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.

Secular change in morphological cranial and mandibular trait frequencies in European Americans born 1824-1987.

OBJECTIVES: Secular change in cranial and postcranial morphometrics and morphological traits has been documented in several studies. However, to date, few studies have addressed temporal changes occurring in the expression of cranial morphological traits commonly used in ancestry estimation. This study examines secular change in the expression of 23 cranial and mandibular morphological traits; accounting for age-at-death, sex, and year-of-birth. MATERIALS & METHODS: Data were collected on 23 morphological cranial and mandibular traits for European American individuals (19-97 years of age) from the Hamann-Todd Skeletal Collection (n = 518) and the William M. Bass Donated Skeletal Collection (n = 602). Individuals were divided into six birth-year cohorts: 1824-1849 (Cohort 1), 1850-1874 (Cohort 2), 1875-1899 (Cohort 3), 1900-1924 (Cohort 4), 1925-1949 (Cohort 5), and 1950-1987 (Cohort 6). RESULTS: Statistical analyses, including Pearson's chi-square, correspondence analysis, and ordinal regression, demonstrate that secular changes have occurred in 11 traits, including: anterior nasal spine (ANS); malar tubercle (MT); nasal bone contour (NBC); postbregmatic depression (PBD); supranasal suture (SPS); transverse palatine suture (TPS); zygomaticomaxillary suture (ZS); ascending ramus shape (ARS); gonial angle flare (GAF); mandibular tori (MDT); and posterior ramus edge inversion (PREI), with changes occurring in both sexes for ANS, MT, TPS, ZS, GAF, MDT, and PREI. Significant changes in trait expression were found predominately between Cohorts 3 and 4, and Cohorts 4 and 5. While the sex of an individual affected the expression of ANS, MT, NBC, PBD, SPS, ZS, ARS, GAF, and PREI, age-at-death only affected MT and PREI. DISCUSSION: This study demonstrates that secular change in morphological cranial and mandibular traits has occurred over the last two centuries in European Americans, with the most considerable change appearing at the turn of the twentieth century. Changes in morphological trait expression over a relatively short period of time correspond with changes seen in craniometric analyses and correlate with the industrialization of society and environmental and cultural changes, such as medical advancements, nutrition, and population health/stress.

Beyond the report: Prospects and challenges in forensic anthropological investigations of structural vulnerability.

Forensic anthropologists are increasingly interested in accounting for embodied marginalization in addition to the biological profile. A structural vulnerability framework, which assesses biomarkers of social marginalization in individuals within forensic casework, is worthwhile but its application must be informed by ethical, interdisciplinary perspectives that reject categorizing suffering within the pages of a case report. Drawing from anthropological perspectives, we explore prospects and challenges of evaluating embodied experience in forensic work. Particular attention is paid to how forensic practitioners and stakeholders utilize a structural vulnerability profile within and beyond the written report. We argue that any investigation of forensic vulnerability must: (1) integrate rich contextual data, (2) be evaluated for potential to perpetuate harm, and (3) serve the needs of a diverse array of stakeholders. We call for a community-oriented forensic practice, wherein anthropologists may act as advocates for policy change to disrupt power structures driving vulnerability trends in their region.

Assessment of carbon, oxygen, strontium, and lead isotopic variation in modern Colombian teeth: An application to human identification.

Colombia faces the complex humanitarian challenges of locating approximately 100,000 missing persons and identifying thousands who are deceased. Identification is a difficult task in many cases, because the skeletonized bodies are deteriorated, missing person data are unavailable for comparison, and the provenance of the remains is often totally unknown. Isotopic analysis of human tissues (e.g., bone, hair, nails, and teeth) aid in the identification process of unknown individuals because they can provide valuable information on possible geographic origin. This project evaluated the isotopic variability of carbon (C), oxygen (O), strontium (Sr), and lead (Pb) in modern Colombian teeth according to city, department (a political designation similar to "state" in the US or Mexico), and one of four geographically determined regions of origin; and assessed its utility for human identification in Colombia. Isotopic data (O-C-Sr-Pb) were analyzed from modern Colombians originating from the cities of Bogotá, Cali, and Neiva (n = 95); and these data were compiled with published Colombian data of individuals mainly from the city of Medellín (n = 61). Results indicate a wide range and overlap of O-C-Sr-Pb isotopic distribution according to the defined categories. However, differences between coastal and lowland individuals are observed when using δ18 O values, and differences between mountainous regions are observed when using 87 Sr/86 Sr values. In addition, this study suggests that the usefulness of isotopic analysis for unidentified individuals in Colombia would be with assigning them geographically using the designations of North, Central Andes, Eastern Andes, or Southwest Andes versus making classifications at a city or department level.

Recommended Practices for Macerating Human Thyroid Cartilage.

Visible abnormalities on the thyroid cartilage may be indicative of perimortem trauma including fractures or sharp force trauma. During autopsy, the thyroid cartilage must be freed of surrounding soft tissue before these abnormalities can be clearly observed. Several processing methods were first experimentally tested on pig ears to narrow down which might work best to process human thyroid cartilage. Several methods in the categories of hot water maceration, chemical/enzyme maceration, and dermestid beetles were then tested on a sample of 37 human thyroid cartilages. An adapted 22-point scoring system was used to score the efficacy of each processing method. Chemical maceration using bleach was found to be the best method for removing surrounding tissue from thyroid cartilage, with Arm & HammerTM powdered laundry detergent as a close second. These methods are inexpensive, quick, and easy to implement, making them a simple addition to busy medical examiner's offices or forensic anthropology laboratories.

Recommendations for Maintaining a Dermestid Beetle Colony (Dermestes maculatus) for Processing Human Remains.

Dermestid beetles (Dermestes maculatus De Geer 1774) are small carrion insects characterized by a rounded or oval-shaped body and white abdomen with black markings. Given their natural propensity to consume soft tissue throughout various stages of decomposition, biological anthropologists have sought to use dermestids as a forensic processing method in addition to traditional chemical tissue removal techniques. Although useful, most of the existing academic literature regarding the upkeep of dermestid colonies for skeletal remains processing either lack specificity or are outdated. Additionally, nonacademic sources that contain information regarding dermestid maintenance are often disjointed, resulting in a difficulty to replicate habitat construction and ideal environmental conditions. Therefore, this technical note presents recommendations for anthropologists interested in establishing and maintaining a D. maculatus population. These recommendations are based on our experiences using several dermestid colonies to process five unembalmed human heads, procured from an anatomical gift company for a larger study on gunshot trauma. Aspects of the dermestids' environment that are crucial for the management of a healthy colony include the type of bedding, food, water, and containment method used, in addition to maintaining appropriate temperature ranges (24-27°C) and humidity levels (35-73%). Although habitat construction and dermestid maintenance involve materials that are relatively inexpensive and readily available, setting up and maintaining a D. maculatus colony can be laborious and time consuming and should only be undertaken when the volume of casework is such that this investment would be offset.

A new method for estimating age-at-death from the first rib.

A new method for estimating adult age-at-death from the first rib was developed as a modification of the Kunos et al. (Am J Phys Anthropol 110 (1999) 303-323) method. Data were collected on three aspects of the first rib (costal face, rib head, and tubercle facet) for 470 known-age males of Balkan ancestry collected as evidence during investigations conducted by the International Criminal Tribunal for the former Yugoslavia (ICTY). Ages-at-death range from 12 to 90 years (mean of 47.7 years). Several variables were extracted from the original study utilizing all three skeletal aspects of the first rib. This list was modified to 11 variables as preliminary tests on seriations of the samples were undertaken. A cumulative probit model with age measured on a log scale was used to calculate the mean and standard deviation of the ages-of-transition for each component. Multivariate analysis of the three components was also performed. The lowest correlation (r = 0.079, controlling for age) was between the geometric shape of the costal face and the surface texture of the tubercle facet. Assuming a correlation of zero, these two traits were used to calculate the highest posterior density regions for estimating individual ages-at-death. Age-at-death estimates generated from 50 and 95% posterior density regions indicate that this method captures age-related change reaching the ninth decade. The Bayesian statistical approach used here produced a valuable and promising new method for estimating age-at-death. Additional research is necessary to determine if these highest posterior density regions produce results highly correlated with age in other samples and its applicability to females.

Assessing the efficacy of isotopic provenancing of human remains in Colombia.

We report isotopic ratios for δ18O and 87Sr/86Sr from 71 individual human permanent teeth, obtained from 61 individuals with known regions of origins from eight of the 32 departments in Colombia. This survey of the applicability of isotopic provenancing is a vital addition to the ongoing identification efforts within Colombia concerning unidentified decedents recovered from clandestine and cemetery burials. At this time, only median isotopic values are reported due to heterogeneity of inter- and intra-departmental variance among the obtained isotopic values. The use of department of origin as a regional assignment schema is inadequate to effectively georeference unidentified human remains, given the wide-ranging topography and climatic diversity within Colombia. Therefore, a critical need for additional isotopic sampling of individual reference material exists, in order to improve the accuracy of potential region of origin estimates of unknown decedents originating from forensic contexts within Colombia.

Metric sex estimation from the postcranial skeleton for the Colombian population.

This research explores the best univariate and multivariate indicators for sex estimation using 51 standard osteometric measurements of all six major postcranial long bones, bones of the shoulder girdle, pelvic girdle, and the calcaneus from a modern, Colombian skeletal collection. The hypotheses being tested are (1) that postcrania will yield accurate sex classification rates and (2) the shoulder girdle will demonstrate the highest discrimination, based on results from previous research. The sample consists of 134 individuals (50 females, 84 males) between the ages of 19 and 93 with a mean age of 47 years. The sample is from the Colombian Skeletal Collection, consisting of skeletons from cemeteries in Bogotá, with recent years of death. The methods include univariate and multivariate discriminant function analysis (DFA). The results for this sample indicate the same general pattern of univariate classification effectiveness as found in research on North Americans; however, here the humerus performs better than the distal femur and proximal tibia as demonstrated in some North American samples. The cross-validated percent correct univariate classification for the postcranial elements ranges from 64.8% to 86.1% (p<0.05). The highest univariate classification rates were for the scapular height (86.1%) and the humeral head diameter (86.0%). The highest multivariate classification rates are with the scapula (93.5%), os coxa (92.0%), clavicle (89.9%), humerus (89.1%), and ulna (89.1%). This study provides sectioning points to easily estimate sex using Colombian population-specific formulae. This research aids in forensic individuation, as the long bones of the postcranial elements are relatively resistant to taphonomic processes. Furthermore, the ability to achieve such a high degree of success from a single bone is preferable for the fast-paced forensic anthropology laboratories in Colombia that process hundreds to thousands of cases each year. This research plays an important role in the development of population standards in Colombia and South America and provides a robust method that can withstand courtroom scrutiny.

The use of orthopedic surgical devices for forensic identification.

Surgically implanted devices have become increasingly common in modern skeletal material. Therefore, having the knowledge of the variety of implanted orthopedic devices, their manufacturer, and where to find and how to use identifying numbers in such implants can assist in the identification process when traditional methods are not applicable. Orthopedic device manufacturers are required by the Safe Medical Devices Act of 1990 and the FDA Modernization Act of 1997 to track permanently implanted devices. Manufacturer information on orthopedic devices associates the orthopedic surgeon who implanted the device with the patient. By providing a current list of the most common orthopedic device manufacturers in the U.S.A. and the associated contact information, investigators will have updated tools for the individuation process. Despite numerous complicating factors regarding how device data are tracked, the information presented here can assist forensic professionals with obtaining presumptive and/or positive identifications.