Why Do Primates Free Their Hands How Is Walking Upright...

Walking upright with two legs is a common daily phenomenon, however, the ability of moving with only two legs is the result of millions of years of evolution and adaptation. During the process of human evolution, the appearance of bipedalism, which describes the terrestrial locomotion where animals move with their rear limbs in the form of walking, hopping or running, is considered as one of the major steps that sets Hominin group apart from other primates. Even though the transition from quadrupedalism to bipedalism has major drawbacks that sacrifice the flexibility and prevent bipeds to effectively practice arboreal locomotion, it provides a new form of locomotion and frees both hands to be capable of completing other projects while†¦show more content†¦Another explanation of bipedalism is that walking upright reduce the energy consumption. Michael Sokol, a professor from University of California, Davis, David Raichlen, a professor from University of Arizona, Tucson, and H erman Pontzer, a professor from Washington University, St. Louis, conduct an experiment that examines the energy consumption level for both humans and adult chimpanzees. Their studies suggest that â€Å"early transitional forms would have reaped some energy savings with minor increases in hip extension and leg length.† According the research, they also conclude that energetics is an important factor in the evolution of bipedalism and the improved efficiency of locomotion â€Å" may accrued very early within the hominin lineage.† Methods As Lovejoy indicates that males need their hands to carry food for their partners and offsprings, so that bipedalism starts to appear. This hypothesis is hard to prove, however, logically speaking, carrying highly energy-rich food such as nuts or fruits is beneficial to the group and community. A study conducted in West Africa suggests that early hominids walk upright to carry resources away from other competitors. Researchers provide piles of oil palm and nuts to 11 chimpanzees, who prefer the nuts. According to the research, the chimps are four times more likely to walk upright with two legs, so that they are able to