As the dominant indigenous minority in southern China, Hmong-Mien-speaking Miao people were thought to be the descendants of Neolithic Yangtze rice farmers. However, the fine-scale population structure and genetic profile of the Miao populations remain unclear due to the limited Miao samples from southern China and Southeast Asia. We genotyped 19 individuals from the two largest Miao tribes in Guizhou Province (Southwest China) via SNP chips and co-analyzed the data with published modern and ancient East Asians. The Guizhou Miao displayed a closer genomic affinity with present-day and Neolithic to Iron Age southern East Asians (SEAs) than with most northern East Asians (NEAs). The genetic substructure within Miao groups was driven by different levels of genetic interaction with other ethnolinguistic groups: Hunan Miao (Central China) harbored higher proportions of NEA-related ancestry; Guizhou Miao (Southwest China) and Vietnam Miao (mainland Southeast Asia) received additional gene flow mainly from surrounding groups with Tai-Kadai-related ancestry. There were also more complex admixture events in the newly studied groups between Guizhou Xijiang Miao and surrounding populations compared with Guizhou Congjiang Miao. The qpAdm model further demonstrated that the primary ancestry of Hunan Miao, Guizhou Miao studied here, and Vietnam Miao derived from ancient SEA-related ancestry (represented by coastal early Neolithic SEA Liangdao2), with the additional gene flow from ancient NEA-related ancestry (represented by spatiotemporally inland Yellow River farmers), with slightly different proportions. Our genomic evidence reveals the complex and distinct demographic history of different Miao tribes.

The TAS2R38 gene is involved in bitter taste perception. This study documents the distinctive diversity patterns in northern Africa of functional single-nucleotide polymorphisms (SNPs) rs713598 and rs1726866 at the TAS2R38 locus and places those patterns in the context of global TAS2R38 diversity. Data previously genotyped with TaqMan assay were analyzed for rs713598 and rs1726866 for 375 unrelated subjects (305 Tunisians from seven locations: Mahdia, Sousse, Kesra, Nebeur, Kairouan, Smar, and Kerkennah; plus 70 Libyans). Data were analyzed to present haplotypes and genotypes before comparison with data from worldwide populations. This study provides information about TAS2R38 diversity in a part of the world that is relatively understudied. Considering the two SNPs rs713598 and rs1726866, the CA nucleotide haplotype leading to the PV amino acid haplotype is extremely rare almost everywhere, but it is relatively frequent (between 6% and 15%) in northern Africa, where it coexists with the globally common amino acid haplotypes PA, AA, and AV. Given its higher frequency in North Africa, the authors propose the CA nucleotide haplotype as a biogeographic marker for forensic purposes.

Toll-like receptors (TLRs) are cellular innate immune receptors that explore microbial molecules. For instance, TLR4 can sense bacterial lipopolysaccharides, inducing cytokines and antimicrobial peptides against the bacteria. Single-nucleotide polymorphisms (SNPs) in TLR4 are associated with diseases such as septic shock. Therefore, investigations of common SNPs may help explain the pathogenesis of diseases and various innate immune responses to infections. This study investigated genotypic frequencies of the two common TLR4 SNPs, Asp299Gly and Thr399Ile, in a Kurdish population using restriction length fragment polymorphisms (RFLPs). Global frequencies of both TLR4 SNPs in different populations of sub-Saharan Africa, North Africa, western Asia, Eurasia, and East Asia were also used to infer human migrations and past settlements. The RFLP data demonstrate that, in the Kurdish population, the genotypic frequencies of both SNPs are similar to Iranian or other West Asian populations, which in turn are comparable to Eurasian populations, suggesting past admixture due to migrations, population intermixing, and common ancestry. Globally, the frequencies of the homozygous wild-types of TLR4 variants are prevalent, but homozygous mutants are rare or lacking in almost all global populations. Frequencies of the heterozygotes varied among populations. For instance, in sub-Saharan Africa the frequency of the Asp299Gly SNP is higher than that of Thr399Ile, whereas in the Arabian Peninsula both SNPs are present at high frequencies. In contrast, East Asian populations lack or have very low frequencies of both TLR4 SNPs of interest. Moreover, co-segregation of the TLR4 SNPs is common in some populations, which may indicate important associations with certain diseases. Future studies are required to link the TLR4 SNPs with either resistance or susceptibility to diseases.

Skeletal estimation methods to reconstruct the juvenile biological profile are largely limited to those estimating age and, to a lesser extent, sex. While body mass is not generally estimated as part of the biological profile in forensic investigations, this is a logical candidate for inclusion in the forensic biological profile, as it has long been of interest in paleoanthropology and several methods to estimate juvenile body mass currently exist. To explore the performance of body mass estimation for juveniles, the authors tested the accuracy and precision of previously published panel regression formulae using two femoral measurements: the breadth of the distal metaphysis and the cross-sectional polar moment of inertia (J). The test sample consisted of measurements of 94 individuals from birth to 12.5 years of age, taken from postmortem computed tomography scans housed at the Office of the Medical Investigator, New Mexico, USA. Results indicate that body mass estimates are more accurate when estimated from cross-sectional than from metaphyseal measures. Both formulae, however, consistently underestimated weight, and the magnitude of the underestimation increased exponentially with age. This suggests that, contrary to what others have argued, body mass estimation is complicated by population variation in body composition. This study reinforces the importance of documenting and investigating the ontogeny of human variation. The global increase in medical imaging in clinical settings can be leveraged to obtain skeletal data for juveniles from a wide range of ontogenic environments, marking an exciting time for the study of human variation.

The 1943 Battle of Tarawa resulted in the loss of approximately 1,000 US service members on or around Betio Island, Tarawa Atoll, Republic of Kiribati. Nearly half these casualties were accounted for after the battle. The Defense POW/MIA Accounting Agency (DPAA) has worked to identify the remaining ∼510 unaccounted-for service members and has successfully identified ∼160 service members to date. Demographic data pulled from historical documentation of the US losses indicate a relatively homogeneous population (99% White, 81% 17-23 years of age, and only two individuals with a documented religious preference other than Protestant or Catholic). Using this demographic data as a framework, three case studies are presented to demonstrate how a holistic biosocial approach to building identity could facilitate forensic identifications. The temporal and sociocultural contextualization of analyses enables anthropologists to navigate inconsistencies between 21st-century and historical (1940s) social identity concepts to overcome challenges to identification. The case studies demonstrate how biological evidence, genetic evidence, and material evidence (material culture) differently contribute to the social identity of an individual and can impact identification efforts when analytical conclusions are incongruent with historical documentation. The first case of US Battle of Tarawa casualties examines how morphometric biological affinity assessments are biased by the fluidity of social identity concepts when complex morphological and metric indicators of biological affinity are not represented in historical race categories. The second case demonstrates how biogeographic genetic affinity predictions, through a discussion of the G2a4 haplogroup, need to be examined holistically in the context of other lines of evidence. The third case highlights how material evidence can further define social identity beyond physicality, genetic structure, and race. The challenges of interpreting identity from human remains, as highlighted through these examples, are commonly encountered by anthropologists working in disaster victim identification and other humanitarian contexts. Thus, it is imperative for anthropologists to be self-aware of implicit biases toward the current prevailing definitions of biological and social identity and to consider historical perceptions of identity when working in these contexts.

Human identification techniques have been a leading tool to hold perpetrators accountable, give families closure, and approximate faces on skulls. This project is a pilot study to critically examine three disciplines that fall under the human identification umbrella: forensic anthropology, forensic genetics, and forensic art. Current facial research in genetics focuses on data from living individuals, identifying specific single-nucleotide polymorphisms (SNPs) that influence specific regions of the face. This study assesses the translation of these regions to craniometric dimensions (interlandmark distances) of the underlying skull itself. The goal of this project is to provide information regarding the correlation of craniometric measurements and SNPs, as well as to encourage interdisciplinary work within the forensic sciences. We examined a selection of candidate SNPs currently identified in the literature to examine correlations between interlandmark distances and these SNPs within the same individual. A series of 99 craniometric landmarks were collected from 17 documented skulls from the Texas State Donated Skeletal Collection using a three-dimensional Microscribe digitizer. Criteria for inclusion in this study included European American ancestry, presence of intact skulls, and presence of associated donor blood cards collected at the time of body donation. Using these blood cards, DNA from each individual was extracted, amplified, and sequenced through next-generation sequencing for the chosen SNPs. Bioinformatics tests were then applied to observe the presence or absence of the major or minor alleles in specific locations on the genome. After determining the presence or absence of an SNP (minor allele), a set of statistical tests were performed, including Spearman's correlation between the craniometric measurements and the individual's genetic data variables; two-way hierarchical clustering and bootstrap forest modeling between variables that demonstrated significant correlation; a principal components analysis on the craniometric data (interlandmark measurements) and genetic data (SNP presence/absence) to check homogeneity of each data set; and a pairwise Procrustes analysis on the correlation of the two data sets as different groups. The results indicate correlations of varying degrees between the targeted craniofacial regions and the targeted SNPs. Eleven SNPs showed significant correlation (p < 0.05), but the correlations were not as expected and showed some interesting results. By group level there was no significant correlation, but there was correlation at the individual level. While some SNPs affected the soft tissues only, others showed correlations with the skull (hard tissue), a finding not previously reported. Combining craniometric and DNA analyses to leverage genotype-phenotype associations has great potential to expand the discourse of current facial approximation and thereby to provide new investigative tools for human identification in forensic anthropology.

Since Frank Livingstone proposed the idea that there are no races, only clines, in 1962, little has changed in how anthropologists study and, ultimately, estimate ancestry. How we talk about the study of human variation may have changed-shifting away from "racial" labels and toward those of supposed ancestral origins-but the methods we use to label and analyze groups, however termed, have remained the same. The author suggests a new theoretical approach to ancestry estimation that does not rely on group labels, using the Howells Craniometric Data Set as an example. In the suggested workflow, the data structures itself into natural clusters, referred to as "morphogroups," without relying on a group label. Each morphogroup is explored for subgroups, and the process is repeated until no further distinctions can be made. At each level an individual is compared to the morphogroup in a descriptive manner, focusing on similarities and differences. Lastly, a multi-iteration classification procedure, using random forest modeling, classifies by morphogroup. In this test, hierarchical clustering identifies the optimal number of natural clusters within the data, and principal components analysis is used to explore morphogroups. (The author provides a markdown file of all code used, at https://rpubs.com/kenyhercz2/717620.) Using this suggested workflow, the author identifies three main morphogroups in the Howells data set, each with different numbers of subclusters ranging from 0 to 8. Morphogroup correct classifications are typically in the mid-90% range, and the accompanying sex estimations, between 93% and 100% correct. The author emphasizes that this is but one of myriad ways ancestry could be estimated. Human variation and identity are not static, and we should help one another rethink and redefine what is possible for our field.

Post-traumatic stress disorder (PTSD) is a common and debilitating psychiatric disorder that may occur in individuals exposed to traumatic events such as accidents, interpersonal violence, war, combat, or natural disasters. Additionally, PTSD has been implicated in the development of a variety of chronic conditions including cardiovascular and metabolic diseases, suggesting that the biological alterations associated with the disorder can manifest themselves as chronic diseases in those suffering from PTSD. The biological underpinnings of the disorder are not well understood. Gene expression studies can illuminate the complex physiology of PTSD reflecting the embodiment of trauma, i.e., the process in which traumatic experiences in our social environments could potentially be manifested in our body by genomic mechanisms. To date, gene expression studies that examine the whole transcriptome are scarce and limited to single-timepoint assessments. Here we applied a transcriptome-wide gene expression screen with RNA-sequencing to whole blood samples from predominantly African-American participants in a community-dwelling setting to elucidate the gene expression signatures associated with the development of PTSD. The study participants (N=72, of whom 21 eventually developed PTSD) are a trauma-exposed subsample of participants enrolled in a longitudinal and prospective cohort study of adults living in Detroit, Michigan. PTSD was assessed in a structured telephone interview and whole blood samples were taken both before and after trauma exposure. We found 45 differentially expressed genes associated with PTSD development with an estimated log2 fold change > 1.5 at a nominal p-value (pPAX6, TSPAN7, PXDN, VWC2, SULF1, and NFATC4 were also ubiquitously expressed in all brain regions. Longitudinal sampling provides a promising mean to elucidate the pathophysiology underlying the embodiment of trauma.

Dental development has been used to assess whether an individual may be below or above an age that serves as a legal threshold. This study used development of the first and second mandibular molars from a large sample of individuals (N = 2,676) to examine the age threshold for minimum age of criminal responsibility. A bivariate ordered probit model was applied to dental scores following the Moorrees et al. (1963) system, with the addition of a crypt-absent/present stage. Then a 10-fold cross-validation within each of the sexes showed that the bivariate models produce unbiased estimates of age but are heteroskedastic (with increasing spread of the estimates against actual age). To address the age threshold problem, a normal prior centered on the threshold is assumed, and the product of the prior and the likelihood is integrated up to the age threshold and again starting at the age threshold. The ratio of these two integrals is a Bayes factor, which because the prior is symmetric around the threshold, can also be interpreted as the posterior odds that an individual is over versus under the age threshold. It was necessary to assume an unreasonably high standard deviation of age in the prior to achieve posterior odds that were well above "evens." These results indicate that dental developmental evidence from the first and second molars is of limited use in examining the question of whether an individual is below or over the minimum age of criminal responsibility. As the third molar is more variable in its development than the first two molars, the question of dental evidence regarding the age of majority (generally 18 years) remains problematic.

The humanitarian crisis on the US-Mexico border is a long-standing and evolving crisis in which nearly 8,000 deaths have been reported in the last two decades. These deaths are largely distributed across the Arizona-Mexico and Texas-Mexico border regions, where demographic trends for immigrants attempting to cross into the United States have shifted dramatically. The demographic change and volume of immigrants seeking shelter in the United States present new challenges for the forensic practitioners entrusted with the identification of individuals who lose their lives during the final segment of their journey. Within this border context, this study investigated how genetic variation inferred from forensically significant microsatellites can provide valuable information on regions of origin for unidentified remains at the group level. To explore how to mobilize these genetic data to inform identification strategies, the authors conducted a comparative genetic analysis of identified and unidentified immigrant cases from the Arizona- and Texas-Mexico contexts, as well as 27 other Latin American groups. Allele frequencies were utilized to calculate FST, and relationships were visually depicted in a multidimensional scaling plot. A Spearman correlation coefficient analysis assessed the strength and significance of population relationships, and an agglomerative clustering analysis assessed population clusters. Results indicate that Arizona-Mexico immigrants have the strongest relationship (>80%) with groups from El Salvador, Guatemala, Mexico, and an indigenous group from southern Mexico. Texas-Mexico immigrants have the strongest relationships (>80%) with groups from Belize, Colombia, Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua. These findings agree with, and are discussed in comparison with, previously reported demographic trends, population genetics research, and population history analyses. The authors emphasize the utility and necessity of coupling genetic variation research with a nuanced anthropological perspective for identification processes in the US-Mexico border context.

The concept of race has a complex history in the field of biological anthropology. Despite increased recognition of the racist origins of the discipline, there remains little agreement about what the concept means, how it is used, or how it is discussed. This study presents the results of a survey of biological anthropologists to investigate the relationship of biological anthropologists with race and ancestry. The survey focuses on the areas of research, public engagement, and teaching as related to these concepts. Results indicate that a large majority of biological anthropologists agree that race (as a social not biological concept) is separate from ancestry. The majority of respondents agreed that ancestry categories should be based on geography (e.g., Asian, European, and African), and more anthropologists thought the terms "Hispanic" and "Latino" were inappropriate ancestry categories. While most respondents felt that discussions of these terms were not matters of "political correctness," nearly a quarter of respondents suggested that concerns over the moral and ethical implications of research (e.g., photos, terminology, and ancestry) result in the silencing of anthropological research. Overwhelmingly, respondents felt that anthropologists have a responsibility to ensure the avoidance of misappropriation of their work by race science and by white nationalists/supremacists. Some differences in survey responses were found relating to respondents' subdiscipline, educational level, location, age, self-identified racial/ethnic categories, and gender. In regard to teaching, survey results indicate that these concepts are minimally covered in university classrooms. When taught, topics focus on the colonialist/racist history of anthropology, the presence of white privilege/supremacy, and racism. Based on the results of this survey, the authors argue for greater public engagement on these concepts, a standardized system of teaching race and ancestry, and a disciplinary conversation about practice and terminology. In this way, biological anthropologists can best place themselves to combat racism in a socially responsible way.

The Austronesian Diaspora is a 5,000-year account of how a small group of Taiwanese farmers expanded to occupy territories reaching halfway around the world. Reconstructing their detailed history has spawned many academic contests across many disciplines. An outline orthodox version has eventually emerged but still leaves many unanswered questions. The remarkable power of whole-genome technology has now been applied to people across the entire region. This review gives an account of this era of genetic investigation and discusses its many achievements, including revelation in detail of many unexpected patterns of population movement and the significance of this information for medical genetics.

Inferences in bioarchaeology and forensic contexts require mathematical stature estimation using long bone lengths. This study aimed to identify predictors of femur length (FL) from epiphyseal and diaphyseal width measurements that are not bound to assumptions of sex or laterality. To compute linear regression models, both standard and new measurements around the diaphyseal dominant nutrient foramina (NF) were collected on modern femora (n = 64) from the unidentified skeletal collection housed at Alexandria University. Four equations were then validated on an ancient Egyptian sample (n = 73) from the Goldman Osteometric Data Set to evaluate the effect of sex subdivision on the accuracy of FL and indirect stature estimations using Raxter's formulas. Most of models reflected significant positive association (r > 0.60) between width variables and FL. Oddly, the distance from the proximal end to the NF correlated weakly with FL (r = 0.34). The stepwise selected equations preferred measurements around NF to midshaft, with the anteroposterior diameter included in the proximal fragment model (r = 0.77), and circumference in diaphyseal fragment model (r = 0.62). Tested equations performed consistently on the ancient Egyptian sample. Measurements from the femoral proximal fragment are more reliable predictors than those from the distal fragment, with the exception of femur neck diameter. However, distal epicondylar breadth is a better predictor of FL in females than in males. Indirect stature estimation showed a reasonable degree of accuracy in both sexes. These models can be applied successfully in contemporary and ancient Egyptian fragmentary remains; however, due to larger size of femora from the Old Kingdom sample, they would be most applicable to individuals from later dynasties.

Social norms regarding who marries whom have changed dramatically in the United States across the 20th century. These changes may influence the level of genetic similarity between spouses. This study investigates whether genetic similarity in height between husband and wife was influenced by a historical transition in spouse selection criteria. The great transition from the companionate marriage to the individualized marriage occurred in the 1960s. In the companionate marriage, husband and wife chose each other as companions, and the emphasis was on playing marital roles well: husbands being good breadwinners and wives being good homemakers. In the individualized marriage, the emphasis switched to individual feelings, and as a result, when choosing their partners people tended to pay less attention to height, suggesting a smaller genetic correlation for height between spouses. Using data from the Health and Retirement Study, we found that the genetic correlation for height declined substantially in the individualized marriage. We conducted a number of analyses to test for the confounding effects of cohort and age and to address population stratification, selection issues, and genetic relatedness between spouses. Evidence suggests that the effect of this transition is robust.