title: Human-like external function of the foot, and fully upright gait, confirmed in the 3.66 million year old Laetoli hominin footprints by topographic statistics, experimental footprint-formation and computer simulation.
abstract: It is commonly held that the major functional features of the human foot (e.g. a functional longitudinal medial arch, lateral to medial force transfer and hallucal (big-toe) push-off) appear only in the last 2 Myr, but functional interpretations of footbones and footprints of early human ancestors (hominins) prior to 2 million years ago (Mya) remain contradictory. Pixel-wise topographical statistical analysis of Laetoli footprint morphology, compared with results from experimental studies of footprint formation; foot-pressure measurements in bipedalism of humans and non-human great apes; and computer simulation techniques, indicate that most of these functional features were already present, albeit less strongly expressed than in ourselves, in the maker of the Laetoli G-1 footprint trail, 3.66 Mya. This finding provides strong support to those previous studies which have interpreted the G-1 prints as generally modern in aspect.
authors.affiliation: Institute of Aging and Chronic Disease, University of Liverpool, Sherrington Buildings, Ashton Street, Liverpool L69 3GE, UK. rhcromp@liv.ac.uk
authors.forename: Robin H
authors.initials: RH
authors.lastname: Crompton
authors.forename: Todd C
authors.initials: TC
authors.lastname: Pataky
authors.forename: Russell
authors.initials: R
authors.lastname: Savage
authors.forename: Kristiaan
authors.initials: K
authors.lastname: D'Août
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Bennett
authors.forename: Michael H
authors.initials: MH
authors.lastname: Day
authors.forename: Karl
authors.initials: K
authors.lastname: Bates
authors.forename: Sarita
authors.initials: S
authors.lastname: Morse
authors.forename: William I
authors.initials: WI
authors.lastname: Sellers
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001696:Biomechanical Phenomena; D001835:Body Weight; D003198:Computer Simulation; D003878:Dermatoglyphics; D005528:Foot / Q000033:anatomy & histology* / Q000502:physiology*; D005580:Fossils; D005684:Gait / Q000502:physiology*; D049690:History, Ancient; D015186:Hominidae / Q000033:anatomy & histology* / Q000502:physiology*; D006801:Humans; D010163:Paleontology; D011312:Pressure; D049490:Systems Biology; D013636:Tanzania