The evolution of bipedalism in australopithecines

Abstract

U ovome seminaru bavim se evolucijom bipedalnog hoda, anatomskim promjenama koje su prethodile njegovom razvoju kao i fosilnim dokazima koji potvrđuju bipedalizam kod australopitecina. Postoji niz teorija koje pokušavaju objasniti zašto i kako je došlo do razvoja bipedalizma, no i dalje ne možemo sa sigurnošću reći da li je ijedna od tih teorija ispravna. Vrlo vjerojatno je do razvoja bipedalnoga hoda došlo kombinacijom više tih teorija. Kako bi moglo doći do pojave bipedalnog hoda, prvo je tijekom evolucije moralo doći do niza anatomskih promjena lokomotornog aparata naših predaka. Tako je došlo do pomicanja foramena magnuma prema bazi lubanje, do promjene u obliku kralježnice prema obliku dvostrukoga slova S kao i pomicanju centra ravnoteže, a također dolazi do promjena u građi kukovlja i naših udova, a prije svega stopala. Iako se bipedalizam prvi put javlja puno prije pojave samih australopitecina (pojavom vrste Sahelanthropus tchadensis), oni se smatraju prvim pravim bipedalnim homininima. Njihov bipedalizam se razlikovao od onoga kakvoga danas poznajemo, no daje nam puno informacija o razvoju uspravnog hoda, kao što su razne anatomske prilagodbe koje su se morale dogoditi da bismo uopće mogli imati uspravan stav, prednost i nedostatci koje smo dobili prelaskom na bipedalizam. Donošenje zaključaka o razvoju bipedalizma i potpuno shvaćanje njegovog razvoja će nam uvelike razjasniti kako je došlo do evolucije današnjega čovjeka i olakšati nam shvaćanje naše prošlosti.In this paper I am dealing with the evolution of bipedalism, the anatomical changes which preceded the development of bipedalism and the fossils that proof bipedalism in australopithecines. There is a series of theories which try to explain why and when the development of bipedalism started, then still we can not know which of the theories are correct. Most likely the evolution of bipedalism is the result of a combination of more of these theories. To come to the evolution of bipedalism first it had to come to a series of anatomical changes in the locomotory system of our ancestors. So it came to the movement of foramen magnum to the base of the cranium, to changes in the shape of the spine to the shape of the double letter S as well as the movement of the center of gravity, also it came to changes in the structure of the hip and limbs, primarily the feet. Although bipedalism occurs much earlier than the appearance of australopithecines (with the appearance of Sahelanthropus tchadensis), they are considered to be the first real bipedal hominins. Their bipedalism is different from the bipedalism we know today, but still it gives us a lot of information of upright gait, as well as a variety of anatomical adaptations that had to happen that have an upright gait, advantages and disadvantages that we got by the transition to bipedalizam. Conclusions about the development of bipedalism and fully understanding its development will help us greatly to clarify how it came to the evolution of modern man and to facilitate our understanding of our past