Among the conceptual but recognized theories surrounding human evolutionary traits and behaviors, the exact forces that specifically promoted bipedalism are still difficult to determine. The controversy lies in the hypothesis that bipedalism arose already 5.8 million years ago, in the late Miocene, but it can be scientifically defined that the first defined bipedal hominid was Australopithecus anamensis in the Pliocene. These findings suggest that bipedalism was evolving between 3.9 and 2.9 million years ago; certain conditions acted as influences on hominids to develop bipedality. Therefore, specific selective pressures have been proposed during evolutionary studies to indicate the exact circumstances that provoked such processes of speciation and adaptation. These cases can be divided into four main categories: dietary situations, ecological forces, energetic processes and sexual selection. Diet: Studying the phylogeny of hominids, Tuttle accentuates the idea that hominins would have had a tendency to stand in a bipedal position when gathering food from tall vegetation (Tuttle, 1981). Furthermore, the ability to jump with the propulsion of the hind limbs allowed for efficient hunting of prey. The availability of two additional limbs provided the basis for more effective food retrieval and it is clear that in this scenario, natural selection and the concept of "survival of the fittest" would support the idea that bipedalism benefited hominins all over the world. 'interior of such a significant feature. of subsistence. Land locomotion presents both opportunities and obstacles. Accessibility to greater amounts of food and introduction to new parts of the environment have understandably reformed the activities of bipedal hominids. High gr...... middle of paper ......solution. Proceedings of the National Academy of Sciences 91:6780-6786.10. McHenry, Henry M, (2004). Head raised, hands free and the evolution of the human walk. In From Biped to Strider: The Emergence of Modern Walking, Running, and Resource Carrying. D. Jeffrey Meldrum and Charles E. Hilton, editors. New York, Kluwer Academic/Plenum Editori. 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 bipedalism and prehensile abilities in hominids. Philosophical Transactions of the Royal Society of London 292:89-94.