venuse8102 on 17 June 2010
a few reasons first those that could use their hands more to create stuff probably lived longer and produced more offspring as well as feed the tribebetter. second bipedal locomotion is actually more efficient and allowed our ancestors to run for longer distance, although not as fast as other predators, allowing them to basically kill their prey by simply wearing them out. thus those that ran upright beat out the ones that ran on all fours. their are probably other reason but ive forgotten.
