BIOLOGY 1M03 Chapter 10: Chapter 10-bio 1m03
15 Dec 2016
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Document Summary
Cooling + climate of the earth led to the evolution of hominins. End of miocene - cooling, less rain, rain seasonality, woodland and savannah spread. Bipedalism ! led to major morphological changes. Hominoids to hominins - many new adaptations. Human pelvis is different from forest-dwelling apes like the chimp. Torque - created by a twisting force from pelvis. Torso does not tip due to abductor muscles that run from outer side of pelvis to the femur ! Lengthening neck of femur add to leverage that he abductors can exert and make bipedal walking more efficient. Feet ! non-grasping big toes and arches. First hominin discovered between 7 to 5 mya ! Chimpanzee sized brain, shares many traits with chimpanzees. Hole in the skull through which the spinal cord passes, suggests bipedal locomotion. Dated to 6 mya, found in kenya. Also similar to chimps ! incisors, canines, premolar. Found in ethiopia ! dry conditions very nice for fossils: ramidus.
