title: Bipedality in chimpanzee (Pan troglodytes) and bonobo (Pan paniscus): testing hypotheses on the evolution of bipedalism.
abstract: A host of ecological, anatomical, and physiological selective pressures are hypothesized to have played a role in the evolution of hominid bipedalism. A referential model, based on the chimpanzee (Pan troglodytes) and bonobo (Pan paniscus), was used to test through experimental manipulation four hypotheses on the evolution of hominid bipedalism. The introduction of food piles (Carry hypothesis) increased locomotor bipedality in both species. Neither the introduction of branches (Display hypothesis) nor the construction of visual barriers (Vigilance hypothesis) altered bipedality in either species. Introduction of raised foraging structures (Forage hypothesis) increased postural bipedality in chimpanzees. These experimental manipulations provided support for carrying of portable objects and foraging on elevated food-items as plausible mechanisms that shaped bipedalism in hominids.
authors.affiliation: Department of Zoology, Miami University, Oxford, Ohio 45056, USA. videanen@muohio.edu
authors.forename: Elaine N
authors.initials: EN
authors.lastname: Videan
authors.forename: W C
authors.initials: WC
authors.lastname: McGrew
mesh_terms: D000818:Animals; D005075:Biological Evolution; D005247:Feeding Behavior; D005260:Female; D008124:Locomotion; D008297:Male; D019974:Pan paniscus / Q000502:physiology*; D002679:Pan troglodytes / Q000502:physiology*; D012641:Selection, Genetic