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Miller CK, DeSilva JM. A review of the distal femur in Australopithecus. Evol Anthropol 2024; 33:e22012. [PMID: 38009942 DOI: 10.1002/evan.22012] [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: 07/22/2023] [Revised: 11/08/2023] [Accepted: 11/09/2023] [Indexed: 11/29/2023]
Abstract
In 1938, the first distal femur of a fossil Australopithecus was discovered at Sterkfontein, South Africa. A decade later, another distal femur was discovered at the same locality. These two fossil femora were the subject of a foundational paper authored by Kingsbury Heiple and Owen Lovejoy in 1971. In this paper, the authors discussed functionally relevant anatomies of these two fossil femora and noted their strong affinity to the modern human condition. Here, we update this work by including eight more fossil Australopithecus distal femora, an expanded comparative dataset, as well as additional linear measurements. Just as Heiple and Lovejoy reported a half-century ago, we find strong overlap between modern humans and cercopithecoids, except for inferiorly flattened condyles and a high bicondylar angle, both of which characterize modern humans and Australopithecus and are directly related to striding bipedalism. All other measured aspects of the femora are by-products of these key morphological traits. Additional fossil material from the early Pliocene will help to inform the evolution of the hominin distal femur and its condition in the Pan-Homo common ancestor that preceded bipedal locomotion.
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Affiliation(s)
- Catherine K Miller
- Department of Anthropology, Dartmouth College, Hanover, New Hampshire, USA
- Ecology, Evolution, Ecosystems, and Society Graduate Program, Dartmouth College, Hanover, New Hampshire, USA
| | - Jeremy M DeSilva
- Department of Anthropology, Dartmouth College, Hanover, New Hampshire, USA
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
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2
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Aramendi J, Mabulla A, Baquedano E, Domínguez-Rodrigo M. Biomechanical and taxonomic diversity in the Early Pleistocene in East Africa: Structural analysis of a recently discovered femur shaft from Olduvai Gorge (bed I). J Hum Evol 2024; 186:103469. [PMID: 38071888 DOI: 10.1016/j.jhevol.2023.103469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 11/14/2023] [Accepted: 11/14/2023] [Indexed: 12/30/2023]
Abstract
Recent Plio-Pleistocene hominin findings have revealed the complexity of human evolutionary history and the difficulties involved in its interpretation. Moreover, the study of hominin long bone remains is particularly problematic, since it commonly depends on the analysis of fragmentary skeletal elements that in many cases are merely represented by small diaphyseal portions and appear in an isolated fashion in the fossil record. Nevertheless, the study of the postcranial skeleton is particularly important to ascertain locomotor patterns. Here we report on the discovery of a robust hominin femoral fragment (OH 84) at the site of Amin Mturi Korongo dated to 1.84 Ma (Olduvai Bed I). External anatomy and internal bone structure of OH 84 were analyzed and compared with previously published data for modern humans and chimpanzees, as well as for Australopithecus, Paranthropus and Homo specimens ranging from the Late Pliocene to Late Pleistocene. Biomechanical analyses based on transverse cross-sections and the comparison of OH 84 with another robust Olduvai specimen (OH 80) suggest that OH 84 might be tentatively allocated to Paranthropus boisei. More importantly, the identification of a unique combination of traits in OH 84 could indicate both terrestrial bipedalism and an arboreal component in the locomotor repertoire of this individual. If interpreted correctly, OH 84 could thus add to the already mounting evidence of substantial locomotor diversity among Early Pleistocene hominins. Likewise, our results also highlight the difficulties in accurately interpreting the link between form and function in the human fossil record based on fragmentary remains, and ultimately in distinguishing between coeval hominin groups due to the heterogeneous pattern of inter- and intraspecific morphological variability detected among fossil femora.
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Affiliation(s)
- Julia Aramendi
- McDonald Institute for Archaeological Research, University of Cambridge, CB2 1TN, UK.
| | - Audax Mabulla
- Department of Archaeology and Heritage Studies, University of Dar Es Salaam, P.O. Box 35050, Dar Es Salaam, Tanzania
| | - Enrique Baquedano
- Archaeological and Paleontological Museum of the Community of Madrid, Plaza de Las Bernardas s/n, 28801, Alcalá de Henares, Spain; Institute of Evolution in Africa (IDEA), University of Alcalá and Archaeological and Paleontological Museum of the Community of Madrid, C/Covarrubias 36, 28010, Madrid, Spain
| | - Manuel Domínguez-Rodrigo
- Institute of Evolution in Africa (IDEA), University of Alcalá and Archaeological and Paleontological Museum of the Community of Madrid, C/Covarrubias 36, 28010, Madrid, Spain; University of Alcalá, Department of History and Philosophy, Area of Prehistory, C/Colegios 2, 28801, Alcalá de Henares, Spain; Rice University, Department of Anthropology, 6100 Main St., Houston, TX, 77005 1827, USA
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3
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Crompton RH, Sellers W, Davids K, McClymont J. Biomechanics and the origins of human bipedal walking: The last 50 years. J Biomech 2023; 157:111701. [PMID: 37451208 DOI: 10.1016/j.jbiomech.2023.111701] [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: 09/20/2022] [Revised: 06/22/2023] [Accepted: 06/23/2023] [Indexed: 07/18/2023]
Abstract
Motion analysis, as applied to evolutionary biomechanics, has experienced its own evolution over the last 50 years. Here we review how an ever-increasing fossil record, together with continuing advancements in biomechanics techniques, have shaped our understanding of the origin of upright bipedal walking. The original, and long-established hypothesis held by Lamarck (1809), Darwin (1859) and Keith (1934), amongst others, maintained that bipedality originated in an arboreal context. However, the first field studies of gorilla and chimpanzees from the 1960's, highlighted their so-called 'knucklewalking' quadrupedalism, leading scientists to assume, semi-automatically, that knucklewalking must have been the precursor to bipedality. It would not be until the discovery of skeletons of early human relatives Australopithecus afarensis and Australopithecus prometheus, and the inclusion of methods of analysis from computer science, biomechanics, sports science and medicine, that the knucklewalking hypothesis would be most robustly challenged. Their short, but human-like lower limbs and human-like hand indicated that knucklewalking was not part of our ancestral locomotor repertoire. Rather, most current research in evolutionary biomechanics agrees it was a combination of climbing and bipedalism, both in an arboreal context, which facilitated upright, terrestrial, bipedal walking over short distances.
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Affiliation(s)
- Robin Huw Crompton
- Musculoskeletal and Ageing Science, The University of Liverpool, William Henry Duncan Building, West Derby Street, Liverpool L7 8TX, UK.
| | - William Sellers
- Earth and Environmental Sciences, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Keith Davids
- Sport and Physical Activity Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB, UK
| | - Juliet McClymont
- Musculoskeletal and Ageing Science, The University of Liverpool, William Henry Duncan Building, West Derby Street, Liverpool L7 8TX, UK
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4
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Stamos PA, Alemseged Z. Hominin locomotion and evolution in the Late Miocene to Late Pliocene. J Hum Evol 2023; 178:103332. [PMID: 36947894 DOI: 10.1016/j.jhevol.2023.103332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 01/26/2023] [Accepted: 01/27/2023] [Indexed: 03/24/2023]
Abstract
In this review, we present on the evolution of the locomotor adaptation of hominins in the Late Miocene to Late Pliocene, with emphasis on some of the prominent advances and debates that have occurred over the past fifty years. We start with the challenging issue of defining hominin locomotor grades that are currently used liberally and offer our own working definitions of facultative, habitual, and obligate bipedalism. We then discuss the nature of the Pan-Homo last common ancestor and characterize the locomotor adaptation of Sahelanthropus, Orrorin, and Ardipithecus-often referred to as facultative bipeds-and examine the debates on the extent of bipedality and arboreality in these taxa. Moreover, the question of Middle Pliocene hominin locomotor diversity is addressed based on information derived from the 'Little Foot' specimen from Sterkfontein, footprints from Laetoli, and the Burtele Foot in Ethiopia. Our review suggests that the most convincing evidence for locomotor diversity comes from Burtele, whereas the evidence from Sterkfontein and Laetoli is unconvincing and equivocal, respectively. Finally, we address the decades old issue of the significance of arboreality in the otherwise habitual biped, Australopithecus, with emphasis on Australopithecus afarensis and its implications for the paleobiology of these creatures. We conclude that many of the apelike features encountered, mostly in the upper part of the Australopithecus skeleton, were retained for their significance in climbing. Approaches that have investigated character plasticity and those exploring internal bone structure have shown that the shoulder and limbs in Au. afarensis and Australopithecus africanus were involved in arboreal activities that are thought to be key for feeding, nesting, and predator avoidance. We conclude that many of the so-called retained ape-like features persisted due to stabilizing selection, that early hominins engaged in a considerable amount of arboreality even after Australopithecus had become a habitual biped, and arboreality only ceased to be an important component of hominin locomotor behavior after the emergence of Homo erectus.
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Affiliation(s)
- Peter A Stamos
- Department of Organismal Biology & Anatomy, The University of Chicago, Anatomy Bldg 201, 1027 E 57th Street, Chicago, IL 60637, USA
| | - Zeresenay Alemseged
- Department of Organismal Biology & Anatomy, The University of Chicago, Anatomy Bldg 201, 1027 E 57th Street, Chicago, IL 60637, 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: 4] [Impact Index Per Article: 4.0] [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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Grine FE, Mongle CS, Fleagle JG, Hammond AS. The taxonomic attribution of African hominin postcrania from the Miocene through the Pleistocene: Associations and assumptions. J Hum Evol 2022; 173:103255. [PMID: 36375243 DOI: 10.1016/j.jhevol.2022.103255] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 08/21/2022] [Accepted: 08/22/2022] [Indexed: 11/06/2022]
Abstract
Postcranial bones may provide valuable information about fossil taxa relating to their locomotor habits, manipulative abilities and body sizes. Distinctive features of the postcranial skeleton are sometimes noted in species diagnoses. Although numerous isolated postcranial fossils have become accepted by many workers as belonging to a particular species, it is worthwhile revisiting the evidence for each attribution before including them in comparative samples in relation to the descriptions of new fossils, functional analyses in relation to particular taxa, or in evolutionary contexts. Although some workers eschew the taxonomic attribution of postcranial fossils as being less important (or interesting) than interpreting their functional morphology, it is impossible to consider the evolution of functional anatomy in a taxonomic and phylogenetic vacuum. There are 21 widely recognized hominin taxa that have been described from sites in Africa dated from the Late Miocene to the Middle Pleistocene; postcranial elements have been attributed to 17 of these. The bones that have been thus assigned range from many parts of a skeleton to isolated elements. However, the extent to which postcranial material can be reliably attributed to a specific taxon varies considerably from site to site and species to species, and is often the subject of considerable debate. Here, we review the postcranial remains attributed to African hominin taxa from the Late Miocene to the Middle and Late Pleistocene and place these assignations into categories of reliability. The catalog of attributions presented here may serve as a guide for making taxonomic decisions in the future.
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Affiliation(s)
- Frederick E Grine
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794-4364, USA; Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY 11794-4364, USA.
| | - Carrie S Mongle
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794-4364, USA; Division of Anthropology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024-5192, USA; Turkana Basin Institute, Stony Brook University, Stony Brook, NY 11794-4364, USA
| | - John G Fleagle
- Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY 11794-4364, USA
| | - Ashley S Hammond
- Division of Anthropology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024-5192, USA; New York Consortium of Evolutionary Primatology (NYCEP), New York, NY 10024, USA
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7
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Sarringhaus L, Lewton KL, Iqbal S, Carlson KJ. Ape femoral-humeral rigidities and arboreal locomotion. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022; 179:624-639. [PMID: 36790629 PMCID: PMC9828227 DOI: 10.1002/ajpa.24632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 06/29/2022] [Accepted: 09/13/2022] [Indexed: 11/07/2022]
Abstract
OBJECTIVES This study investigates patterns of bone functional adaptations in extant apes through comparing hindlimb to forelimb bone rigidity ratios in groups with varying levels of arboreality. MATERIALS AND METHODS Using CT scans, bone rigidity (J) was calculated at three regions of interest (ROI) along femoral and humeral diaphyses in Homo, Pongo, Pan, and Gorilla with further comparisons made between species and subspecies divisions within Pan and Gorilla. RESULTS Consistent with previous work on extant hominoids, species exhibited differences in midshaft femoral to humeral (F/H) rigidity ratios. Results of the present study confirm that these midshaft differences extend to 35% and 65% diaphyseal ROIs. Modern humans, exhibiting larger ratios, and orangutans, exhibiting smaller ratios, bracketed the intermediate African apes in comparisons. Within some African apes, limb rigidity ratios varied significantly between taxonomic groups. Eastern gorillas exhibited the highest mean ratios and chimpanzees the lowest at all three ROIs. In posthoc comparisons, chimpanzees and bonobos did not differ in relative limb rigidity ratios at any of the three ROIs. However, western gorillas were more similar to bonobos than eastern gorillas at 50% and 35% ROIs, but not at the 65% ROI. CONCLUSION Species, and to a lesser extent subspecies, can be distinguished by F/H limb rigidity ratios according to broad positional behavior patterns at multiple regions of interest along the diaphyses. Similarity of bonobos and western gorillas is in line with behavioral data of bonobos being the most terrestrial of Pan species, and western gorillas the most arboreal of the Gorilla groups.
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Affiliation(s)
- Lauren Sarringhaus
- Department of Evolutionary AnthropologyDuke UniversityDurhamNorth CarolinaUSA,Department of AnthropologyUniversity of MichiganAnn ArborMichiganUSA,Department of BiologyJames Madison UniversityHarrisonburgVirginiaUSA
| | - Kristi L. Lewton
- Department of Integrative Anatomical Sciences, Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Safiyyah Iqbal
- School of Animal, Plant and Environmental SciencesUniversity of the WitwatersrandJohannesburgSouth Africa
| | - Kristian J. Carlson
- Department of Integrative Anatomical Sciences, Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCaliforniaUSA,Evolutionary Studies InstituteUniversity of the WitwatersrandJohannesburgSouth Africa
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8
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Caton NR, Dixson BJW. Beyond facial width-to-height ratios: bizygomatic width is highly sexually dimorphic when adjusting for allometry. Biol Lett 2022; 18:20220211. [PMCID: PMC9554718 DOI: 10.1098/rsbl.2022.0211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A large and ever-growing literature implicates male facial width-to-height ratio (bizygomatic width divided by facial height) as a secondary sexual trait linked to numerous physical and psychological perceptions. However, this research is based entirely on the premise that bizygomatic width is sexually dimorphic, which recent research has called into question. Unfortunately, statisticians for the last 125 years have noted that morphological ratio measurements may engender spurious correlations and biased effect-size estimates. In the current study, we find that bizygomatic width is highly sexually dimorphic (equivalent d = 1.39), even after adjusting for 92 allometric measurements, including multiple facial height and other craniofacial measurements (equivalent d = 1.07) in a sample of 6068 men and women. By contrast, facial width-to-height ratio (fWHR) measurements demonstrated a statistical pattern consistent with the age-old argument that morphological ratio measurements may engender spurious correlations and biased effect-size estimates. Thus, when avoiding facial ratio measurements and adjusting for allometry in craniofacial measures, we found strong support for a key premise in the human evolutionary and behavioural sciences that bizygomatic width exhibits male-biased sexual dimorphism.
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Affiliation(s)
- Neil R. Caton
- School of Psychology, The University of Queensland, Saint Lucia, Queensland, Australia
| | - Barnaby J. W. Dixson
- School of Psychology, The University of Queensland, Saint Lucia, Queensland, Australia,School of Psychology, The University of the Sunshine Coast, Sunshine Coast, Queensland, Australia,Evolution & Ecology Research Centre, School of Biological, Earth & Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
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9
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Postcranial evidence of late Miocene hominin bipedalism in Chad. Nature 2022; 609:94-100. [PMID: 36002567 DOI: 10.1038/s41586-022-04901-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 05/24/2022] [Indexed: 11/09/2022]
Abstract
Bipedal locomotion is one of the key adaptations that define the hominin clade. Evidence of bipedalism is known from postcranial remains of late Miocene hominins as early as 6 million years ago (Ma) in eastern Africa1-4. Bipedality of Sahelanthropus tchadensis was hitherto inferred about 7 Ma in central Africa (Chad) based on cranial evidence5-7. Here we present postcranial evidence of the locomotor behaviour of S. tchadensis, with new insights into bipedalism at the early stage of hominin evolutionary history. The original material was discovered at locality TM 266 of the Toros-Ménalla fossiliferous area and consists of one left femur and two, right and left, ulnae. The morphology of the femur is most parsimonious with habitual bipedality, and the ulnae preserve evidence of substantial arboreal behaviour. Taken together, these findings suggest that hominins were already bipeds at around 7 Ma but also suggest that arboreal clambering was probably a significant part of their locomotor repertoire.
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10
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The relative limb size of Homonaledi. J Hum Evol 2022; 170:103235. [PMID: 35994845 DOI: 10.1016/j.jhevol.2022.103235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 07/03/2022] [Accepted: 07/03/2022] [Indexed: 11/20/2022]
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Marchi D, Rimoldi A, García‐Martínez D, Bastir M. Morphological correlates of distal fibular morphology with locomotion in great apes, humans, and Australopithecus afarensis. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022; 178:286-300. [PMID: 36790753 PMCID: PMC9314891 DOI: 10.1002/ajpa.24507] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 01/15/2022] [Accepted: 02/22/2022] [Indexed: 01/27/2023]
Abstract
OBJECTIVES Recent studies highlighted the importance of the fibula to further our understanding of locomotor adaptations in fossil hominins. In this study, we present a three-dimensional geometric morphometric (3D-GM) investigation of the distal fibula in extant hominids and Australopithecus afarensis with the aim of pointing out morphological correlations to arboreal behavior. METHODS Three-dimensional surface meshes of the distal fibula were obtained using computer tomography for 40 extant hominid specimens and laser scanner for five A. afarensis specimens. Distal fibula morphology was quantified positioning 11 fixed landmarks, 40 curve semilandmarks, and 20 surface landmarks on each specimen. A generalized Procrustes analysis (GPA) was carried out on all landmark coordinates followed by Procrustes ANOVA. Principal component analysis (PCA) was performed on the GPA-aligned shape coordinates. Kruskal-Wallis tests and Mann-Whitney test were performed on scores along PCs. RESULTS Great apes are characterized by a shorter subcutaneous triangular surface (STS), more downward facing fibulotalar articular facets, more anteriorly facing lateral malleolus and wider/deeper malleolar fossa than humans. Within great apes, orangutans are characterized by more medially facing fibulotalar articular facets. Australopithecus afarensis shows a unique distal fibular morphology with several traits that are generally associated more to arboreality and less to bipedalism such as a short STS, a more anteriorly facing, laterally pointing malleolus and deeper and larger malleolar fossa. CONCLUSIONS The distal fibula morphology is indicative of locomotor patterns within extant hominids. The 3D-GM method presented here can be successfully used to further our understanding of arboreal adaptations in fossil hominins.
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Affiliation(s)
- Damiano Marchi
- Department of BiologyUniversity of PisaPisa,Centre for the Exploration of the Deep Human JourneyUniversity of the WitwatersrandWits
| | | | - Daniel García‐Martínez
- Centre for the Exploration of the Deep Human JourneyUniversity of the WitwatersrandWits,Centro Nacional de Investigación sobre la Evolución Humana (CENIEH)BurgosSpain,Paleoanthropology GroupMuseo Nacional de Ciencias Naturales (MNCN‐CSIC)MadridSpain
| | - Markus Bastir
- Centre for the Exploration of the Deep Human JourneyUniversity of the WitwatersrandWits,Paleoanthropology GroupMuseo Nacional de Ciencias Naturales (MNCN‐CSIC)MadridSpain
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12
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Ruff CB, Junno JA, Burgess ML, Canington SL, Harper C, Mudakikwa A, McFarlin SC. Body proportions and environmental adaptation in gorillas. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022; 177:501-529. [PMID: 36787793 DOI: 10.1002/ajpa.24443] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 07/22/2021] [Accepted: 10/19/2021] [Indexed: 11/07/2022]
Abstract
OBJECTIVES Limb length and trunk proportions are determined in a large, taxonomically and environmentally diverse sample of gorillas and related to variation in locomotion, climate, altitude, and diet. MATERIALS AND METHODS The sample includes 299 gorilla skeletons, 115 of which are infants and juveniles, distributed between western lowland (G. gorilla gorilla), low and high elevation grauer (G. beringei graueri), and Virunga mountain gorillas (G. b. beringei). Limb bone and vertebral column lengths scaled to body mass are compared between subgroups by age group. RESULTS All G. beringei have relatively short 3rd metapodials and manual proximal phalanges compared to G. gorilla, and this difference is apparent in infancy. All G. beringei also have shortened total limb lengths relative to either body mass or vertebral column length, although patterns of variation in individual skeletal elements are more complex, and infants do not display the same patterns as adults. Mountain gorillas have relatively long clavicles, present in infancy, and a relatively long thoracic (but not lumbosacral) vertebral column. DISCUSSION A variety of environmental factors likely contributed to observed patterns of morphological variation among extant gorillas. We interpret the short hand and foot bones of all G. beringei as genetic adaptations to greater terrestriality in the last common ancestor of G. beringei; variation in other limb lengths to climatic adaptation, both genetic and developmental; and the larger thorax of G. b. beringei to adaptation to reduced oxygen pressure at high altitudes, again as a product of both genetic differences and environmental influences during development.
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Affiliation(s)
- Christopher B Ruff
- Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | | - M Loring Burgess
- Peabody Museum of Archaeology and Ethnology, Harvard University, Cambridge, Massachusetts, USA
| | - Stephanie L Canington
- Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Christine Harper
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, New Jersey, USA
| | - Antoine Mudakikwa
- Rwanda Development Board, Department of Tourism and Conservation, Kigali, Rwanda
| | - Shannon C McFarlin
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, District of Columbia, USA.,Human Origins Program, Smithsonian's National Museum of Natural History, Washington, District of Columbia, USA
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13
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Abstract
The earliest South African hominids (humans and their ancestral kin) belong to the genera Australopithecus, Paranthropus, and Homo, with the oldest being a ca. 3.67 million-year-old nearly complete skeleton of Australopithecus (StW 573) from Sterkfontein Caves. This skeleton has provided, for the first time in almost a century of research, the full anatomy of an Australopithecus individual with indisputably associated skull and postcranial bones that give complete limb lengths. The three genera are also found in East Africa, but scholars have disagreed on the taxonomic assignment for some fossils owing to historical preconceptions. Here we focus on the South African representatives to help clarify these debates. The uncovering of the StW 573 skeleton in situ revealed significant clues concerning events that had affected it over time and demonstrated that the associated stalagmite flowstones cannot provide direct dating of the fossil, as they are infillings of voids caused by postdepositional collapse.
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Affiliation(s)
- Ronald J. Clarke
- Evolutionary Studies Institute, University of the Witwatersrand, WITS 2050 Johannesburg, South Africa
| | - Travis Rayne Pickering
- Evolutionary Studies Institute, University of the Witwatersrand, WITS 2050 Johannesburg, South Africa
- Department of Anthropology, University of Wisconsin–Madison, Madison, Wisconsin 53706, USA
| | - Jason L. Heaton
- Evolutionary Studies Institute, University of the Witwatersrand, WITS 2050 Johannesburg, South Africa
- Department of Biology, Birmingham-Southern College, Birmingham, Alabama 35254, USA
| | - Kathleen Kuman
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, WITS 2050 Johannesburg, South Africa
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14
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Prabhat AM, Miller CK, Prang TC, Spear J, Williams SA, DeSilva JM. Homoplasy in the evolution of modern human-like joint proportions in Australopithecus afarensis. eLife 2021; 10:65897. [PMID: 33978569 PMCID: PMC8116054 DOI: 10.7554/elife.65897] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/19/2021] [Indexed: 11/22/2022] Open
Abstract
The evolution of bipedalism and reduced reliance on arboreality in hominins resulted in larger lower limb joints relative to the joints of the upper limb. The pattern and timing of this transition, however, remains unresolved. Here, we find the limb joint proportions of Australopithecus afarensis, Homo erectus, and Homo naledi to resemble those of modern humans, whereas those of A. africanus, Australopithecus sediba, Paranthropus robustus, Paranthropus boisei, Homo habilis, and Homo floresiensis are more ape-like. The homology of limb joint proportions in A. afarensis and modern humans can only be explained by a series of evolutionary reversals irrespective of differing phylogenetic hypotheses. Thus, the independent evolution of modern human-like limb joint proportions in A. afarensis is a more parsimonious explanation. Overall, these results support an emerging perspective in hominin paleobiology that A. afarensis was the most terrestrially adapted australopith despite the importance of arboreality throughout much of early hominin evolution.
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Affiliation(s)
| | - Catherine K Miller
- Anthropology, Dartmouth College, Hanover, United States.,Ecology, Evolution, Ecosystems, and Society, Dartmouth College, Hanover, United States
| | - Thomas Cody Prang
- Department of Anthropology, Texas A&M University, College Station, 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
| | - 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
| | - Jeremy M DeSilva
- Anthropology, Dartmouth College, Hanover, United States.,Ecology, Evolution, Ecosystems, and Society, Dartmouth College, Hanover, United States
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15
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Stratford D, Crompton R. Introduction to special issue StW 573: A 3.67 Ma Australopithecus prometheus skeleton from Sterkfontein Caves, South Africa-An introduction to the special issue. J Hum Evol 2021; 158:103008. [PMID: 33933277 DOI: 10.1016/j.jhevol.2021.103008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Dominic Stratford
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, WITS, Johannesburg, 2050, South Africa.
| | - Robin Crompton
- Department of Musculoskeletal and Ageing Science, Institute of Life Course & Medical Sciences, and School of Archaeology, Classics and Egyptology, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, UK
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16
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Anthropological Prosociality via Sub-Group Level Selection. Integr Psychol Behav Sci 2021; 56:180-205. [PMID: 33893612 DOI: 10.1007/s12124-021-09606-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2021] [Indexed: 10/21/2022]
Abstract
A perennial challenge of evolutionary psychology is explaining prosocial traits such as a preference for fairness rather than inequality, compassion towards suffering, and an instinctive ability to coordinate within small teams. Considering recent fossil evidence and a novel logical test, we deem present explanations insufficiently explanatory of the divergence of hominins. In answering this question, we focus on the divergence of hominins from the last common ancestor (LCA) shared with Pan. We consider recent fossil discoveries that indicate the LCA was bipedal, which reduces the cogency of this explanation for hominin development. We also review evolutionary theory that claims to explain how hominins developed into modern humans, however it is found that no mechanism differentiates hominins from other primates. Either the mechanism was available to the last common ancestor (LCA) (with P. troglodytes as its proxy), or because early hominins had insufficient cognition to utilise the mechanism. A novel mechanism, sub-group level selection (sGLS) is hypothesised by triangulating two pieces of data rarely considered by evolutionary biologists. These are behavioural dimorphism of Pan (chimpanzees and bonobos) that remain identifiable in modern humans, and the social behaviour of primate troops in a savannah ecology. We then contend that sGLS supplied an exponential effect which was available to LCA who left the forest, but was not sufficiently available to any other primates. In conclusion, while only indirectly supported by various evidence, sGLS is found to be singularly and persuasively explanatory of human's unique evolutionary story.
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17
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Carlson KJ, Green DJ, Jashashvili T, Pickering TR, Heaton JL, Beaudet A, Stratford D, Crompton R, Kuman K, Bruxelles L, Clarke RJ. The pectoral girdle of StW 573 ('Little Foot') and its implications for shoulder evolution in the Hominina. J Hum Evol 2021; 158:102983. [PMID: 33888323 DOI: 10.1016/j.jhevol.2021.102983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 02/20/2021] [Accepted: 02/23/2021] [Indexed: 10/21/2022]
Abstract
The ca. 3.67 Ma adult skeleton known as 'Little Foot' (StW 573), recovered from Sterkfontein Member 2 breccia in the Silberberg Grotto, is remarkable for its morphology and completeness. Preservation of clavicles and scapulae, including essentially complete right-side elements, offers opportunities to assess morphological and functional aspects of a nearly complete Australopithecus pectoral girdle. Here we describe the StW 573 pectoral girdle and offer quantitative comparisons to those of extant hominoids and selected homininans. The StW 573 pectoral girdle combines features intermediate between those of humans and other apes: a long and curved clavicle, suggesting a relatively dorsally positioned scapula; an enlarged and uniquely proportioned supraspinous fossa; a relatively cranially oriented glenoid fossa; and ape-like reinforcement of the axillary margin by a stout ventral bar. StW 573 scapulae are as follows: smaller than those of some homininans (i.e., KSD-VP-1/1 and KNM-ER 47000A), larger than others (i.e., A.L. 288-1, Sts 7, and MH2), and most similar in size to another australopith from Sterkfontein, StW 431. Moreover, StW 573 and StW 431 exhibit similar structural features along their axillary margins and inferior angles. As the StW 573 pectoral girdle (e.g., scapular configuration) has a greater affinity to that of apes-Gorilla in particular-rather than modern humans, we suggest that the StW 573 morphological pattern appears to reflect adaptations to arboreal behaviors, especially those with the hand positioned above the head, more than human-like manipulatory capabilities. When compared with less complete pectoral girdles from middle/late Miocene apes and that of the penecontemporaneous KSD-VP-1/1 (Australopithecus afarensis), and mindful of consensus views on the adaptiveness of arboreal positional behaviors soliciting abducted glenohumeral joints in early Pliocene taxa, we propose that the StW 573 pectoral girdle is a reasonable model for hypothesizing pectoral girdle configuration of the crown hominin last common ancestor.
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Affiliation(s)
- Kristian J Carlson
- Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg WITS 2050, South Africa.
| | - David J Green
- Department of Anatomy, Campbell University School of Osteopathic Medicine, Buies Creek, NC 27506, USA; Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg WITS 2050, South Africa
| | - Tea Jashashvili
- Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Department of Geology and Paleontology, Georgian National Museum, Tbilisi 0105, Georgia
| | - Travis R Pickering
- Department of Anthropology, University of Wisconsin, Madison, WI 53706, USA; Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg WITS 2050, South Africa; Plio-Pleistocene Palaeontology Section, Department of Vertebrates, Ditsong National Museum, Pretoria 0001, South Africa
| | - Jason L Heaton
- Department of Biology, Birmingham-Southern College, Birmingham, AL 35254, USA; Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg WITS 2050, South Africa; Plio-Pleistocene Palaeontology Section, Department of Vertebrates, Ditsong National Museum, Pretoria 0001, South Africa
| | - Amélie Beaudet
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Johannesburg WITS 2050 South Africa; Department of Anatomy, University of Pretoria, PO Box 2034, Pretoria 0001, South Africa
| | - Dominic Stratford
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Johannesburg WITS 2050 South Africa
| | - Robin Crompton
- Department of Musculoskeletal Biology, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK
| | - Kathleen Kuman
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Johannesburg WITS 2050 South Africa
| | - Laurent Bruxelles
- TRACES, UMR 5608 of the French National Centre for Scientific Research, Jean Jaurès University, 31058 Toulouse, France; French National Institute for Preventive Archaeological Researches (INRAP), 30900 Nîmes, France; School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Johannesburg WITS 2050 South Africa
| | - Ronald J Clarke
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg WITS 2050, South Africa
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18
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Yegian AK, Tucker Y, Gillinov S, Lieberman DE. Shorter distal forelimbs benefit bipedal walking and running mechanics: Implications for hominin forelimb evolution. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2021; 175:589-598. [PMID: 33818760 DOI: 10.1002/ajpa.24274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 02/10/2021] [Accepted: 03/07/2021] [Indexed: 11/07/2022]
Abstract
OBJECTIVES Brachial index is a skeletal ratio that describes the relative length of the distal forelimb. Over the course of hominin evolution, a shift toward smaller brachial indices occurred. First, Pleistocene australopiths yield values between extant chimpanzees and humans, with further evolution in Pliocene Homo to the modern human range. We hypothesized that shorter distal forelimbs benefit walking and running performance, notably elbow and shoulder joint torques, and predicted that the benefit would be greater in running compared to walking. MATERIALS AND METHODS We tested our hypothesis in a modern human sample walking and running while carrying hand weights, which increase the inertia (mass and effective length) of the distal forelimb, simulating a larger brachial index. RESULTS We found longer distal forelimbs and the added mass increased elbow muscle torque by 98% while walking and 70% in running, confirming our hypothesis that shorter distal forelimbs benefit walking and running performance. Shoulder muscle torque similarly increased in both gaits with the addition of hand weights due to elongation of the effective forelimb length. Normalized elbow torque, which accounted for the effect on shoulder torque caused by the experimental manipulation, increased by 16% while walking but 52% while running, indicating that shorter distal forelimbs provide a greater benefit for running by approximately three-fold. DISCUSSION Selection for economical bipedal walking in Australopithecus and endurance running in Homo likely contributed to the shift toward relatively smaller distal forelimbs across hominin evolution, with modern human proportions attained in Pleistocene Homo erectus and retained in later species.
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Affiliation(s)
- Andrew K Yegian
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Yanish Tucker
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA.,School of Clinical Medicine, University of Cambridge, Cambridge, England
| | - Stephen Gillinov
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Daniel E Lieberman
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
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19
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Pickering TR, Heaton JL, Clarke RJ, Stratford D, Heile A. Hominin lower limb bones from Sterkfontein Caves, South Africa (1998–2003 excavations). S AFR J SCI 2021. [DOI: 10.17159/sajs.2021/6758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
We describe late Pliocene and early Pleistocene hominin fossils from Sterkfontein Caves (South Africa), including two femoral specimens, as well as a partial tibia and a partial fibula. The fossils are likely assignable to Australopithecus africanus and/or Australopithecus prometheus and the morphology of each corroborates previous interpretations of Sterkfontein hominins as at least facultative bipeds.
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Affiliation(s)
- Travis Rayne Pickering
- Department of Anthropology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
| | - Jason L. Heaton
- Department of Biology, Birmingham- Southern College, Birmingham, Alabama, USA
| | - Ron J. Clarke
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
| | - Dominic Stratford
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Johannesburg, South Africa
| | - A.J. Heile
- Department of Anthropology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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20
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Karakostis FA, Haeufle D, Anastopoulou I, Moraitis K, Hotz G, Tourloukis V, Harvati K. Biomechanics of the human thumb and the evolution of dexterity. Curr Biol 2021; 31:1317-1325.e8. [PMID: 33513351 PMCID: PMC7987722 DOI: 10.1016/j.cub.2020.12.041] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/26/2020] [Accepted: 12/24/2020] [Indexed: 01/02/2023]
Abstract
Systematic tool production and use is one of humanity's defining characteristics, possibly originating as early as >3 million years ago.1-3 Although heightened manual dexterity is considered to be intrinsically intertwined with tool use and manufacture, and critical for human evolution, its role in the emergence of early culture remains unclear. Most previous research on this question exclusively relied on direct morphological comparisons between early hominin and modern human skeletal elements, assuming that the degree of a species' dexterity depends on its similarity with the modern human form. Here, we develop a new approach to investigate the efficiency of thumb opposition, a fundamental component of manual dexterity, in several species of fossil hominins. Our work for the first time takes into account soft tissue as well as bone anatomy, integrating virtual modeling of musculus opponens pollicis and its interaction with three-dimensional bone shape form. Results indicate that a fundamental aspect of efficient thumb opposition appeared approximately 2 million years ago, possibly associated with our own genus Homo, and did not characterize Australopithecus, the earliest proposed stone tool maker. This was true also of the late Australopithecus species, Australopithecus sediba, previously found to exhibit human-like thumb proportions. In contrast, later Homo species, including the small-brained Homo naledi, show high levels of thumb opposition dexterity, highlighting the increasing importance of cultural processes and manual dexterity in later human evolution.
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Affiliation(s)
- Fotios Alexandros Karakostis
- Paleoanthropology, Senckenberg Centre for Human Evolution and Palaeoenvironment, Eberhard Karls University of Tübingen, Rümelinstrasse 23, 72070 Tübingen, Germany
| | - Daniel Haeufle
- Hertie Institute for Clinical Brain Research and Werner Reichardt Centre for Integrative Neuroscience, Eberhard Karls University of Tübingen, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany; Institute for Modelling and Simulation of Biomechanical Systems, University of Stuttgart, Nobelstrasse 15, 70569 Stuttgart, Germany
| | - Ioanna Anastopoulou
- Department of Forensic Medicine and Toxicology, School of Medicine, National and Kapodistrian University of Athens, Mikras Asias Street 75, 11527 Athens, Greece
| | - Konstantinos Moraitis
- Department of Forensic Medicine and Toxicology, School of Medicine, National and Kapodistrian University of Athens, Mikras Asias Street 75, 11527 Athens, Greece
| | - Gerhard Hotz
- Anthropological Collection, Natural History Museum of Basel, Basel 4051, Switzerland
| | - Vangelis Tourloukis
- Paleoanthropology, Senckenberg Centre for Human Evolution and Palaeoenvironment, Eberhard Karls University of Tübingen, Rümelinstrasse 23, 72070 Tübingen, Germany
| | - Katerina Harvati
- Paleoanthropology, Senckenberg Centre for Human Evolution and Palaeoenvironment, Eberhard Karls University of Tübingen, Rümelinstrasse 23, 72070 Tübingen, Germany; DFG Centre of Advanced Studies 'Words, Bones, Genes, Tools', Eberhard Karls University of Tübingen, Rümelinstrasse 23, D-72070 Tübingen, Germany.
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21
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Araiza I, Meyer MR, Williams SA. Is ulna curvature in the StW 573 ('Little Foot') Australopithecus natural or pathological? J Hum Evol 2020; 151:102927. [PMID: 33370642 DOI: 10.1016/j.jhevol.2020.102927] [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: 10/11/2020] [Revised: 12/01/2020] [Accepted: 12/01/2020] [Indexed: 11/26/2022]
Affiliation(s)
- Isabella Araiza
- Department of Anthropology, University of California, Riverside, CA, 92521, USA
| | - Marc R Meyer
- Department of Anthropology, Chaffey College, Rancho Cucamonga, CA, 91737, USA.
| | - Scott A Williams
- Center for the Study of Human Origins, Department of Anthropology, New York University, 25 Waverly Place, New York, NY, 10003, USA; New York Consortium in Evolutionary Primatology, New York, NY, 10024, USA
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22
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Macchiarelli R, Bergeret-Medina A, Marchi D, Wood B. Nature and relationships of Sahelanthropus tchadensis. J Hum Evol 2020; 149:102898. [PMID: 33142154 DOI: 10.1016/j.jhevol.2020.102898] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 09/30/2020] [Accepted: 09/30/2020] [Indexed: 02/08/2023]
Abstract
A partial left femur (TM 266-01-063) was recovered in July 2001 at Toros-Menalla, Chad, at the same fossiliferous location as the late Miocene holotype of Sahelanthropus tchadensis (the cranium TM 266-01-060-1). It was recognized as a probable primate femur in 2004 when one of the authors was undertaking a taphonomic survey of the fossil assemblages from Toros-Menalla. We are confident the TM 266 femoral shaft belongs to a hominid. It could sample a hominid hitherto unrepresented at Toros-Menalla, but a more parsimonious working hypothesis is that it belongs to S. tchadensis. The differences between TM 266 and the late Miocene Orrorin tugenensis partial femur BAR 1002'00, from Kenya, are consistent with maintaining at least a species-level distinction between S. tchadensis and O. tugenensis. The results of our preliminary functional analysis suggest the TM 266 femoral shaft belongs to an individual that was not habitually bipedal, something that should be taken into account when considering the relationships of S. tchadensis. The circumstances of its discovery should encourage researchers to check to see whether there is more postcranial evidence of S. tchadensis among the fossils recovered from Toros-Menalla.
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Affiliation(s)
- Roberto Macchiarelli
- Unité de Formation Géosciences, Université de Poitiers, 86073, Poitiers, France; Département Homme & Environnement, UMR 7194 CNRS, Muséum national d'Histoire naturelle, 75116, Paris, France.
| | | | - Damiano Marchi
- Department of Biology, University of Pisa, 56126, Pisa, Italy; Evolutionary Studies Institute and Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Wits, 2050, South Africa
| | - Bernard Wood
- Center for the Advanced Study of Human Paleobiology and Department of Anthropology, George Washington University, Washington, DC, 20052, USA
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23
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Schroeder L. Revolutionary Fossils, Ancient Biomolecules, and Reflections in Ethics and Decolonization: Paleoanthropology in 2019. AMERICAN ANTHROPOLOGIST 2020. [DOI: 10.1111/aman.13410] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Lauren Schroeder
- Department of Anthropology University of Toronto Mississauga Mississauga ON Canada
- Human Evolution Research Institute University of Cape Town Rondebosch Western Cape South Africa
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24
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Ruff CB, Squyres N, Junno J. Body mass estimation in hominins from humeral articular dimensions. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 173:480-499. [DOI: 10.1002/ajpa.24090] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 04/02/2020] [Accepted: 05/17/2020] [Indexed: 12/31/2022]
Affiliation(s)
- Christopher B. Ruff
- Center for Functional Anatomy and Evolution Johns Hopkins University School of Medicine Baltimore Maryland USA
| | - Nicole Squyres
- Center for Functional Anatomy and Evolution Johns Hopkins University School of Medicine Baltimore Maryland USA
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25
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Abstract
Here we present evidence of hominin locomotor behavior from the trabecular bone of the femur. We show evidence for habitual use of highly flexed hip postures, which could potentially indicate regular climbing in a South African hominin from Sterkfontein, which is either Paranthropus robustus or Homo. Second, we present evidence that Australopithecus africanus likely did not climb at the frequencies seen in extant nonhuman apes, and exhibits a modern, human-like pattern of loading at the hip joint. These results challenge the prevailing view of a single transition to bipedalism within the hominin clade by providing evidence of climbing in a more recent, non-Australopithecus South African hominin, and add to the increasing evidence for locomotor diversity in the hominin clade. Bipedalism is a defining trait of the hominin lineage, associated with a transition from a more arboreal to a more terrestrial environment. While there is debate about when modern human-like bipedalism first appeared in hominins, all known South African hominins show morphological adaptations to bipedalism, suggesting that this was their predominant mode of locomotion. Here we present evidence that hominins preserved in the Sterkfontein Caves practiced two different locomotor repertoires. The trabecular structure of a proximal femur (StW 522) attributed to Australopithecus africanus exhibits a modern human-like bipedal locomotor pattern, while that of a geologically younger specimen (StW 311) attributed to either Homo sp. or Paranthropus robustus exhibits a pattern more similar to nonhuman apes, potentially suggesting regular bouts of both climbing and terrestrial bipedalism. Our results demonstrate distinct morphological differences, linked to behavioral differences between Australopithecus and later hominins in South Africa and contribute to the increasing evidence of locomotor diversity within the hominin clade.
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26
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Beaudet A, Clarke RJ, Heaton JL, Pickering TR, Carlson KJ, Crompton RH, Jashashvili T, Bruxelles L, Jakata K, Bam L, Van Hoorebeke L, Kuman K, Stratford D. The atlas of StW 573 and the late emergence of human-like head mobility and brain metabolism. Sci Rep 2020; 10:4285. [PMID: 32179760 PMCID: PMC7075956 DOI: 10.1038/s41598-020-60837-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/18/2020] [Indexed: 12/24/2022] Open
Abstract
Functional morphology of the atlas reflects multiple aspects of an organism’s biology. More specifically, its shape indicates patterns of head mobility, while the size of its vascular foramina reflects blood flow to the brain. Anatomy and function of the early hominin atlas, and thus, its evolutionary history, are poorly documented because of a paucity of fossilized material. Meticulous excavation, cleaning and high-resolution micro-CT scanning of the StW 573 (‘Little Foot’) skull has revealed the most complete early hominin atlas yet found, having been cemented by breccia in its displaced and flipped over position on the cranial base anterolateral to the foramen magnum. Description and landmark-free morphometric analyses of the StW 573 atlas, along with other less complete hominin atlases from Sterkfontein (StW 679) and Hadar (AL 333-83), confirm the presence of an arboreal component in the positional repertoire of Australopithecus. Finally, assessment of the cross-sectional areas of the transverse foramina of the atlas and the left carotid canal in StW 573 further suggests there may have been lower metabolic costs for cerebral tissues in this hominin than have been attributed to extant humans and may support the idea that blood perfusion of these tissues increased over the course of hominin evolution.
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Affiliation(s)
- Amélie Beaudet
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Johannesburg, WITS, 2050, South Africa. .,Department of Anatomy, University of Pretoria, PO Box 2034, Pretoria, 0001, South Africa.
| | - Ronald J Clarke
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, WITS, 2050, South Africa
| | - Jason L Heaton
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, WITS, 2050, South Africa.,Department of Biology, Birmingham-Southern College, 900 Arkadelphia Road, Birmingham, AL, 35254, United States.,Plio-Pleistocene Palaeontology Section, Department of Vertebrates, Ditsong National Museum of Natural History (Transvaal Museum), 432 Paul Kruger Street, Pretoria Central, Pretoria, South Africa
| | - Travis R Pickering
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, WITS, 2050, South Africa.,Department of Biology, Birmingham-Southern College, 900 Arkadelphia Road, Birmingham, AL, 35254, United States.,Department of Anthropology, University of Wisconsin, Madison, WI, 53706, United States
| | - Kristian J Carlson
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, WITS, 2050, South Africa.,Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, 1975 Zonal Avenue, Los Angeles, CA, 90033, United States
| | - Robin H Crompton
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, WITS, 2050, South Africa.,Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, William Henry Duncan Building, W Derby Street, Liverpool, L7 8TX, United Kingdom
| | - Tea Jashashvili
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, WITS, 2050, South Africa.,Molecular Imaging Center, Department of Radiology, Keck School of Medicine, University of Southern California, 2250 Alcazar Street, Los Angeles, CA, 90033, United States.,Department of Geology and Paleontology, Georgian National Museum, 3 Shota Rustaveli Ave, T'bilisi, 0105, Georgia
| | - Laurent Bruxelles
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Johannesburg, WITS, 2050, South Africa.,French National Institute for Preventive Archaeological Researches (INRAP), 561 rue Etienne Lenoir, 30900, Nîmes, France.,French Institute of South Africa (IFAS), USR 3336 CNRS, 62 Juta Street, Braamfontein, Johannesburg, 2001, South Africa
| | - Kudakwashe Jakata
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg, WITS, 2050, South Africa
| | - Lunga Bam
- South African Nuclear Energy Corporation SOC Ltd. (Necsa), Elias Motsoaledi Street Ext. (Church Street West), R104, Pelindaba, North West Province, South Africa
| | - Luc Van Hoorebeke
- UGCT Department of Physics and Astronomy, Ghent University, Proeftuinstraat 86/N12, B-9000, Gent, Belgium
| | - Kathleen Kuman
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Johannesburg, WITS, 2050, South Africa
| | - Dominic Stratford
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Private Bag 3, Johannesburg, WITS, 2050, South Africa
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Urciuoli A, Zanolli C, Beaudet A, Dumoncel J, Santos F, Moyà-Solà S, Alba DM. The evolution of the vestibular apparatus in apes and humans. eLife 2020; 9:e51261. [PMID: 32122463 PMCID: PMC7054002 DOI: 10.7554/elife.51261] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 01/18/2020] [Indexed: 12/17/2022] Open
Abstract
Phylogenetic relationships among extinct hominoids (apes and humans) are controversial due to pervasive homoplasy and the incompleteness of the fossil record. The bony labyrinth might contribute to this debate, as it displays strong phylogenetic signal among other mammals. However, the potential of the vestibular apparatus for phylogenetic reconstruction among fossil apes remains understudied. Here we test and quantify the phylogenetic signal embedded in the vestibular morphology of extant anthropoids (monkeys, apes and humans) and two extinct apes (Oreopithecus and Australopithecus) as captured by a deformation-based 3D geometric morphometric analysis. We also reconstruct the ancestral morphology of various hominoid clades based on phylogenetically-informed maximum likelihood methods. Besides revealing strong phylogenetic signal in the vestibule and enabling the proposal of potential synapomorphies for various hominoid clades, our results confirm the relevance of vestibular morphology for addressing the controversial phylogenetic relationships of fossil apes.
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Affiliation(s)
- Alessandro Urciuoli
- Institut Català de Paleontologia Miquel CrusafontUniversitat Autònoma de Barcelona, Cerdanyola del VallèsBarcelonaSpain
| | - Clément Zanolli
- Laboratoire PACEA, UMR 5199 CNRS, Université de BordeauxPessacFrance
| | - Amélie Beaudet
- School of Geography, Archaeology and Environmental StudiesUniversity of the WitwatersrandJohannesburgSouth Africa
- Department of AnatomyUniversity of PretoriaPretoriaSouth Africa
| | - Jean Dumoncel
- Laboratoire AMIS, UMR 5288 CNRS, Université de ToulouseToulouseFrance
| | - Frédéric Santos
- Laboratoire PACEA, UMR 5199 CNRS, Université de BordeauxPessacFrance
| | - Salvador Moyà-Solà
- Institut Català de Paleontologia Miquel CrusafontUniversitat Autònoma de Barcelona, Cerdanyola del VallèsBarcelonaSpain
- Institució Catalana de Recerca i Estudis Avançats (ICREA)BarcelonaSpain
- Unitat d’Antropologia (Departament de Biologia Animal, Biologia Vegetal i Ecologia)Universitat Autònoma de Barcelona, Cerdanyola del VallèsBarcelonaSpain
| | - David M Alba
- Institut Català de Paleontologia Miquel CrusafontUniversitat Autònoma de Barcelona, Cerdanyola del VallèsBarcelonaSpain
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Abstract
The relationship of evolution with diet and environment can provide insights into modern disease. Fossil evidence shows apes, and early human ancestors were fruit eaters living in environments with strongly seasonal climates. Rapid cooling at the end of the Middle Miocene (15-12 Ma: millions of years ago) increased seasonality in Africa and Europe, and ape survival may be linked with a mutation in uric acid metabolism. Climate stabilized in the later Miocene and Pliocene (12-5 Ma), and fossil apes and early hominins were both adapted for life on ground and in trees. Around 2.5 Ma, early species of Homo introduced more animal products into their diet, and this coincided with developing bipedalism, stone tool technology and increase in brain size. Early species of Homo such as Homo habilis still lived in woodland habitats, and the major habitat shift in human evolution occurred at 1.8 Ma with the origin of Homo erectus. Homo erectus had increased body size, greater hunting skills, a diet rich in meat, control of fire and understanding about cooking food, and moved from woodland to savannah. Group size may also have increased at the same time, facilitating the transmission of knowledge from one generation to the next. The earliest fossils of Homo sapiens appeared about 300 kyr, but they had separated from Neanderthals by 480 kyr or earlier. Their diet shifted towards grain-based foods about 100 kyr ago, and settled agriculture developed about 10 kyr ago. This pattern remains for many populations to this day and provides important insights into current burden of lifestyle diseases.
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Affiliation(s)
- P Andrews
- From the, Natural History Museum, London University College, London, UK
| | - R J Johnson
- University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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