BIOL 123 Lecture Notes - Lecture 3: Brachiation, Pongidae, Orangutan
Document Summary
Hominoids: brachiating (swinging from branch to branch, e. g. gibbon) Diverged from old world monkeys 25 mya. Ripe fruit specialists (lost vit c gene) No tails (adapted for brachiation, long arms, shorter legs, flat chests, shoulder blades at back, rotating arms) Pongidae (orangutan): hangs out in dense forests in south east asia. Gorillas (2 species): diverged from us and chimps +/- 9 mya. Diverged from humans 8-7 mya when africa became dryer, and when the ardipithecines began walking on two legs. Bonobo chimps: social ties (in chimpanzees: aggression, dominance vs bonobos: sexual acts, relationships). Footprints discovered in 1978 (bipedal walkers 3. 5mya) possibly australopithecus afarenesis. Prints show heel to toe striding weight shifts over big toe (different from chimps) Lots of structural changes needed (neck, lower back, hips and pelvis, thighs, knees, Neck under skull vs behind (balances head on spine) S-shaped spine vs arch (absorbs shock as feet hit ground)
