RESUMO
Climate change is an indisputable threat to human health, especially for societies already confronted with rising social inequality, political and economic uncertainty, and a cascade of concurrent environmental challenges. Archaeological data about past climate and environment provide an important source of evidence about the potential challenges humans face and the long-term outcomes of alternative short-term adaptive strategies. Evidence from well-dated archaeological human skeletons and mummified remains speaks directly to patterns of human health over time through changing circumstances. Here, we describe variation in human epidemiological patterns in the context of past rapid climate change (RCC) events and other periods of past environmental change. Case studies confirm that human communities responded to environmental changes in diverse ways depending on historical, sociocultural, and biological contingencies. Certain factors, such as social inequality and disproportionate access to resources in large, complex societies may influence the probability of major sociopolitical disruptions and reorganizations-commonly known as "collapse." This survey of Holocene human-environmental relations demonstrates how flexibility, variation, and maintenance of Indigenous knowledge can be mitigating factors in the face of environmental challenges. Although contemporary climate change is more rapid and of greater magnitude than the RCC events and other environmental changes we discuss here, these lessons from the past provide clarity about potential priorities for equitable, sustainable development and the constraints of modernity we must address.
Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Mudança Climática , Desenvolvimento Sustentável , ProbabilidadeRESUMO
OBJECTIVES: Linear enamel hypoplasia (LEH) is a common skeletal marker of physiological stress (e.g., malnutrition or illness) that is studied within and across populations, without reference to familial risk. We examine LEH prevalence in a population with known genealogical relationships to determine the potential influence of genetic heritability and shared environment. METHODS: LEH data of 239 individuals from a single population were recorded from the Ohio State University Menegaz-Bock collection dental casts. All individuals were of known age, sex, and genealogy. Narrow-sense heritability estimates were obtained for LEH presence and count data from all unworn, fully erupted teeth (excluding third molars) using SOLAR (v.8.1.1). Age, sex, and age-sex interaction were included as covariates. Models were re-run with a household effect variable. RESULTS: LEH persists across generations in this study population with moderate, significant heritability estimates for presence in four teeth, and count in four teeth (three teeth were significant for both). When a household effect variable was added, no residual heritability remained for LEH count on any tooth. There was no significant household effect for three of the four teeth that had significant heritability estimates for LEH presence. Age was a significant covariate. Further analyses with birth year data revealed a secular trend toward less LEH. CONCLUSIONS: This study provides evidence for familial risk of LEH (genetic and environmental) that has consequences for the broad use of this skeletal marker of stress. These results have repercussions for archaeological assemblages, or population health studies, where genetic relatives and household groups might be heavily represented.
Assuntos
Hipoplasia do Esmalte Dentário , Fragilidade , Arqueologia , Hipoplasia do Esmalte Dentário/epidemiologia , Hipoplasia do Esmalte Dentário/genética , Humanos , Dente Serotino , Estresse FisiológicoRESUMO
OBJECTIVES: This study generates a series of narrow-sense heritability estimates for crown morphology of the deciduous and permanent dentition with two overarching aims. The first is to test the hypothesis that deciduous teeth provide a more faithful reflection of genetic information than their permanent successors. The second is to use quantitative genetic methods to evaluate assumptions underlying common data collection and analysis practices in biodistance research. MATERIALS AND METHODS: Dental morphology data were collected from longitudinal dental casts representing Australian twins and families using Arizona State Dental Anthropology System standards. Polygenic models and estimates of narrow-sense heritability were generated using SOLAR v.8.1.1. Each model considered age, sex, and age/sex interaction as covariates. RESULTS: Heritability estimates significantly differed from zero for the majority of morphological crown characters. Most estimates fell within the 0.4-0.8 range typically observed for crown morphology. Mean heritability was stable across the dental complex, but for paired homologues, permanent traits often yielded higher estimates than their deciduous counterparts. Results indicate directional asymmetry in environmental influence for crown morphology and inform biodistance "best practices" related to data collection and treatment. CONCLUSIONS: Overall, results for this sample support the use of crown morphology as a proxy for genetic variation in evolutionary research. This includes the deciduous dentition, which justifies the expansion of efforts to incorporate subadults into reconstructions of past microevolutionary processes. Results do not indicate that deciduous phenotypes more closely approximate underlying genotype, at least for deciduous/permanent homologues.
Assuntos
Dentição Permanente , Característica Quantitativa Herdável , Coroa do Dente/anatomia & histologia , Dente Decíduo/anatomia & histologia , Gêmeos/genética , Adolescente , Adulto , Austrália , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Adulto JovemRESUMO
OBJECTIVES: This article presents estimates of narrow-sense heritability and bivariate genetic correlation for 14 tooth crown morphological variants scored on permanent premolars, first molars, and second molars. The objective is to inform data collection and analytical practices in dental biodistance and to provide insights on the development of molar crowns as integrated structures. MATERIALS AND METHODS: African American dental casts from the Menegaz-Bock collection were recorded for the Arizona State University Dental Anthropology System. Estimates of narrow-sense heritability and genetic correlation were generated using SOLAR v.8.1.1, which included assessment of age, sex, and birth year as covariates. Both continuous scale and dichotomized estimates are provided. RESULTS: Heritability estimates were nonsignificant for the majority of variables; however, for variables yielding significant estimates, values were moderate to high in magnitude and comparable to previous studies. Comparing left and right-side heritability estimates suggests directional asymmetry in the expression of environmental variance, something not seen in anterior tooth traits. Genetic correlations were moderate among antimeres and metameres and low for different traits scored on the same tooth crown. Although several negative correlations were noted, few reached statistical significance. Results affirm some of the current data cleaning and analytical practices in dental biodistance, but others are called into question. These include the pooling of males and females and combining left and right-side data into a single dataset. CONCLUSIONS: In comparison to anterior tooth crown traits, postcanine heritabilities were more often non-significant; however, those traits with significant heritability also tended to produce higher estimates. Genetic correlations were unremarkable, in part, because they were underpowered. However, M1 results may provide insight into the complex relationship between genes, environment, and development in determining ultimate crown form.
Assuntos
Negro ou Afro-Americano , Dente Canino/anatomia & histologia , Coroa do Dente/anatomia & histologia , Negro ou Afro-Americano/genética , Negro ou Afro-Americano/estatística & dados numéricos , Antropologia Física , Feminino , Humanos , Masculino , OdontometriaRESUMO
OBJECTIVES: The current study seeks to determine if a sample of foragers, farmers, and pastoralists are distinguishable based on their dental microwear texture signatures. MATERIALS AND METHODS: The study included a sample of 719 individuals from 51 archeological sites (450 farmers, 192 foragers, 77 pastoralists). All were over age 12 and sexes were pooled. Using a Sensofar® white-light confocal profiler we collected dental microwear texture analysis (DMTA) data from a single first or second molar from each individual. We leveled and cleaned data clouds following standard procedures and analyzed the data with Sfrax® and Toothfrax® software. The DMTA variables were complexity and anisotropy. Statistics included ANOVA with partial eta squared and Hedges's g. We also performed a follow-up K-means cluster analysis. RESULTS: We found significant differences between foragers and farmers and pastoralists for complexity and anisotropy, with foragers having greater complexity than either the farmers or the pastoralists. The farmers and pastoralists had greater anisotropy than the foragers. The Old World foragers had significantly higher anisotropy values than New World foragers. Old and New World farmers did not differ. Among the Old World farmers, those dating from the Neolithic through the Late Bronze Age had higher complexity values than those from the Iron Age through the medieval period. The cluster analysis discerned foragers and farmers but also indicated similarity between hard food foragers and hard food farmers. DISCUSSION: Our findings reaffirm that DMTA is capable of distinguishing human diets. We found that foragers and farmers, in particular, differ in their microwear signatures across the globe. There are some exceptions, but nothing that would be unexpected given the range of human diets and food preparation techniques. This study indicates that in general DMTA is an efficacious means of paleodietary reconstruction in humans.
Assuntos
Dieta/história , Comportamento Alimentar/fisiologia , Desgaste dos Dentes , Adulto , Antropologia Física , Fazendeiros , Feminino , História Antiga , Humanos , Masculino , Propriedades de Superfície , Dente/patologia , Desgaste dos Dentes/história , Desgaste dos Dentes/patologiaRESUMO
OBJECTIVES: This article presents estimates of narrow-sense heritability and bivariate genetic correlation for a series of morphological crown variants of the anterior dentition. These results provide insight into the value of dental phenotypes as evolutionary proxies, as well as the development of tooth crowns as integrated or modular structures. MATERIALS AND METHODS: African American dental casts from the Menegaz-Bock collection were scored for a standard set of dental morphological variables using the Arizona State Dental Anthropology System. Estimates of narrow-sense heritability and genetic correlations were generated using SOLAR v. 8.1.1, controlling for the covariates of age, sex, and birth year. Analyses were run using ordinal/continuous scale variables that were then dichotomized at various breakpoints, consistent with standard practices in dental anthropology. RESULTS: Heritability estimates were low to moderate for most traits, and lower in magnitude than those reported for odontometric data from the same study sample. Only winging, canine shoveling, and canine double shoveling returned narrow-sense heritabilities that did not differ significantly from zero. Genetic correlations were high among antimeres and metameres and low for different traits scored on the same tooth crown. These results affirm standard data cleaning practices in dental biodistance. Double shoveling was atypical in returning strong negative correlations with other traits, shoveling in particular. CONCLUSIONS: Additive genetic variation contributes to dental morphological variation, although the estimates are uniformly lower than those observed for odontometrics. Patterns of genetic correlation affirm most standard practices in dental biodistance. Patterns of negative pleiotropy involving lingual and labial crown features suggest a genetic architecture and developmental complex that differentially constrain morphological variation of distinct surfaces of the same tooth crown. These patterns warrant greater consideration and cross-population validation.
Assuntos
Negro ou Afro-Americano , Coroa do Dente/anatomia & histologia , Negro ou Afro-Americano/genética , Negro ou Afro-Americano/estatística & dados numéricos , Antropologia Física , Feminino , Genética Populacional , Humanos , Masculino , Odontometria , South CarolinaRESUMO
OBJECTIVES: Dental morphology plays a key role in reconstructing population history and evolutionary relationships at global, regional, and intracemetery scales. At the inter-individual level, it is assumed that close biological kin exhibit greater phenotypic similarity than non-relatives. Heritability estimates provide one measure of phenotypic resemblance but are not easily incorporated into analyses of archaeological samples. In this study we evaluate the assumption that relatives are more similar phenotypically than non-relatives. We compare results for permanent dental morphology to those obtained using deciduous dental morphology in a matched dataset (Paul & Stojanowski, ). MATERIALS AND METHODS: Permanent trait expression was scored from dental casts representing 69 sibling pairs, curated as part of the longitudinal Burlington Growth Study. Simulating a biodistance approach, 22 morphological traits of permanent tooth crowns were used to generate 69 inter-relative and 2,076 non-relative Euclidean distances. Following distance ordination, family-specific dispersion values were calculated from multidimensional scaling coordinates. Output was compared to that of a previous study that focused on deciduous crown variation in the same set of individuals (Paul & Stojanowski, ). Mantel tests were used to evaluate the correlation of a proxy genetic distance matrix to both the permanent and deciduous dental distance matrices. RESULTS: On average, inter-relative distances generated from morphological traits of permanent tooth crowns were smaller than expected by chance based on resampling (p < 0.001). While family-specific dispersion varied greatly for both permanent and deciduous datasets, over 75% of the families exhibited greater dispersion with permanent traits. This suggests that morphological traits of the permanent dentition provide a less faithful reflection of biological relatedness than morphological traits of the deciduous dentition. Mantel tests indicate that both the deciduous and permanent distance matrices are significantly correlated with a matrix of genetic relatedness coefficients; however, the magnitude of the correlations was low. DISCUSSION: Overall, morphological traits of permanent tooth crowns perform moderately well in distinguishing relatives from non-relatives, but deciduous crown variations may provide a more direct reflection of the underlying genetic structure of intra-site or intra-cemetery samples. These findings have implications for bioarchaeological research and biodistance practices. In particular, morphological traits of the deciduous dentition should be incorporated into standard data collection protocols because of their stronger signal of relatedness.
Assuntos
Dentição Permanente , Irmãos , Dente Decíduo/anatomia & histologia , Dente/anatomia & histologia , Adulto , Antropologia Física , Criança , Feminino , Humanos , Masculino , Odontometria , Estatísticas não ParamétricasRESUMO
OBJECTIVES: This article provides estimates of narrow-sense heritability and genetic pleiotropy for mesiodistal tooth dimensions for a sample of 20th century African American individuals. Results inform biological distance analysis and offer insights into patterns of integration in the human dentition. MATERIALS AND METHODS: Maximum mesiodistal crown dimensions were measured using Hillson-FitzGerald calipers on 469 stone dental casts from the Menegaz-Bock Collection. Narrow-sense heritability estimates and genetic and phenotypic correlations were estimated using SOLAR 8.1.1 with covariate screening for age, sex, age*sex interaction, and birth year. RESULTS: Heritability estimates were moderate (â¼0.10 - 0.90; h2 mean = 0.51) for most measured variables with sex as the only significant covariate. Patterns of genetic correlation indicate strong integration across tooth classes, except molars. Comparison of these results to previously published work suggests lower overall heritability relative to other human populations and much stronger genetic integration across tooth classes than obtained from nonhuman primate genetic pleiotropy estimates. CONCLUSIONS: These results suggest that the high heritabilities previously published may reflect overestimates inherent in previous study designs; as such the standard estimate of 0.55 used in biodistance analyses may not be appropriate. For the Gullah, isolation and endogamy coupled with elevated levels of physiological and economic stress may suppress narrow-sense heritability estimates. Pleiotropy analyses suggest a more highly integrated dentition in humans than in other mammals.
Assuntos
Negro ou Afro-Americano/genética , Etnicidade/genética , Tamanho do Órgão/genética , Característica Quantitativa Herdável , Dente/anatomia & histologia , Antropologia Física , Dentição Permanente , Feminino , Humanos , Masculino , Odontometria , South CarolinaRESUMO
OBJECTIVES: Family-centered burial practices influence cemetery structure and can represent social group composition in both modern and ancient contexts. In ancient sites dental phenotypic data are often used as proxies for underlying genotypes to identify potential biological relatives. Here, we test the performance of deciduous dental morphological traits for differentiating sibling pairs from unrelated individuals from the same population. MATERIALS AND METHODS: We collected 46 deciduous morphological traits for 69 sibling pairs from the Burlington Growth Centre's long term Family Study. Deciduous crown features were recorded following published standards. After variable winnowing, inter-individual Euclidean distances were generated using 20 morphological traits. To determine whether sibling pairs are more phenotypically similar than expected by chance we used bootstrap resampling of distances to generate P values. Multidimensional scaling (MDS) plots were used to evaluate the degree of clustering among sibling pairs. RESULTS: Results indicate an average distance between siblings of 0.252, which is significantly less than 9,999 replicated averages of 69 resampled pseudo-distances generated from: 1) a sample of non-relative pairs (P < 0.001), and 2) a sample of relative and non-relative pairs (P < 0.001). MDS plots indicate moderate to strong clustering among siblings; families occupied 3.83% of the multidimensional space on average (versus 63.10% for the total sample). CONCLUSIONS: Deciduous crown morphology performed well in identifying related sibling pairs. However, there was considerable variation in the extent to which different families exhibited similarly low levels of phenotypic divergence.
Assuntos
Odontometria/métodos , Irmãos , Coroa do Dente/anatomia & histologia , Antropologia Física , Feminino , Humanos , Masculino , Reprodutibilidade dos TestesRESUMO
Dental morphology provides important information on human evolution and interpopulation relationships. Dental wear is one of the major limitations of morphological data analysis. Wear figures heavily in existing debates about patterns of New World dental variation with some scholars finding evidence for a more generalized dentition in early New World populations (Powell: Doctoral Dissertation, Texas A&M University, TX (1995)) and others questioning these findings based on the probable effects of dental wear on trait scores (Turner, The First Americans: the Pleistocene Colonization of the New World. San Francisco: California Academy of Sciences (2002) 123-158; Turner: Am J Phys Anthropol 130 (2006) 455-461; Turner and Scott, Handbook of paleoanthropology, Vol. III: Phylogeny of Hominids. New York: Springer (2007) 1901-1941). Here we evaluate these competing claims using data from the Early Archaic Windover sample. Results confirm the dental distinctiveness of Windover with respect to other Old World Asian (i.e., sinodont/sundadont) populations. However, comparison of our results to those of Powell (1995) also highlights significant interobserver error. Statistical analysis of matched wear and morphology scores suggests trait downgrading for some traits. Patterns of missing data present a more challenging (and potentially serious) problem. Use of Little's MCAR test for missing data mechanisms indicates a complex process of data collection in which incidental and opportunistic recording of both highly worn and unerupted teeth introduce a "missing not at random" mechanism into our dataset that biases dental trait frequencies. We conclude that patterns of missingness and formal research designs for "planned missingness" are needed to help mitigate this bias.
Assuntos
Hominidae/anatomia & histologia , Paleodontologia , Desgaste dos Dentes/patologia , Dente/anatomia & histologia , Animais , Fósseis , Humanos , Paleodontologia/métodos , Paleodontologia/normas , Análise de Componente PrincipalRESUMO
Bioarchaeological approaches are well suited for examining past responses to political and environmental changes. In the Andes, we hypothesized that political and environmental changes around AD 1100 resulted in behavioral changes, visible as shifts in paleodiet and paleomobility, among individuals in the San Pedro de Atacama oases and Loa River Valley. To investigate this hypothesis, we generated carbon and oxygen isotope data from cemeteries dating to the early Middle Horizon (Larache, Quitor-5, Solor-3), late Middle Horizon (Casa Parroquial, Coyo Oriental, Coyo-3, Solcor-Plaza, Solcor-3, Tchecar), and Late Intermediate Period (Caspana, Quitor-6 Tardío, Toconce, Yaye-1, Yaye-2, Yaye-3, Yaye-4). Carbon isotope data demonstrate a greater range of carbon sources during the late Middle Horizon compared with the Late Intermediate Period; while most individuals consumed largely C3 sources, some late Middle Horizon individuals consumed more C4 sources. Oxygen isotope data demonstrate greater diversity in drinking water sources during the late Middle Horizon compared with the Late Intermediate Period. Water samples were analyzed to provide baseline data on oxygen isotope variability within the Atacama Desert, and demonstrated that oxygen isotope values are indistinguishable in the San Pedro and Loa Rivers. However, oxygen isotope values in water sources in the high-altitude altiplano and coast are distinct from those in the San Pedro and Loa Rivers. In conclusion, instead of utilizing a wider variety of resources after environmental and political changes, individuals exhibited a wider range of paleodietary and paleomobility strategies during the Middle Horizon, a period of environmental and political stability.
Assuntos
Cemitérios/história , Dieta/história , Migração Humana/história , Adulto , Antropologia Física , Arqueologia , Osso e Ossos/química , Isótopos de Carbono/análise , Chile , Esmalte Dentário/química , Meio Ambiente , Feminino , História Antiga , História Medieval , Humanos , Masculino , PolíticaRESUMO
Bioarchaeology is the contextual analysis of biological remains from past societies. It is a young and growing discipline born during the latter half of the twentieth century from its roots in physical anthropology and archaeology. Although often associated with the study of ancient diet and disease, bioarchaeology leverages variable temporal scales and its global scope to provide a uniquely comparative perspective on human life that transcends traditional boundaries of the natural sciences, social sciences, and humanities. Here, we explore the public face of bioarchaeology and consider the trends in publication practices that reflect diversifying research strategies. Bioarchaeology is a popular topic on web-based science news aggregators. However, we identify a disconnect between bioarchaeology's traditional research emphases, emerging research foci, and findings that actually spark the public imagination. A majority of popular news articles emphasize basic discovery or "natural curiosities." Publication data indicate the field also remains regionally focused with relatively little emphasis on nomothetic goals. Nevertheless, bioarchaeology can do more to leverage its historical perspective and corporeal emphasis to engage a number of topics with importance across traditional academic boundaries. Big data, comparative, multi-investigator, interdisciplinary projects on violence, colonialism, and health offer the most obvious potential for driving research narratives in the biological and social sciences. Humanistic approaches that explore emotional connections to the past can also have merit. The diversity of research outlets and products indicates the field must embrace the importance of nontraditional activities in its value structure to maximize our potential in public arenas.
Assuntos
Antropologia Física , Arqueologia , Disseminação de Informação , Editoração , Antropologia Física/tendências , Arqueologia/tendências , Editoração/tendênciasRESUMO
The Iwo Eleru site in Nigeria preserves the only terminal Pleistocene fossil from tropical West Africa. The peoples of this region contributed to significant population movements throughout the continent during the Holocene. As such, characterizing the phenotype of Late Pleistocene West African populations is critical for disentangling the evolutionary signatures of a highly complex African population history and structure. Previous research approached the calvaria's morphology from a paleoanthropological perspective, noting its mosaic of archaic and modern neurocranial features and distinctiveness from Pleistocene fossil taxa and contemporary modern human samples. In this paper, I compare Iwo Eleru with contemporary Late Pleistocene Africans and also consider the specimen's affinities with Holocene populations of the central and western Sahara, Nile Valley, and East Africa. Craniometric data were recorded for 22 neurocranial dimensions and subjected to principal components analysis and Mahalanobis distance estimation. Multidimensional scaling of distances indicated that Iwo Eleru fell outside the observed range of variation of other terminal Pleistocene supra-equatorial African populations, confirming previous results that documented its divergence from Neanderthals, Upper Paleolithic Europeans, and modern Africans. The calvaria was also distinct from Holocene Saharan, Nile Valley, and East African populations, which suggests limited West African input into the Sahara during the African Humid Period. Results presented here bolster previous research that suggested Iwo Eleru's anatomy reflected either admixture with archaic humans or the long-term survival of populations with more archaic neurocranial anatomy until the end of the Pleistocene.
Assuntos
Antropologia Física , Evolução Biológica , Cefalometria , Fósseis , África Oriental , África do Norte , Humanos , Masculino , Crânio/anatomia & histologiaRESUMO
The African Humid Period witnessed a rapid human re-occupation of the Sahara as numerous lakes formed during the Holocene climatic optimum circa 10-5 kya. Permanent waters attracted a variety of aquatic and terrestrial fauna allowing for long-term occupation of specific paleolake basins. The Gobero paleolake in central Niger was one such location that preserves a unique mortuary record from the southern Sahara. Here, we use radiogenic strontium isotope analysis to investigate how human communities adapted to aridification throughout the Holocene. In particular, we examine the effects of increasing climate instability on patterns of human mobility. Results of radiogenic strontium isotope analysis of enamel and bone samples from Middle Holocene burials (â¼7.2-4.9 kya) indicate predominantly local values with no evidence for sex-based variation. Comparisons of radiogenic strontium isotope data with previously published (Stojanowski and Knudson: Am J Phys Anthropol 146 (2011) 49-61) Early Holocene burials (â¼9.7-8.3 kya) indicate significant differences in both enamel and bone values. Middle Holocene individuals demonstrate a predominantly non-local signature for enamel values and a predominantly local signature for bone values. Those individuals with non-local bone values always demonstrated non-local enamel values; however, the opposite was not the case. This suggests a divergence of mobility strategies during the Middle Holocene with a minority of individuals maintaining a more mobile existence throughout their life and others maintaining a similar strategy as Early Holocene hunter-gatherers that was tied to the paleolake basin. The more mobile individuals likely lived during the terminal phase of the lake's occupation. One response to aridification by Saharan peoples, then, was increasing mobility.
Assuntos
Clima , Migração Humana , Isótopos de Estrôncio/análise , Antropologia Física , Arqueologia , Osso e Ossos/química , Esmalte Dentário/química , Feminino , Humanos , Masculino , NígerRESUMO
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.
Assuntos
Dentição Permanente , Dente Molar , Coroa do Dente , Humanos , Coroa do Dente/anatomia & histologia , Coroa do Dente/crescimento & desenvolvimento , Dente Molar/anatomia & histologia , Dente Molar/crescimento & desenvolvimento , Morfogênese , Dente Decíduo , Odontogênese , Masculino , Criança , FemininoRESUMO
Poor oral health is associated with cardiovascular disease and dementia. Potential pathways include sepsis from oral bacteria, systemic inflammation, and nutritional deficiencies. However, in post-industrialized populations, links between oral health and chronic disease may be confounded because the lower socioeconomic exposome (poor diet, pollution, and low physical activity) often entails insufficient dental care. We assessed tooth loss, caries, and damaged teeth, in relation to cardiovascular and brain aging among the Tsimane, a subsistence population living a relatively traditional forager-horticulturalist lifestyle with poor dental health, but minimal cardiovascular disease and dementia. Dental health was assessed by a physician in 739 participants aged 40-92 years with cardiac and brain health measured by chest computed tomography (CT; nâ =â 728) and brain CT (nâ =â 605). A subset of 356 individuals aged 60+ were also assessed for dementia and mild cognitive impairment (nâ =â 33 impaired). Tooth loss was highly prevalent, with 2.2 teeth lost per decade and a 2-fold greater loss in women. The number of teeth with exposed pulp was associated with higher inflammation, as measured by cytokine levels and white blood cell counts, and lower body mass index. Coronary artery calcium and thoracic aortic calcium were not associated with tooth loss or damaged teeth. However, aortic valve calcification and brain tissue loss were higher in those who had more teeth with exposed pulp. Overall, these results suggest that dental health is associated with indicators of chronic diseases in the absence of typical confounds, even in a population with low cardiovascular and dementia risk factors.
Assuntos
Valva Aórtica , Valva Aórtica/patologia , Encéfalo , Calcinose , Inflamação , Saúde Bucal , Humanos , Feminino , Masculino , Idoso , Pessoa de Meia-Idade , Calcinose/diagnóstico por imagem , Valva Aórtica/diagnóstico por imagem , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Adulto , Perda de Dente/epidemiologia , Demência/epidemiologia , Demência/etiologia , Demência/diagnóstico por imagem , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/epidemiologia , Disfunção Cognitiva , Tomografia Computadorizada por Raios X , Tamanho do ÓrgãoRESUMO
This article presents an analysis of biological and spatial patterning of an Early Classic (A.D. 250-500) Chatino cemetery at the archaeological site of Charco Redondo, located in the lower Río Verde Valley, Oaxaca, Mexico. The Early Classic was a time of political instability positioned between two phases of state-level centralization within the coastal valley. The communal cemetery at Charco Redondo adds significantly to the inventory of excavated graves from this time period and provides novel data on mortuary practices during a critical phase in the development of state level polities in the region. Cluster analysis of mortuary data is combined with intracemetery biodistance approaches to reconstruct how the Charco Redondo cemetery was organized with respect to biological relationships. Cluster analysis of mortuary data identified three groupings of burials. Multidimensional scaling of Euclidean distances and Gower coefficients based on 45 odontometric and 13 dental morphological variables suggests a strong relationship between grave characteristics and locations and phenotypic variation. In other words, the cemetery at Charco Redondo appears biologically kin-structured. The communal nature of the cemetery conflicts with the assumed "household" burial model for this time period. We propose the observed combination of features represents a transitional practice in which aspects of community, kin, and individual identity were signaled simultaneously within the funerary environment during a time of political transition in the Valley. This article highlights the utility of intracemetery biodistance analyses for examining dimensions of kinship, "house," and community throughout Mesoamerica where overarching models often mask regional variability.
Assuntos
Cemitérios , Família , Análise Espacial , Adolescente , Adulto , Antropologia Física , Cemitérios/história , Cemitérios/estatística & dados numéricos , Criança , Feminino , História Antiga , Humanos , Masculino , México , Pessoa de Meia-Idade , Adulto JovemRESUMO
OBJECTIVES: The role of migration in the cultural development of central Mexico has long been debated. Archaeological models suggest that central Mexico likely experienced increased migration during the Epiclassic period (600-900 CE) and that migrants may have originated in northwestern Mexico. While previous biodistance analyses of Classic and Postclassic populations have come to similar conclusions, none have incorporated Epiclassic skeletal populations. This study uses multi-scalar biodistance analyses to directly evaluate archaeological Epiclassic migration models within central Mexico. MATERIALS AND METHODS: This study uses finite mixture and relationship (R) matrix analyses of cervicometric tooth dimensions to reconstruct patterns of biological affinity among Classic and Epiclassic Mesoamerican populations (n = 333), including at the central Mexican Epiclassic shrine site of Non-Grid 4 where the remains of at least 180 individuals were interred. RESULTS: Estimated inter-site phenotypic distances demonstrate support for some degree of both biological continuity and extra-local gene flow within central Mexican populations during the Classic-Epiclassic transition. Furthermore, estimated phenotypic distances and finite mixture posterior probabilities indicate central Mexican Epiclassic populations were biologically diverse, originating from various source populations throughout Mesoamerica, including the Bajío region, the Malpaso Valley, and the Oaxaca Valley. DISCUSSION: Results suggest that emphasizing both local and extra-local gene flow rather than population replacement may be more appropriate to understand central Mexican population structure during the Classic-Epiclassic transition. Moreover, analyses support previous archaeological migration models positing that Epiclassic migrants into central Mexico originated in northwestern Mexico, but also find evidence of Epiclassic migrants originating from previously unanticipated locales like southern Mexico.
Assuntos
Dente , Migrantes , Humanos , México/epidemiologia , Dinâmica Populacional , Meio AmbienteRESUMO
This study aims to expand our understanding of the genetic architecture of crown morphology in the human diphyodont dentition. Here, we present bivariate genetic correlation estimates for deciduous and permanent molar traits and evaluate the patterns of pleiotropy within (e.g., m1-m2) and between (e.g., m2-M1) dentitions. Morphology was observed and scored from dental models representing participants of an Australian twin and family study (deciduous n = 290, permanent n = 339). Data collection followed Arizona State University Dental Anthropology System standards. Genetic correlation estimates were generated using maximum likelihood variance components analysis in SOLAR v.8.1.1. Approximately 23% of deciduous variance components models and 30% of permanent variance components models yielded significant genetic correlation estimates. By comparison, over half (56%) of deciduous-permanent homologues (e.g., m2 hypocone-M1 hypocone) were significantly genetically correlated. It is generally assumed that the deciduous and permanent molars represent members of a meristic molar field emerging from the primary dental lamina. However, stronger genetic integration among m2-M1/M2 homologues than among paired deciduous traits suggests the m2 represents the anterior-most member of a "true" molar field. The results indicate genetic factors act at distinct points throughout development to generate homologous molar form, starting with the m2, which is later replaced by a permanent premolariform crown.