American Journal of Biological Anthropology最新文献

{"title":"Adapting Clinical Tooth Wear Assessment Methods for Biological Anthropology Contexts","authors":"Ian Towle,&nbsp;Luca Fiorenza","doi":"10.1002/ajpa.70080","DOIUrl":"https://doi.org/10.1002/ajpa.70080","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>Tooth wear is increasingly recognized as an adaptive process that can help optimize mastication and maintain oral health. In this study, we apply clinical wear-assessment methods to quantify occlusal tissue loss in first molars of seven Australian Aboriginal individuals from Yuendumu (1950s–1970s), whose diet combined traditional hunter-gatherer foods with processed Western items.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>High-resolution surface scans of dental casts were analyzed using <i>WearCompare</i> to assess wear patterns during dental development and evaluate the applicability of these tools in a biological anthropology context.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Clinical methods designed for assessing pathological wear can effectively capture normal physiological wear in populations with medium-high tissue loss rates. Average annual tissue loss was 4 mm³ (0.05 mm³/mm²), with the highest wear regions losing an average of 215 μm in thickness per year. Substantial temporal variation in the magnitude and distribution of wear, and variation among individuals, was observed, reflecting changes in occlusion, masticatory forces, craniofacial growth, and cultural/dietary behaviors all in association with dental eruption sequences.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Discussion</h3>\u0000 \u0000 <p>These findings highlight the utility of digital quantification of dental tissue loss for anthropological research. In particular, these methods have significant potential for assessing tooth wear in contemporary human and non-human primate samples, and for refining macroscopic wear scoring systems in paleontological and archaeological contexts by using modern analogues for calibration and refinement. These methods can also complement other wear analysis techniques (e.g., microwear analysis, occlusal fingerprint analysis), as well as studies on tooth morphology and structure, offering broader applications in evolutionary inferences and dietary reconstructions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":29759,"journal":{"name":"American Journal of Biological Anthropology","volume":"187 2","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajpa.70080","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144367234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Search for Love in Human Evolution: Primate Social Bonds and a New Science of Emotion","authors":"Aaron A. Sandel","doi":"10.1002/ajpa.70078","DOIUrl":"https://doi.org/10.1002/ajpa.70078","url":null,"abstract":"<p>Love defines the human experience but often defies scientific study. Biological anthropologists flirt with the topic of love by studying monogamy and affiliative relationships. The interest in monogamy, I argue, is misplaced. But the interest in affiliative relationships is productive and deserves greater theoretical and methodological innovation. Social bonds have been carefully described for decades by primatologists, but I suggest that we still lack conceptual clarity and the crucial data needed to distinguish them from other types of relationships. A deeper understanding of social bonds, and pair bonds in particular, will be possible through the application of new methods to study affective states, or “emotions,” in wild primates and other animals. By studying the emotions that underly various relationships, we will make progress toward answering prevailing questions about the origins and future of love, romance, and friendship.</p>","PeriodicalId":29759,"journal":{"name":"American Journal of Biological Anthropology","volume":"187 2","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajpa.70078","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144367233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential Mortality Trends at the Intersection of Climate Change and Urban Growth From 13th to 18th Century Berlin","authors":"Emily J. Brennan","doi":"10.1002/ajpa.70071","DOIUrl":"https://doi.org/10.1002/ajpa.70071","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>The purpose of this study is to evaluate differences in adult mortality risk at the intersection of climate change and urbanization between late medieval (c. 1200–1500) and early modern (c. 1500–1800) Berlin. After the founding of the city in c. 1200, the early modern period saw increased population density and the advent of the Little Ice Age (LIA), whose long winters and wet summers destroyed crop yields.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>To test the hypothesis that mortality risk increased in the early modern period, this study examined Gompertz and Gompertz-Makeham mortality curves for adult individuals (<i>n</i> = 274) dated from c. 1200 to 1717 Berlin. To evaluate the magnitude of differences in mortality by time period and estimated sex, a Cox Proportional Hazards analysis was used.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>All adults faced a decreased risk of mortality in the early modern period compared to the late medieval period. In both time periods, estimated females faced a higher risk of mortality compared to estimated males, though this difference was only statistically significant in the early modern period.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Discussion</h3>\u0000 \u0000 <p>Decreased risk of mortality may indicate protective effects of urban life, even with the climatic variability of the LIA. The early modern period saw the proliferation of public hospitals and an increase in medical publications. Higher mortality risks for estimated females at this time may be a result of differential education and heightened religious tensions that resulted in witchcraft persecutions, possibly affecting social determinants of health for women at the time.</p>\u0000 </section>\u0000 </div>","PeriodicalId":29759,"journal":{"name":"American Journal of Biological Anthropology","volume":"187 2","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajpa.70071","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144339568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occipital Condyle Development in Extant Hominids and Australopithecus afarensis","authors":"Neysa Grider-Potter,&nbsp;Thierra K. Nalley,&nbsp;Jeremiah E. Scott,&nbsp;Faye McGechie,&nbsp;Weldeyared H. Reda,&nbsp;Zeresenay Alemseged","doi":"10.1002/ajpa.70076","DOIUrl":"https://doi.org/10.1002/ajpa.70076","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>Variation in the position and orientation of the occipital condyles is well documented in hominids and has been linked to differences in positional behavior, especially upright posture in bipedal hominins. Less is known about the curvature of the condylar joint surfaces. This study examines the ontogeny of condylar curvature in extant hominids and <i>Australopithecus afarensis</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>Condylar curvature was quantified in 147 chimpanzees, gorillas, humans, orangutans, and five specimens of <i>A. afarensis</i>. Specimens were grouped into juvenile, adolescent, and adult dental age categories. We used resampling methods to test for differences among age groups within genera, and among genera at each developmental stage. We also recorded the timing of fusion of the occipital synchondroses to link ontogenetic changes in curvature to structurally important developmental events.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Condylar curvature increases through ontogeny in all taxa. Adult <i>Homo</i> and <i>Gorilla</i> have flatter condyles than <i>Pan</i> and <i>Pongo</i>. Juvenile morphologies do not predict the adult pattern of similarities and differences. Periods of rapid change in curvature occur prior to complete fusion of the intraoccipital synchondroses in <i>Gorilla</i> and <i>Pongo</i>. <i>A. afarensis</i> specimens suggest a <i>Pan</i>-like morphology and developmental pattern.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Discussion</h3>\u0000 \u0000 <p>Taxonomic and developmental patterns of variation do not align with differences in posture and locomotion. The similarity of <i>A. afarensis</i> to <i>Pan</i> suggests that the flatter condyles of humans and gorillas are convergent. The <i>Pan</i>-like morphology of <i>A. afarensis</i> is also consistent with other evidence indicating that the cervico-occipital region remained plesiomorphic in many ways following the shift to obligate bipedality in early hominins.</p>\u0000 </section>\u0000 </div>","PeriodicalId":29759,"journal":{"name":"American Journal of Biological Anthropology","volume":"187 2","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajpa.70076","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144339316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishing an Ecuadorian Isoscape: The Importance of Baseline Strontium Data in a Volcanic Landscape\u0000 Estableciendo un Iso-Paisaje Ecuatoriano: La Importancia de los Datos de Referencia de Estroncio en un Paisaje Volcánico","authors":"Sara L. Juengst,&nbsp;María Patricia Ordoñez Alvarez","doi":"10.1002/ajpa.70074","DOIUrl":"https://doi.org/10.1002/ajpa.70074","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>Strontium isotopes (⁸⁷Sr/⁸⁶Sr) have been used worldwide to track migrations and identify nonlocal individuals in the past. In South America, these studies often use comparative baseline maps, or isoscapes, established by samples from archaeological fauna and geologic formations. However, baseline research has focused on coastal Peru and the Central and South Andean Highlands. Currently, no comparable isoscape exists for Ecuador. Thus, scholars approximate baselines from predictive models and geologic studies, which may not accurately reflect the biologically available strontium in archaeological samples. This study tested the accuracy of predictive archaeological and geologic models for Ecuadorian strontium.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>We collected 11 faunal samples from eight archaeological sites across three coastal regions and the northern highlands to test for ⁸⁷Sr/⁸⁶Sr. All samples were collected from animals with narrow home ranges. Samples were processed at the University of North Carolina at Chapel Hill.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Strontium values ranged from 0.704226 to 0.709764, with significant regional distribution. The lowest values came from highland samples (mean = 0.704296) and clustered by coastal region from north to south (central coast mean = 0.707561; south coast mean = 0.7064118; far south coast mean = 0.709764).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Discussion</h3>\u0000 \u0000 <p>This pilot study reveals two trends: First, strontium values cluster regionally despite stratigraphic volcanic influences, and second, values do not correspond to predictive models, particularly along the coast. We suggest that the unique geology of Ecuador means that predictive models based on Peruvian baselines are inappropriate for Ecuadorian strontium studies. There is a need for a large-scale baseline study of biologically available strontium in Ecuadorian archaeological samples.</p>\u0000 </section>\u0000 </div>","PeriodicalId":29759,"journal":{"name":"American Journal of Biological Anthropology","volume":"187 2","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajpa.70074","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144339574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Eco-Geographical Variation in Craniofacial Size and Shape, With Emphasis in Cold Adaptation, Through a 3D Approach","authors":"Manuel Domingo D’Angelo del Campo,&nbsp;Gülkan Gökdoğan Aktepe,&nbsp;Markus Bastir,&nbsp;Daniel García Martínez","doi":"10.1002/ajpa.70072","DOIUrl":"https://doi.org/10.1002/ajpa.70072","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>This study examines cranial morphological variations across populations adapted to different climates, with a focus on cold adaptation. Using a 3D geometric morphometric approach, the study analyzes skull variability between populations from various latitudes and climates. Two null hypotheses are tested: (1) differences in skull size and shape are unrelated to climate, and (2) no differences exist between populations with recent versus ancient cold adaptation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Material and Methods</h3>\u0000 \u0000 <p>Skulls from five populations across different climates were analyzed using 3D geometric morphometrics. Landmarks were digitized, and statistical analyses were performed to evaluate size and shape variations among the populations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>One-way ANOVA Bonferroni post hoc analysis revealed significant size differences. Norsemen differed significantly from all other samples, except Sub-Saharan Africans. Cold-adapted populations exhibited larger skull sizes, whereas populations from mild and hot climates had smaller skulls. However, Norsemen exhibited unexpectedly smaller sizes. Notable anatomical disparities are observed along both PCs. PC1+ showed increased prognathism and wider faces in Southern Patagonia and Greenland Thule. PC2+ highlighted larger faces and sloping foreheads in Southern Patagonia and European populations. Median shape analysis reveals pronounced prognathism and wider skulls in Southern Patagonia, with Greenland Thule showing similar traits but with a more globular braincase.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Notable craniofacial similarities associated with extreme cold adaptation, including increased prognathism, prominent glabellar and supraciliary regions, lateral zygomatic expansion, enlarged nasal cavity and orbits, and elongated, flattened braincase, despite genetic differences. However, the Norse sample presents a deviation from expected patterns, exhibiting smaller sizes despite inhabiting a cold region.</p>\u0000 </section>\u0000 </div>","PeriodicalId":29759,"journal":{"name":"American Journal of Biological Anthropology","volume":"187 2","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144292614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Peroration: Hip Width and Metabolic Energy Expenditure of Abductor Muscles","authors":"Patricia Ann Kramer,&nbsp;Adam D. Sylvester","doi":"10.1002/ajpa.70075","DOIUrl":"https://doi.org/10.1002/ajpa.70075","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>We recently reported that functional pelvic width is not a statistically significant predictor of the metabolic energy expenditure of the hip abductor muscles during walking when mass, stature, and progression velocity were controlled. Others revised this analysis, suggesting that a different statistical approach would yield statistical significance. In order to address this suggestion, herein we refine our original analysis and increase our sample size.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>Using a musculoskeletal model of the human body that estimates the metabolic energy expenditure of muscle activation for 66 people (33 females), 1093 trials were evaluated. Metabolic energy consumption for the abductor muscles was summed over a stride to create total abductor energy expenditure. A mixed effects model allowing the coefficient and slope of velocity to be a random effect was fit to the data.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We confirm our original analysis: functional pelvic width is not a statistically significant predictor of muscle metabolic energy expenditure of the hip abductors during walking.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Discussion</h3>\u0000 \u0000 <p>We take as an initial assumption that a constraint on pelvic width exists and seek to establish if evidence for an energetic constraint is present in estimates of hip abductor muscle metabolic energy expenditure in humans. We find no such evidence in a sample of 66 people. Our results do not address whether or not a constraint on pelvic width exists, and we suggest that simulation of pelvic widths substantially wider or narrower than those observed in laboratory settings is necessary to assess this idea.</p>\u0000 </section>\u0000 </div>","PeriodicalId":29759,"journal":{"name":"American Journal of Biological Anthropology","volume":"187 2","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144292613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brown Adipose Tissue, Adiposity, and Menopausal Status in Women at Mid-Life","authors":"Daniel E. Brown,&nbsp;Sofiya Shreyer,&nbsp;Sarah Witkowski,&nbsp;Lynnette Leidy Sievert","doi":"10.1002/ajpa.70073","DOIUrl":"https://doi.org/10.1002/ajpa.70073","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>Change in the amount and distribution of fat during the menopausal transition increases the risk for developing cardiometabolic diseases. Brown adipose tissue (BAT) is activated during cold exposure, leading to increased metabolic activity and may be protective of obesity. Little is known regarding the effects of the menopausal transition on BAT activity in women. Accordingly, this study examines the effect of menopausal status and adiposity on estimated BAT activity in a sample of women.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A sample of 270 women aged 45–55 years was recruited. Menopausal status and age at menopause were derived from recent menstrual characteristics. Height, weight, waist and hip circumferences, skinfolds, and bioelectric impedance were measured. BAT activity was estimated by infrared thermography at the supraclavicular region before and after cold exposure (hand immersed in 17°C water). The relationships between menopausal status, adiposity measures, and BAT were analyzed by means of analyses of variance and logistic and linear regressions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Menopausal status was significantly related to estimated BAT activity, with postmenopausal women having lower activity. Estimated BAT activity was significantly negatively related to the waist-to-hip circumference ratio, but not to measures of general adiposity. There were no significant differences in adiposity measures by menopausal status.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Postmenopausal women in this study showed lowered BAT activity compared to premenopausal women. Women with lower BAT activity averaged larger waist-to-hip circumference ratios, indicating greater fat centrality. These results provide evidence for the possible role of BAT in the increased risk factors for cardiometabolic diseases in women after menopause.</p>\u0000 </section>\u0000 </div>","PeriodicalId":29759,"journal":{"name":"American Journal of Biological Anthropology","volume":"187 2","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144264561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enamel Thickness in Atapuerca Homo antecessor and Sima de Los Huesos Permanent Premolars","authors":"Laura Martín-Francés,&nbsp;Shruti Kamath,&nbsp;Christophe Soligo,&nbsp;Marina Martínez de Pinillos,&nbsp;Song Xing,&nbsp;Juan Luis Arsuaga,&nbsp;José María Bermúdez de Castro,&nbsp;María Martinón-Torres","doi":"10.1002/ajpa.70068","DOIUrl":"https://doi.org/10.1002/ajpa.70068","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>This study investigates premolar tissue proportions in the Atapuerca hominins to assess whether <i>Homo antecessor</i> (TD6) and Sima de los Huesos (SH) specimens exhibit thick or thin enamel, and whether relative enamel thickness is linked to tooth size reduction or enamel–dentine junction (EDJ) complexity. It also examines intrapopulation variability and provides new comparative data.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>New 2D and 3D tissue metrics were derived from mCT images for TD6 (P₃ = 2, P₄ = 1), SH (P³ = 7, P⁴ = 6, P₃ = 12, P₄ = 17), Neanderthals (P³ = 4, P⁴ = 4, P₃ = 4, P₄ = 6), and modern humans (P³ = 15, P⁴ = 12, P₃ = 26, P₄ = 20). These data were combined with published sources for analysis.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Our results suggest different patterns for upper and lower premolars in SH; upper premolars resemble those of Neanderthals, while lower premolars are more similar to modern humans. TD6 upper premolars show high variability, but the lower ones align more closely with Neanderthals. Relative enamel thickness varies with crown size, but not with EDJ complexity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Discussion</h3>\u0000 \u0000 <p>Our findings highlight notable intrapopulation variability in enamel thickness among Atapuerca hominins and support the early emergence of reduced enamel in European populations. Moreover, our results imply that overall crown reduction may contribute to variation in enamel thickness in these populations. These results caution against using enamel thickness alone for taxonomic classification and emphasize the importance of analyzing both upper and lower dentitions across all dental classes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":29759,"journal":{"name":"American Journal of Biological Anthropology","volume":"187 2","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144220432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Technical Note: Using Machine Learning to Predict Locomotor Behavior in Great Apes and Humans From Femur Metaphyseal Shape","authors":"Peter A. Stamos,&nbsp;Abhijit J. Chaudhari,&nbsp;Mark N. Grote,&nbsp;Timothy D. Weaver","doi":"10.1002/ajpa.70066","DOIUrl":"https://doi.org/10.1002/ajpa.70066","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>The morphology of the hominoid distal femoral metaphyseal surface has been demonstrated to reflect locomotor behavior throughout ontogeny. Here, we quantify metaphyseal surface morphology to evaluate its predictive relationship to locomotor behavioral modes in hominoids.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>We collected three-dimensional (3D) surface laser scans of the femora of 177 human and great ape individuals representing all subadult stages of development. We used the landmark-free Global Point Signature (GPS) method to quantify the shape of the morphologically complex but amorphous metaphyseal surface. We then analyzed the GPS quantifications of shape using support vector machines (SVMs), a machine learning technique, to evaluate the predictive relationships between metaphyseal surface morphology and locomotor behavior in hominoids.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We found that metaphyseal surface morphology is a strong predictor of locomotor behavior in hominoids. Our SVM, which relates nonambulation, bipedal walking, knuckle-walking, and climbing behavior with metaphyseal surface morphology, exhibits ~84% out-of-sample predictive accuracy.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our quantitative analyses confirm what has previously been qualitatively described<i>—</i>the metaphyseal surface of the distal femur is highly predictive of the locomotor behavior performed by hominoids during different stages of their lives. These results suggest that this region of the skeleton is suitable for reconstructing the locomotor behavior of extinct hominoid taxa.</p>\u0000 </section>\u0000 </div>","PeriodicalId":29759,"journal":{"name":"American Journal of Biological Anthropology","volume":"187 2","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajpa.70066","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144206526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}