OBJECTIVES:Ontogenetic trajectories in intrinsic hand and foot proportions are likely to vary in primates according to their locomotor adaptations. We analyzed the developmental trajectories of chimpanzees (Pan troglodytes), which exhibit particular locomotor adaptations related to suspensory and climbing abilities, testing whether autopodial growth reflects biomechanical and ecological constraints associated with ontogenetic changes in locomotor behavior. MATERIALS AND METHODS:We analyzed 157 radiographs of 7 female and 198 of 8 male P. troglodytes individuals, from 1.5 to 13 years old. Lengths of metapodials and proximal/intermediate phalanges were measured to compute phalangeal indices (PIs: ratio of summed non-distal phalangeal length to corresponding metapodial length). Ontogenetic allometry was assessed by regressing bone length against body mass, with sex included as a factor. Non-linear Gompertz growth models were fitted to estimate bone-specific growth rates and durations. RESULTS:The results show a positively allometric relationship between all bone lengths and body mass. However, sex-related differences are observed in the allometry of phalanges and metapodials. PIs decline during growth for all digits, with this ontogenetic decline remaining highly similar between sexes. Gompertz models further indicate distinct growth rates between manual and pedal elements. DISCUSSION:Ontogenetic changes in chimpanzees indicate canalized autopodial growth, with reduced intrinsic proportional changes at ~5 years, aligning with their major positional shift. Comparative analyses show species-specific phalangeal trajectories, possibly more pronounced in the foot than in the hand and likely reflecting adaptations to ecological and locomotor demands, such as terrestrial knuckle-walking in large-bodied chimpanzees.
OBJECTIVES:Childbirth complications occur if fetal size is excessive for the maternal birth canal. We hypothesized that young women's metabolic traits (organ and muscle mass, resting energy expenditure (REE)) known to promote fetal growth would correlate with dimensions of the birth canal, and that some of this association would be explained by growth markers (tibia length, height). MATERIALS AND METHODS:We analyzed cross-sectional data on anthropometry, organ mass (magnetic resonance imaging (MRI)), skeletal muscle (dual-energy X-ray absorptiometry), fat mass (4-component model), pelvic dimensions (MRI), and REE (indirect calorimetry) in 68 nulliparous women aged 20-28 years of South Asian ancestry living in the UK. Principal component analysis (PCA) was used to summarize variability in organ/muscle mass and pelvic dimensions (PCApelvis). Associations between metabolic and pelvic traits were assessed using Pearson correlations, and partial correlations adjusting for height or tibia length. RESULTS:Mean height was 161 cm and body mass index 22.3 kg/m2. There were positive correlations between REE, organ/muscle mass, head girth and the first PCApelvis score, which were partly explained by variability in tibia and height. Fat mass was associated with REE and organ/muscle mass but not pelvic dimensions. DISCUSSION:Correlations between metabolic and pelvic traits indicate a degree of coordination: women with greater metabolic capacity to promote fetal growth also have larger pelvic dimensions, partly explained by linear growth patterns. However, body fat in nulliparous women correlates with REE but not pelvic dimensions; hence high adiposity could increase risk of childbirth complications when these women give birth.
OBJECTIVES:Metagenomic investigations of ancient dental calculus provide insights into oral health, disease, and diet. Here, we analyze the dental calculus metagenome of King Richard III of England (1452-1485). MATERIALS AND METHODS:Dental calculus DNA was extracted from three teeth of King Richard III and shotgun sequenced to a depth of nearly 400 million reads. The metagenomic data were taxonomically profiled and compared to new and previously published dental calculus metagenomes from England, Ireland, the Netherlands, and Germany spanning the Neolithic to the present. Sequencing data were de novo assembled, and metagenome-assembled genomes assigned to the genus Tannerella were investigated for phylogenetic relatedness and virulence. Putative dietary DNA was assessed for authenticity. RESULTS:The dental calculus of King Richard III was well-preserved and yielded an exceptionally high quantity of DNA. Oral microbiome species diversity fell within the range previously observed among other northern European populations, suggesting that a royal lifestyle and a rich diet did not substantially impact his oral microbiota. The reconstructed Tannerella genomes contained many virulence factors found today among oral Tannerella species. No putative dietary DNA could be authenticated. DISCUSSION:The dental calculus of King Richard III produced one of the richest ancient oral metagenomes published to date, yet the species diversity was indistinguishable from that of commoners living in northern Europe over the last 7000 years. Insufficient plant and animal DNA were recovered to investigate diet, suggesting that dental calculus may not be a sufficient source of dietary DNA even when exceptionally well-preserved.
OBJECTIVES:This study explores the subsistence strategies of Middle-to-Late Holocene human populations in the Argentinean Pampas and Paraná River Delta by analyzing dental microwear patterns. MATERIALS AND METHODS:We examined occlusal molar microwear textures of individuals from the Middle and Late Holocene recovered from 12 archaeological sites across three ecologically distinct areas: the Upper Delta of the Paraná River, Central Pampas, and the lower Colorado River Valley. RESULTS:Our results reveal both expected and unexpected trends. Individuals from the resource-rich Upper Delta of the Paraná River exhibited the predicted high dietary diversity (indicated by elevated mean heterogeneity (Hasfc81) values) but also showed surprisingly high mean complexity values (Asfc)-exceeding even those from the two semi-arid areas (Central Pampas and lower Colorado River Valley), where environmental abrasives would have been expected to have resulted in greater microwear texture complexity. DISCUSSION:Within the Paraná Delta, significant intra-site variation at Los Tres Cerros 1 suggests differential food access, possibly tied to social stratification in the Goya-Malabrigo archaeological entity. In the Central Pampas, Middle Holocene individuals from the Arroyo Seco 2 archaeological site displayed greater dietary heterogeneity than contemporaneous and Late Holocene sites, contradicting expectations of progressive diversification during this period. These findings underscore that prehistoric subsistence strategies emerged from complex interactions between ecological constraints and cultural practices, including food processing and social organization.
OBJECTIVES:Although there has been copious research on the postcranial functional morphology of Homo floresiensis, there has been relatively little study of its pelvis and its implications for interpretations of H. floresiensis locomotion. Here we present the first comparative morphometric analysis of the pelvis of LB 1, the holotype of H. floresiensis, using data derived from high-resolution micro-CT scans and situated within a broad, Plio-Pleistocene hominin context. This includes a novel quantitative measure of iliac flare in hominins to assess the australopith-like qualities of the LB 1 pelvis described by previous studies. MATERIALS AND METHODS:In a sample of extant humans and African apes and 26 fossil hominin pelves, we quantified linear and angular pelvic traits, with a focus on features that should provide functional insights into H. floresiensis locomotor behavior, including ilium orientation angle and lower ilium length. Morphometric and allometric hypotheses were investigated using Kruskal-Wallis tests, principal component analysis, and least squares regression. RESULTS:Univariate analyses demonstrate that all pelvic features of LB 1 (except for ischium length) are within the ranges of variation exhibited by Homo sapiens. Multivariate analysis reveals that the H. floresiensis pelvis shares similarities with those of other Pleistocene Homo and some australopith individuals. DISCUSSION:Overall, our results suggest that the pelvis of LB 1 is more Homo-like than previously described. While the mix of primitive and derived traits in the postcrania of H. floresiensis makes functional inferences challenging, our results from the pelvis suggest a human-like form of terrestrial bipedalism in this species.
