Editing Bipedalism (section)

===Postural feeding hypothesis===
The postural feeding hypothesis has been recently supported by Dr. Kevin Hunt, a professor at [[Indiana University]].<ref name="Hunt 1996">{{Cite journal |last=Hunt |first=Kevin |date=February 1996 |title=The postural feeding hypothesis: an ecological model for the evolution of bipedalism |journal=South African Journal of Science |volume=92 |pages=77–90 |url=https://www.researchgate.net/publication/288349918 |url-status=live |archive-date=2017-03-05 |archive-url=https://web.archive.org/web/20170305035720/https://www.researchgate.net/publication/288349918_The_postural_feeding_hypothesis_An_ecological_model_for_the_evolution_of_bipedalism}}</ref> This hypothesis asserts that chimpanzees were only bipedal when they eat. While on the ground, they would reach up for fruit hanging from small trees and while in trees, bipedalism was used to reach up to grab for an overhead branch. These bipedal movements may have evolved into regular habits because they were so convenient in obtaining food. Also, Hunt's hypotheses states that these movements coevolved with chimpanzee arm-hanging, as this movement was very effective and efficient in harvesting food. When analyzing fossil anatomy, ''[[Australopithecus afarensis]]'' has very similar features of the hand and shoulder to the chimpanzee, which indicates hanging arms. Also, the ''[[Australopithecus]]'' hip and hind limb very clearly indicate bipedalism, but these fossils also indicate very inefficient locomotive movement when compared to [[human]]s. For this reason, Hunt argues that bipedalism evolved more as a terrestrial feeding posture than as a walking posture.<ref name="Hunt 1996"/>

A related study conducted by [[University of Birmingham]], Professor Susannah Thorpe examined the most arboreal great ape, the [[orangutan]], holding onto supporting branches in order to navigate branches that were too flexible or unstable otherwise. In more than 75 percent of observations, the orangutans used their forelimbs to stabilize themselves while navigating thinner branches. Increased fragmentation of forests where A. afarensis as well as other ancestors of modern humans and other apes resided could have contributed to this increase of bipedalism in order to navigate the diminishing forests. Findings also could shed light on discrepancies observed in the anatomy of A. afarensis, such as the ankle joint, which allowed it to "wobble" and long, highly flexible forelimbs. If bipedalism started from upright navigation in trees, it could explain both increased flexibility in the ankle as well as long forelimbs which grab hold of branches.<ref name=SCI>{{cite news| title=Walk Like an Orangutan: Ape's stroll through the trees may shed light on evolution of human bipedalism| url=https://www.science.org/content/article/walk-orangutan| first=Ann| last=Gibbons| magazine=[[Science Magazine]]| date=31 May 2007}}</ref><ref name=SCAM>{{cite news| title=Orangutans Show First Walking May Have Been on Trees| url=https://www.scientificamerican.com/article/first-walking-may-have-been-on-trees/| first=JR| last=Minkel| magazine=[[Scientific American]]| date=31 May 2007}}</ref><ref name=NATR>{{cite news| title=Upright orangutans point way to walking| url=https://www.nature.com/news/2007/070528/full/news070528-8.html| first=Matt| last=Kaplan| magazine=[[Nature Magazine]]| date=31 May 2007}}</ref><ref name=NSMG>{{cite news| title=Our upright walking started in the trees| url=https://www.newscientist.com/article/dn11965-our-upright-walking-started-in-the-trees/| first=Rowan| last=Hooper| magazine=[[New Scientist Magazine]]| date=31 May 2007}}</ref><ref name=UBHM>{{cite journal| title=Walking the walk: evolution of human bipedalism| url=https://www.cs.bham.ac.uk/research/projects/cogaff/talks/wonac/sue.d/Physics-at-Brum-08-v2.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.cs.bham.ac.uk/research/projects/cogaff/talks/wonac/sue.d/Physics-at-Brum-08-v2.pdf |archive-date=2022-10-09 |url-status=live| first=Susannah| last=Thorpe| journal=[[University of Birmingham]]| date=2007}}</ref><ref>{{Cite journal |last=Stanford |first=Craig B. |date=February 2006 |title=Arboreal bipedalism in wild chimpanzees: Implications for the evolution of hominid posture and locomotion |url=https://onlinelibrary.wiley.com/doi/10.1002/ajpa.20284 |journal=American Journal of Physical Anthropology |language=en |volume=129 |issue=2 |pages=225–231 |doi=10.1002/ajpa.20284 |pmid=16288480 |issn=0002-9483}}</ref>