Apes and Humans – The feet

22. Physical differences between Apes and Humans – The chest

23. Bipedalism V’s Quadrupedalism • Advantages and disadvantages of bipedal (upright) walking

24. Why walk upright? • In Early Africa, Apes lived in a continuous forest and as a result were adapted for an arboreal life. • Climate changed (drier) and forest retreated leaving large areas of grassland. • Divergent evolution occurred – some remaining in the trees and some developing bipedalism as an adaptation for moving between the patches of forest.