PSYC 4030 Chapter : 10 30 13 DM 1 2
Document Summary
Our family tree: fossil record very scant between 10-4 mya, ca. 5-6 mya=time when homin lineage diverge from lineage comprising chimpanzees: two possible earlier ancestors: sahelanthropus tchadensis and ardipithecus ramidus. Sahelanthropus t chadensis: 7mya, still debated whether or not it lived before or after human chimp divergence, discovered in 2001, chad, africa. A afarensis great ape from afar: 3-4 mya, bipedal, brain size ca. 400cc: lucy found by donald johanson and colleagues at hadar, ethiopia in 1874, the laetoli footprints, found by mary leakey 1978, footprints in volcanic ash, 3. 8mya. What are the perks of bipedalism: long distance travelling, protection from predators and increased visibility, control over body temperature in hot, sunny climates, free hands, bipedalism came before tool making and evidence for larger cranium. Inferior placement of foremen magnum: longer legs relative to arms, non-opposable big toe, and arc to the foot, hip bones/pelvis.
