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Koneru MC, Harper CM. Comparing lateral plantar process trabecular structure to other regions of the human calcaneus. Anat Rec (Hoboken) 2024; 307:3152-3165. [PMID: 38357839 DOI: 10.1002/ar.25406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/22/2024] [Accepted: 01/28/2024] [Indexed: 02/16/2024]
Abstract
Investigating skeletal adaptations to bipedalism informs our understanding of form-function relationships. The calcaneus is an important skeletal element to study because it is a weight-bearing bone with a critical locomotor role. Although other calcaneal regions have been well studied, we lack a clear understanding of the functional role of the lateral plantar process (LPP). The LPP is a bony protuberance on the inferolateral portion of the calcaneus thought to aid the tuberosity in transmission of ground reaction forces during heel-strike. Here, we analyze LPP internal trabecular structure relative to other calcaneal regions to investigate its potential functional affinities. Human calcanei (n = 20) were micro-CT scanned, and weighted spherical harmonic analysis outputs were used to position 251 volumes of interest (VOI) within each bone. Trabecular thickness (Tb.Th), spacing (Tb.Sp), degree of anisotropy (DA), and bone volume fraction (BV/TV) were calculated for each VOI. Similarities in BV/TV and DA (p = 0.2741) between the LPP and inferior tuberosity support suggestions that the LPP is a weight-bearing structure that may transmit forces in a similar direction. The LPP significantly differs from the inferior tuberosity in Tb.Th and Tb.Sp (p < 0.05). Relatively thinner, more closely spaced trabeculae in the LPP may serve to increase internal surface area to compensate for its relatively small size compared to the tuberosity. Significant differences in all parameters between LPP and joint articular surfaces indicate that trabecular morphology is differently adapted for the transmission of forces associated with body mass through joints.
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Affiliation(s)
- Manisha C Koneru
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, New Jersey, USA
| | - Christine M Harper
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, New Jersey, USA
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2
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Harper CM, Patel BA. Trabecular bone variation in the gorilla calcaneus. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 184:e24939. [PMID: 38631677 DOI: 10.1002/ajpa.24939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 02/15/2024] [Accepted: 04/02/2024] [Indexed: 04/19/2024]
Abstract
OBJECTIVES Calcaneal external shape differs among nonhuman primates relative to locomotion. Such relationships between whole-bone calcaneal trabecular structure and locomotion, however, have yet to be studied. Here we analyze calcaneal trabecular architecture in Gorilla gorilla gorilla, Gorilla beringei beringei, and G. b. graueri to investigate general trends and fine-grained differences among gorilla taxa relative to locomotion. MATERIALS AND METHODS Calcanei were micro-CT scanned. A three-dimensional geometric morphometric sliding semilandmark analysis was carried out and the final landmark configurations used to position 156 volumes of interest. Trabecular thickness (Tb.Th), trabecular spacing (Tb.Sp), and bone volume fraction (BV/TV) were calculated using the BoneJ plugin for ImageJ and MATLAB. Non-parametric MANOVAs were run to test for significant differences among taxa in parameter raw values and z-scores. Parameter distributions were visualized using color maps and summarized using principal components analysis. RESULTS There are no significant differences in raw BV/TV or Tb.Th among gorillas, however G. b. beringei significantly differs in z-scores for both parameters (p = <0.0271). All three taxa exhibit relatively lower BV/TV and Tb.Th in the posterior half of the calcaneus. This gradation is exacerbated in G. b. beringei. G. b. graueri significantly differs from other taxa in Tb.Sp z-scores (p < 0.001) indicating a different spacing distribution. DISCUSSION Relatively higher Tb.Th and BV/TV in the anterior calcaneus among gorillas likely reflects higher forces associated with body mass (transmitted through the subtalar joint) relative to forces transferred through the posterior calcaneus. The different Tb.Sp pattern in G. b. graueri may reflect proposed differences in foot positioning during locomotion.
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Affiliation(s)
- Christine M Harper
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, New Jersey, USA
| | - Biren A Patel
- Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- Human and Evolutionary Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
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3
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O'Neill MC, Nagano A, Umberger BR. A three-dimensional musculoskeletal model of the pelvis and lower limb of Australopithecus afarensis. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 183:e24845. [PMID: 37671481 DOI: 10.1002/ajpa.24845] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 07/08/2023] [Accepted: 08/17/2023] [Indexed: 09/07/2023]
Abstract
OBJECTIVES Musculoskeletal modeling is a powerful approach for studying the biomechanics and energetics of locomotion. Australopithecus (A.) afarensis is among the best represented fossil hominins and provides critical information about the evolution of musculoskeletal design and locomotion in the hominin lineage. Here, we develop and evaluate a three-dimensional (3-D) musculoskeletal model of the pelvis and lower limb of A. afarensis for predicting muscle-tendon moment arms and moment-generating capacities across lower limb joint positions encompassing a range of locomotor behaviors. MATERIALS AND METHODS A 3-D musculoskeletal model of an adult A. afarensis pelvis and lower limb was developed based primarily on the A.L. 288-1 partial skeleton. The model includes geometric representations of bones, joints and 35 muscle-tendon units represented using 43 Hill-type muscle models. Two muscle parameter datasets were created from human and chimpanzee sources. 3-D muscle-tendon moment arms and isometric joint moments were predicted over a wide range of joint positions. RESULTS Predicted muscle-tendon moment arms generally agreed with skeletal metrics, and corresponded with human and chimpanzee models. Human and chimpanzee-based muscle parameterizations were similar, with some differences in maximum isometric force-producing capabilities. The model is amenable to size scaling from A.L. 288-1 to the larger KSD-VP-1/1, which subsumes a wide range of size variation in A. afarensis. DISCUSSION This model represents an important tool for studying the integrated function of the neuromusculoskeletal systems in A. afarensis. It is similar to current human and chimpanzee models in musculoskeletal detail, and will permit direct, comparative 3-D simulation studies.
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Affiliation(s)
- Matthew C O'Neill
- Department of Anatomy, Midwestern University, Glendale, Arizona, USA
| | - Akinori Nagano
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Brian R Umberger
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA
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4
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Prang TC. The relative size of the calcaneal tuber reflects heel strike plantigrady in African apes and humans. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 183:e24865. [PMID: 38058279 DOI: 10.1002/ajpa.24865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 08/30/2023] [Accepted: 10/10/2023] [Indexed: 12/08/2023]
Abstract
OBJECTIVES The positional repertoire of the human-chimpanzee last common ancestor is critical for reconstructing the evolution of bipedalism. African apes and humans share a heel strike plantigrade foot posture associated with terrestriality. Previous research has established that modern humans have a relatively large and intrinsically robust calcaneal tuber equipped to withstand heel strike forces associated with bipedal walking and running. However, it is unclear whether African apes have a relatively larger calcaneal tuber than non-heel-striking primates, and how this trait might have evolved among anthropoids. Here, I test the hypothesis that heel-striking primates have a relatively larger calcaneal tuber than non-heel-striking primates. METHODS The comparative sample includes 331 individuals and 53 taxa representing hominoids, cercopithecoids, and platyrrhines. Evolutionary modeling was used to test for the effect of foot posture on the relative size of the calcaneal tuber in a phylogenetic framework that accounts for adaptation and inertia. Bayesian evolutionary modeling was used to identify selective regime shifts in the relative size of the calcaneal tuber among anthropoids. RESULTS The best fitting evolutionary model was a Brownian motion model with regime-dependent trends characterized by relatively large calcaneal tubers among African apes and humans. Evolutionary modeling provided support for an evolutionary shift toward a larger calcaneal tuber at the base of the African ape and human clade. CONCLUSIONS The results of this study support the view that African apes and humans share derived traits related to heel strike plantigrady, which implies that humans evolved from a semi-terrestrial quadrupedal ancestor.
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Affiliation(s)
- Thomas C Prang
- Department of Anthropology, Washington University in St. Louis, St. Louis, Missouri, USA
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5
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Cazenave M, Kivell TL. Challenges and perspectives on functional interpretations of australopith postcrania and the reconstruction of hominin locomotion. J Hum Evol 2023; 175:103304. [PMID: 36563461 DOI: 10.1016/j.jhevol.2022.103304] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 12/24/2022]
Abstract
In 1994, Hunt published the 'postural feeding hypothesis'-a seminal paper on the origins of hominin bipedalism-founded on the detailed study of chimpanzee positional behavior and the functional inferences derived from the upper and lower limb morphology of the Australopithecus afarensis A.L. 288-1 partial skeleton. Hunt proposed a model for understanding the potential selective pressures on hominins, made robust, testable predictions based on Au. afarensis functional morphology, and presented a hypothesis that aimed to explain the dual functional signals of the Au. afarensis and, more generally, early hominin postcranium. Here we synthesize what we have learned about Au. afarensis functional morphology and the dual functional signals of two new australopith discoveries with relatively complete skeletons (Australopithecus sediba and StW 573 'Australopithecus prometheus'). We follow this with a discussion of three research approaches that have been developed for the purpose of drawing behavioral inferences in early hominins: (1) developments in the study of extant apes as models for understanding hominin origins; (2) novel and continued developments to quantify bipedal gait and locomotor economy in extant primates to infer the locomotor costs from the anatomy of fossil taxa; and (3) novel developments in the study of internal bone structure to extract functional signals from fossil remains. In conclusion of this review, we discuss some of the inherent challenges of the approaches and methodologies adopted to reconstruct the locomotor modes and behavioral repertoires in extinct primate taxa, and notably the assessment of habitual terrestrial bipedalism in early hominins.
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Affiliation(s)
- Marine Cazenave
- Division of Anthropology, American Museum of Natural History, New York, USA; Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, UK; Department of Anatomy, Faculty of Health Sciences, University of Pretoria, South Africa.
| | - Tracy L Kivell
- Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, UK; Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa
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6
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Hatala KG, Gatesy SM, Falkingham PL. Arched footprints preserve the motions of fossil hominin feet. Nat Ecol Evol 2023; 7:32-41. [PMID: 36604550 DOI: 10.1038/s41559-022-01929-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/07/2022] [Indexed: 01/07/2023]
Abstract
The longitudinal arch of the human foot is viewed as a pivotal adaptation for bipedal walking and running. Fossil footprints from Laetoli, Tanzania, and Ileret, Kenya, are believed to provide direct evidence of longitudinally arched feet in hominins from the Pliocene and Pleistocene, respectively. We studied the dynamics of track formation using biplanar X-ray, three-dimensional animation and discrete element particle simulation. Here, we demonstrate that longitudinally arched footprints are false indicators of foot anatomy; instead they are generated through a specific pattern of foot kinematics that is characteristic of human walking. Analyses of fossil hominin tracks from Laetoli show only partial evidence of this walking style, with a similar heel strike but a different pattern of propulsion. The earliest known evidence for fully modern human-like bipedal kinematics comes from the early Pleistocene Ileret tracks, which were presumably made by members of the genus Homo. This result signals important differences in the foot kinematics recorded at Laetoli and Ileret and underscores an emerging picture of locomotor diversity within the hominin clade.
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Affiliation(s)
- Kevin G Hatala
- Department of Biology, Chatham University, Pittsburgh, PA, USA.
| | - Stephen M Gatesy
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, RI, USA
| | - Peter L Falkingham
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
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Harper CM, Zipfel B, DeSilva JM, McNutt EJ, Thackeray F, Braga J. A new early hominin calcaneus from Kromdraai (South Africa). J Anat 2022; 241:500-517. [PMID: 35373345 PMCID: PMC9296044 DOI: 10.1111/joa.13660] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 12/22/2022] Open
Abstract
The Kromdraai site in South Africa has yielded numerous early hominin fossils since 1938. As a part of recent excavations within Unit P, a largely complete early hominin calcaneus (KW 6302) was discovered. Due to its role in locomotion, the calcaneus has the potential to reveal important form/function relationships. Here, we describe KW 6302 and analyze its preserved morphology relative to human and nonhuman ape calcanei, as well as calcanei attributed to Australopithecus afarensis, Australopithecus africanus, Australopithecus sediba, Homo naledi, and the Omo calcaneus (either Paranthropus or early Homo). KW 6302 calcaneal morphology is assessed using numerous quantitative metrics including linear measures, calcaneal robusticity index, relative lateral plantar process position, Achilles tendon length reconstruction, and a three-dimensional geometric morphometric sliding semilandmark analysis. KW 6302 exhibits an overall calcaneal morphology that is intermediate between humans and nonhuman apes, although closer to modern humans. KW 6302 possesses many traits that indicate it was likely well-adapted for terrestrial bipedal locomotion, including a relatively flat posterior talar facet and a large lateral plantar process that is similarly positioned to modern humans. It also retains traits that indicate that climbing may have remained a part of its locomotor repertoire, such as a relatively gracile tuber and a large peroneal trochlea. Specimens from Kromdraai have been attributed to either Paranthropus robustus or early Homo; however, there are no definitively attributed calcanei for either genus, making it difficult to taxonomically assign this specimen. KW 6302 and the Omo calcaneus, however, fall outside the range of expected variation for an extant genus, indicating that if the Omo calcaneus was Paranthropus, then KW 6302 would likely be attributed to early Homo (or vice versa).
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Affiliation(s)
- Christine M. Harper
- Department of Biomedical SciencesCooper Medical School of Rowan UniversityCamdenNew JerseyUSA
| | - Bernhard Zipfel
- Evolutionary Studies InstituteUniversity of the WitwatersrandJohannesburgSouth Africa
| | | | - Ellison J. McNutt
- Department of Biomedical SciencesOhio University Heritage College of Osteopathic MedicineAthensOhioUSA
| | - Francis Thackeray
- Evolutionary Studies InstituteUniversity of the WitwatersrandJohannesburgSouth Africa
| | - José Braga
- Evolutionary Studies InstituteUniversity of the WitwatersrandJohannesburgSouth Africa
- Centre d'Anthropobiologie et de Génomique de ToulouseUniversité Paul Sabatier Toulouse IIIToulouseFrance
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8
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O'Neill MC, Demes B, Thompson NE, Larson SG, Stern JT, Umberger BR. Adaptations for bipedal walking: Musculoskeletal structure and three-dimensional joint mechanics of humans and bipedal chimpanzees (Pan troglodytes). J Hum Evol 2022; 168:103195. [PMID: 35596976 DOI: 10.1016/j.jhevol.2022.103195] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/19/2022] [Accepted: 03/19/2022] [Indexed: 11/25/2022]
Abstract
Humans are unique among apes and other primates in the musculoskeletal design of their lower back, pelvis, and lower limbs. Here, we describe the three-dimensional ground reaction forces and lower/hindlimb joint mechanics of human and bipedal chimpanzees walking over a full stride and test whether: 1) the estimated limb joint work and power during the stance phase, especially the single-support period, is lower in humans than bipedal chimpanzees, 2) the limb joint work and power required for limb swing is lower in humans than in bipedal chimpanzees, and 3) the estimated total mechanical power during walking, accounting for the storage of passive elastic strain energy in humans, is lower in humans than in bipedal chimpanzees. Humans and bipedal chimpanzees were compared at matched dimensionless and dimensional velocities. Our results indicate that humans walk with significantly less work and power output in the first double-support period and the single-support period of stance, but markedly exceed chimpanzees in the second double-support period (i.e., push-off). Humans generate less work and power in limb swing, although the species difference in limb swing power was not statistically significant. We estimated that total mechanical positive 'muscle fiber' work and power were 46.9% and 35.8% lower, respectively, in humans than in bipedal chimpanzees at matched dimensionless speeds. This is due in part to mechanisms for the storage and release of elastic energy at the ankle and hip in humans. Furthermore, these results indicate distinct 'heel strike' and 'lateral balance' mechanics in humans and bipedal chimpanzees and suggest a greater dissipation of mechanical energy through soft tissue deformations in humans. Together, our results document important differences between human and bipedal chimpanzee walking mechanics over a full stride, permitting a more comprehensive understanding of the mechanics and energetics of chimpanzee bipedalism and the evolution of hominin walking.
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Affiliation(s)
- Matthew C O'Neill
- Department of Anatomy, Midwestern University, Glendale, AZ 85308, USA.
| | - Brigitte Demes
- Department of Anatomical Sciences, Stony Brook University School of Medicine, Stony Brook, NY 11794, USA
| | - Nathan E Thompson
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568, USA
| | - Susan G Larson
- Department of Anatomical Sciences, Stony Brook University School of Medicine, Stony Brook, NY 11794, USA
| | - Jack T Stern
- Department of Anatomical Sciences, Stony Brook University School of Medicine, Stony Brook, NY 11794, USA
| | - Brian R Umberger
- School of Kinesiology, University of Michigan, Ann Arbor, MI 48109-2013, USA
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9
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Williams SA, Prang TC, Meyer MR, Nalley TK, Van Der Merwe R, Yelverton C, García-Martínez D, Russo GA, Ostrofsky KR, Spear J, Eyre J, Grabowski M, Nalla S, Bastir M, Schmid P, Churchill SE, Berger LR. New fossils of Australopithecus sediba reveal a nearly complete lower back. eLife 2021; 10:70447. [PMID: 34812141 PMCID: PMC8610421 DOI: 10.7554/elife.70447] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 10/19/2021] [Indexed: 01/16/2023] Open
Abstract
Adaptations of the lower back to bipedalism are frequently discussed but infrequently demonstrated in early fossil hominins. Newly discovered lumbar vertebrae contribute to a near-complete lower back of Malapa Hominin 2 (MH2), offering additional insights into posture and locomotion in Australopithecus sediba. We show that MH2 possessed a lower back consistent with lumbar lordosis and other adaptations to bipedalism, including an increase in the width of intervertebral articular facets from the upper to lower lumbar column (‘pyramidal configuration’). These results contrast with some recent work on lordosis in fossil hominins, where MH2 was argued to demonstrate no appreciable lordosis (‘hypolordosis’) similar to Neandertals. Our three-dimensional geometric morphometric (3D GM) analyses show that MH2’s nearly complete middle lumbar vertebra is human-like in overall shape but its vertebral body is somewhat intermediate in shape between modern humans and great apes. Additionally, it bears long, cranially and ventrally oriented costal (transverse) processes, implying powerful trunk musculature. We interpret this combination of features to indicate that A. sediba used its lower back in both bipedal and arboreal positional behaviors, as previously suggested based on multiple lines of evidence from other parts of the skeleton and reconstructed paleobiology of A. sediba. One of the defining features of humans is our ability to walk comfortably on two legs. To achieve this, our skeletons have evolved certain physical characteristics. For example, the lower part of the human spine has a forward curve that supports an upright posture; whereas the lower backs of chimpanzees and other apes – which walk around on four limbs and spend much of their time in trees – lack this curvature. Studying the fossilized back bones of ancient human remains can help us to understand how we evolved these features, and whether our ancestors moved in a similar way. Australopithecus sediba was a close-relative of modern humans that lived about two million years ago. In 2008, fossils from an adult female were discovered at a cave site in South Africa called Malapa. However, the fossils of the lower back region were incomplete, so it was unclear whether the female – referred to as Malapa Hominin 2 (MH2) – had a forward-curving spine and other adaptations needed to walk on two legs. Here, Williams et al. report the discovery of new A. sediba fossils from Malapa. The new fossils are mainly bones from the lower back, and they fit together with the previously discovered MH2 fossils, providing a nearly complete lower spine. Analysis of the fossils suggested that MH2 would have had an upright posture and comfortably walked on two legs, and the curvature of their lower back was similar to modern females. However, other aspects of the bones’ shape suggest that as well as walking, A. sediba probably spent a significant amount of time climbing in trees. The findings of Williams et al. provide new insights in to our evolutionary history, and ultimately, our place in the natural world around us. Our lower back is prone to injury and pain associated with posture, pregnancy and exercise (or lack thereof). Therefore, understanding how the lower back evolved may help us to learn how to prevent injuries and maintain a healthy back.
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Affiliation(s)
- Scott A Williams
- Center for the Study of Human Origins, Department of Anthropology, New York University, New York, United States.,New York Consortium in Evolutionary Primatology, New York, United States.,Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa.,Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
| | - Thomas Cody Prang
- Department of Anthropology, Texas A&M University, College Station, United States
| | - Marc R Meyer
- Department of Anthropology, Chaffey College, Rancho Cucamonga, United States
| | - Thierra K Nalley
- Western University of Health Sciences, College of Osteopathic Medicine of the Pacific, Department of Medical Anatomical Sciences, Pomona, United States
| | - Renier Van Der Merwe
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa
| | - Christopher Yelverton
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa.,Department of Chiropractic, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South Africa
| | - Daniel García-Martínez
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa.,Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Burgos, Spain.,Departamento de Biodiversidad, Ecología y Evolución, Universidad Complutense de Madrid (UCM), Madrid, Spain
| | - Gabrielle A Russo
- Department of Anthropology, Stony Brook University, Stony Brook, United States
| | - Kelly R Ostrofsky
- Department of Anatomy, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, United States
| | - Jeffrey Spear
- Center for the Study of Human Origins, Department of Anthropology, New York University, New York, United States.,New York Consortium in Evolutionary Primatology, New York, United States
| | - Jennifer Eyre
- Center for the Study of Human Origins, Department of Anthropology, New York University, New York, United States.,Department of Anthropology, Bryn Mawr College, Bryn Mawr, United States
| | - Mark Grabowski
- Research Centre in Evolutionary Anthropology and Palaeoecology, Liverpool John Moores University, Liverpool, United Kingdom
| | - Shahed Nalla
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa.,Department of Human Anatomy and Physiology, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South Africa
| | - Markus Bastir
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa.,Departamento de Paleobiología, Museo Nacional de Ciencias Naturales (CSIC), Madrid, Spain
| | - Peter Schmid
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa.,Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland
| | - Steven E Churchill
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, United States
| | - Lee R Berger
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa
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10
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Harper CM, Ruff CB, Sylvester AD. Calcaneal shape variation in humans, nonhuman primates, and early hominins. J Hum Evol 2021; 159:103050. [PMID: 34438297 DOI: 10.1016/j.jhevol.2021.103050] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 06/29/2021] [Accepted: 06/29/2021] [Indexed: 01/08/2023]
Abstract
The foot has played a prominent role in evaluating early hominin locomotion. The calcaneus, in particular, plays an important role in weight-bearing. Although the calcanei of early hominins have been previously scrutinized, a three-dimensional analysis of the entire calcaneal shape has not been conducted. Here, we investigate the relationship between external calcaneal shape and locomotion in modern Homo sapiens (n = 130), Gorilla (n = 86), Pan (n = 112), Pongo (n = 31), Papio (n = 28), and hylobatids (Hylobates, Symphalangus; n = 32). We use these results to place the calcanei attributed to Australopithecus sediba, A. africanus, A. afarensis, H. naledi, and Homo habilis/Paranthropus boisei into a locomotor context. Calcanei were scanned using either surface scanning or micro-CT and their external shape analyzed using a three-dimensional geometric morphometric sliding semilandmark analysis. Blomberg's K statistic was used to estimate phylogenetic signal in the shape data. Shape variation was summarized using a principal components analysis. Procrustes distances between all taxa as well as distances between each fossil and the average of each taxon were calculated. Blomberg's K statistic was small (K = 0.1651), indicating weak phylogenetic effects, suggesting variation is driven by factors other than phylogeny (e.g., locomotion or body size). Modern humans have a large calcaneus relative to body size and display a uniquely convex cuboid facet, facilitating a rigid midfoot for bipedalism. More arboreal great apes display relatively deeper cuboid facet pivot regions for increased midfoot mobility. Australopithecus afarensis demonstrates the most human-like calcaneus, consistent with obligate bipedalism. Homo naledi is primarily modern human-like, but with some intermediate traits, suggesting a different form of bipedalism than modern humans. Australopithecus africanus, A. sediba, and H. habilis/P. boisei calcanei all possess unique combinations of human and nonhuman ape-like morphologies, suggesting a combination of bipedal and arboreal behaviors.
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Affiliation(s)
- Christine M Harper
- The Johns Hopkins University School of Medicine, Center for Functional Anatomy and Evolution, 1830 East Monument Street, Room 302, Baltimore, MD 21205, United States; Cooper Medical School of Rowan University, Department of Biomedical Sciences, 401 S Broadway, Room 453, Camden, NJ 08103, United States.
| | - Christopher B Ruff
- The Johns Hopkins University School of Medicine, Center for Functional Anatomy and Evolution, 1830 East Monument Street, Room 302, Baltimore, MD 21205, United States
| | - Adam D Sylvester
- The Johns Hopkins University School of Medicine, Center for Functional Anatomy and Evolution, 1830 East Monument Street, Room 302, Baltimore, MD 21205, United States
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11
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Harper CM, Ruff CB, Sylvester AD. Scaling and relative size of the human, nonhuman ape, and baboon calcaneus. Anat Rec (Hoboken) 2021; 305:100-122. [PMID: 33843151 DOI: 10.1002/ar.24642] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/28/2021] [Accepted: 03/06/2021] [Indexed: 01/04/2023]
Abstract
Among human and nonhuman apes, calcaneal morphology exhibits significant variation that has been related to locomotor behavior. Due to its role in weight-bearing, however, both body size and locomotion may impact calcaneal morphology. Determining how calcaneal morphologies vary as a function of body size is thus vital to understanding calcaneal functional adaptation. Here, we study calcaneus allometry and relative size in humans (n = 120) and nonhuman primates (n = 278), analyzing these relationships in light of known locomotor behaviors. Twelve linear measures and three articular facet surface areas were collected on calcaneus surface models. Body mass was estimated using femoral head superoinferior breadth. Relationships between calcaneal dimensions and estimated body mass were analyzed across the sample using phylogenetic least squares regression analyses (PGLS). Differences between humans and pooled nonhuman primates were tested using RMA ANCOVAs. Among (and within) genera residual differences from both PGLS regressions and isometry were analyzed using ANOVAs with post hoc multiple comparison tests. The relationships between all but two calcaneus dimensions and estimated body mass exhibit phylogenetic signal at the smallest taxonomic scale. This signal disappears when reanalyzed at the genus level. Calcaneal morphology varies relative to both body size and locomotor behavior. Humans have larger calcanei for estimated body mass relative to nonhuman primates as a potential adaptation for bipedalism. More terrestrial taxa exhibit longer calcaneal tubers for body mass, increasing the triceps surae lever arm. Among nonhuman great apes, more arboreal taxa have larger cuboid facet surface areas for body mass, increasing calcaneocuboid mobility.
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Affiliation(s)
- Christine M Harper
- The Johns Hopkins University School of Medicine, Center for Functional Anatomy and Evolution, Baltimore, Maryland, USA.,Cooper Medical School of Rowan University, Department of Biomedical Sciences, Camden, New Jersey, USA
| | - Christopher B Ruff
- The Johns Hopkins University School of Medicine, Center for Functional Anatomy and Evolution, Baltimore, Maryland, USA
| | - Adam D Sylvester
- The Johns Hopkins University School of Medicine, Center for Functional Anatomy and Evolution, Baltimore, Maryland, USA
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12
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Oku H, Ide N, Ogihara N. Forward dynamic simulation of Japanese macaque bipedal locomotion demonstrates better energetic economy in a virtualised plantigrade posture. Commun Biol 2021; 4:308. [PMID: 33686215 PMCID: PMC7940622 DOI: 10.1038/s42003-021-01831-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 02/11/2021] [Indexed: 01/31/2023] Open
Abstract
A plantigrade foot with a large robust calcaneus is regarded as a distinctive morphological feature of the human foot; it is presumably the result of adaptation for habitual bipedal locomotion. The foot of the Japanese macaque, on the other hand, does not have such a feature, which hampers it from making foot-ground contact at the heel during bipedal locomotion. Understanding how this morphological difference functionally affects the generation of bipedal locomotion is crucial for elucidating the evolution of human bipedalism. In this study, we constructed a forward dynamic simulation of bipedal locomotion in the Japanese macaque based on a neuromusculoskeletal model to evaluate how virtual manipulation of the foot structure from digitigrade to plantigrade affects the kinematics, dynamics, and energetics of bipedal locomotion in a nonhuman primate whose musculoskeletal anatomy is not adapted to bipedalism. The normal bipedal locomotion generated was in good agreement with that of actual Japanese macaques. If, as in human walking, the foot morphology was altered to allow heel contact, the vertical ground reaction force profile became double-peaked and the cost of transport decreased. These results suggest that evolutionary changes in the foot structure were important for the acquisition of human-like efficient bipedal locomotion.
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Affiliation(s)
- Hideki Oku
- grid.26091.3c0000 0004 1936 9959Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Naohiko Ide
- grid.26091.3c0000 0004 1936 9959Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Naomichi Ogihara
- grid.26091.3c0000 0004 1936 9959Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, Yokohama, Japan ,grid.26999.3d0000 0001 2151 536XDepartment of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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13
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Harper CM, Ruff CB, Sylvester AD. Gorilla calcaneal morphological variation and ecological divergence. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 174:49-65. [PMID: 32871028 DOI: 10.1002/ajpa.24135] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 06/11/2020] [Accepted: 08/02/2020] [Indexed: 01/19/2023]
Abstract
OBJECTIVES The primate foot has been extensively investigated because of its role in weight-bearing; however, the calcaneus has been relatively understudied. Here we examine entire gorilla calcaneal external shape to understand its relationship with locomotor behavior. MATERIALS AND METHODS Calcanei of Gorilla gorilla gorilla (n = 43), Gorilla beringei graueri (n = 20), and Gorilla beringei beringei (n = 15) were surface or micro-CT scanned. External shape was analyzed through a three-dimensional geometric morphometric sliding semilandmark analysis. Semilandmarks were slid relative to an updated Procrustes average in order to minimize the bending energy of the thin plate spline interpolation function. Shape variation was summarized using principal components analysis of shape coordinates. Procrustes distances between taxa averages were calculated and resampling statistics run to test pairwise differences. Linear measures were collected and regressed against estimated body mass. RESULTS All three taxa exhibit statistically different morphologies (p < .001 for pairwise comparisons). G. g. gorilla demonstrates an anteroposteriorly elongated calcaneus with a deeper cuboid pivot region and mediolaterally flatter posterior talar facet. G. b. beringei possesses the flattest cuboid and most medially-angled posterior talar facets. G. b. graueri demonstrates intermediate articular facet morphology, a medially-angled tuberosity, and an elongated peroneal trochlea. DISCUSSION Articular facet differences separate gorillas along a locomotor gradient. G. g. gorilla is adapted for arboreality with greater joint mobility, while G. b. beringei is adapted for more stereotypical loads associated with terrestriality. G. b. graueri's unique posterolateral morphology may be due to a secondary transition to greater arboreality from a more terrestrial ancestor.
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Affiliation(s)
- Christine M Harper
- Center for Functional Anatomy and Evolution, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Christopher B Ruff
- Center for Functional Anatomy and Evolution, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Adam D Sylvester
- Center for Functional Anatomy and Evolution, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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14
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DeSilva JM, McNutt E, Zipfel B, Ward CV, Kimbel WH. Associated Australopithecusafarensis second and third metatarsals (A.L. 333-133) from Hadar, Ethiopia. J Hum Evol 2020; 146:102848. [PMID: 32717476 DOI: 10.1016/j.jhevol.2020.102848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 06/05/2020] [Accepted: 06/05/2020] [Indexed: 10/23/2022]
Affiliation(s)
- Jeremy M DeSilva
- Department of Anthropology, Dartmouth College, Hanover, NH, 03755, USA.
| | - Ellison McNutt
- Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Bernhard Zipfel
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
| | - Carol V Ward
- Integrative Anatomy Program, Department of Pathology and Anatomical Sciences, School of Medicine, University of Missouri, Columbia, MO, 65212, USA
| | - William H Kimbel
- Institute of Human Origins and School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, 85287, USA
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15
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Berecz B, Cyrille M, Casselbrant U, Oleksak S, Norholt H. Carrying human infants - An evolutionary heritage. Infant Behav Dev 2020; 60:101460. [PMID: 32569907 DOI: 10.1016/j.infbeh.2020.101460] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 05/21/2020] [Accepted: 06/03/2020] [Indexed: 02/08/2023]
Abstract
We propose that infant carrying is a biological norm for human caregiving, given that human infants have evolved a capacity to cling onto an upright caregiver whose body co-evolved to enable offspring carrying. The origins of this mutual adaptation may date back 4 million years, with the emergence of bipedalism, which precluded the infant horizontal and gravity-supported position on the back of a quadrupedal caregiver. We describe infant cooperative reflexes and behaviors, including the carrying-induced calming response and discuss hypotheses for the invention of infant carrier tools. Carrying involves several physiological and behavioral parent-infant co-adaptations that imply it is an evolutionarily conserved strategy. Epigenetic transmission of reproductive behavior through generations affects the development of the offspring, as well as the mental health of the parent. Carrying might have contributed to the evolution of Hominidae, potentially aiding dexterity, handedness, language acquisition, and social interactions. We review the evolutionary milestones and time points where the infant-caregiver interactions might have changed, exploring infant carrying as it intersects with biological and cultural evolution. We briefly summarize the effects of infant carrying on physiological, epigenetic, and socio-emotional outcomes.
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Affiliation(s)
- Bernadett Berecz
- Eotvos Lorand University, Institute of Biology, Pazmany Peter stny. 1/C. H-1117, Budapest, Hungary.
| | | | | | - Sarah Oleksak
- University of Maryland Eastern Shore, Lift Me Up, Inc., United States
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16
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Nozaki S, Watanabe K, Kamiya T, Katayose M, Ogihara N. Three-Dimensional Morphological Variations of the Human Calcaneus Investigated Using Geometric Morphometrics. Clin Anat 2019; 33:751-758. [PMID: 31606898 DOI: 10.1002/ca.23501] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 09/22/2019] [Accepted: 10/08/2019] [Indexed: 11/06/2022]
Abstract
The shape of the calcaneus determines the mechanical interaction of the foot with the ground during the heel-strike in human walking. Detailed knowledge of the pattern of sexual dimorphism of the human calcaneus could help to clarify the pathogenetic mechanism of foot and knee disorders, which are more prevalent in females. Therefore, the aim of this study was to characterize and visualize the three-dimensional shape variations of the calcaneus in relation to sex and age using geometric morphometrics. Computed tomography images of 56 feet without subtalar injuries or disorders were used in this study. Thirty-seven anatomical landmarks were identified on the bone model of the calcaneus to calculate principal components (PCs) of shape variations among specimens. The PC scores were compared between males and females, and their correlations with age were also analyzed. The female calcaneus was longer in length and shorter in height than that of males. The medial process of the calcaneal tuberosity in females was more inferiorly projected and the tuberosity was shifted more laterally. Also, the calcaneus was wider and the sustentaculum tali thickened with aging. Female structural features of the calcaneus alter the kinematics of the foot during walking and could be a structural factor in foot and knee disorders. This study contributes to a comprehensive understanding of shape variations in the human calcaneus. Clin. Anat., 33:751-758, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Shuhei Nozaki
- Laboratory of Human Evolutionary Biomechanics, Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | - Kota Watanabe
- Second Division of Physical Therapy, School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Tomoaki Kamiya
- Department of Orthopedic Surgery, School of Medicine, Sapporo Medical University, Sapporo, Japan.,Center of Sports Medicine, Hokkaido Obihiro Kyokai Hospital, Obihiro, Japan
| | - Masaki Katayose
- Second Division of Physical Therapy, School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Naomichi Ogihara
- Laboratory of Human Evolutionary Biomechanics, Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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17
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DeSilva J, McNutt E, Benoit J, Zipfel B. One small step: A review of Plio‐Pleistocene hominin foot evolution. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 168 Suppl 67:63-140. [DOI: 10.1002/ajpa.23750] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 10/01/2018] [Accepted: 10/05/2018] [Indexed: 01/03/2023]
Affiliation(s)
- Jeremy DeSilva
- Department of AnthropologyDartmouth College Hanover New Hampshire
- Evolutionary Studies Institute and School of GeosciencesUniversity of the Witwatersrand Johannesburg South Africa
| | - Ellison McNutt
- Department of AnthropologyDartmouth College Hanover New Hampshire
| | - Julien Benoit
- Evolutionary Studies Institute and School of GeosciencesUniversity of the Witwatersrand Johannesburg South Africa
| | - Bernhard Zipfel
- Evolutionary Studies Institute and School of GeosciencesUniversity of the Witwatersrand Johannesburg South Africa
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18
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McNutt EJ, Zipfel B, DeSilva JM. The evolution of the human foot. Evol Anthropol 2018; 27:197-217. [DOI: 10.1002/evan.21713] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 04/20/2018] [Accepted: 05/30/2018] [Indexed: 11/07/2022]
Affiliation(s)
- Ellison J. McNutt
- Department of Anthropology; Dartmouth College; Hanover New Hampshire
- Ecology, Evolution, Ecosystems, and Society; Dartmouth College; Hanover New Hampshire
| | - Bernhard Zipfel
- Evolutionary Studies Institute and School of Geosciences; University of the Witwatersrand; Johannesburg South Africa
| | - Jeremy M. DeSilva
- Department of Anthropology; Dartmouth College; Hanover New Hampshire
- Evolutionary Studies Institute and School of Geosciences; University of the Witwatersrand; Johannesburg South Africa
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19
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Holowka NB, Lieberman DE. Rethinking the evolution of the human foot: insights from experimental research. J Exp Biol 2018; 221:221/17/jeb174425. [DOI: 10.1242/jeb.174425] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
ABSTRACT
Adaptive explanations for modern human foot anatomy have long fascinated evolutionary biologists because of the dramatic differences between our feet and those of our closest living relatives, the great apes. Morphological features, including hallucal opposability, toe length and the longitudinal arch, have traditionally been used to dichotomize human and great ape feet as being adapted for bipedal walking and arboreal locomotion, respectively. However, recent biomechanical models of human foot function and experimental investigations of great ape locomotion have undermined this simple dichotomy. Here, we review this research, focusing on the biomechanics of foot strike, push-off and elastic energy storage in the foot, and show that humans and great apes share some underappreciated, surprising similarities in foot function, such as use of plantigrady and ability to stiffen the midfoot. We also show that several unique features of the human foot, including a spring-like longitudinal arch and short toes, are likely adaptations to long distance running. We use this framework to interpret the fossil record and argue that the human foot passed through three evolutionary stages: first, a great ape-like foot adapted for arboreal locomotion but with some adaptations for bipedal walking; second, a foot adapted for effective bipedal walking but retaining some arboreal grasping adaptations; and third, a human-like foot adapted for enhanced economy during long-distance walking and running that had lost its prehensility. Based on this scenario, we suggest that selection for bipedal running played a major role in the loss of arboreal adaptations.
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Affiliation(s)
- Nicholas B. Holowka
- Department of Human Evolutionary Biology, Harvard University, 11 Divinity Ave, Cambridge, MA 02138, USA
| | - Daniel E. Lieberman
- Department of Human Evolutionary Biology, Harvard University, 11 Divinity Ave, Cambridge, MA 02138, USA
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20
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Boyle EK, McNutt EJ, Sasaki T, Suwa G, Zipfel B, DeSilva JM. A quantification of calcaneal lateral plantar process position with implications for bipedal locomotion in Australopithecus. J Hum Evol 2018; 123:24-34. [PMID: 30075872 DOI: 10.1016/j.jhevol.2018.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 05/23/2018] [Accepted: 05/24/2018] [Indexed: 11/25/2022]
Abstract
The evolution of bipedalism in the hominin lineage has shaped the posterior human calcaneus into a large, robust structure considered to be adaptive for dissipating peak compressive forces and energy during heel-strike. A unique anatomy thought to contribute to the human calcaneus and its function is the lateral plantar process (LPP). While it has long been known that humans possess a plantarly positioned LPP and apes possess a more dorsally positioned homologous structure, the relative position of the LPP and intraspecific variation of this structure have never been quantified. Here, we present a method for quantifying relative LPP position and find that, while variable, humans have a significantly more plantar position of the LPP than that found in the apes. Among extinct hominins, while the position of the LPP in Australopithecus afarensis falls within the human distribution, the LPP is more dorsally positioned in Australopithecus sediba and barely within the modern human range of variation. Results from a resampling procedure suggest that these differences can reflect either individual variation of a foot structure/function largely shared among Australopithecus species, or functionally distinct morphologies that reflect locomotor diversity in Plio-Pleistocene hominins. An implication of the latter possibility is that calcaneal changes adaptive for heel-striking bipedalism may have evolved independently in two different hominin lineages.
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Affiliation(s)
- Eve K Boyle
- Center for the Advanced Study of Human Paleobiology, Department of Anthropology, The George Washington University, 800 22nd St. NW, Suite 6000, Washington, DC 20052, USA.
| | - Ellison J McNutt
- Department of Anthropology, Dartmouth College, Hanover, NH 03755, USA; Ecology, Evolution, Ecosystems, and Society, Dartmouth College, Hanover, NH 03755, USA
| | - Tomohiko Sasaki
- The University Museum, The University of Tokyo, Tokyo, Japan
| | - Gen Suwa
- The University Museum, The University of Tokyo, Tokyo, Japan
| | - Bernhard Zipfel
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa; School of Geosciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Jeremy M DeSilva
- Department of Anthropology, Dartmouth College, Hanover, NH 03755, USA; Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
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21
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DeSilva JM, Gill CM, Prang TC, Bredella MA, Alemseged Z. A nearly complete foot from Dikika, Ethiopia and its implications for the ontogeny and function of Australopithecus afarensis. SCIENCE ADVANCES 2018; 4:eaar7723. [PMID: 29978043 PMCID: PMC6031372 DOI: 10.1126/sciadv.aar7723] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 05/22/2018] [Indexed: 05/21/2023]
Abstract
The functional and evolutionary implications of primitive retentions in early hominin feet have been under debate since the discovery of Australopithecus afarensis. Ontogeny can provide insight into adult phenotypes, but juvenile early hominin foot fossils are exceptionally rare. We analyze a nearly complete, 3.32-million-year-old juvenile foot of A. afarensis (DIK-1-1f). We show that juvenile A. afarensis individuals already had many of the bipedal features found in adult specimens. However, they also had medial cuneiform traits associated with increased hallucal mobility and a more gracile calcaneal tuber, which is unexpected on the basis of known adult morphologies. Selection for traits functionally associated with juvenile pedal grasping may provide a new perspective on their retention in the more terrestrial adult A. afarensis.
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Affiliation(s)
- Jeremy M. DeSilva
- Department of Anthropology, Dartmouth College, Hanover, NH 03755, USA
- Corresponding author. (J.M.D.); (Z.A.)
| | - Corey M. Gill
- Department of Anthropology, Boston University, Boston, MA 02215, USA
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Thomas C. Prang
- Center for the Study of Human Origins, Department of Anthropology, New York University, New York, NY 10003, USA
- New York Consortium in Evolutionary Anthropology, New York, NY, USA
| | - Miriam A. Bredella
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Zeresenay Alemseged
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA
- Corresponding author. (J.M.D.); (Z.A.)
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22
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Abstract
The dispersal of the genus Homo out of Africa approximately 1.8 million years ago (Ma) has been understood within the context of changes in diet, behavior, and bipedal locomotor efficiency. While various morphological characteristics of the knee and ankle joints are considered part of a suite of traits indicative of, and functionally related to, habitual bipedal walking, the timing and phylogenetic details of these morphological changes remain unclear. To evaluate the timing of knee and ankle joint evolution, we apply geometric morphometric methods to three-dimensional digital models of the proximal and distal tibiae of fossil hominins, Holocene Homo sapiens, and extant great apes. Two sets of landmarks and curve semilandmarks were defined on each specimen. Because some fossils were incomplete, digital reconstructions were carried out independently to estimate missing landmarks and semilandmarks. Group shape variation was evaluated through shape-and form-space principal component analysis and fossil specimens were projected to assess variation in the morphological space computed from the extant comparative sample. We show that a derived proximal tibia (knee) similar to that seen in living H. sapiens evolved with early Homo at ∼2 Ma. In contrast, derived characteristics in the distal tibia appear later, probably with the arrival of Homo erectus. These results suggest a dissociation of the morphologies of the proximal and distal tibia, perhaps indicative of divergent functional demands and, consequently, selective pressures at these joints. It appears that longer distance dispersals that delivered the Dmanisi hominins to Georgia by 1.8 Ma and H. erectus to east-southeast Asia by 1.6 Ma were facilitated by the evolution of a morphologically derived knee complex comparable to that of recent humans and an ankle that was morphologically primitive. This research sets the foundation for additional paleontological, developmental, and functional research to better understand the mechanisms underlying the evolution of bipedalism.
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Affiliation(s)
- Mélanie A Frelat
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa; Department of Cultural Heritage, University of Bologna, Ravenna, Italy; UMR 7268 ADES, Aix-Marseille Université/EFS/CNRS, Marseille, France.
| | - Colin N Shaw
- PAVE Research Group, Department of Archaeology & Anthropology, University of Cambridge, Cambridge, UK; McDonald Institute for Archaeological Research, Department of Archaeology & Anthropology, University of Cambridge, Cambridge, UK; Cambridge BioTomography Centre, Department of Zoology, University of Cambridge, Cambridge, UK
| | - Simone Sukhdeo
- Department of Anthropology, The Pennsylvania State University, University Park, PA, USA
| | - Jean-Jacques Hublin
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Stefano Benazzi
- Department of Cultural Heritage, University of Bologna, Ravenna, Italy; Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Timothy M Ryan
- Department of Anthropology, The Pennsylvania State University, University Park, PA, USA; Center for Quantitative Imaging, EMS Energy Institute, The Pennsylvania State University, University Park, PA, USA
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23
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DeSilva JM, Laudicina NM, Rosenberg KR, Trevathan WR. Neonatal Shoulder Width Suggests a Semirotational, Oblique Birth Mechanism inAustralopithecus afarensis. Anat Rec (Hoboken) 2017; 300:890-899. [DOI: 10.1002/ar.23573] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 12/20/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Jeremy M. DeSilva
- Department of Anthropology; Dartmouth College; Hanover New Hampshire 03755
| | | | - Karen R. Rosenberg
- Department of Anthropology; University of Delaware; Newark Delaware 19716
| | - Wenda R. Trevathan
- Department of Anthropology; New Mexico State University; Las Cruces New Mexico 88003
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24
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Rein TR, Harrison T, Carlson KJ, Harvati K. Adaptation to suspensory locomotion in Australopithecus sediba. J Hum Evol 2017; 104:1-12. [DOI: 10.1016/j.jhevol.2016.12.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 12/22/2016] [Accepted: 12/23/2016] [Indexed: 10/20/2022]
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25
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Prang TC. Reevaluating the functional implications of Australopithecus afarensis navicular morphology. J Hum Evol 2016; 97:73-85. [DOI: 10.1016/j.jhevol.2016.05.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 05/18/2016] [Accepted: 05/19/2016] [Indexed: 11/27/2022]
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26
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Trabecular architecture in the StW 352 fossil hominin calcaneus. J Hum Evol 2016; 97:145-58. [DOI: 10.1016/j.jhevol.2016.05.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 05/20/2016] [Accepted: 05/23/2016] [Indexed: 11/21/2022]
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27
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Prang TC. Conarticular congruence of the hominoid subtalar joint complex with implications for joint function in Plio-Pleistocene hominins. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 160:446-57. [DOI: 10.1002/ajpa.22982] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Accepted: 02/26/2016] [Indexed: 01/21/2023]
Affiliation(s)
- Thomas C. Prang
- Center for the Study of Human Origins, Department of Anthropology; New York University; New York, NY 10003
- New York Consortium in Evolutionary Primatology (NYCEP)
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28
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Prang TC. The subtalar joint complex of Australopithecus sediba. J Hum Evol 2016; 90:105-19. [DOI: 10.1016/j.jhevol.2015.10.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 10/17/2015] [Accepted: 10/20/2015] [Indexed: 10/22/2022]
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Rearfoot posture of Australopithecus sediba and the evolution of the hominin longitudinal arch. Sci Rep 2015; 5:17677. [PMID: 26628197 PMCID: PMC4667273 DOI: 10.1038/srep17677] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/02/2015] [Indexed: 11/11/2022] Open
Abstract
The longitudinal arch is one of the hallmarks of the human foot but its evolutionary history remains controversial due to the fragmentary nature of the fossil record. In modern humans, the presence of a longitudinal arch is reflected in the angular relationships among the major surfaces of the human talus and calcaneus complex, which is also known as the rearfoot. A complete talus and calcaneus of Australopithecus sediba provide the opportunity to evaluate rearfoot posture in an early hominin for the first time. Here I show that A. sediba is indistinguishable from extant African apes in the angular configuration of its rearfoot, which strongly suggests that it lacked a longitudinal arch. Inferences made from isolated fossils support the hypothesis that Australopithecus afarensis possessed an arched foot. However, tali attributed to temporally younger taxa like Australopithecus africanus and Homo floresiensis are more similar to those of A. sediba. The inferred absence of a longitudinal arch in A. sediba would be biomechanically consistent with prior suggestions of increased midtarsal mobility in this taxon. The morphological patterns in talus and calcaneus angular relationships among fossil hominins suggest that there was diversity in traits associated with the longitudinal arch in the Plio-Pleistocene.
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