1. Human evolution Chapter 34

2. Humans???

4. Archonta 65 mya Small arboreal (tree-dwelling) mammals Large eyes Insect eating Nocturnal Gave rise to bats, tree shrews & primates

5. Primates 1. Grasping fingers & toes Opposable thumb 2. Binocular vision Eyes are shifted in front 2 fields of vision Helps with depth perception

6. Primates Initially insect eating Teeth adapted to eat plants Fewer number of teeth Snout length began to get smaller

7. Primates Split into 2 groups 40 mya 1. Prosimians “before monkey” lemurs, lorises and tarsiers Common in NA, Europe, Asia & Africa Increased visual acuity Fruit, leaves & flowers

8. Lemurs

9. Lorises

10. Tarsiers

11. Primates 2. Anthropoids Monkeys, apes, humans Diurnal: active during the day Feeding fruits & leaves Color vision evolved-daytime foraging Expanded cortex for improved senses

12. Anthropoids Live in groups Complex social interactions Care for young for extended time Nurtures brain development

13. Aye-Aye

14. Spider monkey

15. Anthropoids New World monkeys (Americas) 30 mya migrated to SA Isolated Arboreal (tree-dwelling) Flat spreading noses Prehensile tails Helps hanging in trees

16. Squirrel monkey

17. Capuchins

18. Anthropoids Old world monkeys Ground dwelling Some arboreal Nostrils come together Noses point down Toughened pads of skin to sit upon No prehensile tails

19. Old world monkeys Baboons, mandrills, macaque

20. Mandrill

21. Baboon

22. Pig-tail macaque

23. Anthropoids 25 mya Hominoids (human line) Branched from old world monkeys 1. Hominins (humans) 2. Ape group Gibbons, Orangutans, Gorilla, and Chimpanzees

24. Hominoids

25. Chimpanzee

26. Gibbon

28. Gorilla

29. Orangutans

31. Apes Larger brain than monkeys Lack tails Long arms & short legs Most larger than monkeys Except Gibbon Gibbons & orangutans are arboreal

32. Apes Gorillas & chimpanzees highly social Behavior more adaptable Spread over Africa & Asia None in NA & SA

33. Gorilla

34. Apes Chimpanzee split from common ancestor about 6 mya Genes of human & chimpanzees similar Shares 98.6% of DNA Human Hgb only one aa different

35. Chimpanzee

38. Compare Apes to hominins Common ancestor arboreal climber Hominins bipedal Walking upright Apes are knuckle walkers Support weight on fingers

39. Compare Apes to hominins Vertebral column more curved Spinal cord exits at bottom of the skull Rather than the back Pelvis is more bowl shaped Pelvis bones curve forward to support more weight Legs are longer than arms support more weight

42. Compare Apes to hominins Larger brain Capable of language Manufacture & use tools Reduced jawbones & jaw muscles Shorter digestive tract

43. Primates Prosimians Anthropoids 1. New world monkeys 2. Old world monkeys 3. Hominoids Apes (Gibbons, Orangutans, Gorilla, Chimpanzee) Hominins

45. Paleoanthropology Study of human evolution Chimpanzees & Hominins 2 divergent branches of hominoid tree Homo sapiens Multi branched bush

46. Hominins Upright position came first Enlarged brain coming second Mosaic evolution: Different features evolved at different rates

47. Hominins Why upright? Tools found until 2.5 mya Faster/less energy Pick fruits/carry food See over tall grass

48. Hominins 10 mya climate became drier/cooler Savannas & grasslands More time walking in open habitats Less time in trees

49. Hominins Brain size tripled 400-450 cm 3 to about 1,300 cm 3 in modern humans Reduced size difference between sexes Gorilla & orangutan males 2X heavier than females Humans average male is 1.2X heavier

50. Hominins Two major groups of Hominins Genus Homo (3-7 species) Genus Australopithecus Latin australo, meaning “southern” Greek pithecus meaning “ape” Approximately 7 species Older genus-smaller brains

52. Australopithecus A. africanus Skull 2.8 million years old Walked fully erect Human-like hands & teeth Brain 1/3 size of a modern human

53. Australopithecus “Lucy” Afar region of Ethiopia A.afarensis 40% complete skeleton 3.24 mya

56. Homo 1960 East Africa Homo habilis- “handy man” Fossils of earliest genus Homo. 2.5 to 1.6 mya Found with tools

57. Homo H. ergaster “workman” Fossils date 1.9 to 1.5 mya Larger brain (900cm 3 ) Longer slender legs Hip joints-walking Fingers short & straight Smaller teeth----cooked food Early ancestor to later species of Homo

58. Homo ergaster

59. Homo erectus First hominins to migrate out of Africa Colonizing Asia & Europe “java man” or “Peking man” Lived 1.8 million to 500,000 years ago Larger than Homo habilis-1.5 meters Larger brain (1000 cm 3 ) Sexual dimorphism similar to modern man

60. Homo erectus Social species Lived in tribes of 20-50 people Dwelling in caves Hunted large animals Used flint for fires Lived longer than any other species

61. Homo neanderthalensis Neanderthals Lived in Europe 200,000 to 40,000 years ago Thick boned, heavy hominins Prominent brow Brain size of humans Extinct 30,000 years ago

62. Homo sapiens Originated in Africa-DNA evidence Older species (H.ergaster or H.erectus) gave rise to H. sapiens Oldest fossils dated 195,000 to 160,000 years in Ethiopia Oldest fossils outside of Africa is 40,000 years old

63. Homo sapiens Humans spread to NA 13,000 years Only surviving hominins Increasing brain size Use tools Symbolic language Shape concepts out of experience Transmit experience from one generation to another