4/10 Biological Anthropology- Forward displacement- Side to side movement- These take up a lot of energyo All these features in bipedalism help to decrease the amount of displacement w/ the eyes and decrease the use of a lot of energy- Origins of hominin bipedality coincides w/ the origin of hominis and coincides w/ change in tropical forest to a break up forests- Our ancestors are commited to terrestrial bipedality- Chickens, t rex are all bipedal- Bipedalists are slow but we’re good at endurance walking- Traits that led to hominin originso Bipedalism Hunting? Predator defense? All about feeding? Energetics?  Tools?- Culture (stone tools)o Oldowan tools 2.3 MYA and go till 1.8 MYA; Homo habilis- Bipedalism adaptive- Allow to transfer food- Energy efficiency in walking; decrease heat stress during walkingo Achelles tendon-energy storage - Plantar ligament- Anterior longitudinal ligaments store energy; long ligaments- Great thermoregulation- Decouples respiratory system-when we walk/run we can alternate breathing patterns- Most hominins came from Africa, South Africa and East Africa- Darwin and Huxley believed our homeland was Africa- Australopithecines, East Africao Ehtiopia, Hadar and Aramiso Laetoli, Tanzaniao Kenya, Lake Turkanao Open air sites deposited by rivers and lakes w/ volcanic layers- Know Hadar, West Turkana, Awash, Laetoli, Olduvai Gorge- South Africa siteso Gracile Taung Sterkfontein  Makapansgato Robust Swartkans  Kromdraai Only size of the head is the difference- Geologyo East African Well stratified, deposits interbedded w/ volcanic layerso South African Caves, no strata, use biostratigraphy-relative dating- Afar depression-open air area in East Africa- South African limestone karstic systemso Water erodes down and carves cave systems out- Early Hominido Sahelanthropus tchadensiso Chad, deserto 6-7 MYAo Miocene ape w/ large canines, smalls cranial capacity (340-360cc)o Hominoido Possibly bipedal based on foreamen magnum (more anterior)- Plio-Pleistoceno Orrorin tugenensiso North Kenyao Miocene ape w/ small bunodont molars and small caninso ARdipethicus ramidus and kadabba 4.4 MYA at Aramis large canines, sectorial lower 3rd premoarl, small brain capacity,thin enamel possibly bipedal close to Pan-chimps and bonobos divergent big toe, longer upper limbs, very long fingers w/ a lotof curvature A anamensis 4.2-3.9 MYA, Lake Turkana, mostly dentition found  Thick dental enamel, probably bipedal Earliest and most primitive of genus Australopithecus Similar shelf- strong, bony in the mouth Megadont- larger molars and premolars Difficult to process food itemso A afarensis 4-3.5 MYA Lucy Hadar and Laetoli Megadontia teeth and jaws Footprints at Laetoli Bipedal Simian shelf; arcades are horseshoe shaped Diastema, premolar canine honing complex Committed terrestrial bipedality Bicondylar angle Decrease in length of iliac blade Long upper limbs Sacrum somewhat broad Grasping feet, curved fingers Not endurance walker Short lower limbs- At some point these early forms diverge from each other; 2.5 MYAo A aethiopicus (Paranthropus) o West Turkana, sagittal cresto Zygomatic attachment points for chewingo Large teetho Small brain case, powerful jaw muscles- From neck down they all look the