Monday, April 19, 2010
Pelvis and Hip Bone - human evolution
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Homo Erectus and Homo Neanderthal
Beside the large brain another evidence of human evolution is the hip bone and pelvis. Knuckle walkers have a flat pelvis while distance walkers have a more horizontal pelvis for supporting the upper body. Bent over apes mainly climbed trees. They need less support for walking and more for grasping and climbing.
The earth went through a major drought millions of years ago and it is believe this favored walking upright because the rain forest in Africa were disappearing. Going long distances required the ability to walk upright because knuckle walking was quite expensive energy-wise. Natural selection was favoring distance walkers. They could find food. The great apes remained local, but humans left Africa and travelled to Europe and Asia.
Human - Gorilla - Chimpanzee - Orangutan - Gibbon
Note the pelvis and hip bones. One other feature is how the legs bend inward for humans.
The famous fossil Lucy shows the bottom half as human and the top half as ape.