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Torres-Tamayo N, Rae TC, Hirasaki E, Betti L. Testing the reliability of the rearticulation of osteological primate pelves in comparative morphological studies. Anat Rec (Hoboken) 2024; 307:2816-2833. [PMID: 38112056 DOI: 10.1002/ar.25366] [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: 08/31/2023] [Revised: 11/24/2023] [Accepted: 11/27/2023] [Indexed: 12/20/2023]
Abstract
The evolution of human pelvic form is primarily studied using disarticulated osteological material of living and fossil primates that need rearticulation to approximate anatomical position. To test whether this technique introduces errors that impact biological signals, virtual rearticulations of the pelvis in anatomical position from computed tomography scans were compared with rearticulated models from the same individuals for one female and one male of Homo sapiens, Pan troglodytes, Macaca mulatta, Lepilemur mustelinus, Galago senegalensis, and Nycticebus pygmaeus. "Cadaveric" pelvic bones were first analyzed in anatomical position, then the three bones were segmented individually, intentionally scattered, and "rearticulated" to test for rearticulation error. Three-dimensional landmarks and linear measurements were used to characterize the overall pelvis shape. Cadaveric and rearticulated pelves were not identical, but inter-specific and intra-specific shape differences were higher than the landmarking error in the cadaveric individuals and the landmarking/rearticulation error in the rearticulated pelves, demonstrating that the biological signal is stronger than the noise introduced by landmarking and rearticulation. The rearticulation process, however, underestimates the medio-lateral pelvic measurements in species with a substantial pubic gap (e.g., G. senegalensis, N. pygmaeus) possibly because the greater contribution of soft tissue to the pelvic girdle introduces higher uncertainty during rearticulation. Nevertheless, this discrepancy affects only the caudal-most part of the pelvis. This study demonstrates that the rearticulation of pelvic bones does not substantially affect the biological signal in comparative 3D morphological studies but suggests that anatomically connected pelves of species with wide pubic gaps should be preferentially included in these studies.
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Affiliation(s)
| | - Todd C Rae
- School of Life Sciences, University of Sussex, Brighton, UK
| | - Eishi Hirasaki
- Centre for Evolutionary Origins of Human Behavior, Kyoto University, Inuyama, Japan
| | - Lia Betti
- Department of Anthropology, University College London, London, UK
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2
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Kanahashi T, Matsubayashi J, Imai H, Yamada S, Otani H, Takakuwa T. Sexual dimorphism of the human fetal pelvis exists at the onset of primary ossification. Commun Biol 2024; 7:538. [PMID: 38714799 PMCID: PMC11076513 DOI: 10.1038/s42003-024-06156-y] [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: 12/13/2023] [Accepted: 04/08/2024] [Indexed: 05/10/2024] Open
Abstract
Human adolescent and adult skeletons exhibit sexual dimorphism in the pelvis. However, the degree of sexual dimorphism of the human pelvis during prenatal development remains unclear. Here, we performed high-resolution magnetic resonance imaging-assisted pelvimetry on 72 human fetuses (males [M]: females [F], 34:38; 21 sites) with crown-rump lengths (CRL) of 50-225 mm (the onset of primary ossification). We used multiple regression analysis to examine sexual dimorphism with CRL as a covariate. Females exhibit significantly smaller pelvic inlet anteroposterior diameters (least squares mean, [F] 8.4 mm vs. [M] 8.8 mm, P = 0.036), larger subpubic angle ([F] 68.1° vs. [M] 64.0°, P = 0.034), and larger distance between the ischial spines relative to the transverse diameters of the greater pelvis than males. Furthermore, the sacral measurements indicate significant sex-CRL interactions. Our study suggests that sexual dimorphism of the human fetal pelvis is already apparent at the onset of primary ossification.
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Affiliation(s)
- Toru Kanahashi
- Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
| | - Jun Matsubayashi
- Center for Clinical Research and Advanced Medicine, Shiga University of Medical Science, Shiga, Japan
| | - Hirohiko Imai
- Department of Informatics, Graduate School of Informatics, Kyoto University, Kyoto, Japan
| | - Shigehito Yamada
- Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Congenital Anomaly Research Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroki Otani
- Department of Developmental Biology, Faculty of Medicine, Shimane University, Shimane, Japan
| | - Tetsuya Takakuwa
- Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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3
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Kleisner K, Pokorný Š, Černý V. Sexually dimorphic traits are associated with subsistence strategy in African faces from the Sahel/Savannah belt. Am J Hum Biol 2024; 36:e24008. [PMID: 37897188 DOI: 10.1002/ajhb.24008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/30/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
OBJECTIVES Previous research revealed that in some African populations, food-production strategies are associated with facial shape. Nomadic pastoralists living in the African Sahel/Savannah belt have a different facial morphology than their sedentary neighbors. We investigated whether the lifestyle associated with a subsistence pattern has an impact on sexual dimorphism in the facial structure. METHODS We employed several methods from geometric morphometrics and demonstrated such effect in four ethnically distinct populations that share the same geographic space. RESULTS We show that the facial traits which correlate with a subsistence strategy are systematically associated with levels of facial sex-typicality. In particular, we found that faces with more pronounced pastoralist features have on average more masculine facial traits and that this effect is more pronounced in men than in women. CONCLUSIONS In general, though, the magnitude of overall facial dimorphism does not differ between pastoralists and farmers. Pastoralists (in contrast to farmers) tend to have a more masculine facial morphology but facial differences between the sexes are in both groups the same.
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Affiliation(s)
- Karel Kleisner
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czech Republic
| | - Šimon Pokorný
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czech Republic
| | - Viktor Černý
- Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague, Czech Republic
- Archaeogenetics Laboratory, Institute of Archaeology of the Academy of Sciences of the Czech Republic, Prague, Czech Republic
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Rmoutilová R, Brůžek J, Gómez-Olivencia A, Madelaine S, Couture-Veschambre C, Holliday T, Maureille B. Sex estimation of the adult Neandertal Regourdou 1 (Montignac, France): Implications for sexing human fossil remains. J Hum Evol 2024; 189:103470. [PMID: 38552260 DOI: 10.1016/j.jhevol.2023.103470] [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: 12/05/2022] [Revised: 11/17/2023] [Accepted: 11/17/2023] [Indexed: 04/08/2024]
Abstract
Sex is a biological trait fundamental to the study of hominin fossils. Among the many questions that can be addressed are those related to taxonomy, biological variability, sexual dimorphism, paleoobstetrics, funerary selection, and paleodemography. While new methodologies such as paleogenomics or paleoproteomics can be used to determine sex, they have not been systematically applied to Pleistocene human remains due to their destructive nature. Therefore, we estimated sex from the coxal bone of the newly discovered pelvic remains of the Regourdou 1 Neandertal (Southwest France, MIS 5) based on morphological and metric data employing two methods that have been recently revised and shown to be reliable in multiple studies. Both methods calculate posterior probabilities of the estimate. The right coxal bone of Regourdou 1 was partially reconstructed providing additional traits for sex estimation. These methods were cross validated on 14 sufficiently preserved coxal bones of specimens from the Neandertal lineage. Our results show that the Regourdou 1 individual, whose postcranial skeleton is not robust, is a male, and that previous sex attributions of comparative Neandertal specimens are largely in agreement with those obtained here. Our results encourage additional morphological research of fossil hominins in order to develop a set of methods that are applicable, reliable, and reproducible.
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Affiliation(s)
- Rebeka Rmoutilová
- Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Viničná 7, 128 00, Prague, Czech Republic; University of Bordeaux, CNRS, MC, PACEA, UMR 5199, F-33600, Pessac, France; Hrdlicka Museum of Man, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czech Republic.
| | - Jaroslav Brůžek
- Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Viničná 7, 128 00, Prague, Czech Republic; University of Bordeaux, CNRS, MC, PACEA, UMR 5199, F-33600, Pessac, France
| | - Asier Gómez-Olivencia
- Departamento de Geología, Facultad de Ciencia y Tecnología, Universidad Del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Leioa, Spain; Sociedad de Ciencias Aranzadi, Donostia-San Sebastián, Spain; Centro UCM-ISCIII de Investigacion Sobre Evolución y Comportamiento Humanos, Madrid, Spain
| | - Stéphane Madelaine
- University of Bordeaux, CNRS, MC, PACEA, UMR 5199, F-33600, Pessac, France; Musée National de Préhistoire, 1 Rue Du Musée, 24620, Les Eyzies-de-Tayac Sireuil, France
| | | | - Trenton Holliday
- Tulane University, Department of Anthropology, 101 Dinwiddie Hall, New Orleans, LA, 70118, USA; Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Private Bag 3, Wits, 2050, RSA, South Africa
| | - Bruno Maureille
- University of Bordeaux, CNRS, MC, PACEA, UMR 5199, F-33600, Pessac, France
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Mitteroecker P, Fischer B. Evolution of the human birth canal. Am J Obstet Gynecol 2024; 230:S841-S855. [PMID: 38462258 DOI: 10.1016/j.ajog.2022.09.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 09/07/2022] [Accepted: 09/07/2022] [Indexed: 03/12/2024]
Abstract
It seems puzzling why humans have evolved such a small and rigid birth canal that entails a relatively complex process of labor compared with the birth canal of our closest relatives, the great apes. This study reviewed insights into the evolution of the human birth canal from recent theoretical and empirical studies and discussed connections to obstetrics, gynecology, and orthopedics. Originating from the evolution of bipedality and the large human brain million years ago, the evolution of the human birth canal has been characterized by complex trade-off dynamics among multiple biological, environmental, and sociocultural factors. The long-held notion that a wider pelvis has not evolved because it would be disadvantageous for bipedal locomotion has not yet been empirically verified. However, recent clinical and biomechanical studies suggest that a larger birth canal would compromise pelvic floor stability and increase the risk of incontinence and pelvic organ prolapse. Several mammals have neonates that are equally large or even larger than human neonates compared to the size of the maternal birth canal. In these species, the pubic symphysis opens widely to allow successful delivery. Biomechanical and developmental constraints imposed by bipedality have hindered this evolutionary solution in humans and led to the comparatively rigid pelvic girdle in pregnant women. Mathematical models have shown why the evolutionary compromise to these antagonistic selective factors inevitably involves a certain rate of fetopelvic disproportion. In addition, these models predict that cesarean deliveries have disrupted the evolutionary equilibrium and led to new and ongoing evolutionary changes. Different forms of assisted birth have existed since the stone age and have become an integral part of human reproduction. Paradoxically, by buffering selection, they may also have hindered the evolution of a larger birth canal. Many of the biological, environmental, and sociocultural factors that have influenced the evolution of the human birth canal vary globally and are subject to ongoing transitions. These differences may have contributed to the global variation in the form of the birth canal and the difficulty of labor, and they likely continue to change human reproductive anatomy.
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Affiliation(s)
- Philipp Mitteroecker
- Unit for Theoretical Biology, Department of Evolutionary Biology, University of Vienna, Vienna, Austria.
| | - Barbara Fischer
- Unit for Theoretical Biology, Department of Evolutionary Biology, University of Vienna, Vienna, Austria
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6
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Bugeja JM, Xia Y, Chandra SS, Murphy NJ, Crozier S, Hunter DJ, Fripp J, Engstrom C. Analysis of cam location characteristics in FAI syndrome patients from 3D MR images demonstrates sex-specific differences. J Orthop Res 2024; 42:385-394. [PMID: 37525546 DOI: 10.1002/jor.25674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 06/22/2023] [Accepted: 07/26/2023] [Indexed: 08/02/2023]
Abstract
Cam femoroacetabular impingement (FAI) syndrome is associated with hip osteoarthritis (OA) development. Hip shape features, derived from statistical shape modeling (SSM), are predictive for OA incidence, progression, and arthroplasty. Currently, no three-dimensional (3D) SSM studies have investigated whether there are cam shape differences between male and female patients, which may be of potential clinical relevance for FAI syndrome assessments. This study analyzed sex-specific cam location and shape in FAI syndrome patients from clinical magnetic resonance examinations (M:F 56:41, age: 16-63 years) using 3D focused shape modeling-based segmentation (CamMorph) and partial least squares regression to obtain shape features (latent variables [LVs]) of cam morphology. Two-way analysis of variance tests were used to assess cam LV data for sex and cam volume severity differences. There was no significant interaction between sex and cam volume severity for the LV data. A sex main effect was significant for LV 1 (cam size) and LV 2 (cam location) with medium to large effect sizes (p < 0.001, d > 0.75). Mean results revealed males presented with a superior-focused cam, whereas females presented with an anterior-focused cam. When stratified by cam volume, cam morphologies were located superiorly in male and anteriorly in female FAI syndrome patients with negligible, mild, or moderate cam volumes. Both male and female FAI syndrome patients with major cam volumes had a global cam distribution. In conclusion, sex-specific cam location differences are present in FAI syndrome patients with negligible, mild, and moderate cam volumes, whereas major cam volumes were globally distributed in both male and female patients.
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Affiliation(s)
- Jessica M Bugeja
- Australian e-Health Research Centre, Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation, Brisbane, QLD, Australia
| | - Ying Xia
- Australian e-Health Research Centre, Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation, Brisbane, QLD, Australia
| | - Shekhar S Chandra
- School of Information Technology and Electrical Engineering, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, Brisbane, QLD, Australia
| | - Nicholas J Murphy
- Kolling Institute of Medical Research, Sydney Musculoskeletal Health, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- Department of Orthopaedic Surgery, John Hunter Hospital, Newcastle, NSW, Australia
| | - Stuart Crozier
- School of Information Technology and Electrical Engineering, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, Brisbane, QLD, Australia
| | - David J Hunter
- Kolling Institute of Medical Research, Sydney Musculoskeletal Health, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- Department of Rheumatology, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - Jurgen Fripp
- Australian e-Health Research Centre, Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation, Brisbane, QLD, Australia
| | - Craig Engstrom
- School of Human Movement and Nutrition Sciences, Faculty of Health and Behavioural Sciences, The University of Queensland, Brisbane, QLD, Australia
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7
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Del Bove A, Menéndez L, Manzi G, Moggi-Cecchi J, Lorenzo C, Profico A. Mapping sexual dimorphism signal in the human cranium. Sci Rep 2023; 13:16847. [PMID: 37803023 PMCID: PMC10558540 DOI: 10.1038/s41598-023-43007-y] [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: 06/06/2023] [Accepted: 09/18/2023] [Indexed: 10/08/2023] Open
Abstract
The study of sexual dimorphism in human crania has important applications in the fields of human evolution and human osteology. Current, the identification of sex from cranial morphology relies on manual visual inspection of identifiable anatomical features, which can lead to bias due to user's expertise. We developed a landmark-based approach to automatically map the sexual dimorphism signal on the human cranium. We used a sex-known sample of 228 individuals from different geographical locations to identify which cranial regions are most sexually dimorphic taking into account shape, form and size. Our results, which align with standard protocols, show that glabellar and supraciliary regions, the mastoid process and the nasal region are the most sexually dimorphic traits (with an accuracy of 73%). The accuracy increased to 77% if they were considered together. Surprisingly the occipital external protuberance resulted to be not sexually dimorphic but mainly related to variations in size. Our approach here applied could be expanded to map other variable signals on skeletal morphology.
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Affiliation(s)
- Antonietta Del Bove
- Department of History and History of Arts, University Rovira i Virgli, Avinguda de Catalunya 35, 43002, Tarragona, Spain.
- Catalan Institute of Human Paleoecology and Social Evolution (IPHES-CERCA), Zona Educacional 4, Campus Sescelades URV (Edifici W3), 43007, Tarragona, Spain.
| | - Lumila Menéndez
- Department of Anthropology of the Americas, University of Bonn, Oxfordstraße 15, 53111, Bonn, Germany
- Department of Evolutionary Biology, University of Vienna, Djerassiplatz 1, 1030, Vienna, Austria
| | - Giorgio Manzi
- Department of Environmental Biology, Sapienza University of Rome, 00185, Rome, Italy
| | - Jacopo Moggi-Cecchi
- Department of Biology, University of Florence, Via del Proconsolo, 12, 50122, Florence, Italy
| | - Carlos Lorenzo
- Department of History and History of Arts, University Rovira i Virgli, Avinguda de Catalunya 35, 43002, Tarragona, Spain
- Catalan Institute of Human Paleoecology and Social Evolution (IPHES-CERCA), Zona Educacional 4, Campus Sescelades URV (Edifici W3), 43007, Tarragona, Spain
| | - Antonio Profico
- Department of Biology, University of Pisa, Via Luca Ghini, 13, 56126, Pisa, Italy
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8
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Warrener A. The multifactor pelvis: An alternative to the adaptationist approach of the obstetrical dilemma. Evol Anthropol 2023; 32:260-274. [PMID: 37527355 DOI: 10.1002/evan.21997] [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: 07/31/2022] [Revised: 02/23/2023] [Accepted: 07/08/2023] [Indexed: 08/03/2023]
Abstract
The obstetrical dilemma describes the competing demands that a bipedally adapted pelvis and a large-brained neonate place on human childbirth and is the predominant model within which hypotheses about the evolution of the pelvis are framed. I argue the obstetrical dilemma follows the adaptationist program outlined by Gould and Lewontin in 1979 and should be replaced with a new model, the multifactor pelvis. This change will allow thorough consideration of nonadaptive explanations for the evolution of the human pelvis and avoid negative social impacts from considering human childbirth inherently dangerous. First, the atomization of the pelvis into discrete traits is discussed, after which current evidence for both adaptive and nonadaptive hypotheses is evaluated, including childbirth, locomotion, shared genetics with other traits under selection, evolutionary history, genetic drift, and environmental and epigenetic influences on the pelvis.
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Affiliation(s)
- Anna Warrener
- Department of Anthropology, University of Colorado Denver, Denver, Colorado, USA
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9
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Grunstra NDS, Betti L, Fischer B, Haeusler M, Pavlicev M, Stansfield E, Trevathan W, Webb NM, Wells JCK, Rosenberg KR, Mitteroecker P. There is an obstetrical dilemma: Misconceptions about the evolution of human childbirth and pelvic form. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2023; 181:535-544. [PMID: 37353889 PMCID: PMC10952510 DOI: 10.1002/ajpa.24802] [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: 02/12/2023] [Revised: 05/27/2023] [Accepted: 06/11/2023] [Indexed: 06/25/2023]
Abstract
Compared to other primates, modern humans face high rates of maternal and neonatal morbidity and mortality during childbirth. Since the early 20th century, this "difficulty" of human parturition has prompted numerous evolutionary explanations, typically assuming antagonistic selective forces acting on maternal and fetal traits, which has been termed the "obstetrical dilemma." Recently, there has been a growing tendency among some anthropologists to question the difficulty of human childbirth and its evolutionary origin in an antagonistic selective regime. Partly, this stems from the motivation to combat increasing pathologization and overmedicalization of childbirth in industrialized countries. Some authors have argued that there is no obstetrical dilemma at all, and that the difficulty of childbirth mainly results from modern lifestyles and inappropriate and patriarchal obstetric practices. The failure of some studies to identify biomechanical and metabolic constraints on pelvic dimensions is sometimes interpreted as empirical support for discarding an obstetrical dilemma. Here we explain why these points are important but do not invalidate evolutionary explanations of human childbirth. We present robust empirical evidence and solid evolutionary theory supporting an obstetrical dilemma, yet one that is much more complex than originally conceived in the 20th century. We argue that evolutionary research does not hinder appropriate midwifery and obstetric care, nor does it promote negative views of female bodies. Understanding the evolutionary entanglement of biological and sociocultural factors underlying human childbirth can help us to understand individual variation in the risk factors of obstructed labor, and thus can contribute to more individualized maternal care.
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Affiliation(s)
- N. D. S. Grunstra
- Department of Evolutionary Biology, Unit for Theoretical BiologyUniversity of ViennaViennaAustria
- Mammal CollectionNatural History Museum ViennaViennaAustria
| | - L. Betti
- School of Life and Health SciencesUniversity of RoehamptonLondonUK
| | - B. Fischer
- Department of Evolutionary Biology, Unit for Theoretical BiologyUniversity of ViennaViennaAustria
| | - M. Haeusler
- Institute of Evolutionary MedicineUniversity of ZurichZurichSwitzerland
| | - M. Pavlicev
- Department of Evolutionary Biology, Unit for Theoretical BiologyUniversity of ViennaViennaAustria
| | - E. Stansfield
- Department of Evolutionary Biology, Unit for Theoretical BiologyUniversity of ViennaViennaAustria
| | - W. Trevathan
- School for Advanced ResearchSanta FeNew MexicoUSA
| | - N. M. Webb
- Institute of Evolutionary MedicineUniversity of ZurichZurichSwitzerland
- Institute of Archaeological Sciences, Senckenberg Centre for Human Evolution and PalaeoenvironmentEberhard‐Karls University of TübingenTübingenGermany
| | - J. C. K. Wells
- UCL Great Ormond Street Institute of Child Health, Population, Policy and Practice Research and Teaching ProgrammeChildhood Nutrition Research CentreLondonUK
| | - K. R. Rosenberg
- Department of AnthropologyUniversity of DelawareNewarkDelawareUSA
| | - P. Mitteroecker
- Department of Evolutionary Biology, Unit for Theoretical BiologyUniversity of ViennaViennaAustria
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10
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Kubicka AM. Changes in plasticity of the pelvic girdle from infancy to late adulthood in Homo sapiens. Sci Rep 2023; 13:9698. [PMID: 37322042 PMCID: PMC10272276 DOI: 10.1038/s41598-023-36703-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 06/08/2023] [Indexed: 06/17/2023] Open
Abstract
Previous research on the effects of body mass on the pelvic girdle focused mostly on adult females and males. Because the ontogenetic plasticity level in the pelvis remains largely unknown, this study investigated how the association between body mass index (BMI) and pelvic shape changes during development. It also assessed how the large variation in pelvic shape could be explained by the number of live births in females. Data included CT scans of 308 humans from infancy to late adulthood with known age, sex, body mass, body stature, and the number of live births (for adult females). 3D reconstruction and geometric morphometrics was used to analyze pelvic shape. Multivariate regression showed a significant association between BMI and pelvic shape in young females and old males. The association between the number of live births and pelvic shape in females was not significant. Less plasticity in pelvic shape in adult females than during puberty, perhaps reflects adaptation to support the abdominopelvic organs and the fetus during pregnancy. Non-significant susceptibility to BMI in young males may reflect bone maturation accelerated by excessive body mass. Hormonal secretion and biomechanical loading associated with pregnancy may not have a long-term effect on the pelvic morphology of females.
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Affiliation(s)
- Anna Maria Kubicka
- Department of Zoology, Poznań University of Life Sciences, Wojska Polskiego 71C, 60-625, Poznań, Poland.
- PaleoFED Team, Département Homme et Environnement, Muséum National d'Histoire Naturelle. Musée de l'Homme, UMR 7194, CNRS, Place du Trocadéro 17, 75016, Paris, France.
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11
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Starrach T, Schmidhuber L, Elger L, Franz M, Buechel J, Hübener C, Kolben T, Koliogiannis V, Mahner S, Hasbargen U, Fischer B. Pelvic inlet area is associated with birth mode. Acta Obstet Gynecol Scand 2022; 102:59-66. [PMID: 36320156 PMCID: PMC9780724 DOI: 10.1111/aogs.14478] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/11/2022] [Accepted: 10/16/2022] [Indexed: 11/05/2022]
Abstract
INTRODUCTION To determine whether a pelvis is wide enough for spontaneous delivery has long been the subject of obstetric research. A number of variables have been proposed as predictors, all with limited accuracy. In this study, we use a novel three-dimensional (3D) method to measure the female pelvis and assess which pelvic features influence birth mode. We compare the 3D pelvic morphology of women who delivered vaginally, women who had cesarean sections, and nulliparous women. The aim of this study is to identify differences in pelvic morphology between these groups. MATERIAL AND METHODS This observational study included women aged 50 years and older who underwent a CT scan of the pelvis for any medical indication. We recorded biometric data including height, weight, and age, and obtained the obstetric history. The bony pelvis was extracted from the CT scans and reconstructed in three dimensions. By placing 274 landmarks on each surface model, the pelvises were measured in detail. The pelvic inlet was measured using 32 landmarks. The trial was registered at the German Clinical Trials Register DRKS (DRKS00017690). RESULTS For this study, 206 women were screened. Exclusion criteria were foreign material in the bony pelvis, unknown birth mode, and exclusively preterm births. Women who had both a vaginal birth and a cesarean section were excluded from the group comparison. We compared the pelvises of 177 women between three groups divided by obstetric history: vaginal births only (n = 118), cesarean sections only (n = 21), and nulliparous women (n = 38). The inlet area was significantly smaller in the cesarean section group (mean = 126.3 cm2 ) compared with the vaginal birth group (mean = 134.9 cm2 , p = 0.002). The nulliparous women were used as a control group: there was no statistically significant difference in pelvic inlet area between the nulliparous and vaginal birth groups. CONCLUSIONS By placing 274 landmarks on a pelvis reconstructed in 3D, a very precise measurement of the morphology of the pelvis is possible. We identified a significant difference in pelvic inlet area between women with vaginal delivery and those with cesarean section. A unique feature of this study is the method of measurement of the bony pelvis that goes beyond linear distance measurements as used in previous pelvimetric studies.
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Affiliation(s)
- Teresa Starrach
- Department of Obstetrics and GynecologyUniversity Hospital, Ludwig Maximilian UniversityMunichGermany
| | - Lisa Schmidhuber
- Department of Obstetrics and GynecologyUniversity Hospital, Ludwig Maximilian UniversityMunichGermany
| | - Luisa Elger
- Department of Obstetrics and GynecologyUniversity Hospital, Ludwig Maximilian UniversityMunichGermany
| | - Marie Franz
- Department of Obstetrics and GynecologyUniversity Hospital, Ludwig Maximilian UniversityMunichGermany
| | - Johanna Buechel
- Department of Obstetrics and GynecologyUniversity Hospital, Ludwig Maximilian UniversityMunichGermany
| | - Christoph Hübener
- Department of Obstetrics and GynecologyUniversity Hospital, Ludwig Maximilian UniversityMunichGermany
| | - Thomas Kolben
- Department of Obstetrics and GynecologyUniversity Hospital, Ludwig Maximilian UniversityMunichGermany
| | - Vanessa Koliogiannis
- Department of RadiologyUniversity Hospital, Ludwig Maximilian UniversityMunichGermany
| | - Sven Mahner
- Department of Obstetrics and GynecologyUniversity Hospital, Ludwig Maximilian UniversityMunichGermany
| | - Uwe Hasbargen
- Department of Obstetrics and GynecologyUniversity Hospital, Ludwig Maximilian UniversityMunichGermany
| | - Barbara Fischer
- Department of Evolutionary Biology, Unit for Theoretical BiologyUniversity of ViennaViennaAustria
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Haeusler M, Grunstra ND, Martin RD, Krenn VA, Fornai C, Webb NM. The obstetrical dilemma hypothesis: there's life in the old dog yet. Biol Rev Camb Philos Soc 2021; 96:2031-2057. [PMID: 34013651 PMCID: PMC8518115 DOI: 10.1111/brv.12744] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 05/06/2021] [Accepted: 05/10/2021] [Indexed: 12/17/2022]
Abstract
The term 'obstetrical dilemma' was coined by Washburn in 1960 to describe the trade-off between selection for a larger birth canal, permitting successful passage of a big-brained human neonate, and the smaller pelvic dimensions required for bipedal locomotion. His suggested solution to these antagonistic pressures was to give birth prematurely, explaining the unusual degree of neurological and physical immaturity, or secondary altriciality, observed in human infants. This proposed trade-off has traditionally been offered as the predominant evolutionary explanation for why human childbirth is so challenging, and inherently risky, compared to that of other primates. This perceived difficulty is likely due to the tight fit of fetal to maternal pelvic dimensions along with the convoluted shape of the birth canal and a comparatively low degree of ligamentous flexibility. Although the ideas combined under the obstetrical dilemma hypothesis originated almost a century ago, they have received renewed attention and empirical scrutiny in the last decade, with some researchers advocating complete rejection of the hypothesis and its assumptions. However, the hypothesis is complex because it presently captures several, mutually non-exclusive ideas: (i) there is an evolutionary trade-off resulting from opposing selection pressures on the pelvis; (ii) selection favouring a narrow pelvis specifically derives from bipedalism; (iii) human neonates are secondarily altricial because they are born relatively immature to ensure that they fit through the maternal bony pelvis; (iv) as a corollary to the asymmetric selection pressure for a spacious birth canal in females, humans evolved pronounced sexual dimorphism of pelvic shape. Recently, the hypothesis has been challenged on both empirical and theoretical grounds. Here, we appraise the original ideas captured under the 'obstetrical dilemma' and their subsequent evolution. We also evaluate complementary and alternative explanations for a tight fetopelvic fit and obstructed labour, including ecological factors related to nutrition and thermoregulation, constraints imposed by the stability of the pelvic floor or by maternal and fetal metabolism, the energetics of bipedalism, and variability in pelvic shape. This reveals that human childbirth is affected by a complex combination of evolutionary, ecological, and biocultural factors, which variably constrain maternal pelvic form and fetal growth. Our review demonstrates that it is unwarranted to reject the obstetrical dilemma hypothesis entirely because several of its fundamental assumptions have not been successfully discounted despite claims to the contrary. As such, the obstetrical dilemma remains a tenable hypothesis that can be used productively to guide evolutionary research.
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Affiliation(s)
- Martin Haeusler
- Institute of Evolutionary MedicineUniversity of ZurichWinterthurerstrasse 190Zürich8057Switzerland
| | - Nicole D.S. Grunstra
- Konrad Lorenz Institute (KLI) for Evolution and Cognition ResearchMartinstrasse 12Klosterneuburg3400Austria
- Department of Evolutionary BiologyUniversity of ViennaUniversity Biology Building (UBB), Carl Djerassi Platz 1Vienna1030Austria
- Mammal CollectionNatural History Museum ViennaBurgring 7Vienna1010Austria
| | - Robert D. Martin
- Institute of Evolutionary MedicineUniversity of ZurichWinterthurerstrasse 190Zürich8057Switzerland
- The Field Museum1400 S Lake Shore DrChicagoIL60605U.S.A.
| | - Viktoria A. Krenn
- Institute of Evolutionary MedicineUniversity of ZurichWinterthurerstrasse 190Zürich8057Switzerland
- Department of Evolutionary AnthropologyUniversity of ViennaUniversity Biology Building (UBB), Carl Djerassi Platz 1Vienna1030Austria
| | - Cinzia Fornai
- Institute of Evolutionary MedicineUniversity of ZurichWinterthurerstrasse 190Zürich8057Switzerland
- Department of Evolutionary AnthropologyUniversity of ViennaUniversity Biology Building (UBB), Carl Djerassi Platz 1Vienna1030Austria
| | - Nicole M. Webb
- Institute of Evolutionary MedicineUniversity of ZurichWinterthurerstrasse 190Zürich8057Switzerland
- Senckenberg Research Institute and Natural History Museum FrankfurtSenckenberganlage 25Frankfurt am Main60325Germany
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