Robert Kidd | University of South Australia (original) (raw)
Papers by Robert Kidd
The Foot, 1998
When studying biological form and function, it is revealing to examine structure from an evolutio... more When studying biological form and function, it is revealing to examine structure from an evolutionary perspective. The ape foot and that of modern humans differ in many areas, two of which are the absence of a divergent first ray and the reduced range of motion at the midtarsal joint. Two principle modifications are required to reduce the range of motion at the human midtarsal joint, one in each of the talo-navicular and calcaneo-cuboid articulations. A suite of data was obtained from the hindtarsus of humans, chimpanzees, gorillas, orangutans and the OH8 fossil foot. Multivariate analyses revealed the functional affinities of the fossil to be mixed, the medial column being ape-like while the lateral column was found to be human-like. Phylogenetic implications are that the lateral part of the foot became adapted for terrestrial bipedalism first with the medial column being subsequent. It is suggested that pathology resulting from disturbances of normal ontogeny should reflect this trend with mild disturbance affecting the medial column alone and severe disturbance affecting both medial and lateral columns.
Science, 2011
Australopithecus sediba had a human-like ankle and arch but an ape-like heel and tibia, implying ... more Australopithecus sediba had a human-like ankle and arch but an ape-like heel and tibia, implying that while bipedal, this species was also adept at climbing trees.
HOMO, 2005
The part of the fossil assemblage Stw573 consisting of some medial foot bones was initially repor... more The part of the fossil assemblage Stw573 consisting of some medial foot bones was initially reported by Clarke & Tobias (Science 269 (2002) 521). They found it to have both ape- and human-like qualities, being human-like proximally and ape-like distally. We have undertaken a re-examination of this pedal assemblage using a multivariate analysis; while we also found ape- and human-like qualities, they are in direct conflict with the original findings of Clarke and Tobias. We report an essentially ape-like morphology proximally and a human-like morphology distally; the talus and navicular were found to be ape-like and the medial cuneiform human-like. We also undertook a morphometric analysis of the medial cuneiform from the fossil assemblage OH8, as this was not included in the original OH8 study of Kidd et al (J Hum Evol 31 (1996) 269); this cuneiform was found to have a human-like morphology. Thus, the medial column findings from the two assemblages are very similar. This finding, coupled with the re-evaluation of the stratigraphy at Sterkfontein (Am J Phys Anthrop 119 (2002) 192), suggests that the two may have been contemporaneous. We also note that three broad patterns of modification have been identified, equating to proximal-distal lateral-medial (cranio-caudal) and dorsal plantar (posterior-anterior). It has not escaped our notice that these patterns are each controlled by specific genes or growth factors; we thus see a morphometric expression of our developmental past.
Journal of the American Podiatric Medical Association, 1999
The evolution of the human foot presents an obfuscation: explanations for its occurrence and the ... more The evolution of the human foot presents an obfuscation: explanations for its occurrence and the exact nature of mechanisms of change are still not fully understood. This article outlines a model of adaptation from a primitive ape foot and presents this as a hypothesis. Evidence substantiating the hypothesis is then presented, which explains many of the large-scale features distinctive to the human foot. Further evidence is then presented that goes some way toward explaining the sequence of modification with first the lateral side becoming adapted for terrestrial function followed by the medial side. Paradoxically, this was hypothesized by Morton more than half a century ago in his "hypothetical prehuman foot," though it was not accepted favorably at the time.
American Journal of Physical Anthropology, 2009
StW 114/115, from Sterkfontein, South Africa, is the earliest complete hominin fifth metatarsal. ... more StW 114/115, from Sterkfontein, South Africa, is the earliest complete hominin fifth metatarsal. Comparisons of StW 114/115 to modern humans, extant apes, and partial hominin metatarsals AL 333-13, AL 333-78, SKX 33380, OH 8, and KNM-ER 803f reveal a similar morphology in all six fossils consistent with habitual bipedality. Although StW 114/115 possesses some primitive characters, the proximal articular morphology and internal torsion of the head are very human-like, suggesting a stable lateral column and the likely presence of lateral longitudinal and transverse tarsal arches. We conclude that, at least in the lateral component of the foot of the StW 114/115 individual, the biomechanical pattern is very similar to that of modern humans. This, however, may not have been the case in the medial column of the foot, as a mosaic pattern of hominin foot evolution and function has been suggested. The results of this study may support the hypothesis of an increased calcaneo-cuboid stability having been an early evolutionary event in the history of terrestrial bipedalism.
The Foot, 1998
When studying biological form and function, it is revealing to examine structure from an evolutio... more When studying biological form and function, it is revealing to examine structure from an evolutionary perspective. The ape foot and that of modern humans differ in many areas, two of which are the absence of a divergent first ray and the reduced range of motion at the midtarsal joint. Two principle modifications are required to reduce the range of motion at the human midtarsal joint, one in each of the talo-navicular and calcaneo-cuboid articulations. A suite of data was obtained from the hindtarsus of humans, chimpanzees, gorillas, orangutans and the OH8 fossil foot. Multivariate analyses revealed the functional affinities of the fossil to be mixed, the medial column being ape-like while the lateral column was found to be human-like. Phylogenetic implications are that the lateral part of the foot became adapted for terrestrial bipedalism first with the medial column being subsequent. It is suggested that pathology resulting from disturbances of normal ontogeny should reflect this trend with mild disturbance affecting the medial column alone and severe disturbance affecting both medial and lateral columns.
Science, 2011
Australopithecus sediba had a human-like ankle and arch but an ape-like heel and tibia, implying ... more Australopithecus sediba had a human-like ankle and arch but an ape-like heel and tibia, implying that while bipedal, this species was also adept at climbing trees.
HOMO, 2005
The part of the fossil assemblage Stw573 consisting of some medial foot bones was initially repor... more The part of the fossil assemblage Stw573 consisting of some medial foot bones was initially reported by Clarke & Tobias (Science 269 (2002) 521). They found it to have both ape- and human-like qualities, being human-like proximally and ape-like distally. We have undertaken a re-examination of this pedal assemblage using a multivariate analysis; while we also found ape- and human-like qualities, they are in direct conflict with the original findings of Clarke and Tobias. We report an essentially ape-like morphology proximally and a human-like morphology distally; the talus and navicular were found to be ape-like and the medial cuneiform human-like. We also undertook a morphometric analysis of the medial cuneiform from the fossil assemblage OH8, as this was not included in the original OH8 study of Kidd et al (J Hum Evol 31 (1996) 269); this cuneiform was found to have a human-like morphology. Thus, the medial column findings from the two assemblages are very similar. This finding, coupled with the re-evaluation of the stratigraphy at Sterkfontein (Am J Phys Anthrop 119 (2002) 192), suggests that the two may have been contemporaneous. We also note that three broad patterns of modification have been identified, equating to proximal-distal lateral-medial (cranio-caudal) and dorsal plantar (posterior-anterior). It has not escaped our notice that these patterns are each controlled by specific genes or growth factors; we thus see a morphometric expression of our developmental past.
Journal of the American Podiatric Medical Association, 1999
The evolution of the human foot presents an obfuscation: explanations for its occurrence and the ... more The evolution of the human foot presents an obfuscation: explanations for its occurrence and the exact nature of mechanisms of change are still not fully understood. This article outlines a model of adaptation from a primitive ape foot and presents this as a hypothesis. Evidence substantiating the hypothesis is then presented, which explains many of the large-scale features distinctive to the human foot. Further evidence is then presented that goes some way toward explaining the sequence of modification with first the lateral side becoming adapted for terrestrial function followed by the medial side. Paradoxically, this was hypothesized by Morton more than half a century ago in his "hypothetical prehuman foot," though it was not accepted favorably at the time.
American Journal of Physical Anthropology, 2009
StW 114/115, from Sterkfontein, South Africa, is the earliest complete hominin fifth metatarsal. ... more StW 114/115, from Sterkfontein, South Africa, is the earliest complete hominin fifth metatarsal. Comparisons of StW 114/115 to modern humans, extant apes, and partial hominin metatarsals AL 333-13, AL 333-78, SKX 33380, OH 8, and KNM-ER 803f reveal a similar morphology in all six fossils consistent with habitual bipedality. Although StW 114/115 possesses some primitive characters, the proximal articular morphology and internal torsion of the head are very human-like, suggesting a stable lateral column and the likely presence of lateral longitudinal and transverse tarsal arches. We conclude that, at least in the lateral component of the foot of the StW 114/115 individual, the biomechanical pattern is very similar to that of modern humans. This, however, may not have been the case in the medial column of the foot, as a mosaic pattern of hominin foot evolution and function has been suggested. The results of this study may support the hypothesis of an increased calcaneo-cuboid stability having been an early evolutionary event in the history of terrestrial bipedalism.