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Carretero JM, Rodríguez L, García-González R, Arsuaga JL. Main morphological characteristics and sexual dimorphism of hominin adult femora from the Sima de los Huesos Middle Pleistocene site (Sierra de Atapuerca, Spain). Anat Rec (Hoboken) 2024; 307:2575-2605. [PMID: 37794824 DOI: 10.1002/ar.25331] [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: 12/20/2022] [Revised: 08/28/2023] [Accepted: 08/28/2023] [Indexed: 10/06/2023]
Abstract
The excellent fossil record from Sima de los Huesos (SH) includes three well-known complete adult femora and several partial specimens that have not yet been published in detail. This fossil record provides an opportunity to analyze the morphology of European pre-Neandertal adult femur and its variation with different evolution patterns. Currently, there are a minimum of five adult individuals (males or females). In this study, we compiled previously published basic anatomical and biometric characteristics of SH adult femora, emphasizing the most relevant features compared to other recent and fossil hominins. The SH femora exhibited a primitive morphological pattern common to all non-Homo sapiens femora, as well as most of the Neandertal traits. Therefore, the complete Upper Pleistocene Neandertal pattern was well-established in Middle Pleistocene ancestors long before the proper Neandertals appeared. Additionally, we highlight that the SH and Neandertal femora share some morphological traits and proportions with modern humans that hold sexual significance in our species, regardless of size. Keeping this in mind, we discussed the sex determination of the complete SH specimens and re-evaluated sex allocation in two of them.
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Affiliation(s)
- José-Miguel Carretero
- Dpto. de Ciencias Históricas y Geografía, Laboratorio de Evolución Humana, Universidad de Burgos, Burgos, Spain
- Unidad Asociada de I+D+i al CSIC, Vidrio y Materiales del Patrimonio Cultural (VIMPAC), Burgos, Spain
| | - Laura Rodríguez
- Dpto. de Ciencias Históricas y Geografía, Laboratorio de Evolución Humana, Universidad de Burgos, Burgos, Spain
- Area de Antropología Física, Departamento de Biodiversidad y Gestión Ambiental, Universidad de León, León, Spain
| | - Rebeca García-González
- Dpto. de Ciencias Históricas y Geografía, Laboratorio de Evolución Humana, Universidad de Burgos, Burgos, Spain
| | - Juan-Luis Arsuaga
- Centro UCM-ISCIII de Investigación sobre Evolución y Comportamiento Humanos, Madrid, Spain
- Facultad de Ciencias Geológicas, Departamento de Paleontología, Universidad Complutense de Madrid, Madrid, Spain
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2
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Ruff CB, Wallace IJ, Toya C, Muñoz MAP, Meyer JV, Busby T, Reynolds AZ, Martinez J, Miller-Moore M, Rios R. The effects of the industrial transition on lower limb bone structure: A comparison of the inhabitants of Pecos Pueblo and present-day Indigenous peoples of New Mexico. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 184:e24922. [PMID: 38409941 DOI: 10.1002/ajpa.24922] [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: 12/18/2023] [Revised: 02/01/2024] [Accepted: 02/13/2024] [Indexed: 02/28/2024]
Abstract
OBJECTIVES Comparisons between Indigenous peoples over time and within a particular geographic region can shed light on the impact of environmental transitions on the skeleton, including relative bone strength, sexual dimorphism, and age-related changes. Here we compare long bone structural properties of the inhabitants of the late prehistoric-early historic Pecos Pueblo with those of present-day Indigenous individuals from New Mexico. MATERIALS AND METHODS Femora and tibiae of 126 adults from Pecos Pueblo and 226 present-day adults were included in the study. Cross-sectional diaphyseal properties-areas and second moments of area-were obtained from past studies of the Pecos Pueblo skeletal sample, and from computed tomography scans of recently deceased individuals in the present-day sample. RESULTS Femora and tibiae from Pecos individuals are stronger relative to body size than those of present-day Indigenous individuals. Present-day individuals are taller but not wider, and this body shape difference affects cross-sectional shape, more strongly proximally. The tibia shows anteroposterior strengthening among Pecos individuals, especially among males. Sexual dimorphism in midshaft bone shape is stronger within the Pecos Pueblo sample. With aging, Pecos individuals show more medullary expansion but also more subperiosteal expansion than present-day individuals, maintaining bone strength despite cortical thinning. DISCUSSION Higher activity levels, carried out over rough terrain and throughout adult life, likely explain the relatively stronger lower limb bones of the Pecos individuals, as well as their greater subperiosteal expansion with aging. Greater sexual dimorphism in bone structure among Pecos individuals potentially reflects greater gender-based differences in behavioral patterns.
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Affiliation(s)
- Christopher B Ruff
- Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Ian J Wallace
- Department of Anthropology, University of New Mexico, Albuquerque, New Mexico, USA
| | | | | | - Jana Valesca Meyer
- Department of Anthropology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Taylor Busby
- Department of Anthropology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Adam Z Reynolds
- Department of Anthropology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Jordan Martinez
- Department of Anthropology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Marcus Miller-Moore
- Department of Anthropology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Roberto Rios
- Department of Anthropology, University of New Mexico, Albuquerque, New Mexico, USA
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3
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Bell AV. Selection and adaptation in human migration. Evol Anthropol 2023; 32:308-324. [PMID: 37589279 DOI: 10.1002/evan.22003] [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: 07/06/2022] [Revised: 06/18/2023] [Accepted: 08/07/2023] [Indexed: 08/18/2023]
Abstract
This article reviews the ways migration shapes human biology. This includes the physiological and genetic, but also socio-cultural aspects such as organization, behavior, and culture. Across disciplines I highlight the multiple levels of cultural and genetic selection whereby individuals and groups adapt to pressures along a migration timeline: the origin, transit, and destination. Generally, the evidence suggests that selective pressures and adaptations occur at the individual, family, and community levels. Consequently, across levels there are negotiations, interactions, and feedbacks that shape migration outcomes and the trajectory of evolutionary change. The rise and persistence of migration-relevant adaptations emerges as a central question, including the maintenance of cumulative culture adaptations, the persistence of "cultures of migration," as well as the individual-level physiological and cognitive adaptations applied to successful transit and settlement in novel environments.
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Affiliation(s)
- Adrian Viliami Bell
- Department of Anthropology, University of Utah, Salt Lake City, Utah, USA
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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Chevalier T, Colard T. Inferring the mobility of a middle Upper Paleolithic female skeleton from Caviglione (Liguria, Italy): Impact of trauma and mountainous terrain. J Hum Evol 2023; 184:103428. [PMID: 37741140 DOI: 10.1016/j.jhevol.2023.103428] [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: 01/16/2023] [Revised: 08/25/2023] [Accepted: 08/26/2023] [Indexed: 09/25/2023]
Abstract
Mobility and territory occupation, the participation of injured individuals in group activities, and the role of women in early human groups are crucial issues in human evolution. Previously, a biomechanical study showed evidence of several traumas to the upper limb of the well-preserved middle Upper Paleolithic (UP) female skeleton from Caviglione (Caviglione 1, Liguria, Italy) but did not characterize their impact on locomotor behavior. Furthermore, mobility in the European UP context is thoroughly documented in males but not in females. Therefore, we examined whether this trauma-affected female skeleton shows bone adaptation to high mobility, as expected in UP groups, and to frequent foot eversion and inversion, as expected, given the mountainous area in which it was discovered. This study investigated the structural properties of the femur, tibia, fibula, and first metatarsal to infer the mobility level and pattern of Caviglione 1. We analyzed the diaphyseal 'shape', robusticity, fibular cortical distribution, and relative robusticity (fibula versus tibia). No substantial findings were derived from the first metatarsal. The fibular cortical distribution can discriminate 'active' (nomadic or settled) and recent sedentary human groups; these findings indicated Caviglione 1 belonged to the former. Interestingly, compared with ancient and recent sedentary humans and some UP individuals, Caviglione 1 had femurs with strong relative anteroposterior rigidity and robust tibias and fibulas reflecting an adaptation to extremely high levels of mobility. The very high relative fibular robusticity of Caviglione 1, higher than that of Middle UP males, is consistent with bone adaptation to frequent travel through mountainous terrain. Such fibular robusticity may also be a consequence of imbalance, due to upper limb traumas, when traveling downhill. These findings indicate that injured individuals may have participated in subsistence activities in past populations and describe an UP female with bone adaptations to habitual high mobility, notably in mountainous terrain.
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Affiliation(s)
- Tony Chevalier
- UMR 7194 HNHP, University of Perpignan via Domitia, EPCC-CERP de Tautavel, Avenue Léon Jean Grégory, Tautavel 66720, France.
| | - Thomas Colard
- UMR 5199 PACEA, University of Bordeaux, CNRS, MCC; Bâtiment B8, Allée Geoffroy Saint-Hilaire, CS50023, Pessac F-33615, France; Department of Oral and Maxillofacial Radiology, University of Lille, CHU Lille, Lille F-59000, France
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Lawson R, Thomas NDA. A systematic review of the measures that have been used to assess surface characteristics in relation to their impact on walking and falling. Syst Rev 2023; 12:155. [PMID: 37660050 PMCID: PMC10474776 DOI: 10.1186/s13643-023-02315-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 08/09/2023] [Indexed: 09/04/2023] Open
Abstract
We investigated whether an impediment to progress in understanding the environmental factors that cause falls may be the difficulty in comparing results across studies because walking surfaces are poorly defined and underspecified. We conducted a systematic review of 384 studies from 370 articles that tested how different surfaces influenced human walking and falling. For each study, we report which categories of surfaces were used (indoor, outdoor, treadmill, virtual reality and qualitative), the nature of each surface (stairs, slopes, slippery, compliant, rough or default) and how information about each surface was measured. We found that minimal information was provided for many surfaces, making it impossible to meaningfully compare results for different types of surfaces across studies. We conclude that most published studies of walking and falling provide insufficient data to describe the surfaces that they used and we provide recommendations about how to improve the reporting of walking surfaces.
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Affiliation(s)
- Rebecca Lawson
- Institute of Population Health, University of Liverpool, Liverpool, L69 7ZA, UK.
| | - Nicholas D A Thomas
- Institute of Population Health, University of Liverpool, Liverpool, L69 7ZA, UK
- Institute of Life Course & Medical Sciences, University of Liverpool, Liverpool, L7 8TX, UK
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Two Late Pleistocene human femora from Trinil, Indonesia: Implications for body size and behavior in Southeast Asia. J Hum Evol 2022; 172:103252. [PMID: 36162353 DOI: 10.1016/j.jhevol.2022.103252] [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: 05/31/2022] [Revised: 08/15/2022] [Accepted: 08/15/2022] [Indexed: 11/23/2022]
Abstract
Late Pleistocene hominin postcranial specimens from Southeast Asia are relatively rare. Here we describe and place into temporal and geographic context two partial femora from the site of Trinil, Indonesia, which are dated stratigraphically and via Uranium-series direct dating to ca. 37-32 ka. The specimens, designated Trinil 9 and 10, include most of the diaphysis, with Trinil 9 being much better preserved. Microcomputed tomography is used to determine cross-sectional diaphyseal properties, with an emphasis on midshaft anteroposterior to mediolateral bending rigidity (Ix/Iy), which has been shown to relate to both body shape and activity level in modern humans. The body mass of Trinil 9 is estimated from cortical area and reconstructed length using new equations based on a Pleistocene reference sample. Comparisons are carried out with a large sample of Pleistocene and Holocene East Asian, African, and European/West Asian femora. Our results show that Trinil 9 has a high Ix/Iy ratio, most consistent with a relatively narrow-bodied male from a mobile hunting-gathering population. It has an estimated body mass of 55.4 kg and a stature of 156 cm, which are small relative to Late Pleistocene males worldwide, but larger than the penecontemporaneous Deep Skull femur from Niah Cave, Malaysia, which is very likely female. This suggests the presence of small-bodied active hunter-gatherers in Southeast Asia during the later Late Pleistocene. Trinil 9 also contrasts strongly in morphology with earlier partial femora from Trinil dating to the late Early-early Middle Pleistocene (Femora II-V), and to a lesser extent with the well-known complete Femur I, most likely dating to the terminal Middle-early Late Pleistocene. Temporal changes in morphology among femoral specimens from Trinil parallel those observed in Homo throughout the Old World during the Pleistocene and document these differences within a single site.
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Temple DH, Rosa ER, Hunt DR, Ruff CB. Adapting in the Arctic: Habitual activity and landscape interaction in Late Holocene hunter-gatherers from Alaska. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2021; 176:3-20. [PMID: 33782942 DOI: 10.1002/ajpa.24250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/11/2021] [Accepted: 01/29/2021] [Indexed: 11/08/2022]
Abstract
OBJECTIVES This study compares lower limb diaphyseal robusticity between Native Alaskan hunter-gatherers to reconstruct patterns of mobility and engagement with terrain. MATERIALS AND METHODS Ancestral remains included in this study date between 600 and 1800 C.E. and were divided into three regions: Coastal Bay, Far North Coastal, and Inland/Riverine. Cross-sectional properties were determined at femoral and tibial midshafts and standardized by powers of body mass and bone length. RESULTS Consistently elaevated areas and second moments of area were found in ancestral remains from the Far North Coastal, while the Coastal Bay remains had reduced diaphyseal robusticity. Individuals from the Inland/Riverine region were intermediate in robusticity for male femora, but similar to the Coastal Bay group for females. Sexual dimorphism was greatest in the Inland/Riverine ancestral remains and comparable between Coastal Bay and Far North Coastal regions. CONCLUSIONS Ancestral remains from the Far North Coastal region have the greatest diaphyseal robusticity in response to intensive hunting and travel over rugged terrain. Reduced sexual dimorphism in the Far North Coastal region suggest female participation in hunting activities. Intermediate diaphyseal robusticity among Inland/Riverine males and increased sexual dimorphism reflects diverse patterns of mobility in relation to the hunting cycle between males and females. Reduced diaphyseal robusticity and sexual dimorphism among the Coastal Bay group is associated with sedentary villages established around net fishing in regions with low relief. Such findings argue against technocentric views of sedentism in hunter-gatherer lifeways and generally reflect diverse adaptive strategies and interaction with local terrain among Indigenous Late Holocene hunter-gatherers of Alaska.
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Affiliation(s)
- Daniel H Temple
- Department of Sociology and Anthropology, George Mason University, Fairfax, Virginia, USA
| | - Emily R Rosa
- Department of Sociology and Anthropology, George Mason University, Fairfax, Virginia, USA
| | - David R Hunt
- National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, USA
| | - Christopher B Ruff
- Center for Functional Anatomy and Evolution, Johns Hopkins University, Baltimore, Maryland, USA
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Jiménez-Brobeil SA, Charisi D, Laffranchi Z, Maroto Benavides RM, Delgado Huertas A, Milella M. Sex differences in diet and life conditions in a rural Medieval Islamic population from Spain (La Torrecilla, Granada): An isotopic and osteological approach to gender differentiation in al-Andalus. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2021; 175:794-815. [PMID: 33772756 DOI: 10.1002/ajpa.24277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 02/02/2021] [Accepted: 03/05/2021] [Indexed: 02/04/2023]
Abstract
OBJECTIVES Gender differentiation can influence the diet, physical activity, and health of human populations. Multifaceted approaches are therefore necessary when exploring the biological consequences of gender-related social norms in the past. Here, we explore the links between diet, physiological stress, physical activity, and gender differentiation in the Medieval Islamic population of La Torrecilla (Granada, Spain, 13th-15th century AD), by analyzing stable isotope patterns, stature, and long bone diaphyseal measurements. MATERIALS AND METHODS The sample includes 96 individuals (48 females, 48 males) classified as young and middle adults (20-34 and 35-50 years of age respectively). Diet was reconstructed through the analysis of δ13 C and δ15 N. Stature, humeral and femoral diaphyseal shape and product of diaphyseal diameters served as proxies of physiological stress and physical activity. RESULTS Isotopic ratios suggest a substantial dietary contribution of C4 plants (e.g., sorghum, millet), a variable access to animal proteins, and no differences between the sexes. Sexual dimorphism in stature derives from a markedly low female stature. Long bone diaphyseal properties suggest that men performed various physically stressful activities, whereas women were involved in less physically demanding activities (possibly related to household work). DISCUSSION Gender differentiation in La Torrecilla was expressed by a possibly differential parental investment in male versus female offspring and by culturally sanctioned gender differences in the performance of physical tasks. Diet was qualitatively homogenous between the sexes, although we cannot rule out quantitative differences. Our results shed new light on the effects of gender-related social norms on human development and lifestyle.
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Affiliation(s)
- Sylvia A Jiménez-Brobeil
- Department of Legal Medicine, Toxicology and Physical Anthropology, Faculty of Medicine, University of Granada, Granada, Spain
| | - Drosia Charisi
- Department of Legal Medicine, Toxicology and Physical Anthropology, Faculty of Medicine, University of Granada, Granada, Spain
| | - Zita Laffranchi
- Department of Legal Medicine, Toxicology and Physical Anthropology, Faculty of Medicine, University of Granada, Granada, Spain.,Department of Physical Anthropology, Institute of Forensic Medicine, University of Bern, Bern, Switzerland
| | - Rosa M Maroto Benavides
- Department of Legal Medicine, Toxicology and Physical Anthropology, Faculty of Medicine, University of Granada, Granada, Spain
| | - Antonio Delgado Huertas
- Biogeochemistry of Stable Isotopes Laboratory, Andalusian Institute of Earth Sciences, (IACT-CSIC-UGR), Granada, Spain
| | - Marco Milella
- Department of Physical Anthropology, Institute of Forensic Medicine, University of Bern, Bern, Switzerland
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Hagihara Y. Dorso-palmar elongation of the diaphysis of the third metacarpal bone in prehistoric Jomon people. Anat Sci Int 2020; 96:119-131. [PMID: 32920735 DOI: 10.1007/s12565-020-00570-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 09/01/2020] [Indexed: 11/30/2022]
Abstract
This study investigated cross-sectional morphological differences in the diaphysis of the third metacarpal bone (MC3) between prehistoric Jomon hunter-gatherers and modern Japanese people. Overall, 179 skeletal remains of 119 individuals (73 men and 46 women) from the Middle-to-Final Jomon period (3500 BC-500 BC) and 60 modern Japanese people (35 men and 25 women) were included in the analysis. Analyses were performed at the mid-shaft of the MC3 using linear measurement, elliptic Fourier analysis, and cross-sectional geometric properties. The standardized polar section modulus (ZpSTD) indicated sexual differences in both populations. The right MC3 was generally stronger than the left side. There was no populational difference in the ZpSTD in both sexes. In both men and women, the cross-sectional shape of the MC3 was relatively larger in the dorso-palmar direction than in the radioulnar direction in the Jomon population compared to the modern Japanese population. Sexual differences in cross-sectional shape were recognized only in the Jomon population, with the dorso-palmar elongation being greater in Jomon men than in women (particularly when comparing the left MC3). There was a significant side difference in the diaphyseal shape among Jomon women, with the right MC3 being relatively larger in the dorso-palmar direction. These findings were consistent, although skeletal remains of the Jomon population were excavated from different regions. Differences in the diaphyseal cross-sectional shape between populations suggest differences in habitual loading on MC3 associated with differences in subsistence behavior. Furthermore, differences in diaphyseal shape and strength between Jomon men and women suggest sexual division of labor, with men performing bimanual tasks and women performing unimanual tasks.
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Affiliation(s)
- Yasuo Hagihara
- Department of Medical Technology, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata, Niigata, 950-3198, Japan.
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Mulder B, Stock JT, Saers JPP, Inskip SA, Cessford C, Robb JE. Intrapopulation variation in lower limb trabecular architecture. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 173:112-129. [DOI: 10.1002/ajpa.24058] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 02/20/2020] [Accepted: 03/21/2020] [Indexed: 01/05/2023]
Affiliation(s)
- Bram Mulder
- University of Cambridge, McDonald Institute for Archaeological Research Cambridge UK
| | - Jay T. Stock
- University of Cambridge, McDonald Institute for Archaeological Research Cambridge UK
- Department of Anthropology University of Western Ontario London Canada
- Department of Archaeology Max Planck Institute for the Science of Human History Jena Germany
| | - Jaap P. P. Saers
- University of Cambridge, McDonald Institute for Archaeological Research Cambridge UK
| | - Sarah A. Inskip
- University of Cambridge, McDonald Institute for Archaeological Research Cambridge UK
| | - Craig Cessford
- University of Cambridge, McDonald Institute for Archaeological Research Cambridge UK
| | - John E. Robb
- University of Cambridge, McDonald Institute for Archaeological Research Cambridge UK
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Friedl L, Claxton AG, Walker CS, Churchill SE, Holliday TW, Hawks J, Berger LR, DeSilva JM, Marchi D. Femoral neck and shaft structure in Homo naledi from the Dinaledi Chamber (Rising Star System, South Africa). J Hum Evol 2019; 133:61-77. [PMID: 31358184 DOI: 10.1016/j.jhevol.2019.06.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 01/27/2023]
Abstract
The abundant femoral assemblage of Homo naledi found in the Dinaledi Chamber provides a unique opportunity to test hypotheses regarding the taxonomy, locomotion, and loading patterns of this species. Here we describe neck and shaft cross-sectional structure of all the femoral fossils recovered in the Dinaledi Chamber and compare them to a broad sample of fossil hominins, recent humans, and extant apes. Cross-sectional geometric (CSG) properties from the femoral neck (base of neck and midneck) and diaphysis (subtrochanteric region and midshaft) were obtained through CT scans for H. naledi and through CT scans or from the literature for the comparative sample. The comparison of CSG properties of H. naledi and the comparative samples shows that H. naledi femoral neck is quite derived with low superoinferior cortical thickness ratio and high relative cortical area. The neck appears superoinferiorly elongated because of two bony pilasters on its superior surface. Homo naledi femoral shaft shows a relatively thick cortex compared to the other hominins. The subtrochanteric region of the diaphysis is mediolaterally elongated resembling early hominins while the midshaft is anteroposteriorly elongated, indicating high mobility levels. In term of diaphyseal robusticity, the H. naledi femur is more gracile that other hominins and most apes. Homo naledi shows a unique combination of characteristics in its femur that undoubtedly indicate a species committed to terrestrial bipedalism but with a unique loading pattern of the femur possibly consequence of the unique postcranial anatomy of the species.
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Affiliation(s)
- Lukas Friedl
- Department of Anthropology, University of West Bohemia, Plzeň, Czech Republic
| | - Alex G Claxton
- Department of Anthropology, Dartmouth College, 409 Silsby, HB 6047, Hanover, USA
| | - Christopher S Walker
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA; Evolutionary Studies Institute and Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa; Department of Evolutionary Anthropology, Duke University, 04 Bio Sci Bldg, Durham, NC, 27708, USA
| | - Steven E Churchill
- Department of Evolutionary Anthropology, Duke University, 04 Bio Sci Bldg, Durham, NC, 27708, USA; Evolutionary Studies Institute and Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa
| | - Trenton W Holliday
- Department of Anthropology, Tulane University, 417 Dinwiddie Hall, New Orleans, LA, 70118, USA; Evolutionary Studies Institute and Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa
| | - John Hawks
- Department of Anthropology, University of Wisconsin, 5325 Sewell Social Science Building, Madison, WI, 53706, USA; Evolutionary Studies Institute and Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa
| | - Lee R Berger
- Evolutionary Studies Institute and Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa
| | - Jeremy M DeSilva
- Department of Anthropology, Dartmouth College, 409 Silsby, HB 6047, Hanover, USA; Evolutionary Studies Institute and Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa
| | - Damiano Marchi
- Department of Biology, University of Pisa, vis Derna 1, Pisa, 56126, Italy; Evolutionary Studies Institute and Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Private Bag 3, Wits, 2050, South Africa.
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