A history of forensic anthropology

Forensic anthropology represents a dynamic and rapidly evolving complex discipline within anthropology and forensic science. Academic roots extend back to early European anatomists but development coalesced in the Americas through high-profile court testimony, assemblage of documented collections and focused research. Formation of the anthropology section of the American Academy of Forensic Sciences in 1972, the American Board of Forensic Anthropology in 1977/1978 and other organizational advances provided important stimuli for progress. While early pioneers concentrated on analysis of skeletonized human remains, applications today have expanded to include complex methods of search and recovery, the biomechanics of trauma interpretation, isotopic analysis related to diet and region of origin, age estimation of the living and issues related to humanitarian and human rights investigations.     

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.     

Statistical inference for stochastic simulation models--theory and application

Statistical models are the traditional choice to test scientific theories when observations, processes or boundary conditions are subject to stochasticity. Many important systems in ecology and biology, however, are difficult to capture with statistical models. Stochastic simulation models offer an alternative, but they were hitherto associated with a major disadvantage: their likelihood functions can usually not be calculated explicitly, and thus it is difficult to couple them to well-established statistical theory such as maximum likelihood and Bayesian statistics. A number of new methods, among them Approximate Bayesian Computing and Pattern-Oriented Modelling, bypass this limitation. These methods share three main principles: aggregation of simulated and observed data via summary statistics, likelihood approximation based on the summary statistics, and efficient sampling. We discuss principles as well as advantages and caveats of these methods, and demonstrate their potential for integrating stochastic simulation models into a unified framework for statistical modelling.     

Ontogeny of the spheno‐occipital synchondrosis in a modern Queensland,Australian population using computed tomography

Due to disparity regarding the age at which skeletal maturation of the spheno‐occipital synchondrosis occurs in forensic and biological literature, this study provides recalibrated multislice computed tomography (MSCT) age standards for the Australian (Queensland) population, using a Bayesian statistical approach. The sample comprises retrospective cranial/cervical MSCT scans obtained from 448 males and 416 females aged birth to 20 years from the Skeletal Biology and Forensic Anthropology Research Osteological Database. Fusion status of the synchondrosis was scored using a modified six‐stage scoring tier on an MSCT platform, with negligible observer error (κ = 0.911 ± 0.04, intraclass correlation coefficient = 0.994). Bayesian transition analysis indicates that females are most likely to transition to complete fusion at 13.1 years and males at 15.6 years. Posterior densities were derived for each morphological stage, with complete fusion of the synchondrosis attained in all Queensland males over 16.3 years of age and females aged 13.8 years and older. The results demonstrate significant sexual dimorphism in synchondrosis fusion and are suggestive of intrapopulation variation between major geographic regions in Australia. This study contributes to the growing repository of contemporary anthropological standards calibrated for the Queensland milieu to improve the efficacy of the coronial process for medicolegal death investigation. As a stand‐alone age indicator, the basicranial synchondrosis may be consulted as an exclusion criterion when determining the age of majority that constitutes 17 years in Queensland forensic practice. Am J Phys Anthropol 157:42–57, 2015. © 2014 Wiley Periodicals, Inc.     

Statistical power in physical anthropology: a technical report

A statistical power analysis of The American Journal of Physical Anthropology (Volume 44, 1976) was conducted. Twenty-five articles, which included 3,304 major significance tests, constituted the final sample. Resultant power estimates of 0.38, 0.62, and 0.81, corresponding to small, medium, and large population effects respectively, were obtained. Although the medium effect size estimate falls short of the recommended 0.80 level, the statistical power of physical anthropological research fares well relative to several of the social scientific fields of inquiry.     

A sensory approach for multispecies anthropology

This special issue suggests that the need to examine the entangled lives of species, selves and other beings through a multisensory perspective is crucial and timely. Developing on a sensory analysis, one that emerges through what Anna Tsing refers to as the ‘arts of noticing’ (2015), this introductory paper explores how both nonhuman and human lives are intertwined, and how their close examination can guide anthropologists in their ability to capture the subtleties of more‐than‐human engagement, connection and relatedness. Through articles within this issue from Australian anthropology and beyond, we ask how becoming‐with more‐than‐humans helps us to construct a post‐humanist analysis in the combination of sensory anthropology and multispecies anthropology. Through a combination of these two fields, the paper suggests, anthropology can take up the opportunity to think about animals as subjects, through our ability to communicate beyond language and to engage in a more meaningful way through interspecies knowledge‐making.     

Biomechanics in anthropology

Biomechanics is the set of tools that explain organismal movement and mechanical behavior and links the organism to the physicality of the world. As such, biomechanics can relate behaviors and culture to the physicality of the organism. Scale is critical to biomechanical analyses, as the constitutive equations that matter differ depending on the scale of the question. Within anthropology, biomechanics has had a wide range of applications, from understanding how we and other primates evolved to understanding the effects of technologies, such as the atlatl, and the relationship between identity, society, culture, and medical interventions, such as prosthetics. Like any other model, there is great utility in biomechanical models, but models should be used primarily for hypothesis testing and not data generation except in the rare case where models can be robustly validated. The application of biomechanics within anthropology has been extensive, and holds great potential for the future.     

DNA evidence: Wrong answers or wrong questions?

Much of the controversy over DNA evidence is due to the way in which forensic scientific evidence has classically been presented. The orthodox approach is to consider whether two samples match according to a predetermined criterion. If they do, the fact of match is reported along with an estimate of the frequency of the characteristics. This method fails to address the questions raised in court cases, diverts argument into irrelevancies and stultifies research. Presentation of evidence in the form of likelihood ratios, on the other hand, forces the witness to answer the questions the court is interested in and makes apparent lines of research required to increase our understanding.Editor's commentsThe authors reiterate the crucial role of likelihood ratios in presenting forensic evidence, and so continue the crusade mounted by Evett, Buckleton and others.     

Estimating the length of incomplete long bones: forensic standards from Guatemala

We report on new standards for estimating long bone length from incomplete bones for use in forensic and archaeological contexts in Central America. The measurements we use closely follow those defined by Steele ([1970] Personal Identification in Mass Disasters; Washington, DC: Smithsonian Institution), but we add several new landmarks. We measured the femur, humerus, tibia, and fibula of 100 Maya skeletons (68 males, 32 females) recovered from forensic exhumations. We derived the equations by regressing bone segment length on bone length, and solved for bone length to maximize the utility of the equations for taller populations. We generated equations for all segments that were significantly correlated with bone length for males, for females, and for both sexes combined, but accepted only regressions with r(2) > 0.85 as reliable. Landmarks defined by muscle attachment sites were more variable in location than landmarks on articular architecture; thus we retained few equations that use these landmarks. We tested the male and combined sex equations on 36 males of unknown ethnicity exhumed from a military base in Guatemala, and found that the equations performed satisfactorily. We also evaluated the performance of equations by Steele ([1970] Personal Identification in Mass Disasters; Washington, DC: Smithsonian Institution) and Jacobs ([1992] Am J Phys Anthropol 89:333-345) on the Maya bones, and conclude that significant population variation in long bone proportions hinders their application in Central America.     

Understanding racism in physical (biological) anthropology

The mainstream of American physical anthropology began as racist and eugenical science that defended slavery, restricted “non-Nordic” immigration, and justified Jim Crow segregation. After World War II, the field became more anti-racial than anti-racist. It has continued as a study of natural influences on human variation and thus continues to evade the social histories of inequitable biological variation. Also reflecting its occupancy of white space, biological anthropology continues to deny its own racist history and marginalizes the contributions of Blacks. Critical disciplinary history and a shift toward biocultural studies might begin an anti-racist human biology.     

Classification systems for discrete variables used in forensic anthropology

In recent years a number of papers have been presented on the usefulness of non-metric traits of the cranial and infracranial skeleton in order that one, some few, or a subsample of crania may be allocated to a pair, family, or larger group. These papers have explored (1) which traits should be used, (2) the theoretical implications of assignment, and (3) the methodology for making these assignments. This paper addresses itself to the theoretical implications of assignment and the methodology for making these assignments. Classification techniques based on the Bayes' theorem, weight of evidence procedures, linear discriminant functions, tally method and the Rubison procedure, were utilized in the first level of analysis. The result suggests that methodologies used must contain an accommodation for correlation between bilateral traits and that pairwise classification procedures are often more applicable than multiple classification procedures considering a large number of groups. The accuracy of various methods starts at slightly better than 50%, while the better methods produce results above the 90% level. Results further show that when acceptable assignments are made the theoretical implications of these assignments do not necessarily suggest the use of a particular methodology, and for ease of analysis the simplest methodology should be used.     

Evaluation of the suchey–brooks method of age estimation in an Australian subpopulation using computed tomography of the pubic symphyseal surface

Despite the prominent use of the Suchey–Brooks (S–B) method of age estimation in forensic anthropological practice, it is subject to intrinsic limitations, with reports of differential interpopulation error rates between geographical locations. This study assessed the accuracy of the S–B method to a contemporary adult population in Queensland, Australia and provides robust age parameters calibrated for our population. Three‐dimensional surface reconstructions were generated from computed tomography scans of the pubic symphysis of male and female Caucasian individuals aged 15–70 years (n = 195) in Amira® and Rapidform®. Error was analyzed on the basis of bias, inaccuracy and percentage correct classification for left and right symphyseal surfaces. Application of transition analysis and Chi‐square statistics demonstrated 63.9 and 69.7% correct age classification associated with the left symphyseal surface of Australian males and females, respectively, using the S–B method. Using Bayesian statistics, probability density distributions for each S–B phase were calculated, providing refined age parameters for our population. Mean inaccuracies of 6.77 (±2.76) and 8.28 (±4.41) years were reported for the left surfaces of males and females, respectively; with positive biases for younger individuals (<55 years) and negative biases in older individuals. Significant sexual dimorphism in the application of the S–B method was observed; and asymmetry in phase classification of the pubic symphysis was a frequent phenomenon. These results recommend that the S–B method should be applied with caution in medico‐legal death investigations of Queensland skeletal remains and warrant further investigation of reliable age estimation techniques. Am J Phys Anthropol, 2013. © 2013 Wiley Periodicals, Inc.     

Statistical Issues in Ecological Risk Assessment

Ecological risk assessment (ERA) is concerned with making decisions about the natural environment under uncertainty. Statistical methodology provides a natural framework for risk characterization and manipulation with many quantitative ERAs relying heavily on Neyman-Pearson hypothesis testing and other frequentist modes of inference. Bayesian statistical methods are becoming increasingly popular in ERA as they are seen to provide legitimate ways of incorporating subjective belief or expert opinion in the form of prior probability distributions. This article explores some of the concepts, strengths and weaknesses, and difficulties associated with both paradigms. The main points are illustrated with an example of setting a risk-based “trigger” level for uranium concentrations in the Magela Creek catchment of the Northern Territory of Australia.     

Good anthropology in dark times: Critical appraisal and ethnographic application

‘Dark Anthropology’ and its complementary ‘Anthropology of the Good’ have become influential and debated notions in anthropology in recent years. I here parse distinctive features of these emphases, address their relation to theory and to ethnography, and consider the stakes involved in concretely applying their conceptual designations. I discuss the general shift in anthropology from grand theory to key concept, and the topical delimitation of theory that results. In larger purview, Dark Anthropology and the Anthropology of the Good both have long theoretical genealogies as well as practical contexts of political and social understanding, including vis‐à‐vis recent events in the U.S. and elsewhere. I suggest that considering the relationship between politico‐economically structured inequality and attempts to assert positive meaning and purpose is the most productive way to ethnographically apply their alternative conceptualisations. This brings to greater focus the thorny question of whose understanding of inequality or suffering, or of moral value and positive wellbeing, is being articulated—the sentiments of the people studied, or the concepts of the analyst? It seems vital to examine both analytic and indigenous views of dark times, and of the good, to refine our understanding of both, that is, in order to consider our complementary conceptualisations in relation to both sides of the emic/etic coin. This refines our understanding of local sensibilities and also of the appropriate limit points of our own conceptual associations.