title: Comment on "Origin of human bipedalism as an adaptation for locomotion on flexible branches".
abstract: Thorpe et al. (Reports, 1 June 2007, p. 1328) concluded that human bipedalism evolved from a type of bipedal posture they observed in extant orangutans with seemingly human-like extended knees. However, humans share knuckle-walking characters with African apes that are absent in orangutans. These are most parsimoniously explained by positing a knuckle-walking precursor to human bipedalism.
authors.affiliation: Department of Anthropology, University of Toronto, Toronto, ON, M5S 2S2, Canada. begun@chass.utoronto.ca
authors.forename: D R
authors.initials: DR
authors.lastname: Begun
authors.forename: B G
authors.initials: BG
authors.lastname: Richmond
authors.forename: D S
authors.initials: DS
authors.lastname: Strait
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D005075:Biological Evolution; D001696:Biomechanical Phenomena; D006225:Hand; D015186:Hominidae / Q000502:physiology; D006801:Humans; D011148:Pongo pygmaeus / Q000502:physiology*; D011187:Posture; D014197:Trees; D016138:Walking