Quote:
Originally Posted by Baron von Richthofen
Up to a few months ago I would have agreed with you but a recent find squashed all that, the common ancestry to man and primates walked upright and did not live in trees, primates developed independently like man, so man has never climbed out of the trees and always walked upright
It was on the news about 6 weeks ago
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You have a few misconceptions which I will clear up for you. Firstly, the common ancestor of the chimpanzee and human line split from the rest of the apes around 8-10Ma (million years ago). Secondly, by around 6-8Ma, when the line that developed into us split from the chimps, we were already walking upright. The adaptation to walking upright, with the accompanying pelvic and spinal structure, was already well advanced by then and evident in the fossil record. Upright posture was an adaptation to walking along the branched in the trees. It allowed those early ancestors to move quickly through the trees (much faster than if they were on all fours) and to be able to see better over much longer distances. By the time we had migrated down to the ground semi-permanently, our spinal and pelvic structures were already fully adapted to walking upright (if a little clumsily compared to where we are now). Knuckle walking in chimpanzees is a secondary evolutionary trait that developed after the split with humans i.e. in the last 6-8Ma. It's a condition that was an adaptation to walking along the ground in those early primates and still is evident in the modern great apes.
Have a look at the way gibbons move through the trees when they're not swinging from branch to branch. They actually walk upright, supporting themselves using their arms to hold overhead branches. They then walk along the branches using their legs. When a gibbon comes down to the ground, they walk upright and hold their arms in the air above their heads to balance themselves. That's how it was most likely done in the first place, much like the gibbons.