In Depth
- Author
- Hunt, Kevin D.
- Address
- Department of Anthopology, Indiana University, Bloomington, IN 47405, USA
- Title
- The Evolution of Human Bipedality: Ecology and Functional Morphology.
- Source
- Journal of Human Evolution (1994); 26: pp 183-202
- Abstract
- Contexts that elicit bipedalism in extant apes may provide
evidence of the selective pressures that led to hominid
bipedalism. Bipedalism was observed most commonly among
chimpanzees when they fed on the small fruits of diminutive,
open-forest trees. Chimpanzees fed bipedally from such trees
either by reaching up to pick fruit while standing on the
ground, or from within the tree, in which case bipedalism was
frequently stabilised by grasping an overhead branch. The food-
gathering function of chimpanzee bipedalism suggests that
hominid bipedalism may have evolved in conjunction with arm-
hanging as a specialised feeding adaptation that allowed for
efficient harvesting of fruits among open-forest or woodland
trees. Such evidence is particularly valuable when it is in
accord with fossil anatomy. Australopithecus afarensis
has features of the hand, shoulder and torso that have been
related to arm-hanging in chimpanzees. The Australopithecine hip
and hind limb clearly indicate bipedalism, but also indicate a
less than optimal adaptation to bipedal locomotion compared to
modern humans. Locomotor inefficiency supports the hypothesis
that bipedalism evolved more as a terrestrial feeding posture
than as a walking adaptation. A bipedal postural feeding
adaptation may have been a preadaptation for the fully realised
locomotor bipedalism realised in Homo erectus.
Click here to go back to the main index.
Click here to go back to the AAT index.
Click here to go back to the AAT references.