Human Evolutionary Traits and Behjaviours: Bipedalism

Throughout the conceptual yet acknowledged theories surrounding human evolutionary traits and behaviours, the exact forces that specifically promoted bipedalism are still difficult to determine. Controversy lies with the suggestion that bipedalism arose from as early as 5.8 million years ago, in the late Miocene era, but it can be scientifically defined that the first definite bipedal hominin was the Australopithecus anamensis in the Pliocene. These findings suggest that at 3.9-2.9 million years ago, bipedalism was evolving; certain conditions acted as influences upon the hominins to develop bipedality. As such, specific selection pressures have since been proposed during evolutionary studies to indicate the exact circumstances which prompted such speciation and adaptation processes. These cases can be divided into four main categories: dietary situations, ecological forces, energetics and sexual selection processes.

Diet:

In studying the phylogeny of the hominins, Tuttle accentuates the idea that hominins would have tended to stand bipedally during the gathering of foods from high vegetation (Tuttle, 1981). In addition, the potentiality for hind limb-propelled jumping enabled efficient hunting of prey. The availability of two extra limbs provided the basis for more effective retrieval of food stuffs and it is clear that in this scenario, natural selection and a ‘survival of the fittest’ concept would support the idea that bipedalism benefitted the hominins within such a significant feature of subsistence.

Terrestrial locomotion proposes both opportunities and obstacles. Accessibility to more food and the introduction to new parts of the environment understandably reformed the activities of the bipedal hominins. Tall gr...

... middle of paper ...

...lution. Proceedings of the National Academy of Sciences 91:6780-6786.

10. McHenry, Henry M, (2004). Uplifted head, free hands, & the evolution of human walking. In From Biped to Strider: The Emergence of Modern Human Walking, Running, and Resource Transport. D. Jeffrey Meldrum and Charles E. Hilton, editors. New York, Kluwer Academic/Plenum Publishers. Pp.203-210.

11. McHenry, Henry M, (2004). Origin of human bipedality. Evolutionary Anthropology 13:116-119.

12. Rodman, Peter S, McHenry HM, (1980). Bioenergetics and the origin of hominid bipedalism. American Journal of Physical Anthropology 52: 130-106.

13. Stanford, C, (2003). The Evolutionary Key to Becoming Human. Mifflin Company, Boston, Houghton.

14. Tuttle, Russell H, (1981). Evolution of hominid bipedalism and prehensile capabilities. Philosophical Transactions of the Royal Society of London 292:89-94.