Sex estimation from the long bones of modern South Africans

Abstract

Best scientific practice for sex estimation incorporates accurate techniques that employ appropriate standards and population- and period-specific data. Single measurements provide accurate sex estimations, but multiple measurements and multivariate techniques offer greater validity to biological profile assessments. Appropriate, modern standards for sex estimation are limited to the cranium in South Africans (SA), which warrants the examination of the potential for sex estimation using the postcrania of socially defined SA blacks, whites and coloureds through multivariate models and advanced statistical techniques. A total of 39 standard osteometric measurements were taken from the postcrania of 360 socially defined SA blacks, whites and coloureds (equal sex and ancestry). Univariate and multivariate models were evaluated. Multivariate models, with cross-validation and equal priors, were explored with linear and flexible discriminant analysis (LDA and FDA, respectively). Classification accuracies associated with univariate models ranged from 56 to 89%, whereas multivariate classification accuracies using bone models (i.e. all measurements from one element) ranged from 75 to 91%. The highest correct classifications were achieved with multivariate subsets (i.e. combinations of measurements from different bones) and ranged from 90 to 98%. Overall, FDA and LDA yielded similar accuracy rates. Postcranial bones achieve comparable classification accuracies to the pelvis and higher accuracies than metric or morphological techniques using the cranium. While LDA is the most commonly used classification statistic in biological anthropology, FDA provides a good alternative for classification.

Subadult sex estimation from diaphyseal dimensions

“…Specifically, employing FDA or logistic regression with a large number of predictor variables (i.e., multiple variable subsets), an anthropologist can estimate sex from the long bones, or a combination of, for individuals between birth and 12 years up to 93% bootstrapped accuracy. The bootstrapped accuracies of the multiple variable subsets are comparable to results using morphological indicators of the pelvis and metric variables of the postcrania for adults (Klales, Ousley, & Vollner, ; Krüger, L'abbe, & Stull, ; Spradley & Jantz, ).…”

“…Proximal and distal breadth measurements (i.e., FDB, TPB, HDB, HPB and TDB) were consistently recognized as important measurements in model creation. Similar measurements produce the highest classification accuracies in adult sex estimation (Krüger et al, ; Spradley & Jantz, ). While previous research did not find any significant differences in midshaft cross‐sectional area of prepubertal boys and girls matched for age, height, and weight, midshaft breadths were still retained in model creation, even though their overall contribution to models is generally lower than the distal or proximal breadths (Gilsanz et al, ; Nieves et al, ; Schoenau, Neu, Beck, Manz, & Rauch, ).…”

Estimation of sex from metatarsals using discriminant function and logistic regression analyses

“…In addition, several studies have shown the usefulness of intact long bones of upper and lower limbs 13,[30][31][32][33][34][35][36][37][38][39][40] for sex prediction in different parts of the world. In South Africa, local osteometric standards for sex estimation from skeletons have also been formulated from measurements of the skull [41][42][43] , long bones of the limbs [44][45][46][47][48][49][50][51][52] , sternum 53 , pelvis 54 and patella 55,56 . Similarly, measurements from the largest bones of the foot such as the talus 57,58 and calcaneus 59,60 have also been used for sex estimation.…”

Sex estimation of os coxae using DSP2 software: A validation study of a Greek sample

“…Forensic Anthropology methods for estimating the biological profile of unidentified remains are increasing during the last decades focusing on different anatomical elements, different populations and various statistical procedures which are heavily scrutinised to fulfil the expectations of the court. Amongst the basic biological features sex is the most studied with several methods marking high accuracies [1][2][3]. Scholars agree that most osteometric methods are population specific [4][5][6] with the exception of the pelvis [1,7].…”