Understanding race and human variation: Why forensic anthropologists are good at identifying race

Human identification: an investigation of 3D models of paranasal sinuses to establish a biological profile on a modern UK population

Medical imaging is a valuable source for facilitating empirical research and provides an accessible gateway for developing novel forensic anthropological methods for analysis including 3D modelling. This is especially critical for the United Kingdom (UK), where methods developed from modern UK populations do not currently exist. This study introduces a new approach to assist in human identification using 3D models of the paranasal sinuses. The models were produced from a database of 500 modern CT scans provided by University College London Hospital. Linear measurements and elliptic Fourier coefficients taken from 1500 three-dimensional models across six ethnic groups assessed by one-way ANOVA and discriminant function analysis showed a range of classification rates with certain rates reaching 75-85.7% (p < 0.05) in correctly classifying age and sex according to size and shape. The findings offer insights into the potential for employing paranasal sinuses as an attribute for establishing the identification of unknown human remains in future crime reconstructions.

Population affinity estimation using pelvic measurements based on computed tomographic data acquired from Japanese and Western Australian populations

The present study analyzes morphological differences in the pelvis of Japanese and Western Australian individuals and investigates the feasibility of population affinity classification based on computed tomography (CT) data. The Japanese and Western Australian samples comprise CT scans of 207 (103 females; 104 males) and 158 (78 females; 80 males) adult individuals, respectively. Following volumetric reconstruction, a total of 19 pelvic landmarks were obtained on each sample, and 11 measurements, including two angles, were calculated. Machine learning methods (random forest modeling [RFM] and support vector machine [SVM]) were used to classify population affinity. Classification accuracy of the two-way models was approximately 80% for RFM: the two-way sex-specific and sex-mixed models for SVM achieved > 90% and > 85%, respectively. The sex-specific models had higher accurate classification rates than the sex-mixed models, except for the Japanese male sample. The classification accuracy of the four-way sex and population affinity model had an overall classification accuracy of 76.71% for RFM and 87.67% for SVM. All the correct classification rates were higher in the Japanese relative to the Western Australian sample. Our data suggest that pelvic morphology is sufficiently distinct between Japanese and Western Australian individuals to facilitate the accurate classification of population affinity based on measurements acquired in CT images. To the best of our knowledge, this is the first study investigating the feasibility of population affinity estimation based on CT images of the pelvis, which appears as a viable supplement to traditional approaches based on cranio-facial morphology.

Automated reconstruction: Predictive models based on facial morphology matrices

Forensic Facial Approximation (FFA) has evolved, with techniques advancing to refine the intercorrelation between the soft-tissue facial profile and the underlying skull. FFA has become essential for identifying unknown persons in South Africa, where the high number of migrant and illegal labourers and many unidentified remains make the identification process challenging. However, existing FFA methods are based on American or European standards, rendering them inapplicable in a South African context. We addressed this issue by conducting a study to create prediction models based on the relationships between facial morphology and known factors, such as population affinity, sex, and age, in white South African and French samples. We retrospectively collected 184 adult cone beam computed tomography (CBCT) scans representing 76 white South Africans (29 males and 47 females) and 108 French nationals (54 males and 54 females) to develop predictive statistical models using a projection onto latent structures regression algorithm (PLSR). On training and untrained datasets, the accuracy of the estimated soft-tissue shape of the ears, eyes, nose, and mouth was measured using metric deviations. The predictive models were optimized by integrating additional variables such as sex and age. Based on trained data, the prediction errors for the ears, eyes, nose, and mouth ranged between 1.6 mm and 4.1 mm for white South Africans; for the French group, they ranged between 1.9 mm and 4.2 mm. Prediction errors on non-trained data ranged between 1.6 mm and 4.3 mm for white South Africans, whereas prediction errors ranging between 1.8 mm and 4.3 mm were observed for the French. Ultimately, our study provided promising predictive models. Although the statistical models can be improved, the inherent variability among individuals restricts the accuracy of FFA. The predictive validity of the models was improved by including sex and age variables and considering population affinity. By integrating these factors, more customized and accurate predictive models can be developed, ultimately strengthening the effectiveness of forensic analysis in the South African region.

Estimation of ancestry from cranial measurements based on MDCT data acquired in a Japanese and Western Australian population

The estimation of ancestry is important not only towards establishing identity but also as a required precursor to facilitating the accurate estimation of other attributes such as sex, age at death, and stature. The present study aims to analyze morphological variation in the crania of Japanese and Western Australian individuals and test predictive models based on machine learning for their potential forensic application. The Japanese and Western Australian samples comprise computed tomography (CT) scans of 230 (111 female; 119 male) and 225 adult individuals (112 female; 113 male), respectively. A total of 18 measurements were calculated, and machine learning methods (random forest modeling, RFM; support vector machine, SVM) were used to classify ancestry. The two-way unisex model achieved an overall accuracy of 93.2% for RFM and 97.1% for SVM, respectively. The four-way sex and ancestry model demonstrated an overall classification accuracy of 84.0% for RFM and 93.0% for SVM. The sex-specific models were most accurate in the female samples (♀ 95.1% for RFM and 100% for SVM; ♂91.4% for RFM and 97.4% for SVM). Our findings suggest that cranial measurements acquired in CT images can be used to accurately classify Japanese and Western Australian individuals into their respective population. This is the first study to assess the feasibility of ancestry estimation using three-dimensional CT images of the skull.

Exploring cranial macromorphoscopic variation and classification accuracy in a South African sample

To date South African forensic anthropologists are only able to successfully apply a metric approach to estimate population affinity when constructing a biological profile from skeletal remains. While a non-metric, or macromorphoscopic approach exists, limited research has been conducted to explore its use in a South African population. This study aimed to explore 17 cranial macromorphoscopic traits to develop improved methodology for the estimation of population affinity among black, white and coloured South Africans and for the method to be compliant with standards of best practice. The trait frequency distributions revealed substantial group variation and overlap, and not a single trait can be considered characteristic of any one population group. Kruskal-Wallis and Dunn's tests demonstrated significant population differences for 13 of the 17 traits. Random forest modelling was used to develop classification models to assess the reliability and accuracy of the traits in identifying population affinity. Overall, the model including all traits obtained a classification accuracy of 79% when assessing population affinity, which is comparable to current craniometric methods. The variable importance indicates that all the traits contributed some information to the model, with the inferior nasal margin, nasal bone contour, and nasal aperture shape ranked the most useful for classification. Thus, this study validates the use of macromorphoscopic traits in a South African sample, and the population-specific data from this study can potentially be incorporated into forensic casework and skeletal analyses in South Africa to improve population affinity estimates.

Evaluating postcranial macromorphoscopic traits to estimate population variation among modern South Africans

Population overlap and the variation within and among populations have been globally observed but is often difficult to quantify. To achieve this, numerous different methods need to be explored and validated to assist with the creation of an accurate biological profile. The current lack of databases for postcranial macromorphoscopic traits indicates the need to further investigate if the method can be employed repeatably in a forensic context. The current study aimed to assess the prevalence of eleven postcranial macromorphoscopic traits in a South African sample. A total of 271 postcrania of adult black, coloured, and white South Africans were assessed. The intra- and inter-observer agreement ranged from fair to almost perfect except for the accessory transverse foramen of C1, which had poor agreement between observers. Only seven traits differed significantly between at least two of the groups. Univariate and multivariate random forest models were created to test the positive predictive performance of the traits to classify population affinity. The classification accuracies for the univariate models ranged from 33.3% to 53.0% and ranged from 54.6% to 62.1% for the multivariate models. Based on the variable importance, the traits assessing spinous process bifurcation were the most discriminatory variables. The results indicate that the postcranial MMS approach does not outperform current methods employed to estimate population affinity. Further research needs to be done for the method to have practical applicability for medicolegal casework in South Africa.

Ancestry estimation in forensic anthropology: accuracy of the AncesTrees software in a Brazilian sample

The objective of this study is to analyze the accuracy and applicability of the AncesTrees software with respect to a set of cranial measurements of a Brazilian sample consisting of 114 identified skulls from two osteological collections, predominantly composed of European (n = 59), African (n = 35), and admixed individuals (n = 20). Twenty-four different craniometric measurements are performed and input to AncesTrees via two algorithms, one of which is used in three configurations, with different ancestral groups integrated in the model. The software exhibits superior performance in the estimation of European individuals, reaching 73% accuracy, compared with 66% in the African individuals. Those individuals classified as admixed produce a variety of ancestral classifications, mainly European. Overall, the most accurate combination of AncesTrees is obtained using ancestralForest with only the European and African groups integrated into the algorithm, where the accuracy reaches 70%. The applicability of this software to a specific population is fragile because of the high admixing load, making it necessary to create a more representative anthropometric database of the Brazilian people.

Key points

Ancestry estimation methods are seldom validated in Brazil.AncesTrees performed poorly on our sample, with a maximum accuracy of 70%.Brazil's highly mixed population hinders ancestry estimation.Mixed individuals (pardos) are predominantly classified as Europeans.The insertion of Brazilian metric data into the AncesTrees database would produce better results.

Comparing Genetic and Physical Anthropological Analyses for the Biological Profile of Unidentified and Identified Bodies in Milan

When studying unknown human remains, the estimation of skeletal sex and ancestry is paramount to create the victim's biological profile and attempt identification. In this paper, a multidisciplinary approach to infer the sex and biogeographical ancestry of different skeletons, using physical methods and routine forensic markers, is explored. Forensic investigators, thus, encounter two main issues: (1) the use of markers such as STRs that are not the best choice in terms of inferring biogeographical ancestry but are routine forensic markers to identify a person, and (2) the concordance of the physical and molecular results. In addition, a comparison of physical/molecular and then antemortem data (of a subset of individuals that are identified during our research) was evaluated. Antemortem data was particularly beneficial to evaluate the accuracy rates of the biological profiles produced by anthropologists and classification rates obtained by molecular experts using autosomal genetic profiles and multivariate statistical approaches. Our results highlight that physical and molecular analyses are in perfect agreement for sex estimation, but some discrepancies in ancestry estimation were observed in 5 out of 24 cases.

Differences in the predicted nasoseptal flap length among races: A propensity score matching analysis

OBJECTIVES

We compared the lengths of a nasoseptal flap (NSF) and skull base according to race, age, and sex.

METHODS

We performed paranasal sinus computed tomography in 19,961 adult patients between 2003 and 2022. The race of the patients was East Asian (n = 71), Caucasian (n = 71), or Middle Eastern (n = 71). The expected lengths of the NSF and anterior skull base defect were measured and analyzed according to race, age, and sex.

RESULTS

Compared with Caucasians and Middle Easterners, East Asians had a shorter NSF length (p < 0.001) and lower ratio of the expected NSF length to the expected defect length (p < 0.001). There was no difference in the values among age groups. The expected NSF length was longer, and the ratio of the expected NSF length to the expected defect length was higher, in males than females (p < 0.001 for both).

CONCLUSIONS

East Asians and females had a shorter NSF length and lower ratio of expected NSF to surgical defect lengths after anterior skull base reconstruction compared with the other races and with males, respectively. Anatomical differences should be considered when long NSF lengths are required, such as for anterior skull base reconstruction.

Effects of caste, birth season, and family income on digit ratios

OBJECTIVES

The contributions of latitude and ethnicity in the determination of cross-society differences in digit ratios are unclear. In India, different castes (endogamous groups) have been living in the same areas (villages or towns) for the last 1500 years and, therefore, these groups may have different gene pools without a latitude-related difference component. Thus, in the present study, we studied the effect of caste on digit ratios. We also studied the effects of sex, birth season, and family income on digit ratios.

METHODS

We selected a sample of 301 college students (age: M = 19.9 years, SD = 2.63) in Muzaffarnagar city of western Uttar Pradesh, India, and asked participants for information regarding their birth month, religion, caste, and monthly family income. We measured participants' dorsal and palmar digit lengths (of all fingers, except the thumb, in both hands) using vernier calipers of 0.01 mm accuracy.

RESULTS

Other backward castes (intermediate castes) had longer digit lengths than general castes (upper castes), scheduled castes (lower castes), and Muslims. However, there was no difference in digit ratios of caste groups (scheduled castes vs. other backward castes vs. general castes vs. Muslims) or specific castes (Chamar-Jatav vs. Jat vs. Pandit-Tyagi). Winter-born women had lower left dorsal 2D:4D and 3D:4D ratios than summer-born women. Family income was related to higher dorsal 2D:4D and 3D:4D ratios among women. Moreover, in dorsal digit ratios, sex difference (men < women) occurred in digit ratios constituting digit 5, whereas, in palmar digit ratios, sex difference occurred in digit ratios constituting digit 2.

CONCLUSIONS

The present study suggests that endogamy-led genetic difference in ethnic/caste groups is not a determinant, whereas birth season (i.e., the exposure to sunlight) and family income might be determinants of digit ratios. In addition, compared to palmar digit ratios, dorsal digit ratios are better markers of sexual dimorphism.

Associations between 44 nonmetric permanent dental traits or anomalies with skeletal sagittal malocclusions and sex, besides correlations across the variations or abnormalities

Introduction

Nonmetric dental traits and the shape, size, or number of dental anomalies are essential to various dental fields such as orthodontics, dental anatomy, anthropology, pathology, and forensic dentistry. Nonetheless, many are not well assessed worldwide. Moreover, most studies are limited to a few nonmetric traits. Therefore, we aimed to examine several nonmetric dental traits/anomalies.

Methods

In this cross-sectional epidemiological study, ~ 9000 permanent teeth of 331 non-syndromic orthodontic patients (radiographs and dental casts) with fully erupted permanent dentitions (except the third molars and some cases of a few teeth missing or excluded) were evaluated by two observers, each twice, in search for 62 nonmetric traits/shape-number-size anomalies. The traits/anomalies of interest were supernumerary, microdontia, peg-shaped lateral, shovelings, talon cusps, Carabelli cusps, fifth/sixth/seventh cusps on the molars, hypocone/hypoconulid absence, protostylid, deflecting wrinkle‏s, canine mesial ridge, distal trigonid crest, canine distal accessory ridge, accessory cusps in the mesial/distal marginal ridges, mesial/distal accessory ridges, and accessory cusps in the lingual of the mandibular premolars and second molars). Data, at both patient/quarter levels, were analyzed regarding the associated factors (skeletal Angle classes, crowding, sex, and sides) as well as the correlations among traits, using the chi-square test and Spearman correlation coefficient (α = 0.05).

Results

Prevalence rates of 44 traits/anomalies were reported (18 out of the 62 searched traits/anomalies were not found [prevalence = 0%]). Microdontia and accessory cusps on the marginal ridge of the second mandibular molars were significantly more common in women (P < 0.05). Canine talon cusp and distal trigonid crest of the second mandibular molars were more prevalent in men (P < 0.05). Shoveling, canine talon cusp, canine distal accessory ridge, and accessory cusp in the first premolar might be more prevalent in skeletal Angle class II; whereas, accessory cusp in the mesial marginal ridge of the second premolar might be rather more prevalent in skeletal Angle class I (P < 0.05). Few dental traits were positively and moderately or strongly correlated with each other (Spearman Rho ≥ 0.4, P < 0.0005).

Conclusions

Sex dimorphism was uncommon in nonmetric dental traits/anomalies. Skeletal malocclusions may be associated with a few dental abnormalities or variations.

Sexual Dimorphism of Cranial Morphological Traits in an Italian Sample: A Population-Specific Logistic Regression Model for Predicting Sex

Simple Summary

Despite the fact that sex estimation methods from crania are very popular in forensic anthropology, few validation studies have verified their accuracy and reliability in different populations. Different from craniometrics, for which validation studies have remarkably increased lately, the methods based on cranial morphology still need to be thoroughly investigated, even if a large consensus exists on the effects of population variability on sexual cranial dimorphism. When dealing with forensic contexts, appropriately-validated methods should be applied for building accurate biological profiles. Since the possible sexual dimorphism variation of cranial morphological traits needs to be evaluated properly in various populations, in this study, we analyzed the accuracy of existing regression models for predicting sex from cranial morphological traits in an Italian contemporary/modern population. In addition, we propose new logistic regression models that are more accurate and specific for our sample. The results also update the reference standards for populations of this geographical area and provide an additional important warning on sexual dimorphism to anthropologists working in forensic contexts.

Abstract

Although not without subjectivity, the cranial trait scoring method is an easy visual method routinely used by forensic anthropologists in sex estimation. The revision presented by Walker in 2008 has introduced predictive models with good accuracies in the original populations. However, such models may lead to unsatisfactory performances when applied to populations that are different from the original. Therefore, this study aimed to test the sex predictive equations reported by Walker on a contemporary Italian population (177 individuals) in order to evaluate the reliability of the method and to identify potential sexual dimorphic differences between American and Italian individuals. In order to provide new reference data to be used by forensic experts dealing with human remains of modern/contemporary individuals from this geographical area, we designed logistic regression models specific to our population, whose accuracy was evaluated on a validation sample from the same population. In particular, we fitted logistic regression models for all possible combinations of the five cranial morphological traits (i.e., nuchal crest, mastoid process, orbital margin, glabella, and mental eminence). This approach provided a comprehensive set of population-specific equations that can be used in forensic contexts where crania might be retrieved with severe taphonomic damages, thus limiting the application of the method only to a few morphological features. The results proved once again that the effects of secular changes and biogeographic ancestry on sexual dimorphism of cranial morphological traits are remarkable, as highlighted by the low accuracy (from 56% to 78%) of the six Walker’s equations when applied to our female sample. Among our fitted models, the one including the glabella and mastoid process was the most accurate since these features are more sexually dimorphic in our population. Finally, our models proved to have high predictive performances in both training and validation samples, with accuracy percentages up to 91.7% for Italian females, which represents a significant success in minimizing the potential misclassifications in real forensic scenarios.

Anatomic Study of the Medial Collateral Ligament in Thai Population: A Cadaveric Study of 56 Elbows

PURPOSE

This study aims to elucidate basic anatomic and geometric features of MCL, providing more accurate and detailed information, as guidance for surgeons, to improve patient's outcome of the treatment.

METHODS

The anterior bundle (AB), posterior bundle (PB) and transverse bundle (TB) ligament of 56 fresh frozen Thai cadaveric elbows, were measured and recorded, comprise key ligament's geometric features, footprints and dimensions, and its relation to bony landmarks. Sagittal and coronal planes were used in respect of the anatomical position.

RESULTS

The mean distance between the center of AB origin and the apex of medial epicondyle is as follows: 2.97 ± 2.21 mm anteriorly, 4.73 ± 1.60 mm inferiorly in the sagittal plane, and 4.23 ± 1.13 mm deep from the epicondyle in the coronal plane. Its dimension is 6.23 ± 1.02 mm in width and 45.97 ± 6.75 mm in length. The ligament's insertion triangular shape has its base located 28.44 ± 3.51 mm anterior from the posterior olecranon border, and 22.52 ± 2.49 mm superior from the inferior ulnar border. The tip located 50.79 ± 4.86 mm anterior from the posterior olecranon border and 17.64 ± 2.80 mm superior from the inferior ulnar border.

CONCLUSION

Apprehension of the precise geometries and distances of the ligament's footprint relative to key anatomical point is crucial. This stereographically comprehended data are useful for surgeon as reference points to obtain stability, motion, kinetic, and kinematic properties of the elbow.

LEVEL OF EVIDENCE

Level V evidence.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-022-00648-x.

The need to incorporate human variation and evolutionary theory in forensic anthropology: A call for reform

In 1992, Norm Sauer called for a language shift in which practitioners would move away from the socially loaded term "race" and replace it with the less provocative term "ancestry." While many heeded the call and moved towards ancestry in their research and reports, the actual approach to research and analysis did not change. In response to this change, there was a large growth in ancestry estimation method development in the early decade of the 2000s. However, the practice of ancestry estimation did not adequately incorporate evolutionary theory in interpretation or trait selection and continued with little critical reflection. In the past decade, there has been an increase in ancestry validation methods with little critique of the "race" concept or discussion of modern human variation or reference samples. To advance, forensic anthropologists need to reckon with the practice of ancestry estimation as it is currently practiced. We are calling for another reform in the axiom focusing on evolutionary theory, population history, trait selection, and population-level reference samples. The practice needs to abandon the terms ancestry and race completely and recalibrate to an analysis of population affinity. Population affinity is a statistical approach based on the underlying population structure that would allow the understanding of how microevolutionary forces act in concert with historical events (e.g., colonization, the Transatlantic Slave Trade, etc.) to shape modern human variation. This is not to be confused with geographic ancestry that all too often can be perceived as interchangeable with social race and as an affirmation of the biological concept of race. It is time to critically evaluate the social and scientific implications of the current practice of ancestry estimation, and re-frame our approach to studying and analyzing modern human variation through a population structure approach.

Ancestry Studies in Forensic Anthropology: Back on the Frontier of Racism

One of the parameters forensic anthropologists have traditionally estimated is ancestry, which is used in the United States as a proxy for social race. Its use is controversial because the biological race concept was debunked by scientists decades ago. However, many forensic anthropologists contend, in part, that because social race categories used by law enforcement can be predicted by cranial variation, ancestry remains a necessary parameter for estimation. Here, we use content analysis of the Journal of Forensic Sciences for the period 2009-2019 to demonstrate the use of various nomenclature and resultant confusion in ancestry estimation studies, and as a mechanism to discuss how forensic anthropologists have eschewed a human variation approach to studying human morphological differences in favor of a simplistic and debunked typological one. Further, we employ modern geometric morphometric and spatial analysis methods on craniofacial coordinate anatomical landmarks from several Latin American samples to test the validity of applying the antiquated tri-continental approach to ancestry (i.e., African, Asian, European). Our results indicate groups are not patterned by the ancestry trifecta. These findings illustrate the benefit and necessity of embracing studies that employ population structure models to better understand human variation and the historical factors that have influenced it.

Diversity aboard a Tudor warship: investigating the origins of the Mary Rose crew using multi-isotope analysis

The great Tudor warship, the Mary Rose, which sank tragically in the Solent in 1545 AD, presents a rare archaeological opportunity to research individuals for whom the precise timing and nature of death are known. A long-standing question surrounds the composition of the Tudor navy and whether the crew were largely British or had more diverse origins. This study takes a multi-isotope approach, combining strontium (⁸⁷Sr/⁸⁶Sr), oxygen (δ¹⁸O), sulfur (δ³⁴S), carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope analysis of dental samples to reconstruct the childhood diet and origins of eight of the Mary Rose crew. Forensic ancestry estimation was also employed on a subsample. Provenancing isotope data tentatively suggests as many as three of the crew may have originated from warmer, more southerly climates than Britain. Five have isotope values indicative of childhoods spent in western Britain, one of which had cranial morphology suggestive of African ancestry. The general trend of relatively high δ¹⁵N and low δ¹³C values suggests a broadly comparable diet to contemporaneous British and European communities. This multi-isotope approach and the nature of the archaeological context has allowed the reconstruction of the biographies of eight Tudor individuals to a higher resolution than is usually possible.

Evaluating population affinity estimates in forensic anthropology: Insights from the forensic anthropology database for assessing methods accuracy (FADAMA)

Using a sample of anonymized U.S. forensic anthropology cases (n = 251) from the FADAMA database, we assess the degree of concordance between decedents' social identifiers and anthropologists' continental-based classifications. We report high success rates (>90%) that generally support previous findings, yet we acknowledge the limitations of assessing "ancestry" accuracy based on resolved cases and draw attention to situations in which our methods fail. For example, forensic anthropologists achieve just 20% accuracy when classifying individuals as "other" or "mixed"-problematic categories that we argue should be rejected. Leveraging our findings, we ask: what are we really estimating when we perform a skeletal assessment of "ancestry" in the US context? We argue that the "ancestry estimates" historically and routinely produced in forensic anthropology instead give information on population affinity: a measure of how similar a given case is to one among several socially relevant groups of interest. Distancing forensic anthropology from genetics and other disciplines that estimate ancestry, the approach of population affinity assesses similarities to both social and biological groupings, potentially at a fine-grained level, attempting to account for the complex histories, shared biologies, and wide ranges of diversity that characterize our communities and our casework. Population affinity is a flexible and inclusive approach that more accurately describes current forensic anthropological analyses of human variation. Going forward, we must acknowledge and build on the contributions of previous scholars as we work together toward our shared goal of theoretically grounded analyses of human variation that accurately and equitably serve all casework decedents.

Use of craniometric data to facilitate migrant identifications at the United States/Mexico border

OBJECTIVES

Thousands of migrants have died along the United States/Mexico border and many remain unidentified. The purpose of this research is to test whether estimations of population affinity, derived from craniometric data, can facilitate identification of migrant remains and provide a geographic region of origin rather than the broad label Hispanic. The appropriateness of current forensic reference data will also be assessed.

METHODS

A case study combined with craniometric data from positively identified and unidentified migrants from the Pima County Office of the Medical Examiner (n = 489) in Arizona and operation identification (n = 201) in Texas were compared to skeletal data representing Guatemalan (n = 87) and Mexican (n = 65) Mayans. Biological distance and discriminant function analyses were used to assess overall population relationships and classificatory models for forensic anthropological application.

RESULTS

The majority of evidence indicates that estimations of population affinity can assist in the facilitation identification of migrant remains, even when a broad classification is used. Biological distances among the groups suggest that positively identified Guatemalan and Mexican migrants are similar to one another but differ from Guatemalan and Mexican Mayans.

CONCLUSIONS

Population affinity estimations can aid migrant identification, and current reference data used in forensic anthropological practice should be replaced with data from positive identifications. Estimates of geographic origin may be more useful than the broad generic term Hispanic for narrowing down the search for a missing person, but more data and research is needed to achieve this goal. Although, the utility of geographic origin estimates relies on transnational data centralization and sharing, which is not always the case.

Uncloaking a Lost Cause: Decolonizing ancestry estimation in the United States

Since the professionalization of US‐based forensic anthropology in the 1970s, ancestry estimation has been included as a standard part of the biological profile, because practitioners have assumed it necessary to achieve identifications in medicolegal contexts. Simultaneously, forensic anthropologists have not fully considered the racist context of the criminal justice system in the United States related to the treatment of Black, Indigenous, and People of Color; nor have we considered that ancestry estimation might actually hinder identification efforts because of entrenched racial biases. Despite ongoing criticisms from mainstream biological anthropology that ancestry estimation perpetuates race science, forensic anthropologists have continued the practice. Recent years have seen the prolific development of retooled typological approaches with 21st century statistical prowess to include methods for estimating ancestry from cranial morphoscopic traits, despite no evidence that these traits reflect microevolutionary processes or are suitable genetic proxies for population structure; and such approaches have failed to critically evaluate the societal consequences for perpetuating the biological race concept. Around the country, these methods are enculturated in every aspect of the discipline ranging from university classrooms, to the board‐certification examination marking the culmination of training, to standard operating procedures adopted by forensic anthropology laboratories. Here, we use critical race theory to interrogate the approaches utilized to estimate ancestry to include a critique of the continued use of morphoscopic traits, and we assert that the practice of ancestry estimation contributes to white supremacy. Based on the lack of scientific support that these traits reflect evolutionary history, and the inability to disentangle skeletal‐based ancestry estimates from supporting the biological validity of race, we urge all forensic anthropologists to abolish the practice of ancestry estimation.

Janus-faced race: Is race biological, social, or mythical?

As belief in the reality of race as a biological category among U.S. anthropologists has fallen, belief in the reality of race as a social category has risen in its place. The view that race simply does not exist-that it is a myth-is treated with suspicion. While racial classification is linked to many of the worst evils of recent history, it is now widely believed to be necessary to fight back against racism. In this article, I argue that race is indeed a biological fiction, but I critique the claim that race is socially real. I defend a form of anti-realist reconstructionism about race, which says that there are no races, only racialized groups-groups mistakenly believed to be races. I argue that this is the most attractive position about race from a metaphysical perspective, and that it is also the position most conductive to public understanding and social justice.

Language use in ancestry research and estimation

Recent discussions have revolved around the concept of ancestry and ancestry estimation; however, the associated terminology and its theoretical underpinnings have not been similarly examined. This research evaluates the concepts (e.g., race, ancestry, ethnicity) currently in use, examines if they are consistent with the groups employed to illustrate them (e.g., Black, European, Hispanic), and looks for patterns in language usage. Articles in the Anthropology, Odontology, and General sections of the Journal of Forensic Sciences between 2009 and 2019 were evaluated for ancestry-related language use. For each article, the concepts, examples, and bibliographic information were recorded, and the relationship between concept and example was examined. These data were cross-tabulated to evaluate relationships between the variables. Cramer's V was used to assess the strength of association of these relationships. In this sample, ancestry predominates, especially recently The concept used is significantly associated with all variables except publication date and authors' institution(s). Despite the prevalence of the ancestry concept, racially based terms for individual groups were common. The use of ancestry, over race, in forensic contexts has been suggested to be a primarily linguistic change; these results may support that assertion. Inconsistent language usage leads to a lack of clarity in meaning among researchers and misinterpretation of the data. It is critical to recognize that inconsistencies exist, but also to understand why they exist. These results underscore the long overdue need for the inclusion of diverse perspectives in forensic anthropology, especially in the current conversations surrounding ancestry and ancestry estimation.

Nose approximation among South African groups from cone-beam computed tomography (CBCT) using a new computer-assisted method based on automatic landmarking

Considering the high demand for the identification of unknown remains in South Africa, a need exists to establish reliable facial approximation techniques that will take into account sex and age and, most importantly, be useful within the South African context. This study aimed to provide accurate statistical models for predicting nasal soft-tissue shape from information about the underlying skull subtract among a South African sample. The database containing 200 cone-beam computer tomography (CBCT) scans (100 black South Africans and 100 white South Africans). The acquisition and extraction of the 3D relevant anatomical structures (hard- and soft-tissue) were performed by an automated three-dimensional (3D) method based on an automatic dense landmarking procedure using MeVisLab © v. 2.7.1 software. An evaluation of shape differences attributed to known factors (ancestry, sex, size, and age) was performed using geometric morphometric and statistical models of prediction were created using a Projection onto Latent Structures Regression (PLSR) algorithm. The accuracy of the estimated soft-tissue nose was evaluated in terms of metric deviations on training and un-trained datasets. Our findings demonstrated the influence of factors (sex, aging, and allometry) on the variability of the hard- and soft-tissue among two South African population groups. This research provides accurate statistical models optimized by including additional information such as ancestry, sex, and age. When using the landmark-to landmark distances, the prediction errors ranged between 1.769mm and 2.164mm for black South Africans at the tip of the nose and the alae, while they ranged from 2.068mm to 2.175mm for the white subsample. The prediction errors on un-trained data were slightly larger, ranging between 2.139mm and 2.833mm for the black South African sample at the tip of the nose and the alae and ranging from 2.575mm to 2.859mm for the white South African sample. This research demonstrates the utilization of an automated 3Dmethod based on an automatic landmarking method as a convenient prerequisite for providing a valid and reliable nose prediction model that meets population-specific standards for South Africans.

Craniometric variation and ancestry estimation in two contemporary Caribbean populations

Ancestry estimation of skeletonized remains by forensic anthropologists is conducted through comparative means, and a lack of population-specific data results in possible misclassifications. This is especially germane to individuals of Latin American ancestry. Generally, each country in Latin America can trace their ancestral lineage through three main parental groups: Indigenous, European, and African. However, grouping all Latin American individuals under the broad "Hispanic" category ignores the specific genetic contributions from each parental group, which is variable and dependent on the population histories and sociocultural dynamics of each country. This study analyzes the craniometric ancestry of Hispaniola (the Dominican Republic and Haiti) using 190 cranial Computed Tomography (CT) scans (f=103; m=87), along with the island's history, to explore similarities and differences between the two groups. MANOVA results indicate that 53.6% and 71.4% of the 28 cranial measurements differ between the ancestries and sexes, respectively; and intraobserver error analyses demonstrate that 85.7% of measurements from CT scans are good-excellent in reliability. Further, a total of 12 canonical discriminant function analyses produced cross-validated classification accuracies of 73.7-78.6% for females, 71.8-87.5% for males, and 72.0-77.8% for pooled sex. This study demonstrates that, despite sharing a small island, Dominican and Haitian individuals can be differentiated with a fair amount of statistical certainty, which is possible due to complex socio-cultural, -political, and -demographic factors that have produced and maintained genetic heterogeneity. Moreover, the discriminant functions provided here can be used by the international forensic science community to identify individuals living on Hispaniola.

Soylent Is People, and WEIRD Is White: Biological Anthropology, Whiteness, and the Limits of the WEIRD

WEIRD populations, or those categorized as Western, educated, industrialized, rich, and democratic, are sampled in the majority of quantitative human subjects research. Although this oversampling is criticized in some corners of social science research, it is not always clear what we are critiquing. In this article, we make three interventions into the WEIRD concept and its common usage. First, we seek to better operationalize the terms within WEIRD to avoid erasing people with varying identities who also live within WEIRD contexts. Second, we name whiteness as the factor that most strongly unites WEIRD research and researchers yet typically goes unacknowledged. We show how reflexivity is a tool that can help social scientists better understand the effects of whiteness within the scientific enterprise. Third, we look at the positionality of biological anthropology, as not cultural anthropology and not psychology, and how that offers both promise and pitfalls to the study of human variation. We offer other perspectives on what constitutes worthy and rigorous biological anthropology research that does not always prioritize replicability and statistical power, but rather emphasizes the full spectrum of the human experience. From here, we offer several ways forward to produce more inclusive human subjects research, particularly around existing methodologies such as grounded theory, Indigenous methodologies, and participatory action research, and call on biological anthropology to contribute to our understanding of whiteness.

Population Demography, Ancestry, and the Biological Concept of Race

For more than 50 years, biological anthropology has argued against the use of the biological race concept. Despite such efforts, aspects of the concept remain in circulation within society and within the discipline itself. As commonly articulated, anthropology's rejection of the biological race concept lacks an evolutionarily based explanatory grounding. Biological patterns of variation in living humans do not map onto commonly utilized categorizations of race, but this knowledge does not explain why human evolution has not produced such structures. This article attempts to offer one such explanation by constructing a biocultural framing of race around ancestry. By examining ancestry through two related lenses, genealogical and genetic, it is shown that the coherence of race as a biological concept has been disrupted by demographic changes in our recent evolutionary past. The biological construction of race is invalid not because it is impossible but because evolutionary forces have actively worked against such patterns in our evolutionary past.

The Fallacy of Equating the Hereditarian Hypothesis with Racism

There is a large amount of evidence that groups differ in average cognitive ability. The hereditarian hypothesis states that these differences are partly or substantially explained by genetics. Despite being a positive claim about the world, this hypothesis is frequently equated with racism, and scholars who defend it are frequently denounced as racists. Yet equating the hereditarian hypothesis with racism is a logical fallacy. The present article identifies ten common arguments for why the hereditarian hypothesis is racist and demonstrates that each one is fallacious. The article concludes that society will be better served if the hereditarian hypothesis is treated the same way as any other scientific claim—critically, but dispassionately.

Morphometric analysis of the humerus in an adult South African cadaveric sample

Recent studies using geometric morphometrics have shown that estimations of demographic parameters can be made using skeletal elements previously not thought useful for such purposes. This study used geometric morphometrics to assess humeral morphological variation in an adult South African sample, and evaluated the accuracy of sex and ancestry estimations based on this variation. Humeri of 1046 adult South African individuals (464 females, 582 males) were digitized. Data sets were rotated and scaled to a common centroid using Generalized Procrustes Analysis. Mean centroid sizes between groups were compared using parametric tests, while morphological variation was evaluated using multivariate analyses. Discriminant Function Analysis coupled with leave-one-out cross-validation tests were used to assess the reliability of sex and ancestry classifications based on this variation. Male humeri were relatively larger and presented with morphological features indicative of larger muscle mass and smaller carrying angles than females. White individuals had relatively larger but morphologically less robust humeri than Black or Coloured individuals, likely a reflection of both genetic and socio-economic differences between the groups as enforced under Apartheid law. When sex and ancestry were assessed together, similar variations were detected than when either parameter was individually assessed. Classification accuracy was relatively low when sex was independently assessed (73.3%), but increased when considered in conjunction with ancestry, indicating greater variation between-groups (ancestry) than within-groups. Ancestry estimation accuracies exceeded 80%, even for the highly diverse Coloured group. Classification accuracies of sex-ancestry groups all exceeded 76%. These results show that humerus morphological variation is present and may be used to estimate parameters, such as sex and ancestry, even in complex groups such as the Coloured sample of this study.

Skeletal dimensions as predictors for the shape of the nose in a South African sample: A cone-beam computed tomography (CBCT) study

The profile of the nose is an important feature for facial approximations. Although several manual and semi-automated prediction guidelines exist for estimating the shape of the nose, the reliability and applicability of these methods to South Africans groups are unknown. The aim of this study was to predict the displacements of capulometric landmarks from hard-tissue planes to facilitate nasal soft-tissue reconstruction in a South African sample. Cone beam computed tomography (CBCT) scans of 120 adult South Africans were selected from the Oral and Dental Hospital, University of Pretoria, South Africa. Measurements involving craniometric and capulometric landmarks of the nose were obtained as plane-to-plane distances. Correlation coefficients between hard- and soft-tissue measurements were determined, and regression equations computed to assist in the prediction of the most probable shape and size of the nose. All hard- and soft-tissue measurements appeared significantly different between groups, except for the distance between the pronasale and nasion in the transverse plane and for the distance between the alare and the nasion in the coronal plane. The nasal height, nasal bone length and the nasal bone projection were significant predictors of the pronasale, subnasale and alare positions. More precisely, the nasal height and the nasal bone length were significant predictors of the pronasale position in both groups. Nasal bone projection was only useful for predicting shape in white South Africans. The variation in the skeletal predictors of the external shape of the nose noted between black and white South Africans and the results of the cross-validation testing emphasize the need for population specific guidelines.

Cranial secular change from the nineteenth to the twentieth century in modern German individuals compared to modern Euro-American individuals

Studying secular changes on human skulls is a central issue in anthropological research, which is however insufficiently investigated for modern German populations. With our study, we focus on morphological cranial variations within Germans during the nineteenth and twentieth centuries. To study this, we recorded different facial landmarks from a cohort study of about 540 German individuals of different age and sex by calculating their cranial size, shape dimensions, and cranial module and cranial capacity to get information about variations occurring during the decades. According to this, measured variables for Germans and Americans, to which we compared our results, were maximum cranial length (glabello-occipital length), basion-bregma height (BBH), basion-nasion length (BNL), maximum cranial breadth (XCB), and cranial base breadth (AUB). Cranial size was calculated as the geometric mean of GOL, BBH, and XCB. Samples were organized into quarter century birth cohorts, with birth years ranging from 1800 to 1950. One-way ANOVA was used to test for variation among cohorts. Over the past 150 years, Americans and Germans showed significant parallel changes, but the American cranium remained relatively higher, with a longer cranial base, as well as narrower than the German cranium. Our results should also lead to the extension of the range of populations listed and investigated for Fordisc®, a forensic software to identify unknown individuals as from their skeletal remains or just parts of them. Fordisc cannot provide a satisfying identification of European individuals yet because the database is missing enough European reference samples.

A Qualitative Analysis of How Anthropologists Interpret the Race Construct

This article assesses anthropological thinking about the race concept and its applications. Drawn from a broader national survey of geneticists' and anthropologists' views on race, in this analysis, we provide a qualitative account of anthropologists' perspectives. We delve deeper than simply asserting that "race is a social construct." Instead, we explore the differential ways in which anthropologists describe and interpret how race is constructed. Utilizing the heuristic of constructors, shifters, and reconcilers, we also illustrate the ways in which anthropologists conceptualize their interpretations of race along a broad spectrum as well as what these differential approaches reveal about the ideological and biological consequences of socially defined races, such as racism in general and racialized health disparities in particular. [race concept, social construction, racism, health disparities].

The vanishing Black Indian: Revisiting craniometry and historic collections

OBJECTIVES

This article uses craniometric allocation as a platform for discussing the legacy of Samuel G. Morton's collection of crania, the process of racialization, and the value of contextualized biohistoric research perspectives in biological anthropology.

MATERIALS AND METHODS

Standard craniometric measurements were recorded for seven Seminoles in the Samuel G. Morton Crania Collection and 10 European soldiers from the Fort St. Marks Military Cemetery; all individuals were men and died in Florida during the 19th century. Fordisc 3.1 was used to assess craniometric affinity with respect to three samples: the Forensic Data Bank, Howells data set, and an archival sample that best fits the target populations collected from 19th century Florida. Discriminant function analyses were used to evaluate how allocations change across the three comparative databases, which roughly reflect a temporal sequence.

RESULTS

Most Seminoles allocated as Native American, while most soldiers allocated as Euro-American. Allocation of Seminole crania, however, was unstable across analysis runs with more individuals identifying as African Americans when compared to the Howells and Forensic Data Bank. To the contrary, most of the soldiers produced consistent allocations across analyses. Repeatability for the St. Marks sample was lower when using the archival sample database, contrary to expectations. For the Seminole crania, Cohen's κ indicates significantly lower repeatability. A possible Black Seminole individual was identified in the Morton Collection.

DISCUSSION

Recent articles discussing the merits and weaknesses of comparative craniometry focus on methodological issues. In our biohistoric approach, we use the patterning of craniometric allocations across databases as a platform for discussing social race and its development during the 19th century, a process known as racialization. Here we propose that differences in repeatability for the Seminoles and Euro-American soldiers reflect this process and transformation of racialized identities during 19th century U.S. nation-building. In particular, notions of whiteness were and remain tightly controlled, while other racial categorizations were affected by legal, social, and political contexts that resulted in hybridity in lieu of boundedness.

No association between latent toxoplasmosis and multiple body measures in U.S. adults

Toxoplasma gondii (Nicolle et Manceaux, 1908) is an intracellular parasite that can cause ongoing latent infection persisting for the duration of a non-definitive host's life. Affecting approximately one-third of the world's population, latent toxoplasmosis has been associated with neuropsychological outcomes and a previous report suggested an association between latent toxoplasmosis and adult height. Given the large number of people with latent toxoplasmosis and its potential associations with human height, we sought to better understand the association between latent toxoplasmosis and human morphology by evaluating seropositivity for T. gondii and multiple body measures reported in the National Health and Nutrition Examination Survey III (NHANES III) and in the more recent continuous NHANES data sets from the United States Centers for Disease Control and Prevention for which data on T. gondii are available. In these analyses, latent toxoplasmosis was not associated with any of the body measures assessed in the NHANES datasets even after taking into account interactions between latent toxoplasmosis and testosterone suggesting that in these samples, latent toxoplasmosis is not associated with adult morphology including height.