Importance of Bipedalism to Human Evolution

Importance of Bipedalism to Human Evolution

A biped is an animal or machine that moves on two rear limbs or legs. This is a form of terrestrial locomotion. Biped means two feet that is bi for two and ped for foot. Bipedal movements range from walking, running, or hopping. In the process of human evolution, this is considered as one of the major steps as it was the transition from quadrupedalism in terrestrial ancestor to bipedalism in early man. Understanding the evolution of human bipedalism will provide valuable insights in physiological characteristics of locomotion in modern man. This paper therefore explores the motivational factors that lead to the adaptation of the bipedal posture and the importance of bipedalism to human evolution.

There are several importance of the evolution of bipedalism in human beings, First, there was the need by the quadrupedal to use the rear limbs to stand and facilitate the eating of tree leaves and other shrubs and general eating where one has to hold prey (Schmitt and Lemelin, 2002). It was also important in facilitating arm hanging. In addition, there was the need for social, sexual, and reproductive conduct in early hominids (Schmitt and Lemelin, 2002). This adaptation influenced survivorship and birthrate, monogamous mating structure and male provisioning of food to mate and off springs. a At some point in human evolution, there was increased need to reduce body temperatures through increased heat loss, increased cooling, reduced heat gain and reduced water requirements. For these reasons, the bipedal stance was the most preferred and it was adapted in hot, tropical climates.

Motorized necessities of primates locomotion on thin supple branches (Schmitt and Lemelin, 2002), leads to strong functional differentiation between forelimbs and hind limbs. This may have facilitated the use of forelimbs in tension during climbing and arm-swinging modern monkeys and apes.

References
Schmitt, D. and Lemelin, P. (2002).

References: Schmitt, D. and Lemelin, P. (2002). The origins of primate locomotion: gait mechanics of the woolly opossum. American Journal of Physiological Anthropology. 118,231 -238. Essay on The Evolution Of Bipedal Locomotion Subject: Evolution of Bipedal Locomotion What are we? To the biologist we are members of a sub-species called Homo sapiens sapiens, which represents a division of the species known as Homo sapiens. The most interesting aspect about our species is that we are able to and can walk upright on our hind legs at all times. This is defiantly not the usual way of getting around for a mammal. The view of evolution is to see it as the product of steady environmental pressure exerted on each species, improving its adaptation to its habitat. This pressure, which has been termed natural selection is responsible for this. Natural selection works on the premise that in any population, no two individuals are exactly alike. Most of the differences between them are inherited from their parents, and are thus capable of being passed along to the next generation. Each generation will be slightly different from the one before it, and a little better adapted to the prevailing condition (Hand, 1993). Habitually walking around on the hindlimbs, leaving the forelimbs free for other jobs, is an unusual mode of locomotion. Once our ancestors had adopted an upright stance, many things associated with being human became possible, such as fine manipulation with the hands, and the carrying of food back to a base camp (Leakey, 1981). This does not suggest that some four million years or so ago primitive hominids evolved upright walking in order to use their hands in refined ways or to develop a food-sharing economy. Indeed, this cannot be the case, because these behaviors did not arise until several million years after the development of upright walking. Nevertheless, the origin of bipedalism must be seen as one of the major steps, if not the major step, in human evolution. A principle characteristic of the earliest hominids was probably the adoption of an upright posture and a certain way of walking with the posture. When looking at why these changes occoured, it is important to realize that these changes did not occour as in inevitable trend towards modern man. Why did our ancestors start to walk upright and when did they start to, are questions which need to be examined when figuring out the Evolution of Bipedal locomotion. Upon examination of all the evidence, there seems to be many different explanations. The most significant claim is that Autralopithecus afarensis is probably the first ancestor to all homonids. When studying the bones of A. afarensis they look very modern below the neck. For example, the knee looks very much like a modern human joint; the pelvis is fully adapted for upright walking; and the foot with both modern and primitive features, is adequately structured for bipedalism. Some of the bones in the feet are slightly curved, and look like the bones you would expect to see in a human ancestral who climbed trees (Hunt, 1993). The adoption of upright walking, combined with an analysis of the environments in which hominid bones are found, implies that our ancestors of two million years ago lived in much more open country than did their forebears (Hand,1993). It is Probably at this point in human evolution with respect to bipedalism, A. afarensis was starting to leave behind its arboreal habits. Even still A. afarensis was probably capable of climbing trees in times of danger, and it is likely that they slept in trees, as baboons do, in areas where there are no caves for shelter. However, the body skeleton of these early humans was very different from ours, most