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Polvadore TA, Yoakum CB, Taylor PM, Holmes MA, Laird MF, Chalk-Wilayto J, Kanno CM, de Oliveira JA, Terhune CE. Ontogenetic biomechanics of tufted (Sapajus) and untufted (Cebus) capuchin mandibles. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024:e25006. [PMID: 39049552 DOI: 10.1002/ajpa.25006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 07/02/2024] [Accepted: 07/09/2024] [Indexed: 07/27/2024]
Abstract
OBJECTIVES Cortical bone geometry is commonly used to investigate biomechanical properties of primate mandibles. However, the ontogeny of these properties is less understood. Here we investigate changes in cortical bone cross-sectional properties throughout capuchin ontogeny and compare captive versus wild, semi-provisioned groups. Tufted capuchins (Sapajus spp.) are known to consume relatively hard/tough foods, while untufted capuchins (Cebus spp.) exploit less mechanically challenging foods. Previous research indicates dietary differences are present early in development and adult Sapajus mandibles can resist higher bending/shear/torsional loads. MATERIALS AND METHODS This study utilized microCT scans of 22 Cebus and 45 Sapajus from early infancy to adulthood from three sample populations: one captive Cebus, one captive Sapajus, and one semi-provisioned, free-ranging Sapajus. Mandibular cross-sectional properties were calculated at the symphysis, P3, and M1. If the tooth had not erupted, its position within the crypt was used. A series of one-way ANOVAs were performed to assess differences between and within the sample populations. RESULTS Mandible robusticity increases across ontogeny for all three sample populations. Sapajus were better able to withstand bending and torsional loading even early in ontogeny, but no difference in shear resistance was found. Semi-provisioned, free-ranging Sapajus tend to show increased abilities to resist bending and torsional loading but not shear loading compared to captive Sapajus. DISCUSSION This study helps advance our understanding of the primate masticatory system development and opens the door for further studies into adaptive plasticity in shaping the masticatory apparatus of capuchins and differences in captive versus free-ranging sample populations.
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Affiliation(s)
- Taylor A Polvadore
- Department of Anthropology, University of Arkansas, Fayetteville, Arkansas, United States
| | - Caitlin B Yoakum
- Department of Anatomy, Arkansas College of Osteopathic Medicine, Arkansas Colleges of Health Education, Fort Smith, Arkansas, United States
| | - Parker M Taylor
- Department of Anthropology, University of Arkansas, Fayetteville, Arkansas, United States
| | - Megan A Holmes
- Department of Family Medicine and Community Health, Duke University School of Medicine, Durham, North Carolina, United States
| | - Myra F Laird
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Janine Chalk-Wilayto
- Department of Biomedical Sciences, Mercer University School of Medicine, Macon, Georgia, United States
| | - Cláudia Misue Kanno
- Research Center "Núcleo de Procriação de Macacos-Prego", Araçatuba Dental School, Universidade Estadual Paulista-UNESP, Araçatuba, Brazil
| | - José Américo de Oliveira
- Research Center "Núcleo de Procriação de Macacos-Prego", Araçatuba Dental School, Universidade Estadual Paulista-UNESP, Araçatuba, Brazil
| | - Claire E Terhune
- Department of Anthropology, University of Arkansas, Fayetteville, Arkansas, United States
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Holmes MA, Terhune CE, Chalk-Wilayto J, Yoakum CB, Taylor P, Ramirez R, Solís MP, Polvadore TA, Ross CF, Taylor AB, Fogaca MD, Laird MF. Ontogenetic changes in jaw leverage and skull shape in tufted and untufted capuchins. J Morphol 2024; 285:e21705. [PMID: 38704727 DOI: 10.1002/jmor.21705] [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: 01/26/2024] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 05/07/2024]
Abstract
The ontogeny of feeding is characterized by shifting functional demands concurrent with changes in craniofacial anatomy; relationships between these factors will look different in primates with disparate feeding behaviors during development. This study examines the ontogeny of skull morphology and jaw leverage in tufted (Sapajus) and untufted (Cebus) capuchin monkeys. Unlike Cebus, Sapajus have a mechanically challenging diet and behavioral observations of juvenile Sapajus suggest these foods are exploited early in development. Landmarks were placed on three-dimensional surface models of an ontogenetic series of Sapajus and Cebus skulls (n = 53) and used to generate shape data and jaw-leverage estimates across the tooth row for three jaw-closing muscles (temporalis, masseter, medial pterygoid) as well as a weighted combined estimate. Using geometric morphometric methods, we found that skull shape diverges early and shape is significantly different between Sapajus and Cebus throughout ontogeny. Additionally, jaw leverage varies with age and position on the tooth row and is greater in Sapajus compared to Cebus when calculated at the permanent dentition. We used two-block partial least squares analyses to identify covariance between skull shape and each of our jaw muscle leverage estimates. Sapajus, but not Cebus, has significant covariance between all leverage estimates at the anterior dentition. Our findings show that Sapajus and Cebus exhibit distinct craniofacial morphologies early in ontogeny and strong covariance between leverage estimates and craniofacial shape in Sapajus. These results are consistent with prior behavioral and comparative work suggesting these differences are a function of selection for exploiting mechanically challenging foods in Sapajus, and further emphasize that these differences appear quite early in ontogeny. This research builds on prior work that has highlighted the importance of understanding ontogeny for interpreting adult morphology.
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Affiliation(s)
- Megan A Holmes
- Department of Family Medicine and Community Health, Duke University School of Medicine, Durham, North Carolina, USA
| | - Claire E Terhune
- Department of Anthropology, University of Arkansas, Fayetteville, North Carolina, USA
| | - Janine Chalk-Wilayto
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia, USA
| | - Caitlin B Yoakum
- Department of Anatomy, Arkansas College of Health Education, Fort Smith, Arkansas, USA
| | - Parker Taylor
- Department of Anthropology, University of Arkansas, Fayetteville, North Carolina, USA
| | - Rocio Ramirez
- Department of Integrative Anatomical Sciences, University of Southern California, Los Angeles, California, USA
| | - Megan P Solís
- Department of Anthropology, Stony Brook University, Stony Brook, New York, USA
| | - Taylor A Polvadore
- Department of Anthropology, University of Arkansas, Fayetteville, North Carolina, USA
| | - Callum F Ross
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois, USA
| | - Andrea B Taylor
- Department of Foundational Biomedical Sciences, Touro University California, Vallejo, California, USA
| | | | - Myra F Laird
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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3
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Mihaminekena TH, Rakotonanahary AN, Frasier CL, Randriahaingo HNT, Sefczek TM, Tinsman J, Randrianarimanana HL, Ravaloharimanitra M, Rakotoarinivo TH, Ratsimbazafy J, King T, Louis EE. Dietary flexibility of the greater bamboo lemur (Prolemur simus), a specialized feeder, in eastern Madagascar. Am J Primatol 2024; 86:e23609. [PMID: 38409820 DOI: 10.1002/ajp.23609] [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: 03/20/2023] [Revised: 01/23/2024] [Accepted: 02/10/2024] [Indexed: 02/28/2024]
Abstract
The degree of dietary flexibility in primates is species specific; some incorporate a wider array of resources than others. Extreme interannual weather variability in Madagascar results in seasonal resource scarcity which has been linked to specialized behaviors in lemurs. Prolemur simus, for example, has been considered an obligate specialist on large culm bamboo with >60% of its diet composed of woody bamboos requiring morphological and physiological adaptations to process. Recent studies reported an ever-expanding list of dietary items, suggesting that this species may not be an obligate specialist. However, long-term quantitative feeding data are unavailable across this species' range. To explore the dietary flexibility of P. simus, we collected data at two northern sites, Ambalafary and Sahavola, and one southern site, Vatovavy, from September 2010 to January 2016 and May 2017 to September 2018, respectively. In total, we recorded 4022 h of behavioral data using instantaneous sampling of adult males and females from one group in Ambalafary, and two groups each in Sahavola and Vatovavy. We recorded 45 plant species eaten by P. simus over 7 years. We also observed significant differences in seasonal dietary composition between study sites. In Ambalafary, bamboo was the most frequently observed resource consumed (92.2%); however, non-bamboo resources comprised nearly one-third of the diet of P. simus in Sahavola and over 60% in Vatovavy. Consumption of all bamboo resources increased during the dry season at Ambalafary and during the wet season at Vatovavy, but never exceeded non-bamboo feeding at the latter. Culm pith feeding was only observed at Ambalafary, where it was more common during the dry season. We identify P. simus as a bamboo facultative specialist capable of adjusting its feeding behavior to its environment, indicating greater dietary flexibility than previously documented, which may enable the species to survive in increasingly degraded habitats.
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Affiliation(s)
- T Hasimija Mihaminekena
- The Aspinall Foundation Madagascar Programme, Antananarivo, Madagascar
- Zoologie et Anthropologie Biologique, Université d'Antananarivo, Antananarivo, Madagascar
| | - Ando N Rakotonanahary
- Mention Science de la Vie et de l'Environnement, Faculté des Sciences de Technologie et de l'Environnement (FSTE), Université de Mahajanga, Mahajanga, Madagascar
- Madagascar Biodiversity Partnership NGO (MBP), Antananarivo, Madagascar
| | - Cynthia L Frasier
- Conservation Genetics Department, Omaha's Henry Doorly Zoo and Aquarium, Omaha, Nebraska, USA
| | | | - Timothy M Sefczek
- Conservation Genetics Department, Omaha's Henry Doorly Zoo and Aquarium, Omaha, Nebraska, USA
- School of Global Integrative Studies, University of Nebraska, Lincoln, Nebraska, USA
| | - Jen Tinsman
- Conservation Genetics Department, Omaha's Henry Doorly Zoo and Aquarium, Omaha, Nebraska, USA
| | | | | | | | - Jonah Ratsimbazafy
- Groupe d'Etude et de Recherche sur les Primates (GERP), Antananarivo, Madagascar
| | - Tony King
- The Aspinall Foundation Madagascar Programme, Antananarivo, Madagascar
- The Aspinall Foundation, Port Lympne Reserve, Kent, UK
- School of Anthropology and Conservation, Durrell Institute of Conservation and Ecology, University of Kent, Kent, UK
| | - Edward E Louis
- Madagascar Biodiversity Partnership NGO (MBP), Antananarivo, Madagascar
- Conservation Genetics Department, Omaha's Henry Doorly Zoo and Aquarium, Omaha, Nebraska, USA
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Jung H, Strait D, Rolian C, Baab KL. Evaluating modularity in the hominine skull related to feeding biomechanics. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 183:39-59. [PMID: 37982349 DOI: 10.1002/ajpa.24875] [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: 04/07/2023] [Revised: 10/25/2023] [Accepted: 11/03/2023] [Indexed: 11/21/2023]
Abstract
OBJECTIVES Modular architecture of traits in complex organisms can be important for morphological evolution at micro- and sometimes macroevolutionary scales as it may influence the tempo and direction of changes to groups of traits that are essential for particular functions, including food acquisition and processing. We tested several distinct hypotheses about craniofacial modularity in the hominine skull in relation to feeding biomechanics. MATERIALS AND METHODS First, we formulated hypothesized functional modules for craniofacial traits reflecting specific demands of feeding biomechanics (e.g., masseter leverage/gape or tooth crown mechanics) in Homo sapiens, Pan troglodytes, and Gorilla gorilla. Then, the pattern and strength of modular signal was quantified by the covariance ratio coefficient and compared across groups using covariance ratio effect size. Hierarchical clustering analysis was then conducted to examine whether a priori-defined functional modules correspond to empirically recovered clusters. RESULTS There was statistical support for most a priori-defined functional modules in the cranium and half of the functional modules in the mandible. Modularity signal was similar in the cranium and mandible, and across the three taxa. Despite a similar strength of modularity, the empirically recovered clusters do not map perfectly onto our priori functional modules, indicating that further work is needed to refine our hypothesized functional modules. CONCLUSION The results suggest that modular structure of traits in association with feeding biomechanics were mostly shared with humans and the two African apes. Thus, conserved patterns of functional modularity may have facilitated evolutionary changes to the skull during human evolution.
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Affiliation(s)
- Hyunwoo Jung
- Department of Anatomy, College of Graduate Studies, Midwestern University, Glendale, Arizona, USA
| | - David Strait
- Department of Anthropology, Washington University in St. Louis, St. Louis, Missouri, USA
- Palaeo-Research Institute, University of Johannesburg, Johannesburg, South Africa
- DFG Center for Advanced Studies "Words, Bones, Genes, Tools", University of Tübingen, Tübingen, Germany
| | - Campbell Rolian
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | - Karen L Baab
- Department of Anatomy, College of Graduate Studies, Midwestern University, Glendale, Arizona, USA
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5
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Jung H, Strait D, Rolian C, Baab KL. Functional morphological integration related to feeding biomechanics in the hominine skull. J Hum Evol 2023; 182:103401. [PMID: 37647749 DOI: 10.1016/j.jhevol.2023.103401] [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: 11/21/2022] [Revised: 05/19/2023] [Accepted: 05/21/2023] [Indexed: 09/01/2023]
Abstract
Quantifying and characterizing the pattern of trait covariances is crucial for understanding how population-level patterns of integration might constrain or facilitate craniofacial evolution related to the feeding system. This study addresses an important gap in our knowledge by investigating magnitudes and patterns of morphological integration of biomechanically informative traits in the skulls of Homo sapiens, Pan troglodytes, and Gorilla gorilla. We predicted a lower magnitude of integration among human biomechanical traits since humans eat a softer, less biomechanically challenging diet than apes. Indeed, compared to African apes, the magnitudes of integration were lower in H. sapiens skulls for form data (raw dimensions) but were similar or higher for shape data (raw dimensions scaled by geometric mean). Patterns of morphological integration were generally similar, but not identical, across the three species, particularly for the form data compared to the shape data. Traits that load heavily on the primary axis of variation in morphospace are generally associated with size and/or shape of the temporalis and masseter muscles and with dimensions related to the constrained lever model of jaw biomechanics. Given the conserved nature of morphological integration, skull adaptations for food processing in African apes and humans may have been constrained to occur along certain paths of high evolvability. The conserved pattern of functional integration also indicates that extant hominine species can operate as reasonable analogues for extinct hominins in studies that require population-level patterns of trait variance/covariance.
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Affiliation(s)
- Hyunwoo Jung
- Department of Anatomy, College of Graduate Studies, Midwestern University, Glendale, AZ 85308, USA.
| | - David Strait
- Department of Anthropology, Washington University in St. Louis, St. Louis, MO 63130, USA; Palaeo-Research Institute, University of Johannesburg, Auckland Park, Johannesburg 2092, South Africa
| | - Campbell Rolian
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 0C7, Canada
| | - Karen L Baab
- Department of Anatomy, College of Graduate Studies, Midwestern University, Glendale, AZ 85308, USA
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6
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Knigge RP, Hardin AM, Middleton KM, McNulty KP, Oh H, Valiathan M, Duren DL, Sherwood RJ. Craniofacial growth and morphology among intersecting clinical categories. Anat Rec (Hoboken) 2022; 305:2175-2206. [PMID: 35076186 PMCID: PMC9309194 DOI: 10.1002/ar.24870] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/21/2021] [Accepted: 11/23/2021] [Indexed: 11/08/2022]
Abstract
Differential patterns of craniofacial growth are important sources of variation that can result in skeletal malocclusion. Understanding the timing of growth milestones and morphological change associated with adult skeletal malocclusions is critical for developing individualized orthodontic growth modification strategies. To identify patterns in the timing and geometry of growth, we used Bayesian modeling of cephalometrics and geometric morphometric analyses with a dense, longitudinal sample consisting of 15,407 cephalograms from 1,913 individuals between 2 and 31 years of age. Individuals were classified into vertical facial types (hyper-, normo-, hypo-divergent) and anteroposterior (A-P) skeletal classes (Class I, Class II, Class III) based on adult mandibular plane angle and ANB angle, respectively. These classifications yielded eight facial type-skeletal class categories with sufficient sample sizes to be included in the study. Four linear cephalometrics representing facial heights and maxillary and mandibular lengths were fit to standard double logistic models generating type-class category-specific estimates for age, size, and rate of growth at growth milestones. Mean landmark configurations were compared among type-class categories at four time points between 6 and 20 years of age. Overall, morphology and growth patterns were more similar within vertical facial types than within A-P classes and variation among A-P classes typically nested within variation among vertical types. Further, type-class-associated variation in the rate and magnitude of growth in specific regions identified here may serve as targets for clinical treatment of complex vertical and A-P skeletal malocclusion and provide a clearer picture of the development of variation in craniofacial form.
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Affiliation(s)
- Ryan P. Knigge
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, 55455
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO 65201
- Department of Orthopaedic Surgery, University of Missouri School of Medicine, Columbia, MO 65201
| | - Anna M. Hardin
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO 65201
- Department of Biology, Western Oregon University, Monmouth, OR, 97361
| | - Kevin M. Middleton
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO 65201
| | - Kieran P. McNulty
- Department of Anthropology, University of Minnesota, Minneapolis, MN, 55455
| | - Heesoo Oh
- Department of Orthodontics, Arthur A. Dugoni School of Dentistry, University of the Pacific, San Francisco, CA
| | - Manish Valiathan
- Department of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland, OH
| | - Dana L. Duren
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO 65201
- Department of Orthopaedic Surgery, University of Missouri School of Medicine, Columbia, MO 65201
| | - Richard J. Sherwood
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO 65201
- Department of Orthopaedic Surgery, University of Missouri School of Medicine, Columbia, MO 65201
- Department of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland, OH
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7
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López-Aguirre C, Hand SJ, Simmons NB, Silcox MT. Untangling the ecological signal in the dental morphology in the bat superfamily Noctilionoidea. J MAMM EVOL 2022. [DOI: 10.1007/s10914-022-09606-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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8
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Raidan C, de Andrade Costa BM, Marroig G, Aprígio Assis AP, Paresque R. Morphological integration and cranial modularity in six genera of echimyid rodents (Rodentia: Echimyidae). J Mammal 2021. [DOI: 10.1093/jmammal/gyab151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Rodents of the family Echimyidae present a wide variety of life histories and ecomorphological adaptations. This study evaluated morphological integration patterns, modularity, and evolutionary flexibility in six Echimyid genera representing ecomorphological extremes within the family. The relationships between traits were evaluated by comparing estimated covariance and correlations matrices of populations. The presence of modules was investigated by comparing the patterns of integration between traits and using hypothetical matrices based on shared development/function and masticatory stress. The results point to a common covariance and correlation pattern among the six echimyid genera, suggesting a conserved pattern of covariation (associations among traits) throughout the evolution of this group. The overall magnitude of integration, however, varied greatly. We also found a high degree of modularity in all six echimyid genera. Finally, we observed a clear association between flexibility, i.e., the ability of a species to respond to the direction of selection, with the overall magnitude of integration and degree of modularization. The results of this study provide hypotheses concerning the underlying effects of the association among traits, which may have facilitated or constrained the evolution of morphological variation in the diverse family Echimyidae.
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Affiliation(s)
- Carolline Raidan
- Pós graduação em Ciências Biológicas (curso Biologia Animal), Centro de Ciências Humanas e Naturais, Universidade Federal do Espírito, UFES, 29075-010, Vitória, ES, Brasil
| | | | - Gabriel Marroig
- Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, USP, 05508-090, São Paulo, SP, Brasil
| | - Ana Paula Aprígio Assis
- Departamento de Ecologia, Instituto de Biociência, Universidade de São Paulo, USP, 05508-090, São Paulo, SP, Brasil
| | - Roberta Paresque
- Pós graduação em Ciências Biológicas (curso Biologia Animal), Centro de Ciências Humanas e Naturais, Universidade Federal do Espírito, UFES, 29075-010, Vitória, ES, Brasil
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9
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Hogg RT, Elokda A. Quantification of enamel decussation in gracile and robust capuchins (Cebus, Sapajus, Cebidae, Platyrrhini). Am J Primatol 2021; 83:e23246. [PMID: 33638563 DOI: 10.1002/ajp.23246] [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: 09/15/2020] [Revised: 01/14/2021] [Accepted: 02/13/2021] [Indexed: 11/06/2022]
Abstract
Multiple behavioral and biomechanical analyses have demonstrated that capuchin monkeys (Cebus and Sapajus) are specialized for breaking down hard-object foods as compared to other cebid monkeys. In addition to a complex suite of craniodental adaptations, it has specifically been demonstrated that capuchins possess highly complex dental enamel, with extensive Hunter-Schreger banding and other decussation, that likely serve as an adaptation to resist crack propagation during hard-object feeding. Furthermore, it has been demonstrated that robust capuchins (Sapajus spp., formerly Cebus apella) demonstrate further adaptation for hard-object feeding than other capuchins, routinely breaking down extremely mechanically challenging foods. However, there has been no comparison of dental enamel complexity in robust versus gracile capuchins, to assess whether the dental enamel in Sapajus follows this same pattern of further specialization. Therefore, this study compares dental enamel complexity in images of dental thin sections from a sample of robust versus gracile capuchins using image compression ratio (ICR) analysis. ICR is a variable that correlates with enamel complexity, such that higher ICR values are indicative of increased complexity in the form of enamel decussation. We found no significant difference between robust and gracile capuchins when assessing all teeth in our sample together, however, we did find that robust capuchins have significantly higher ICR values than gracile capuchins for canine teeth, specifically. Our results support prior studies suggesting that robust capuchins are specialized to generate increased masticatory loads with their anterior dentition, specifically, as compared to gracile species.
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Affiliation(s)
- Russell T Hogg
- Department of Rehabilitation Sciences, Florida Gulf Coast University, Fort Myers, Florida, USA
| | - Abdallah Elokda
- Department of Biological Sciences, Florida Gulf Coast University, Fort Myers, Florida, USA
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10
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Villamil CI. The role of developmental rate, body size, and positional behavior in the evolution of covariation and evolvability in the cranium of strepsirrhines and catarrhines. J Hum Evol 2021; 151:102941. [PMID: 33482561 DOI: 10.1016/j.jhevol.2020.102941] [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: 03/05/2020] [Revised: 12/14/2020] [Accepted: 12/14/2020] [Indexed: 12/30/2022]
Abstract
Recent studies on hominin craniofacial evolution have focused on phenotypic integration or covariation among traits. Covariation is thought to significantly affect evolutionary trajectories, shaping the ways in which hominins and other primates could have evolved. However, the ways in which covariation itself evolves are not well understood. This study aims to investigate the role of phylogeny, development, body size, and positional behavior in shaping the strength of covariation in strepsirrhine and catarrhine primate crania (n = 1009, representing 11 genera). These factors may have been catalysts for change in the magnitude of covariation, and they have changed significantly during primate evolution and particularly hominin evolution. Modern humans in particular have slow developmental trajectories, large bodies, and a unique form of locomotion in the form of orthograde bipedalism. Variance of eigenvalues, mean integration, mean evolvability, and mean conditional evolvability was estimated and their relationship to the various factors described earlier was assessed using phylogenetic and nonphylogenetic analyses. Results indicate that some phylogenetic signal is present, but it is not equivalent across integration statistics or cranial regions. In particular, these results suggest that closely related species are more similar than more distantly related species in evolvability of the cranial base and integration of the face. Two divergent patterns were also identified, in which covariation and evolvability of the cranial base are linked to developmental rate, but those of the face are linked to body size. Neither locomotion nor posture appears related to covariation or evolvability of the primate cranium. These results suggest that overall low covariation observed in the hominin cranium may be a result of separate trends in different cranial regions.
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Affiliation(s)
- Catalina I Villamil
- School of Chiropractic, Universidad Central Del Caribe, PO Box 60327, Bayamón, PR, 00960-6032, USA; 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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11
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López-Aguirre C, Hand SJ, Koyabu D, Tu VT, Wilson LAB. Phylogeny and foraging behaviour shape modular morphological variation in bat humeri. J Anat 2020; 238:1312-1329. [PMID: 33372711 DOI: 10.1111/joa.13380] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 01/18/2023] Open
Abstract
Bats show a remarkable ecological diversity that is reflected both in dietary and foraging guilds (FGs). Cranial ecomorphological adaptations linked to diet have been widely studied in bats, using a variety of anatomical, computational and mathematical approaches. However, foraging-related ecomorphological adaptations and the concordance between cranial and postcranial morphological adaptations remain unexamined in bats and limited to the interpretation of traditional aerodynamic properties of the wing (e.g. wing loading [WL] and aspect ratio [AR]). For this reason, the postcranial ecomorphological diversity in bats and its drivers remain understudied. Using 3D virtual modelling and geometric morphometrics (GMM), we explored the phylogenetic, ecological and biological drivers of humeral morphology in bats, evaluating the presence and magnitude of modularity and integration. To explore decoupled patterns of variation across the bone, we analysed whole-bone shape, diaphyseal and epiphyseal shape. We also tested whether traditional aerodynamic wing traits correlate with humeral shape. By studying 37 species from 20 families (covering all FGs and 85% of dietary guilds), we found similar patterns of variation in whole-bone and diaphyseal shape and unique variation patterns in epiphyseal shape. Phylogeny, diet and FG significantly correlated with shape variation at all levels, whereas size only had a significant effect on epiphyseal morphology. We found a significant phylogenetic signal in all levels of humeral shape. Epiphyseal shape significantly correlated with wing AR. Statistical support for a diaphyseal-epiphyseal modular partition of the humerus suggests a functional partition of shape variability. Our study is the first to show within-structure modular morphological variation in the appendicular skeleton of any living tetrapod. Our results suggest that diaphyseal shape correlates more with phylogeny, whereas epiphyseal shape correlates with diet and FG.
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Affiliation(s)
- Camilo López-Aguirre
- Earth and Sustainability Science Research Centre, School of Biological, Earth & Environmental Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Suzanne J Hand
- Earth and Sustainability Science Research Centre, School of Biological, Earth & Environmental Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Daisuke Koyabu
- Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong.,Department of Molecular Craniofacial Embryology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Vuong Tan Tu
- Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, Hanoi, Vietnam.,Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Laura A B Wilson
- Earth and Sustainability Science Research Centre, School of Biological, Earth & Environmental Sciences, University of New South Wales, Sydney, NSW, Australia.,School of Archaeology & Anthropology, Australian National University, Canberra, ACT, Australia
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12
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Monson TA. Patterns and magnitudes of craniofacial covariation in extant cercopithecids. Anat Rec (Hoboken) 2020; 303:3068-3084. [PMID: 32220100 DOI: 10.1002/ar.24398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 01/15/2020] [Accepted: 01/25/2020] [Indexed: 01/17/2023]
Abstract
The cranium contains almost all of the vertebrate sensory organs and plays an essential role in vertebrate evolution. Research on the primate cranium has revealed that it is both highly integrated and modular, but studies have historically focused on covariance between the neurocranium and facial skeleton rather than on bones specific to special senses such as vision. The goal of this work is to investigate patterns and magnitudes of craniofacial covariation in extant cercopithecids with particular attention to the orbits. This study takes a quantitative approach using data collected from 38 homologous cranial landmarks across 11 genera of cercopithecid monkeys (Cercopithecidae, N = 291). These data demonstrate that both patterns and magnitudes of craniofacial covariation differ across Cercopithecidae at subfamily, tribe, and genus levels, with the strongest integration in the papionins (and specifically Papio) and significantly weaker covariation in the colobines, particularly Presbytis. Orbital height does not covary with other measurements of the cranium to the same degree as other cranial traits in Cercopithecidae and is highly constrained across the family. This study has important implications for our understanding of the evolution and development of morphological diversity in the cercopithecid cranium and evolution of the primate eye. This study also highlights the potential error of broad assumptions about generalizing patterns and magnitudes of modularity and integration across primates. Additionally, these findings reiterate the importance of trait selection for interpreting fossil taxonomy, as craniofacial covariation may impact phenotypes commonly used to differentiate fossil primate species.
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Affiliation(s)
- Tesla A Monson
- Department of Anthropology, Western Washington University, Bellingham, Washington, USA
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13
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Neaux D, Sansalone G, Ledogar JA, Heins Ledogar S, Luk TH, Wroe S. Basicranium and face: Assessing the impact of morphological integration on primate evolution. J Hum Evol 2018; 118:43-55. [DOI: 10.1016/j.jhevol.2018.02.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 02/09/2018] [Accepted: 02/12/2018] [Indexed: 12/11/2022]
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14
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Conaway MA, Schroeder L, von Cramon-Taubadel N. Morphological integration of anatomical, developmental, and functional postcranial modules in the crab-eating macaque (Macaca fascicularis). AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 166:661-670. [DOI: 10.1002/ajpa.23456] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 02/23/2018] [Accepted: 02/26/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Mark A. Conaway
- Buffalo Human Evolutionary Morphology Lab, Department of Anthropology; University at Buffalo; Buffalo New York 14261
| | - Lauren Schroeder
- Buffalo Human Evolutionary Morphology Lab, Department of Anthropology; University at Buffalo; Buffalo New York 14261
- Department of Anthropology; University of Toronto Mississauga; L5L 1C6, Ontario Canada
| | - Noreen von Cramon-Taubadel
- Buffalo Human Evolutionary Morphology Lab, Department of Anthropology; University at Buffalo; Buffalo New York 14261
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15
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Profico A, Piras P, Buzi C, Di Vincenzo F, Lattarini F, Melchionna M, Veneziano A, Raia P, Manzi G. The evolution of cranial base and face in Cercopithecoidea and Hominoidea: Modularity and morphological integration. Am J Primatol 2017; 79. [DOI: 10.1002/ajp.22721] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 01/05/2023]
Affiliation(s)
- Antonio Profico
- Dipartimento di Biologia Ambientale; Sapienza Università di Roma; Rome Italy
| | - Paolo Piras
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Nefrologiche, Anestesiologiche e Geriatriche; Sapienza Università di Roma; Rome Italy
- Dipartimento di Ingegneria Strutturale e Geotecnica; Sapienza Università di Roma; Rome Italy
| | - Costantino Buzi
- Dipartimento di Biologia Ambientale; Sapienza Università di Roma; Rome Italy
| | - Fabio Di Vincenzo
- Dipartimento di Biologia Ambientale; Sapienza Università di Roma; Rome Italy
| | - Flavio Lattarini
- Dipartimento di Biologia Ambientale; Sapienza Università di Roma; Rome Italy
| | - Marina Melchionna
- Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse; Università di Napoli, Federico II; Naples Italy
| | - Alessio Veneziano
- School of Natural Sciences and Psychology; John Moores University; Liverpool United Kingdom
| | - Pasquale Raia
- Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse; Università di Napoli, Federico II; Naples Italy
| | - Giorgio Manzi
- Dipartimento di Biologia Ambientale; Sapienza Università di Roma; Rome Italy
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16
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Ornelas-García CP, Bautista A, Herder F, Doadrio I. Functional modularity in lake-dwelling characin fishes of Mexico. PeerJ 2017; 5:e3851. [PMID: 28951817 PMCID: PMC5611896 DOI: 10.7717/peerj.3851] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 09/05/2017] [Indexed: 01/21/2023] Open
Abstract
Modular evolution promotes evolutionary change, allowing independent variation across morphological units. Recent studies have shown that under contrasting ecological pressures, patterns of modularity could be related to divergent evolution. The main goal of the present study was to evaluate the presence of modular evolution in two sister lacustrine species, Astyanax aeneus and A. caballeroi, which are differentiated by their trophic habits. Two different datasets were analyzed: (1) skull X-rays from 73 specimens (35 A. aeneus and 38 A. caballeroi) to characterize skull variation patterns, considering both species and sex effects. For this dataset, three different modularity hypotheses were tested, previously supported in other lacustrine divergent species; (2) a complete body shape dataset was also tested for four modularity hypotheses, which included a total of 196 individuals (110 Astyanax aeneus and 86 A. caballeroi). Skull shape showed significant differences among species and sex (P < 0.001), where Astyanax caballeroi species showed an upwardly projected mandible and larger preorbital region. For the skull dataset, the modularity hypothesis ranked first included three partitioning modules. While for the complete body dataset the best ranked hypothesis included two modules (head vs the rest of the body), being significant only for A. caballeroi.
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Affiliation(s)
- Claudia Patricia Ornelas-García
- Colección Nacional de Peces, Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico
| | - Amando Bautista
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, Mexico
| | - Fabian Herder
- Sektion Ichthyologie, Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Germany
| | - Ignacio Doadrio
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales, Madrid, Spain
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17
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Stelzer S, Gunz P, Neubauer S, Spoor F. Hominoid arcade shape: Pattern and magnitude of covariation. J Hum Evol 2017; 107:71-85. [PMID: 28526290 DOI: 10.1016/j.jhevol.2017.02.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 02/24/2017] [Accepted: 02/28/2017] [Indexed: 12/21/2022]
Abstract
The shape of the dental arcade and canine size distinguish extant humans from all apes. Humans are characterized by a parabolic arcade with short postcanine tooth rows and small canines, whereas apes have long, U-shaped arcades with large canines. The evolutionary and biomechanical mechanisms underlying arcade shape differences between and within groups are not well understood. It is unclear, for example, whether evolutionary changes in the covariation among modules comprising the upper and lower jaws are the cause and/or consequence of different arcade shapes. Here we use 3D geometric morphometric methods to explore to what extent the morphological differences in arcade shape between living hominoids are related to differences in covariation of upper and lower jaws, and the premaxilla and the maxilla. We show that all extant hominoids follow a very similar covariation pattern between upper and lower dental arcades, as well as between the premaxilla and the maxilla. We find comparably high magnitudes of covariation between the premaxilla and the maxilla in all groups. Between the upper and lower jaws, levels of covariation are similar in apes (Pan, Gorilla, Pongo, and Hylobates), but overall lower in extant humans. Our results demonstrate an independence of the pattern of arcade shape covariation from dental spatial arrangements. Importantly, we show that a shared hominoid pattern of covariation between premaxilla and maxilla together with the covariation of upper and lower jaw is consistent with major evolutionary arcade shape changes in hominoids. We suggest that with the reduction of canine and diastema size in hominins, the incisors move posteriorly and the tooth row becomes more parabolic. Our study provides a framework for addressing questions about fossil hominin dentognathic diversity, including inter- and intraspecific variation and associations of upper and lower jaw morphology.
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Affiliation(s)
- Stefanie Stelzer
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany.
| | - Philipp Gunz
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany
| | - Simon Neubauer
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany
| | - Fred Spoor
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany; Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
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18
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Esteve-Altava B. In search of morphological modules: a systematic review. Biol Rev Camb Philos Soc 2016; 92:1332-1347. [DOI: 10.1111/brv.12284] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 05/06/2016] [Accepted: 05/10/2016] [Indexed: 12/25/2022]
Affiliation(s)
- Borja Esteve-Altava
- Department of Comparative Biomedical Sciences; Royal Veterinary College; Hawkshead Lane, North Mymms Hatfield Hertfordshire AL9 7TA UK
- Department of Anatomy; College of Medicine, Howard University; 520 W Street, NW, Numa Adams Building Washington DC 20059 USA
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19
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Delgado MN, Galbany J, Górka K, Pérez-Pérez A. Taxonomic Implications of Molar Morphology Variability in Capuchins. INT J PRIMATOL 2015. [DOI: 10.1007/s10764-015-9850-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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20
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Esteve-Altava B, Boughner JC, Diogo R, Villmoare BA, Rasskin-Gutman D. Anatomical network analysis shows decoupling of modular lability and complexity in the evolution of the primate skull. PLoS One 2015; 10:e0127653. [PMID: 25992690 PMCID: PMC4438065 DOI: 10.1371/journal.pone.0127653] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 04/17/2015] [Indexed: 12/26/2022] Open
Abstract
Modularity and complexity go hand in hand in the evolution of the skull of primates. Because analyses of these two parameters often use different approaches, we do not know yet how modularity evolves within, or as a consequence of, an also-evolving complex organization. Here we use a novel network theory-based approach (Anatomical Network Analysis) to assess how the organization of skull bones constrains the co-evolution of modularity and complexity among primates. We used the pattern of bone contacts modeled as networks to identify connectivity modules and quantify morphological complexity. We analyzed whether modularity and complexity evolved coordinately in the skull of primates. Specifically, we tested Herbert Simon’s general theory of near-decomposability, which states that modularity promotes the evolution of complexity. We found that the skulls of extant primates divide into one conserved cranial module and up to three labile facial modules, whose composition varies among primates. Despite changes in modularity, statistical analyses reject a positive feedback between modularity and complexity. Our results suggest a decoupling of complexity and modularity that translates to varying levels of constraint on the morphological evolvability of the primate skull. This study has methodological and conceptual implications for grasping the constraints that underlie the developmental and functional integration of the skull of humans and other primates.
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Affiliation(s)
- Borja Esteve-Altava
- Theoretical Biology Research Group, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, 46071, Valencia, Spain
- Department of Anatomy, Howard University College of Medicine, Washington, DC, United States of America
| | - Julia C. Boughner
- Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Rui Diogo
- Department of Anatomy, Howard University College of Medicine, Washington, DC, United States of America
| | - Brian A. Villmoare
- Department of Anthropology, University of Nevada Las Vegas, Las Vegas, NV, United States of America
- Department of Anthropology, University College London, London, United Kingdom
| | - Diego Rasskin-Gutman
- Theoretical Biology Research Group, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, 46071, Valencia, Spain
- * E-mail:
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21
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Noback ML, Harvati K. Covariation in the Human Masticatory Apparatus. Anat Rec (Hoboken) 2014; 298:64-84. [DOI: 10.1002/ar.23067] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 10/11/2014] [Indexed: 01/05/2023]
Affiliation(s)
- Marlijn L. Noback
- Paleoanthropology Section, Senckenberg Center for Human Evolution and Paleoenvironment; Eberhard Karls Universität Tübingen; Tübingen Germany
| | - Katerina Harvati
- Paleoanthropology Section, Senckenberg Center for Human Evolution and Paleoenvironment; Eberhard Karls Universität Tübingen; Tübingen Germany
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22
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Craniofacial modularity, character analysis, and the evolution of the premaxilla in early African hominins. J Hum Evol 2014; 77:143-54. [DOI: 10.1016/j.jhevol.2014.06.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 03/21/2014] [Accepted: 06/26/2014] [Indexed: 01/08/2023]
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23
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Makedonska J. New insights into the phenotypic covariance structure of the anthropoid cranium. J Anat 2014; 225:634-58. [PMID: 25406861 DOI: 10.1111/joa.12246] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2014] [Indexed: 12/27/2022] Open
Abstract
In complex organisms, suites of non-random, highly intercorrelated phenotypic traits, organized according to their developmental history and forming semi-autonomous units (i.e. modules), have the potential to impose constraints on morphological diversification or to improve evolvability. Because of its structural, developmental and functional complexity, the cranium is arguably one of the best models for studying the interplay between developmental history and the need for various parts of a structure to specialize in different functions. This study evaluated the significance of two specific types of developmental imprints in the adult anthropoid cranium, those imposed by ossification pattern (i.e. ossification with and without a pre-existing cartilaginous phase) and those imposed by tissue origin (i.e. tissues derived principally from neural-crest vs. those derived from paraxial mesoderm). Specifically, this study tests the hypothesis that the face and the basicranium form two distinct modules with higher within-unit trait integration magnitudes compared with the cranium as a whole. Data on 12 anthropoid primate species were collected in the form of 20 three-dimensional landmarks digitized on cranial surface models that sample the basicranium as well as regions of functional importance during feeding [corrected]. The presence of a significant modularity imprint in the adult cranium was assessed using a between-region within-species comparison of multivariate correlations (RV coefficients) obtained with partial least-squares, using within-module within-species eigenvalue variance (EV), and using cluster analyses and non-metric multidimensional scaling. In addition to addressing the validity of the cranial modularity hypothesis in anthropoids, this study addressed methodological aspects of the interspecific comparison of morphological integration, namely the effect of sample size and the effect of landmark number on integration magnitudes. Two methodological findings that are of significance to research in morphological integration are that: (i) a smaller sample size increases integration magnitude, but preserves the pattern of variation of integration magnitudes from block to block within species; and that (ii) the number of landmarks per cranial block does not significantly impact block integration magnitude measured as EV. Results from the analyses testing for cranial modularity imprints in the adult anthropoid cranium show that some facial landmarks covary more strongly with basicranial landmarks than with other facial landmarks. Cluster methods, non-metric multidimensional scaling and, to an extent, RV results show that the rostral and the zygomatic landmarks covary more strongly with the basicranial landmarks than they do with the molar landmarks. However, the rostral-zygomatic-basicranial block, the molar block, the facial block, the basicranial block and the other analyzed cranial and facial blocks are not more integrated than the cranium. Thus, the morphological variation in the adult anthropoid cranium is not significantly constrained by at least two of the potential developmental sources of its covariance structure.
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Affiliation(s)
- Jana Makedonska
- Department of Anthropology, State University of New York at Albany, Albany, NY, USA
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24
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Resampling-based approaches to study variation in morphological modularity. PLoS One 2013; 8:e69376. [PMID: 23874956 PMCID: PMC3712944 DOI: 10.1371/journal.pone.0069376] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Accepted: 06/07/2013] [Indexed: 12/05/2022] Open
Abstract
Modularity has been suggested to be connected to evolvability because a higher degree of independence among parts allows them to evolve as separate units. Recently, the Escoufier RV coefficient has been proposed as a measure of the degree of integration between modules in multivariate morphometric datasets. However, it has been shown, using randomly simulated datasets, that the value of the RV coefficient depends on sample size. Also, so far there is no statistical test for the difference in the RV coefficient between a priori defined groups of observations. Here, we (1), using a rarefaction analysis, show that the value of the RV coefficient depends on sample size also in real geometric morphometric datasets; (2) propose a permutation procedure to test for the difference in the RV coefficient between a priori defined groups of observations; (3) show, through simulations, that such a permutation procedure has an appropriate Type I error; (4) suggest that a rarefaction procedure could be used to obtain sample-size-corrected values of the RV coefficient; and (5) propose a nearest-neighbor procedure that could be used when studying the variation of modularity in geographic space. The approaches outlined here, readily extendable to non-morphometric datasets, allow study of the variation in the degree of integration between a priori defined modules. A Java application – that will allow performance of the proposed test using a software with graphical user interface – has also been developed and is available at the Morphometrics at Stony Brook Web page (http://life.bio.sunysb.edu/morph/).
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25
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Klingenberg CP, Marugán-Lobón J. Evolutionary Covariation in Geometric Morphometric Data: Analyzing Integration, Modularity, and Allometry in a Phylogenetic Context. Syst Biol 2013; 62:591-610. [DOI: 10.1093/sysbio/syt025] [Citation(s) in RCA: 267] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Christian Peter Klingenberg
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK; and 2Unidad de Paleontología, Departamento de Biología, C/Darwin 2, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
| | - Jesús Marugán-Lobón
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK; and 2Unidad de Paleontología, Departamento de Biología, C/Darwin 2, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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