The ability of man to walk in an upright manner is theorized to be brought by the bipedalism undergone by the supposed to be man’s ancestors called collectively as the hominids. As investigations in human paleontology states, the gradual change of weather through time is the main factor why the ape-like ancestors of man had went through this process. As cited in the Origin of Bipedalism (Paleoanthropology in the 1990’s Essays by James Q.
Jacobs), Wheeler’s thermoregulatory model suggest that quadropedal ancestors of man had slowly chose to become bipedal in order to withstand the heat during the post Ice Age era. Being upright will raises the mean body surface higher above the ground, where more approving wind speeds and temperatures prevail. This structure of the vertebra would in turn yields to higher convective heat loss that would now scrap the idea that the hominids ancestors must climb up a tree in order to endure times of too much heat.
This also gives the chance to the hominids, to do their other necessities such as gathering their daily food but still withstanding the heat they were not at first accustomed to. Gradual change to bipedal of the human ancestor’s gave them a better chance for survival in open, savannah-like habitats. After experiencing long period of cold weather, the earth had then gradually change its temperatures up to extremely hot weather conditions. Thus bipedalism had been the way in order that our ancestors survived and then evolved as modern day humans.
It is also been taught that the hominids reduction of canine size had happened along with the change from being quadropedal to bipedal. A. anamensis, A. Afarensis and A. africanus were three chronologically suggested to be ancestors of man exhibits decreasing canine size. This had been theorized then as the ancestor’s response to the change in behavior of hominids that went through the process of bipedalism.
References:
Origin of Bipedalism. 4 July 2000. Paleoanthropology in the 1990’s essay by James Q. Jacobs.