title: Human evolution. Human-like hand use in Australopithecus africanus.
abstract: The distinctly human ability for forceful precision and power "squeeze" gripping is linked to two key evolutionary transitions in hand use: a reduction in arboreal climbing and the manufacture and use of tools. However, it is unclear when these locomotory and manipulative transitions occurred. Here we show that Australopithecus africanus (~3 to 2 million years ago) and several Pleistocene hominins, traditionally considered not to have engaged in habitual tool manufacture, have a human-like trabecular bone pattern in the metacarpals consistent with forceful opposition of the thumb and fingers typically adopted during tool use. These results support archaeological evidence for stone tool use in australopiths and provide morphological evidence that Pliocene hominins achieved human-like hand postures much earlier and more frequently than previously considered.
authors.affiliation: School of Anthropology and Conservation, University of Kent, Canterbury CT2 7NR, UK. Department of Anthropology, University College London, London WC1H 0BW, UK. Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig Germany. Evolutionary Studies Institute and Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa. m.skinner@kent.ac.uk t.l.kivell@kent.ac.uk.
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Skinner
authors.affiliation: Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig Germany.
authors.forename: Nicholas B
authors.initials: NB
authors.lastname: Stephens
authors.affiliation: Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig Germany.
authors.forename: Zewdi J
authors.initials: ZJ
authors.lastname: Tsegai
authors.affiliation: Department of Anthropology, University College London, London WC1H 0BW, UK.
authors.forename: Alexandra C
authors.initials: AC
authors.lastname: Foote
authors.affiliation: Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig Germany.
authors.forename: N Huynh
authors.initials: NH
authors.lastname: Nguyen
authors.affiliation: Institute of Lightweight Design and Structural Biomechanics, Vienna University of Technology, Gusshausstrasse 27-29, 1040 Wien, Vienna, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gross
authors.affiliation: Institute of Lightweight Design and Structural Biomechanics, Vienna University of Technology, Gusshausstrasse 27-29, 1040 Wien, Vienna, Austria.
authors.forename: Dieter H
authors.initials: DH
authors.lastname: Pahr
authors.affiliation: Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig Germany.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Hublin
authors.affiliation: School of Anthropology and Conservation, University of Kent, Canterbury CT2 7NR, UK. Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig Germany. Evolutionary Studies Institute and Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa. m.skinner@kent.ac.uk t.l.kivell@kent.ac.uk.
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Kivell
mesh_terms: D000818:Animals; D001106:Archaeology; D005075:Biological Evolution; D015186:Hominidae / Q000033:anatomy & histology; D006801:Humans; D050279:Metacarpal Bones / Q000033:anatomy & histology*; D008663:Metacarpus / Q000033:anatomy & histology* / Q000502:physiology; D059125:Neanderthals / Q000033:anatomy & histology; D011187:Posture; D013933:Thumb / Q000033:anatomy & histology* / Q000502:physiology