American Journal of Biological Anthropology

Mammalian diet and feeding ecology are often reflected by craniofacial skeleton specializations, but feeding requires skeletal actuation by a complex suite of muscles with varying sizes, lines of action, and mechanical function. While muscles play a critical role in feeding mechanics, and hence diet, it remains unclear how well variation in jaw muscle morphology predicts diet in mammals. We quantified the evolutionary interplay between mammalian muscle morphology and diet using a large and taxonomically broad sample. We measured the relative proportions and putative force production capacity, quantified as muscle physiological cross-sectional area (PCSA), for the major adductor complexes, along with a key jaw depressor, in 91 mammalian species (30 chiropterans, 33 primates, and 28 ungulates, carnivorans, rodents, and marsupials). We recovered clear dietary signals for several muscle complexes, with the medial pterygoid (larger in herbivores) and temporalis (larger in carnivores) performing best as dietary predictors. The medial pterygoid is particularly relevant for the mechanical innovation in mammals of moving the mandible along non-orthal, medio-lateral trajectories during mastication. Our findings underscore the intuitive, yet previously unquantified, importance of muscles in the evolution of mandibular roll, yaw, and lateral translation, all mammalian hallmarks of processing diverse types of food.

Genome-wide technologies can generate investigative leads in cold cases by determining the genetic ancestry of the forensic sample. Increasingly, DNA extraction and whole-genome sequencing or genotyping are being used to analyze early or middle-20th century skeletal remains. Here, we present the first case, to our knowledge, of whole-genome sequencing of a middle-20th-century bone sample from the Middle East. A femur discovered in a cave in Central Israel was proposed to belong to a person of Ashkenazi Jewish ancestry who was missing since 1948. Following DNA extraction and single-stranded library preparation, whole-genome sequencing generated nearly 500 million reads. However, only 0.5% of the reads mapped to the human genome, providing depth of coverage of 0.07x. After quality control and male sex inference, ancestry assignment was performed using principal components and ADMIXTURE analyses. The results suggested that the genome definitively belonged to a person of Arab ancestry, refuting the hypothesis of an Ashkenazi Jewish origin.

Humans are widely regarded as unusually slow to develop, exhibiting prolonged childhood and extended dependence on caregivers. However, this view is based primarily on comparisons with other primates, leaving unresolved whether humans remain distinctive within the broader diversity of mammals. We addressed this question by situating human development in a comparative framework using gestation length, weaning age, and age at sexual maturity for both sexes across 462 mammalian species representing 25 orders. Each trait was examined both as an absolute value and as a proportion of the longest verified captive lifespan. In absolute terms, human developmental traits fell within the upper range of mammalian variation. When expressed relative to lifespan, however, gestation shifted toward the lower end of the distribution, whereas weaning age and sexual maturity occupied intermediate positions, indicating that human developmental timing largely follows general mammalian scaling patterns rather than representing a pronounced outlier. These findings suggest that key features of human dependency are better understood as extensions of broader evolutionary trends than as uniquely human life-history characteristics.

Describing and interpreting spatiotemporal patterns in human culture has been a central focus of anthropology and archaeology for over a century. Recent ethnographic studies have highlighted the complexity of the processes generating these patterns, including isolation-by-distance, homophily, and common descent. However, investigating these processes in prehistoric archaeology remains challenging. Here we make use of a new interdisciplinary database and a combined dataset of ancient DNA (aDNA) genomic sequences to analyse the relationship between spatiotemporal patterns in cultural and genomic variation, by testing whether broadly defined clusters of genomic affinities correspond to spatiotemporal changes in burial rites, while controlling for other factors, using a Gaussian process model. We use data from the Big Interdisciplinary Archaeological Database (BIAD), linking mortuary information from [~]4,200 individuals with genetic ancestry and mobility data inferred from over 1,300 human genomes, from Western Eurasia [~]10,000-2000 BP. By integrating and modelling these diverse datasets, we aim to provide a detailed understanding of how genomic history intersects with cultural evolution, offering new insights into the dynamics behind these complex processes, and the extent to which genes and culture are transmitted in parallel. In the case of burial orientation, we found that cultural affiliation was the main factor accounting for variation with little to no role for ancestry, while for body position the picture was more mixed but cultural affiliation also played an important role.

Classic Maya societies (250-900 CE) carved out urban centers in the rainforest reaching population heights and political complexity previously unknown in the Mesoamerican tropics. Kinship was a central feature of the social fabric, and rulership was legitimized through claims of direct descent from mythical ancestors. Mortuary practices kept the dead close to the living, and ancestor veneration sometimes produced complex deposits of disarticulated remains that are difficult to identify and whose biological relationships to one another cannot be understood without genetic data. We screened 487 human tooth and bone samples and successfully generated genome-wide data for 430 of them. Of these, 341 samples representing 107 distinct individuals were recovered from both elite and non-elite tombs in a Classic period kingdom (250-900) CE in the rugged Maya Mountains of Belize. Remarkably, 24 of these individuals have skeletal elements in both an elite tomb and in a ritual tooth cache in a distant cave located 26.5km away on the other side of the Maya Mountains. These results indicate that elite lineages created ancestors from their deceased relatives in geographically expansive ways and highlights the importance of caves in the belief system of Classic Maya elites.

South Asia is central to debates on early human dispersals, particularly the Out of Africa model and Eurasian colonization. Studies of M haplogroups have been used to support both Northern and Southern route hypotheses, but current archaeological and genetic evidence in the region remains contradictory. In the present work, we find that in addition to haplogroup M lineages, a few R lineages exhibit ancient, locally rooted variation, with R30 being one of the widespread haplogroup of R lineages across South Asia. To better understand South Asian demographic history, we investigated the phylogeographic distribution of haplogroup R30, an indigenous lineage. We used 190 complete modern and ancient sequences from diverse mainland and island populations including incorporation of 44 newly generated sequences which enabled the refinement of the R30 phylogeny and the identification of a novel basal lineage, R30c. Bayesian and {rho}-based age estimates suggest that R30 originated in the Indian subcontinent ~50 kya. Early diversification likely occurred in Northern India, giving rise to R30b (~44 kya), while R30a and R30c differentiated primarily in Southern India. Several subclades of haplogroup R30 exhibit strong signatures of founder effects, particularly among the language isolate Vedda of Sri Lanka, Uru Kurumban of Southern India, and the populations of the Lakshadweep archipelago. Bayesian skyline analyses indicate long-term demographic stability followed by rapid lineage expansion ~20 kya and more recent declines consistent with localised drift and relatively recent founder events. The presence of early-diverging R30 lineages in Thailand and Indonesia further supports long-term connections between South and Southeast Asia. Overall, archaeological and genetic evidence point towards the multiple migrations for South Asia colonizations.

Human dental morphology is diverse and varies both within and between populations worldwide. Common variants include different numbers of cusps and roots, as well as different configurations in the fissures, ridges, and grooves on tooth crowns. Because teeth preserve well in taphonomic contexts and retain strong genetic signatures in their morphology, researchers across disciplines use dental form for research ranging from population affinity identification in forensic cases to the reconstruction of population history in archaeological and paleontological studies, and to explore the genetic underpinnings of dental development. However, these analyses are limited, as no publicly available comprehensive database of human dental morphological variation currently exists. Data are typically shared only within professional networks, excluding scientists outside those circles. Information is dispersed across repositories and the supplementary materials that accompany peer-reviewed publications, creating a fragmented and difficult-to-navigate data landscape. Although numberous dental anthropologists devoted their careers to collecting extensive datasets from thousands of individuals worldwide, their data have not yet been published in raw form nor made compatible. Here, we introduce the Dental Morphological Database (DeMoDa), an open access repository comprising 246 dental traits for 17,308 individuals across 32 major geographic regions worldwide spanning the past several thousand years. These data are from the legacy datasets of Turner, Hanihara, Scott, and Irish. Because these researchers used different scoring systems, we developed a scoring system with two steps that enables the three most-common scoring systems to be combined. We provide two versions of the data that correspond to these two steps: one with more nuanced trait scores at the cost of a smaller sample size, and another with less nuanced trait scores but broader sample coverage. We discuss the implications of publishing these legacy data and outline our decision-making process that guided their release in accordance with both the FAIR and CARE principles of open science.

The diversity of body shapes is one of the most prominent features of phenotypic variation in mammals. Yet, mammalian body shapes are poorly quantified and the underlying components contributing to its diversity as well as its relationship to other components of the skeleton are rarely tested. Here, we use lagomorphs (hares, rabbits and pikas) as a model system to (1) investigate which components of the skeleton contributed the most to body shape diversity, (2) examine the relationships between body shape and relative limb lengths, and (3) test how body size, ecotype, burrowing behavior, and locomotor mode influenced variation in lagomorph body shape and appendicular morphology. We quantified the body shape and functional proxies of the appendicular skeleton in 40 lagomorph species from osteological specimens held at museum collections. Using phylogenetic comparative methods, we found the relative length of the ribs and elongation or shortening of the thoracic and lumbar regions contributed the most to body shape evolution across lagomorphs. Second, we found that only leporids (hares and rabbits) exhibited a significant relationship between limb length and body shape, where more elongate species exhibit relatively shorter forelimbs and hindlimbs. Lastly, we found that models incorporating body size were the best predictors of lagomorph body shape and the majority of the appendicular traits, whereas models incorporating burrowing behavior and locomotor mode were largely poor fits. Broadly, these results indicate that larger lagomorphs tend to exhibit more robust body shapes with longer, more gracile forelimbs, whereas smaller lagomorphs tend to exhibit more elongate body shapes with shorter, more robust forelimbs. Overall, this work contributes to the growing understanding of mammalian body shape evolution and demonstrates the importance of not omitting body size in ecomorphological analyses.

Cities are characterized by elevated temperatures, increased pollution, and high-density human populations which often are accompanied by changes in available resources, like food. These shifts have the potential to drive phenotypic divergence in urban wildlife. Functional morphological traits, like body size, can mediate interactions between wildlife and habitat and are closely tied to life history and fitness. While examples of functional morphological variation associated with urbanization are increasing, variation in such traits as a response to urbanization remains unexplored for most taxa. Here, we investigated morphological divergence between urban and rural populations of house mice (Mus musculus domesticus). House mice are globally distributed in diverse habitats and are a model system with a wealth of phenotypic data, making them useful for the study of the impacts of urbanization on morphology. Using a paired replicate design, we sampled urban and rural populations in three distinct metropolitan regions in the eastern United States. We found that body size was smaller in urban populations. Using 3D geometric morphometrics, we also analyzed variation in cranial shape across habitats. Differences in cranial shape were largely allometric, that is, driven by differences in body size. However, we also uncovered evidence of cranial shape variation between habitats not explained by size. In contrast, we did not find evidence for habitat-driven differences in cranial capacity independent of size. Overall, our results suggest a key role for body size in mediating morphological responses to urbanization and highlight the potential of house mice as a globally-distributed model for urbanization.

The population of Madagascar exhibits a globally unique combination of African and Asian genetic ancestries. Previous studies have described the admixture history of Madagascar at island-wide scales [1,2], but less focus has been paid to fine-scale population structure across the island. We present new genome-wide genetic data from 192 individuals sampled across five regions of Madagascar. We identify population structure at extremely fine spatial scales ([~]10 km) among the Merina of the central highlands. By analysing subpopulations separately, we found one Merina group exhibited similarity to coastal populations in f4 ratios, estimated admixture dates, and pairwise FST distances, while another group was similar to other highland individuals in the same measures. This fine-scale substructure is likely associated with historical coastal-to-highland migration during the 18th and 19th centuries. In contrast, we also observe macro-scale structure in estimated timing of admixture across the island, with southeastern coastal groups exhibiting the earliest estimated admixture timings, and northern groups exhibiting the latest. This pattern corroborates previous results [1,2], and may suggest differing histories of admixture timing among Malagasy populations. Our results emphasise the importance of deep micro-geographic sampling to complement macro-scale analysis when characterising demographic history.

Anseriformes (waterfowl) and Galliformes (landfowl) are among the worlds most recognisable groups of birds, together comprising the clade Galloanserae. Despite their close evolutionary relationship, the skulls of adult anseriforms and galliforms exhibit strikingly distinct morphologies, the developmental basis and evolutionary history of which is poorly understood. To illuminate the developmental and evolutionary underpinnings of cranial disparity between and within these major extant bird clades, we quantitatively investigated ontogenetic changes in cranial morphology across galloanseran phylogenetic diversity, focusing on the previously unexplored post-hatching interval during which adult morphology takes shape. Our results reveal the combined effects of multiple heterochronic shifts early in galloanseran evolutionary history including anseriform hypermorphosis, along with influential non-heterochronic changes leading to substantially more disparate ontogenetic trajectories--and greater cranial variability--in anseriforms than galliforms. Key galloanseran fossils help clarify the polarity of evolutionary shifts in cranial development through galloanseran phylogenetic history and demonstrate that extant galliform cranial morphology is more constrained and retains a more plesiomorphic morphology than that of anseriforms. Our work helps illuminate the developmental basis of the iconic differences in cranial form between waterfowl and landfowl and illustrates the importance of broad phylogenetic and ontogenetic sampling for clarifying patterns of post-hatching developmental divergence among major vertebrate clades.

Extremely elongate necks have convergently evolved in several amniote lineages, including both aquatic and terrestrial forms (Fig. 1). The development of such a feature brings with it advantages in obtaining food items, but also biomechanical challenges, such as flexibility, stability, lift, and inertia. In Tanystropheus, a particularly long-necked Triassic archosauromorph, the neck is composed of only 13, mostly extraordinarily elongated and slender cervical vertebrae and accompanying rod-like, overlapping ribs, making it arguably the most extreme example of neck elongation in tetrapod evolution (Fig. 1;1-6). Understanding the function of this remarkable neck provides insights into the limits of neck elongation in amniotes and the evolution of morphological novelties in Triassic reptiles. Here we present the first quantitative biomechanical analysis of the Tanystropheus neck using a digital model based on three-dimensionally preserved bones. We assessed its range of motion (ROM) and performed finite element analysis (FEA) on the individual cervical ribs and the neck model in different configurations. Our results indicate that the neck of Tanystropheus was not extremely stiff, as previously postulated, and the ribs likely did not impair its movements. They transferred tensile forces towards the base of the neck, similar to what hypothesized for sauropods7. This study elucidates the bauplan of an extremely specialized animal and brings us closer to understanding the patterns of achieving neck elongation in vertebrates.

Birds evolved large, cognitively capable forebrains independently of mammals, yet comparative analyses of avian brain organization have been constrained by the lack of standardized resources capable of resolving internal parcellation and long-range connectivity across species. Here, we present a comparative MRI resource spanning 16 avian species representing major clades and diverse ecological niches. We analyzed high-resolution T2-weighted and diffusion-weighted datasets suitable for direct interspecific comparison. T2-weighted morphometry revealed pronounced region-specific variation in internal brain architecture, including lineage-dependent differences in the relative prominence of major brain divisions and commissural structures, supporting a pattern of mosaic diversification rather than uniform scaling. To validate MRI-derived anatomical boundaries, we compared MRI parcellations with complementary histological analyses in three representative taxa (the large-billed crow, gentoo penguin, and mandarin duck), demonstrating close correspondence between MRI-defined borders and cytoarchitectonic transitions identified by Nissl staining, as well as major myelinated compartments visualized by Luxol Fast Blue staining. Moreover, diffusion MRI tractography and fractional anisotropy (FA) mapping further revealed both conserved and species-specific features of large-scale brain organization. Seed-based tractography of the optic lobe, dorsal cortex, cerebellum, and anterior cortex in chick, gentoo penguin, and large-billed crow revealed conserved within-compartment trajectory patterns alongside marked region-specific interspecific differences, particularly in optic-lobe-associated long-range trajectories. Whole-brain FA maps revealed complementary variation in regional microstructural organization across taxa. Together, this comparative MRI framework provides a cross-validated foundation for linking internal brain anatomy and long-range connectivity to ecological and evolutionary diversification in birds, with broader applications to comparative neuroanatomy across amniotes.

Reconstructing the spatio-temporal history of human genetic lineages is fundamental to understanding human evolution and population distribution. While succinct tree sequences and maximum parsimony reconstruction methods applied to large-scale genomic data have improved our ability to trace the geographic history of genetic ancestry, they have essentially relied on Euclidean distances, which ineluctably ignore opportunity costs that have shaped human mobility patterns since the earliest human migrations and settlement formations. Here we propose an approach to incorporate realistic geographical migration costs through a human movement friction surface. Using simulated data mimicking the dispersal process of human migration out of Africa, we found that, compared to the Euclidean-based benchmark (M0), the proposed friction-based model (Mf) leads to a more accurate estimation of the geographical origin (n = 346, accuracy M0 = 0.18, f = 0.27) and genetic flux (n = 30, MSE M0 = 0.20, Mf = 0.12) through the Mandeb corridor in the Horn of Africa. We further illustrate these findings in a case study, in which our model seems to better identify plausible human migration paths from Eurasia to the Americas by accounting for geographic factors affecting migration opportunity costs, such as the Alaska Range and Rocky Mountains that represent physical barriers that constraint migration. While important migration drivers such as climate change, technological advances, social organization, and culture remain omitted here, our work highlights the importance of explicitly accounting for geographic constraints to improve our ability to reconstruct past human mobility and, ultimately, understand the evolution of human populations.

Teriparatide (PTH 1-34) is an anabolic agent used to treat osteoporosis, yet clinical response varies widely among patients. To investigate genetic and sex-specific determinants of skeletal response, we administered intermittent PTH to male and female mice from eight genetically diverse inbred strains. Mice were treated for four weeks, and bone phenotypes were assessed via DXA, microCT, and mechanical testing. Response to PTH was highly strain- and sex-dependent, with some strains responding at the femur but not the spine, and vice versa. Heritability estimates for PTH-induced changes in bone mineral density (BMD), cortical area, breaking strength, and trabecular bone volume fraction (BV/TV) ranged from moderate to high, with BV/TV showing the strongest genetic influence. Cortical bone response mechanisms differed by sex: males exhibited periosteal expansion, while females showed endosteal remodeling. These findings mirror clinical observations where hip non-response is more prevalent than spine non-response and suggest that genetic background and sex significantly influence therapeutic outcomes. Our data support the use of genetically diverse mouse models to elucidate the genetic architecture of PTH response and highlight the potential for personalized approaches in osteoporosis treatment. Future genome-wide association studies in outbred mice may identify specific loci mediating skeletal responsiveness to PTH, advancing precision medicine strategies for bone anabolic therapies. LAY SUMMARYTeriparatide, a drug used to treat osteoporosis, consists of the active portion of parathyroid hormone (PTH). Information from clinical studies suggests that not all patients will respond to this medication. We used eight strains of inbred mice to study the impact of genetic background and sex on the response to PTH. We learned that response to PTH is driven by both genetics and sex. Some strains responded at the femur, but not the spine and vice versa. These results may explain why a failure to respond at the hip in humans is more common than at the spine.

Sharks exhibit extraordinary morphological diversity across a wide range of ecological niches, yet large-scale, high-resolution digital datasets of their internal anatomy remain limited. Here we present an open-access 3D shark anatomical repository derived from published X-ray computed tomography (CT) data, featuring manually segmented and systematically annotated models of the chondrocranium, visceral arches, axial skeleton, musculature, and viscera in standard STL format. The dataset comprises 117 individuals, representing 72 species across 25 families and all nine extant shark orders, with 115 full-body reconstructions and two head-only models. This open-access dataset offers a comprehensive resource for comparative anatomy, biomechanical simulations, evolutionary developmental biology and biomimetics research of extant sharks.

During the European Neolithic transition, migrating Anatolian farmers admixed with local hunter-gatherers, coinciding with major shifts in diet, environment, and lifestyle that imposed strong selective pressures. Local ancestry inference is widely used to detect selection following admixture, but most methods were developed and validated on present-day populations. Their performance in ancient DNA, where reference panels are smaller, data sparser, and admixture more ancient, remains unresolved. We benchmark six local ancestry inference methods on 176 imputed Neolithic genomes, comparing ancestry proportions, tract length distributions, and selection signatures. While individual-level ancestry estimates are highly correlated across methods, inferred tract lengths and admixture time estimates vary by over an order of magnitude. Integrating results across methods and replicating across methods and in two independent datasets (n=378 and 1,121) identifies robust ancestry deviations at SLC24A5 and FADS1/2, consistent with adaptation on pigmentation and metabolism, respectively. We also identify PER3 (circadian rhythm) and IRAK4 (innate immunity) as candidate loci, but with less consistent signals across methods. Finally, we replicate previous reports of excess hunter-gatherer ancestry at the HLA, but these results are inconsistent across methods and suggest that they may be affected by bias in local ancestry inference. Our findings demonstrate that while local ancestry inference recovers biologically meaningful signals in ancient genomes, results can be sensitive to the methods used for inference, particularly in complex regions like the HLA. Method choice critically influences inferred ancestry patterns and selection signals, underscoring the importance of multi-method validation.

Adrenarche, the pre-pubertal rise in adrenal androgens, particularly dehydroepiandrosterone (DHEA) and its sulfated form DHEAS, is a critical driver of middle childhood cognitive and social development in modern humans. Compared to other apes, modern human adrenarche is more prolonged, with higher DHEAS levels. Whether this uniquely prolonged human adrenarche is a derived trait of Homo sapiens or has deeper hominin roots remains unresolved. Here, we examine the Neanderthal genetic variation in five key DHEAS biosynthesis genes (HSD3B2, CYP17A1, POR, CYB5A, SULT2A1). We also examine archaic introgression in these genes by comparing high-coverage Neanderthal genomes with globally diverse modern human sequences from the 1000 Genomes Project. We identify 29 Neanderthal-derived single nucleotide variants across these genes. Key steroidogenic genes in the biosynthesis pathway show no evidence of introgression, consistent with selection on pleiotropic regulators of steroidogenesis. In contrast, accessory genes carried introgressed Neanderthal haplotypes at moderate frequencies in non-African human populations, indicating Neanderthal variants are compatible with the human DHEAS synthesis pathway. All Neanderthal-specific variants were in non-coding regions, with three variants associated with reduced enzyme efficiency or DHEAS production in adults. Additionally, for all 29 positions, the modern human major allele is ancestral, and there is no evidence for a suite of novel adrenarche-extending variants. We conclude that the genetic foundation for extended adrenarche is shared between Homo sapiens and Neanderthals, and may have deeper hominin roots. Any phenotypic variation in adrenarche between modern humans and Neanderthals is more likely attributable to differential gene expression than to divergence in protein-coding sequences.

Accurate biological sex estimation is a key objective in archaeological and bioanthropological research but remains challenging when skeletal remains are fragmented, juvenile, or poorly preserved. Paleoproteomics approaches based on the detection of sex-specific amelogenin peptides (AMELX/AMELY) have emerged as a powerful alternative to osteological and genetic methods. However, current workflows often lack standardized criteria for peptide-level confidence assessment, potentially affecting the reproducibility and reliability of sex assignments. In this study, I evaluated the impact of peptide-level confidence filtering on paleoproteomics-based sex estimation through the reanalysis of 164 Homo sapiens individuals from 10 published datasets and 26 Bos taurus individuals from 3 datasets, spanning contexts from the Pleistocene to the present. To address methodological inconsistencies, I developed SexPeptID, an R/Shiny-based framework that integrates Posterior Error Probability (PEP) filtering, standardized peptide selection, and explicit uncertainty assessment. Application of SexPeptID revealed that peptide-level filtering substantially affects sex assignment outcomes: 17 previously classified males (10.4%) were reclassified as non-conclusive, while 5 individuals (3.1%) were identified as potentially female. Despite this sensitivity, AMELX/AMELY-based sex estimation remained robust overall, with stable signal ratios observed across archaeological periods. Variability in peptide intensities was primarily associated with dataset-specific factors rather than temporal differences, highlighting the influence of analytical workflows and preservation conditions. By incorporating confidence-based filtering and a non-conclusive classification category, SexPeptID improves the transparency, reproducibility, and reliability of palaeoproteomics sex estimation, providing a standardized framework for future archaeological and bioanthropological studies. HighlightsO_LISexPeptID provides a reproducible framework for amelogenin-based sex estimation. C_LIO_LIPeptide-level confidence filtering significantly affects paleoproteomics sex estimates. C_LIO_LI13.4% of published male assignments were revised after confidence filtering. C_LIO_LIAMELX/AMELY ratios show temporal stability from modern to Pleistocene samples. C_LIO_LIStandardized uncertainty assessment strengthens palaeoproteomics inference. C_LI

Family environments may contribute to childrens long-term health through biological processes, including epigenetic regulation such as DNA methylation (DNAm). However, most studies in this area focus on Euro-American populations while also rarely including fathering data. The current study investigated childrens blood DNAm associations with positive (father caregiving) and negative (parental conflict) family dynamics in a smaller-scale subsistence society living in the Congo Basin rainforest. We measured DNAm from dried blood spots of 54 children (mean age=8.48 years) and conducted three epigenome-wide association studies aimed at discovering differential co-methylated regions (CMRs) associated with family dynamics. Via path models, we investigated the health implications and shared contribution of family factors of the identified CMRs. Differential DNAm associated with family dynamics was localized to genes related to stress, immunology, development, and aging, thus possibly linking to childrens physical health and were simultaneously connected to other family factors such as number of siblings. Our findings suggested similarities in biological embedding of family factors across socio-ecologically diverse contexts.