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Kenessey DE, Stojanowski CM, Paul KS. Evaluating predictions of the patterning cascade model of crown morphogenesis in the human lower mixed and permanent dentition. PLoS One 2024; 19:e0304455. [PMID: 38935640 DOI: 10.1371/journal.pone.0304455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 05/13/2024] [Indexed: 06/29/2024] Open
Abstract
OBJECTIVE The patterning cascade model of crown morphogenesis has been studied extensively in a variety of organisms to elucidate the evolutionary history surrounding postcanine tooth form. The current research is the first to use a large modern human sample to examine whether the crown configuration of lower deciduous and permanent molars aligns with expectations derived from the model. This study has two main goals: 1) to determine if metameric and antimeric pairs significantly differ in size, accessory trait expression, and relative intercusp spacing, and 2) assess whether the relative distance among early-forming cusps accounts for observed variation in accessory cusp expression. METHODS Tooth size, intercusp distance, and morphological trait expression data were collected from 3D scans of mandibular dental casts representing participants of the Harvard Solomon Islands Project. Paired tests were utilized to compare tooth size, accessory trait expression, and relative intercusp distance between diphyodont metameres and permanent antimeres. Proportional odds logistic regression was implemented to investigate how the odds of greater accessory cusp expression vary as a function of the distance between early-developing cusps. RESULTS/SIGNIFICANCE Comparing paired molars, significant differences were identified for tooth size and cusp 5 expression. Several relative intercusp distances emerged as important predictors of cusp 6 expression, however, results for cusp 5 and cusp 7 did not match expected patterns. These findings support previous quantitative genetic results and suggest the development of neighboring crown structures represents a zero-sum partitioning of cellular territory and resources. As such, this study contributes to a better understanding of the foundations of deciduous and permanent molar crown variation in humans.
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Affiliation(s)
- Dori E Kenessey
- Department of Anthropology, U niversity of Nevada, Reno, Nevada, United States of America
| | - Christopher M Stojanowski
- Center for Bioarchaeological Research, School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, United States of America
| | - Kathleen S Paul
- Department of Anthropology, University of Arkansas, Fayetteville, Arkansas, United States of America
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Gade L, Kamble PP, Kanna ASA, Patil K, Saraf K, Singh BP. The Prevalence and Association of Non-metric Dental Traits With Dentoskeletal Malocclusion and ABO Blood Groups in the Maharashtrian Population. Cureus 2024; 16:e59853. [PMID: 38854309 PMCID: PMC11157158 DOI: 10.7759/cureus.59853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2024] [Indexed: 06/11/2024] Open
Abstract
Introduction Non-metric dental traits (NMDTs) are a fundamental data source in forensic dentistry. Nevertheless, the insufficiency of data regarding the occurrence of these traits has instigated the present research endeavor aimed at ascertaining the prevalence, sexual dimorphism, and extent of inter-trait correlations within the Maharashtrian population of India. The secondary objective was to determine the correlations between NMDTs, dentoskeletal malocclusion, and ABO blood groups. Materials and methods This prospective, observational study included 528 individuals aged 18-30 years with dentoskeletal Class I, II, and III malocclusions. NMDTs such as the presence of Cusp of Carabelli (CoC) on the upper first molars, hypocone on the upper second molars, and tri- or bicuspid lower second premolars were observed on the dental casts of all individuals. The dental relationship was assessed clinically according to Angle's system for the classification of malocclusion. The skeletal relationship was assessed using lateral cephalograms of the individuals. ABO blood groups were obtained from their medical records. The Chi-square test of independence was used to assess the associations between various variables. The correlation between each measurement was determined using Spearman's correlation test. Multivariate analysis enabled the identification of parameters that exhibited independent associations with NMDTs. A multinomial logistic regression model was constructed using NMDTs as the outcome variable. Results The mean age of males was 20.82 ± 1.71 years and 21.15 ± 1.76 years was in females. NMDTs were predominantly seen in females (n=394, 75%), with Class II dentoskeletal malocclusion (n=265, 50%) and B blood group ((n=199, 38%). All traits showed bilateral predominance. A statistically significant association was found between CoC, dentoskeletal malocclusion, hypocone, and tricuspid lower second premolars (p <0.05). All NMDTs showed a negative correlation with sex, a positive correlation between age and the presence of hypocones and CoC, a negative correlation between age and tricuspid lower second premolars, a strong positive correlation with dentoskeletal malocclusion, and a weak positive correlation with ABO blood groups. Multinomial logistic regression model analysis revealed that none of the independent variables were statistically significant predictors of the presence of CoC and tricuspid lower second premolars, while dentoskeletal malocclusion and sex were significant predictors of the presence of the hypocone trait. Conclusion NMDTs showed a female predilection with bilateral predominance. A significant association was observed between these traits and dentoskeletal malocclusions. The most commonly observed NMDT was the presence of a hypocone on the upper second molars, followed by the tricuspid lower second premolars and the CoC.
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Affiliation(s)
- Lalitkumar Gade
- Department of Oral Pathology, Sau Mathurabai Bhausaheb Thorat (SMBT) Dental College and Hospital, Sangamner, IND
| | - Priyanka P Kamble
- Department of Oral Pathology, Jawahar Medical Foundation (JMF) Annasaheb Chudaman Patil Memorial (ACPM) Dental College, Dhule, IND
| | - Abdul Suban A Kanna
- Department of Orthodontics, Sri Ramakrishna Dental College and Hospital, Coimbatore, IND
| | - Kishor Patil
- Department of Oral Pathology, Sau Mathurabai Bhausaheb Thorat (SMBT) Dental College and Hospital, Sangamner, IND
| | - Ketan Saraf
- Department of Oral Pathology, Sau Mathurabai Bhausaheb Thorat (SMBT) Dental College and Hospital, Sangamner, IND
| | - Bhanu P Singh
- Department of Orthodontics, Kothiwal Dental College and Research Centre, Moradabad, IND
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Scaggion C, Marinato M, Dal Sasso G, Nodari L, Saupe T, Aneli S, Pagani L, Scheib CL, Rigo M, Artioli G. A fresh perspective on infrared spectroscopy as a prescreening method for molecular and stable isotopes analyses on ancient human bones. Sci Rep 2024; 14:1028. [PMID: 38200208 PMCID: PMC10781948 DOI: 10.1038/s41598-024-51518-5] [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: 06/08/2023] [Accepted: 01/06/2024] [Indexed: 01/12/2024] Open
Abstract
Following the development of modern genome sequencing technologies, the investigation of museum osteological finds is increasingly informative and popular. Viable protocols to help preserve these collections from exceedingly invasive analyses, would allow greater access to the specimens for scientific research. The main aim of this work is to survey skeletal tissues, specifically petrous bones and roots of teeth, using infrared spectroscopy as a prescreening method to assess the bone quality for molecular analyses. This approach could overcome the major problem of identifying useful genetic material in archaeological bone collections without resorting to demanding, time consuming and expensive laboratory studies. A minimally invasive sampling of archaeological bones was developed and bone structural and compositional changes were examined, linking isotopic and genetic data to infrared spectra. The predictive model based on Infrared parameters is effective in determining the occurrence of ancient DNA (aDNA); however, the quality/quantity of aDNA cannot be determined because of the influence of environmental and local factors experienced by the examined bones during the burial period.
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Affiliation(s)
- Cinzia Scaggion
- Department of Geosciences, University of Padova, 35131, Padova, Italy.
- INSTM, National Interuniversity Consortium of Materials Science and Technology, 50121, Firenze, Italy.
| | - Maurizio Marinato
- Department of Cultural Heritage: Archaeology and History of Art, Cinema and Music, University of Padova, 35139, Padova, Italy
| | - Gregorio Dal Sasso
- Institute of Geosciences and Earth Resources, Italian National Research Council-CNR, 35131, Padova, Italy
| | - Luca Nodari
- Institute of Condensed Matter Chemistry and Technologies for Energy, Italian National Research Council-CNR, 35127, Padova, Italy
| | - Tina Saupe
- Estonian Biocentre, Institute of Genomics, University of Tartu, 51010, Tartu, Estonia
| | - Serena Aneli
- Department of Biology, University of Padova, 35122, Padova, Italy
- Department of Public Health Sciences and Pediatrics, University of Torino, 10126, Torino, Italy
| | - Luca Pagani
- Estonian Biocentre, Institute of Genomics, University of Tartu, 51010, Tartu, Estonia
- Department of Biology, University of Padova, 35122, Padova, Italy
| | - Christiana L Scheib
- Estonian Biocentre, Institute of Genomics, University of Tartu, 51010, Tartu, Estonia
| | - Manuel Rigo
- Department of Geosciences, University of Padova, 35131, Padova, Italy
- Institute of Geosciences and Earth Resources, Italian National Research Council-CNR, 35131, Padova, Italy
| | - Gilberto Artioli
- Department of Geosciences, University of Padova, 35131, Padova, Italy
- INSTM, National Interuniversity Consortium of Materials Science and Technology, 50121, Firenze, Italy
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Scott GR, Navega D, Vlemincq-Mendieta T, Dern LL, O'Rourke DH, Hlusko LJ, Hoffecker JF. Peopling of the Americas: A new approach to assessing dental morphological variation in Asian and Native American populations. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2023. [PMID: 38018312 DOI: 10.1002/ajpa.24878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 10/24/2023] [Accepted: 11/03/2023] [Indexed: 11/30/2023]
Abstract
OBJECTIVES Through biodistance analyses, anthropologists have used dental morphology to elucidate how people moved into and throughout the Americas. Here, we apply a method that focuses on individuals rather than sample frequencies through the application rASUDAS2, based on a naïve Bayes' algorithm. MATERIALS AND METHODS Using the database of C.G. Turner II, we calculated the probability that an individual could be assigned to one of seven biogeographic groups (American Arctic, North & South America, East Asia, Southeast Asia & Polynesia, Australo-Melanesia, Western Eurasia, & Sub-Saharan Africa) through rASUDAS2. The frequency of classifications for each biogeographic group was determined for 1418 individuals from six regions across Asia and the Americas. RESULTS Southeast Asians show mixed assignments but rarely to American Arctic or "American Indian." East Asians are assigned to East Asia half the time while 30% are assigned as Native American. People from the American Arctic and North & South America are assigned to Arctic America or non-Arctic America 75%-80% of the time, with 10%-15% classified as East Asian. DISCUSSION All Native American groups have a similar degree of morphological affinity to East Asia, as 10%-15% are classified as East Asian. East Asians are classified as Native American in 30% of cases. Individuals in the Western Hemisphere are decreasingly classified as Arctic the farther south they are located. Equivalent levels of classification as East Asian across all Native American groups suggests one divergence between East Asians and the population ancestral to all Native Americans. Non-arctic Native American groups are derived from the Arctic population, which represents the Native American founder group.
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Affiliation(s)
- G Richard Scott
- Department of Anthropology, University of Nevada Reno, Reno, Nevada, USA
| | - David Navega
- Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | | | - Laresa L Dern
- Department of Anthropology, University of Nevada Reno, Reno, Nevada, USA
| | - Dennis H O'Rourke
- Department of Anthropology, University of Kansas, Lawrence, Kansas, USA
| | | | - John F Hoffecker
- Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado, USA
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Maaranen N, Stantis C, Kharobi A, Zakrzewski S, Schutkowski H, Doumet-Serhal C. The rise of coastal Middle Bronze Age Levant - A multidisciplinary approach for investigating in Sidon, Lebanon. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2023; 182:428-439. [PMID: 37560788 DOI: 10.1002/ajpa.24831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 07/21/2023] [Accepted: 07/26/2023] [Indexed: 08/11/2023]
Abstract
OBJECTIVES The Levantine Middle Bronze Age (MBA, circa 2000-1500 BCE) marks a period of increased trade and regional interaction, spurred on by technological developments. In light of previous research exhibiting limited mobility in Sidon, further investigation was conducted using biodistance analysis to understand local population history and site development. MATERIALS AND METHODS Dental nonmetric traits, a proxy for genetic information, were explored using ASUDAS on a sub-sample of primary inhumations (n = 35). The biodistance matrix was generated using Gower distance measures, and further tested using PERMDISP, PERMANOVA, Mantel test and hierarchical cluster analysis. The data was also contrasted to 87 Sr/86 Sr and δ18 O as well as δ13 C and δ15 N values. RESULTS There were no significant diachronic differences in isotopes values, and there was biological continuity (n = 35, Mantel test r = 0.11, p = 0.02, comparing local phases and biodistance). The analysis also suggested of a sub-group of individuals with biological proximity shared a more limited range of mobility and dietary habits. CONCLUSIONS The isotopes (87 Sr/86 Sr, δ18 O, δ13 C, δ15 N) and biodistance analysis conducted on the Sidon College site skeletal assemblage exhibits stability and continuity of the people, despite the site's increasing role in the maritime network. This continuity may have been a key factor in Sidon's success, allowing it to accumulate wealth and resources for centuries to come.
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Affiliation(s)
- N Maaranen
- Department of Archaeology and Anthropology, Bournemouth University, Poole, UK
- Department of Archaeology, University of Sheffield, Sheffield, UK
| | - C Stantis
- Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah, USA
| | - A Kharobi
- Department of Anthropology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - S Zakrzewski
- Department of Archaeology, University of Southampton, Southampton, UK
| | - H Schutkowski
- Department of Archaeology and Anthropology, Bournemouth University, Poole, UK
| | - C Doumet-Serhal
- Director of Sidon Excavation, Sidon, Lebanon
- Laboratoire UMR8167 Orient et Méditerranée, CNRS, Paris, France
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Rathmann H, Perretti S, Porcu V, Hanihara T, Scott GR, Irish JD, Reyes-Centeno H, Ghirotto S, Harvati K. Inferring human neutral genetic variation from craniodental phenotypes. PNAS NEXUS 2023; 2:pgad217. [PMID: 37457893 PMCID: PMC10338903 DOI: 10.1093/pnasnexus/pgad217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/14/2023] [Accepted: 06/20/2023] [Indexed: 07/18/2023]
Abstract
There is a growing consensus that global patterns of modern human cranial and dental variation are shaped largely by neutral evolutionary processes, suggesting that craniodental features can be used as reliable proxies for inferring population structure and history in bioarchaeological, forensic, and paleoanthropological contexts. However, there is disagreement on whether certain types of data preserve a neutral signature to a greater degree than others. Here, we address this unresolved question and systematically test the relative neutrality of four standard metric and nonmetric craniodental data types employing an extensive computational genotype-phenotype comparison across modern populations from around the world. Our computation draws on the largest existing data sets currently available, while accounting for geographically structured environmental variation, population sampling uncertainty, disparate numbers of phenotypic variables, and stochastic variation inherent to a neutral model of evolution. Our results reveal that the four data types differentially capture neutral genomic variation, with highest signals preserved in dental nonmetric and cranial metric data, followed by cranial nonmetric and dental metric data. Importantly, we demonstrate that combining all four data types together maximizes the neutral genetic signal compared with using them separately, even with a limited number of phenotypic variables. We hypothesize that this reflects a lower level of genetic integration through pleiotropy between, compared to within, the four data types, effectively forming four different modules associated with relatively independent sets of loci. Therefore, we recommend that future craniodental investigations adopt holistic combined data approaches, allowing for more robust inferences about underlying neutral genetic variation.
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Affiliation(s)
| | - Silvia Perretti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara 44121, Italy
| | - Valentina Porcu
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara 44121, Italy
| | - Tsunehiko Hanihara
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara 252-0374, Japan
| | - G Richard Scott
- Department of Anthropology, University of Nevada, Reno, NV 89557, USA
| | - Joel D Irish
- Research Centre in Evolutionary Anthropology and Palaeoecology, School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool L3 3AF, UK
- The Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg WITS 2050, South Africa
| | - Hugo Reyes-Centeno
- Department of Anthropology, University of Kentucky, Lexington, KY 40506, USA
- William S. Webb Museum of Anthropology, University of Kentucky, Lexington, KY 40504, USA
- DFG Center for Advanced Studies ‘Words, Bones, Genes, Tools’, University of Tübingen, Tübingen 72070, Germany
| | - Silvia Ghirotto
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara 44121, Italy
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Yang G, Chen Y, Li Q, Benítez D, Ramírez LM, Fuentes-Guajardo M, Hanihara T, Scott GR, Acuña Alonzo V, Gonzalez Jose R, Bortolini MC, Poletti G, Gallo C, Rothhammer F, Rojas W, Zanolli C, Adhikari K, Ruiz-Linares A, Delgado M. Dental size variation in admixed Latin Americans: Effects of age, sex and genomic ancestry. PLoS One 2023; 18:e0285264. [PMID: 37141293 PMCID: PMC10159210 DOI: 10.1371/journal.pone.0285264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 04/19/2023] [Indexed: 05/05/2023] Open
Abstract
Dental size variation in modern humans has been assessed from regional to worldwide scales, especially under microevolutionary and forensic contexts. Despite this, populations of mixed continental ancestry such as contemporary Latin Americans remain unexplored. In the present study we investigated a large Latin American sample from Colombia (N = 804) and obtained buccolingual and mesiodistal diameters and three indices for maxillary and mandibular teeth (except third molars). We evaluated the correlation between 28 dental measurements (and three indices) with age, sex and genomic ancestry (estimated using genome-wide SNP data). In addition, we explored correlation patterns between dental measurements and the biological affinities, based on these measurements, between two Latin American samples (Colombians and Mexicans) and three putative parental populations: Central and South Native Americans, western Europeans and western Africans through PCA and DFA. Our results indicate that Latin Americans have high dental size diversity, overlapping the variation exhibited by the parental populations. Several dental dimensions and indices have significant correlations with sex and age. Western Europeans presented closer biological affinities with Colombians, and the European genomic ancestry exhibited the highest correlations with tooth size. Correlations between tooth measurements reveal distinct dental modules, as well as a higher integration of postcanine dentition. The effects on dental size of age, sex and genomic ancestry is of relevance for forensic, biohistorical and microevolutionary studies in Latin Americans.
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Affiliation(s)
- Guangrui Yang
- Ministry of Education Key Laboratory of Contemporary Anthropology and Collaborative Innovation Center of Genetics and Development, School of Life Sciences and Human Phenome Institute, Fudan University, Shanghai, China
| | - Yingjie Chen
- Ministry of Education Key Laboratory of Contemporary Anthropology and Collaborative Innovation Center of Genetics and Development, School of Life Sciences and Human Phenome Institute, Fudan University, Shanghai, China
| | - Qing Li
- Ministry of Education Key Laboratory of Contemporary Anthropology and Collaborative Innovation Center of Genetics and Development, School of Life Sciences and Human Phenome Institute, Fudan University, Shanghai, China
| | - Daniel Benítez
- Department of Anthropology, University of Kentucky, Lexington, Kentucky, United States of America
| | | | - Macarena Fuentes-Guajardo
- Departamento de Tecnología Médica, Facultad de Ciencias de la Salud, Universidad de Tarapacá, Arica, Chile
| | - Tsunehiko Hanihara
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Japan
| | - G Richard Scott
- Department of Anthropology, University of Nevada Reno, Reno, Nevada, United States of America
| | - Victor Acuña Alonzo
- Molecular Genetics Laboratory, National School of Anthropology and History, Mexico City, Mexico
| | - Rolando Gonzalez Jose
- Instituto Patagónico de Ciencias Sociales y Humanas, Centro Nacional Patagónico, CONICET, Puerto Madryn, Argentina
| | - Maria Catira Bortolini
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil
| | - Giovanni Poletti
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Carla Gallo
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | | | - Winston Rojas
- GENMOL (Genética Molecular), Universidad de Antioquia, Medellín, Colombia
| | | | - Kaustubh Adhikari
- School of Mathematics and Statistics, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, United Kingdom
| | - Andres Ruiz-Linares
- Ministry of Education Key Laboratory of Contemporary Anthropology and Collaborative Innovation Center of Genetics and Development, School of Life Sciences and Human Phenome Institute, Fudan University, Shanghai, China
- Laboratory of Biocultural Anthropology, Law, Ethics, and Health (Centre National de la Recherche Scientifique and Etablissement Français du Sang, UMR-7268), Aix-Marseille University, Marseille, France
| | - Miguel Delgado
- Ministry of Education Key Laboratory of Contemporary Anthropology and Collaborative Innovation Center of Genetics and Development, School of Life Sciences and Human Phenome Institute, Fudan University, Shanghai, China
- División Antropología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata, República Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, CONICET, Buenos Aires, República Argentina
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Schroeder L, Ackermann RR. Moving beyond the adaptationist paradigm for human evolution, and why it matters. J Hum Evol 2023; 174:103296. [PMID: 36527977 DOI: 10.1016/j.jhevol.2022.103296] [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: 04/25/2022] [Revised: 11/12/2022] [Accepted: 11/12/2022] [Indexed: 12/23/2022]
Abstract
The Journal of Human Evolution (JHE) was founded 50 years ago when much of the foundation for how we think about human evolution was in place or being put in place, providing the main framework for how we consider our origins today. Here, we will explore historical developments, including early JHE outputs, as they relate to our understanding of the relationship between phenotypic variation and evolutionary process, and use that as a springboard for considering our current understanding of these links as applied to human evolution. We will focus specifically on how the study of variation itself has shifted us away from taxonomic and adaptationist perspectives toward a richer understanding of the processes shaping human evolutionary history, using literature searches and specific test cases to highlight this. We argue that natural selection, gene exchange, genetic drift, and mutation should not be considered individually when considering the production of hominin diversity. In this context, we offer suggestions for future research directions and reflect on this more complex understanding of human evolution and its broader relevance to society. Finally, we end by considering authorship demographics and practices in the last 50 years within JHE and how a shift in these demographics has the potential to reshape the science of human evolution going forward.
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Affiliation(s)
- Lauren Schroeder
- Department of Anthropology, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada; Human Evolution Research Institute, University of Cape Town, Rondebosch, 7701, South Africa.
| | - Rebecca Rogers Ackermann
- Human Evolution Research Institute, University of Cape Town, Rondebosch, 7701, South Africa; Department of Archaeology, University of Cape Town, Rondebosch, 7701, South Africa.
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Pojar T, Langstieh BT, Hemphill BE. An initial investigation of dental morphology variation among three southern Naga ethnic groups of Northeast India. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022; 179:184-210. [PMID: 36790681 DOI: 10.1002/ajpa.24605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 04/29/2022] [Accepted: 07/28/2022] [Indexed: 11/07/2022]
Abstract
OBJECTIVES This study examines dental morphology trait prevalence among three southern Naga groups and compares them to 10 ethnic groups from other regions of South Asia to accomplish two objectives: assess the biological relationship of these Tibeto-Burman-speakers to speakers of non-Tibeto-Burman languages in other South Asian regions, and determine which traits distinguish northeast Indians from other South Asians. METHODS Dental morphology traits were scored with the Arizona State University Dental Anthropology System. Tooth-trait combinations were evaluated for significant inter-trait correlation and intra-trait correspondence within dental fields. Comparisons were based on simple trait prevalence and with Smith's MMD. Affinities based on the former were accomplished with correspondence analysis and principal components analysis. Affinities based on the latter were undertaken with neighbor-joining cluster analysis and multidimensional scaling. RESULTS After elimination due to inter-trait correlations and uniform prevalence, biodistances based on the remaining 17 tooth-trait combinations identify significant differences between northeast Indians and other South Asian ethnic groups due to high frequencies of shoveling on the maxillary incisors and Cusp 6 on the mandibular molars coupled with low frequencies of Carabelli's trait and Cusp 5 on UM1 and UM2, respectively. CONCLUSIONS Patterns of biodistances obtained from dental morphology are consilient with those obtained from DNA indicating statistically significant differences between northeast Indians from members of ethnic groups of other regions of South Asia. Researchers should explore the sex-specific patterns. Biodistances should not be limited to "key" teeth within dental fields, for in almost every case traits present on mesial and distal teeth yield non-redundant information.
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Affiliation(s)
- Tsiapisa Pojar
- Department of Anthropology, North-Eastern Hill University, Shillong, India
| | | | - Brian E Hemphill
- Department of Anthropology, University of Alaska, Fairbanks, Fairbanks, Alaska, USA
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10
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Gellis JJ, Foley RA. Patterns of variation in canal and root number in human post-canine teeth. J Anat 2022; 241:896-918. [PMID: 36082500 PMCID: PMC9482695 DOI: 10.1111/joa.13729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 11/28/2022] Open
Abstract
Descriptive morphology of tooth roots traditionally focuses on number of canals and roots. However, how or if canal and root number are related is poorly understood. While it is often assumed that canal number is concomitant with root number and morphology, in practice canal number and morphology do not always covary with external root features. To investigate the relationship between canal and root number, fully developed, adult post‐canine teeth were examined and quantified from computerized tomography scans from a global sample of 945 modern humans. We tested the hypotheses that root and canal number do not follow a 1:1 ratio, that canal to root ratios differ between teeth, and that canal to root ratios differ across major human geographical groups. Results indicate that not only is root number dependent on canal number, but that this relationship becomes more variable as canal number increases, varies between individual teeth and by major geographical group, and changes as these groups increase in geographical distance from Sub‐Saharan Africa. These results show that the ratio of canal number to root number is an important indicator of variation in dental phenotypes.
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Affiliation(s)
- Jason J Gellis
- University of Cambridge Leverhulme Centre for Human Evolutionary Studies, Cambridge, UK
| | - Robert A Foley
- University of Cambridge Leverhulme Centre for Human Evolutionary Studies, Cambridge, UK
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11
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López-Onaindia D, Schmitt A, Gibaja JF, Subirà ME. Non-metric dental analysis of human interactions around the Pyrenees during the Neolithic and their biological impact. Ann Anat 2022; 242:151895. [DOI: 10.1016/j.aanat.2022.151895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 09/10/2021] [Accepted: 01/17/2022] [Indexed: 12/26/2022]
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Gellis J, Foley R. A novel system for classifying tooth root phenotypes. PLoS One 2021; 16:e0251953. [PMID: 34739489 PMCID: PMC8570528 DOI: 10.1371/journal.pone.0251953] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 09/16/2021] [Indexed: 11/19/2022] Open
Abstract
Human root and canal number and morphology are highly variable, and internal root canal form and count does not necessarily co-vary directly with external morphology. While several typologies and classifications have been developed to address individual components of teeth, there is a need for a comprehensive system, that captures internal and external root features across all teeth. Using CT scans, the external and internal root morphologies of a global sample of humans are analysed (n = 945). From this analysis a method of classification that captures external and internal root morphology in a way that is intuitive, reproducible, and defines the human phenotypic set is developed. Results provide a robust definition of modern human tooth root phenotypic diversity. The method is modular in nature, allowing for incorporation of past and future classification systems. Additionally, it provides a basis for analysing hominin root morphology in evolutionary, ecological, genetic, and developmental contexts.
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Affiliation(s)
- Jason Gellis
- Department of Archaeology, The Leverhulme Centre for Human Evolutionary Studies, University of Cambridge, Cambridge, England
| | - Robert Foley
- Department of Archaeology, The Leverhulme Centre for Human Evolutionary Studies, University of Cambridge, Cambridge, England
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13
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Šimková PG, Weber GW, Ramirez Rozzi FV, Slimani L, Sadoine J, Fornai C. Morphological variation of the deciduous second molars in the Baka Pygmies. Sci Rep 2021; 11:16480. [PMID: 34389746 PMCID: PMC8363745 DOI: 10.1038/s41598-021-95524-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 07/16/2021] [Indexed: 11/09/2022] Open
Abstract
The Baka Pygmies are known for their short stature resulting from a reduced growth rate during infancy. They are peculiar also for their teeth erupt earlier than in any other African population, and their posterior dentition is larger than in non-Pygmy populations. However, the Baka's dental morphology, like several other aspects of their biology, is still understudied. Here, we explore the variation of the Baka's deciduous upper and lower second molars (dm2s) in comparison to a geographically heterogeneous human sample by means of 3D geometric morphometrics and analysis of dental traits. Our results show that the different populations largely overlap based on the shape of their dm2s, especially the lower ones. Their distal region and the height of the dentinal crown differ the most, with the Baka showing the most extreme range of variation. Upper and lower dm2s covary to a great extent (RV = 0.82). The Baka's and South Americans' dm2s were confirmed among the largest in our sample. Despite the Baka's unique growth pattern, long-lasting isolation, and extreme dental variation, it is not possible to distinguish them from other populations based on their dm2s' morphology only.
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Affiliation(s)
- Petra G Šimková
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria.
| | - Gerhard W Weber
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
- Core Facility for Micro-Computed Tomography, University of Vienna, Vienna, Austria
| | - Fernando V Ramirez Rozzi
- UMR7206 Ecoanthropologie, MNHN, CNRS, UP, Musée de L'Homme, Paris, France
- EA 2496 Pathologies, Imagerie et biothérapies oro-faciales, Université Paris Descartes, Montrouge, France
| | - Lotfi Slimani
- UR2496 - Plateforme Imageries du Vivant, Université de Paris, Montrouge, France
| | - Jérémy Sadoine
- UR2496 - Plateforme Imageries du Vivant, Université de Paris, Montrouge, France
| | - Cinzia Fornai
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria.
- Institute of Evolutionary Medicine, University of Zurich, Zurich, Switzerland.
- Vienna School of Interdisciplinary Dentistry, Klosterneuburg, Austria.
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14
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Fidalgo D, Hubbe M, Wesolowski V. Population history of Brazilian south and southeast shellmound builders inferred through dental morphology. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2021; 176:192-207. [PMID: 34115384 DOI: 10.1002/ajpa.24342] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/13/2021] [Accepted: 05/23/2021] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The Southeast and South Coast of Brazil was inhabited during most of the Holocene by shellmound builders. Although there are cultural differences in the archaeological record between regions, it is still debatable how these differences may relate to different population histories. Here, we contribute to this discussion by exploring dental morphological affinities between several regional series. MATERIALS AND METHODS Dental morphology of 385 individuals from 14 archaeological sites was analyzed using the Arizona State University Dental Anthropology System. Fifteen traits were used to explore morphological affinities among series through Euclidean distance, Mean Measure of Divergence, and Principal Component Analysis. Mantel matrix correlation and partial correlation tests were used to examine the association between biological, geographic, and chronological distances. RESULTS Morphological affinities show that ceramic and nonceramic South Coast groups cluster and differ from most Southeast series. In contrast, Southeast coastal and riverine groups display high morphological variance, showing less biological coherence among them. These biological distances between regions are partially explained by geography, but not by chronology. CONCLUSIONS The results support that these coastal populations were low-mobility groups. Although interactions between individuals of different regions likely existed, gene flow occurred mostly among individuals from local or adjacent areas. The introduction of ceramic in the South Coast is not associated with changes in dental morphology patterns, suggesting its adoption is not exclusively associated with the arrival of different biological groups. Southeast coastal and riverine groups show high phenotypic diversity, suggesting a different history of human occupation and cultural development than observed in the South Coast.
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Affiliation(s)
- Daniel Fidalgo
- Museu de Arqueologia e Etnologia, Universidade de São Paulo, São Paulo, Brazil.,Centro de Investigação em Antropologia e Saúde, Universidade de Coimbra, Calçada Martim de Freitas, Coimbra, Portugal
| | - Mark Hubbe
- Department of Anthropology, Ohio State University, Columbus, Ohio, USA.,Instituto de Arqueología y Antropología, Universidad Católica del Norte, San Pedro de Atacama, Chile
| | - Veronica Wesolowski
- Museu de Arqueologia e Etnologia, Universidade de São Paulo, São Paulo, Brazil
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Paul KS, Stojanowski CM, Hughes T, Brook A, Townsend GC. The genetic architecture of anterior tooth morphology in a longitudinal sample of Australian twins and families. Arch Oral Biol 2021; 129:105168. [PMID: 34174590 DOI: 10.1016/j.archoralbio.2021.105168] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 12/21/2022]
Abstract
OBJECTIVE This study presents a quantitative genetic analysis of human anterior dental morphology in a longitudinal sample of known genealogy. The primary aim of this work is to generate a suite of genetic correlations within and between deciduous and permanent characters to access patterns of integration across the diphyodont dental complex. DESIGN Data were recorded from casted tooth crowns representing participants of a long-term Australian twin and family study (deciduous n = 290, permanent n = 339). Morphological trait expression was observed and scored following Arizona State University Dental Anthropology System standards. Bivariate genetic correlations were estimated using maximum likelihood variance decomposition models in SOLAR v.8.1.1. RESULTS Genetic correlation estimates indicate high levels of integration between antimeres but low to moderate levels among traits within a tooth row. Only 9% of deciduous model comparisons were significant, while pleiotropy was indicated for one third of permanent trait pairs. Canine characters stood out as strongly integrated, especially in the deciduous dentition. For homologous characters across dentitions (e.g., deciduous i1 shoveling and permanent I1 shoveling), ∼70% of model comparisons yielded significant genetic correlations. CONCLUSIONS Patterns of genetic correlation suggest a morphological canine module that spans the primary and secondary dentition. Results also point to the existence of a genetic mechanism conserving morphology across the diphyodont dental complex, such that paired deciduous and permanent traits are more strongly integrated than characters within individual tooth rows/teeth.
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Affiliation(s)
- Kathleen S Paul
- Department of Anthropology, University of Arkansas, Fayetteville, AR 72701, United States.
| | - Christopher M Stojanowski
- Center for Bioarchaeological Research, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287, United States
| | - Toby Hughes
- Adelaide Dental School, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Alan Brook
- Adelaide Dental School, The University of Adelaide, Adelaide, SA 5005, Australia; Barts and the London Dental Institute, Queen Mary University of London, London, E1, UK
| | - Grant C Townsend
- Adelaide Dental School, The University of Adelaide, Adelaide, SA 5005, Australia
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16
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Abstract
Teeth have been studied for decades and continue to reveal information relevant to human evolution. Studies have shown that many traits of the outer enamel surface evolve neutrally and can be used to infer human population structure. However, many of these traits are unavailable in archaeological and fossil individuals due to processes of wear and taphonomy. Enamel-dentine junction (EDJ) morphology, the shape of the junction between the enamel and the dentine within a tooth, captures important information about tooth development and vertebrate evolution and is informative because it is subject to less wear and thus preserves more anatomy in worn or damaged specimens, particularly in mammals with relatively thick enamel like hominids. This study looks at the molar EDJ across a large sample of human populations. We assessed EDJ morphological variation in a sample of late Holocene modern humans (n = 161) from archaeological populations using μ-CT biomedical imaging and geometric morphometric analyses. Global variation in human EDJ morphology was compared to the statistical expectations of neutral evolution and "Out of Africa" dispersal modeling of trait evolution. Significant correlations between phenetic variation and neutral genetic variation indicate that EDJ morphology has evolved neutrally in humans. While EDJ morphology reflects population history, its global distribution does not follow expectations of the Out of Africa dispersal model. This study increases our knowledge of human dental variation and contributes to our understanding of dental development more broadly, with important applications to the investigation of population history and human genetic structure.
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Testing the utility of dental morphological trait combinations for inferring human neutral genetic variation. Proc Natl Acad Sci U S A 2020; 117:10769-10777. [PMID: 32376635 DOI: 10.1073/pnas.1914330117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Researchers commonly rely on human dental morphological features in order to reconstruct genetic affinities among past individuals and populations, particularly since teeth are often the best preserved part of a human skeleton. Tooth form is considered to be highly heritable and selectively neutral and, therefore, to be an excellent proxy for DNA when none is available. However, until today, it remains poorly understood whether certain dental traits or trait combinations preserve neutral genomic signatures to a greater degree than others. Here, we address this long-standing research gap by systematically testing the utility of 27 common dental traits and >134 million possible trait combinations in reflecting neutral genomic variation in a worldwide sample of modern human populations. Our analyses reveal that not all traits are equally well-suited for reconstructing population affinities. Whereas some traits largely reflect neutral variation and therefore evolved primarily as a result of genetic drift, others can be linked to nonstochastic processes such as natural selection or hominin admixture. We also demonstrate that reconstructions of population affinity based on many traits are not necessarily more reliable than those based on only a few traits. Importantly, we find a set of highly diagnostic trait combinations that preserve neutral genetic signals best (up to [Formula: see text] r = 0.580; 95% r range = 0.293 to 0.758; P = 0.001). We propose that these trait combinations should be prioritized in future research, as they allow for more accurate inferences about past human population dynamics when using dental morphology as a proxy for DNA.
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Humans inherit the traits of their teeth. Br Dent J 2020; 228:665-666. [DOI: 10.1038/s41415-020-1605-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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