Determining ancestry from morphoscopic traits of the skull: inclusion of an Asian population
Emily Niespodziewanski*, MA and Joseph T. Hefner, PhD. Michigan State University Council of Graduate Students Sixth Annual Graduate Academic Conference 2014.
Ancestry can be assessed visually using the skull. Traditionally, this method compared features of the skull against “ideal” or extreme trait lists (e.g., Rhine 1990). However, Hefner (2009) has pushed for an emphasis on statistical analysis using defined character states and has had success in a two-group analysis differentiating between American Blacks and American Whites. The present study predicted that statistical analysis of categorical data could successfully determine ancestry among three groups: American Blacks, American Whites, and Thais. Data was collected from 95 male and 99 female skulls from the Khon Kaen University (Thailand) skeletal collection and added to the existing dataset.
Preliminary results support the hypothesis that ancestry can be successfully predicted from morphoscopic traits of the skull. Discriminant function analysis using ten variables produced an overall classification rate of 76.7% (cross-validated). This study contributes to ongoing research to improve ancestry classification based on cranial morphology. Quantitative analysis is vital to this method, so that results can properly be considered scientific. The inclusion of Southeast Asian individuals fills a significant gap in the data, and results support the continued use of morphoscopic traits for determination of ancestry.
Human Identification via Lateral Patella Radiographs: A Validation Study.
Niespodziewanski E, Stephan CN, Guyomarc’h P, Fenton TW. Journal of Forensic Sciences, 2015. DOI: 10.1111/1556-4029.12898
Preliminary results of this research were presented at the American Academy of Forensic Sciences Annual Meeting, Washington, D.C., 2013.
The goals of this presentation are twofold: (1) to report the findings of research investigating the use of lateral patella radiographs as a means of positive radiographic identification of unknown human remains; and (2) to report the results of quantitative matching of two-dimensional patellae images using Elliptical Fourier Analysis. This presentation will impact the forensic community by demonstrating the accuracy of positive identification utilizing medical radiographs of the lateral patella, as well as demonstrate the feasibility for quantified methods to match 2D images of bone scans with radiographs. Two hypotheses were tested: (1) Experienced forensic anthropologists can accurately match lateral patella radiographs; and (2) Three-dimensionally imaged patellae can be accurately matched with lateral patella radiographs using Elliptical Fourier analysis (EFA).
Radiographs were taken using a General Electric Amx2 portable X-ray unit. All specimens were radiographed once, then five were radiographed a second time attempting to match the angle of the first image. An antemortem pool (n=20) and the five reset radiographs (n=5) comprised the survey radiographs. Images were blocked out with cardstock, leaving only the patella visible. Practicing forensic anthropologists and graduate students in forensic anthropology were asked to match postmortem to antemortem images, or answer “no match.” A NextEngine® scanner digitized each patella’s surface in 3D (n=23). A series of 2D images were serially captured from the 3D model for comparison to the 2D radiographs. The SHAPE v1.3 suite generated Fourier descriptors for all images using 40 harmonics. The sum of the squared differences between the Fourier descriptors for the 3D model and the radiographs was calculated and individuals ranked according to this number. The top-ranked image was accurately matched to the radiographic outline in question in 72% of cases. In 20 of 22 specimens, a correct match was found within the top 5 of 345 images (1.4%).
This project has demonstrated the distinguishing characteristics of the human patella in two ways. The survey results indicate that medical radiographs of the lateral patella are valid for use in human identification due to trabecular patterns, bony spurs, and overall shape. It conforms to Daubert standards in reporting observer accuracy and error rates for expert comparisons of xrays (radiographs) of knee images. In addition, this study adds to the literature on the value of EFA in human identification because the lateral outlines of patellae are quantitatively distinguishable, reinforcing that these structures are valuable in forensic casework. This project is a collaboration between forensic anthropologists at Michigan State University in East Lansing, Michigan and the Joint POW/MIA Accounting Command Central Identification Laboratory at Hickam Airforce Base in Honolulu, Hawai’i.
Testing Stature Regression Equations on a Medieval Sudanese Population
Emily Niespodziewanski, MA. American Association of Physical Anthropologists Annual Meeting, Calgary, AB, 2014. Preliminary results of this study were also presented at the Michigan State University Graduate Academic Conference, East Lansing, MI, 2013.
Stature estimation is a component of the “biological profile,” along with age, sex, and ancestry. Stature is usually estimated by inserting femur length into a stature regression equation; average body proportions make this possible. However, because body proportions in humans vary geographically and over time, population-specific equations are necessary. This study hypothesized that equations developed from modern American whites and blacks (Trotter 1970) and from ancient Egyptians (Raxter et al. 2008) will systematically overestimate stature in the Mis Island population.
This study utilizes the MSU Nubian Bioarchaeology Collection, from Mis Island and surrounding area in medieval Sudan and currently on long-term loan from the British Museum. Fully Revised living statures (Raxter et al. 2006) were calculated for 36 males, 31 females, and 3 adults of unknown sex from the collection. Measurements comprising skeletal height were recorded for all individuals, from both sides when possible. Additional long bone measurements and age and sex estimations from earlier data collection phases were used. The Fully Revised method of stature estimation was used to calculate living statures from the well-preserved remains in the collection. Preliminary results show that both of these publications systematically overestimate stature in medieval Nubians by 1.0-1.5cm with an average absolute error of 2.4cm. This suggests that new equations should be developed for this temporally and geographically distinct population. New, more accurate equations can be applied to more fragmentary remains in other collections from this time period or region.
Talus, a new mobile application for biological profiling of human skeletal remains
Emily Niespodziewanski, MA. American Association of Physical Anthropologists Annual Meeting (Plenary Session), Knoxville, TN. 2013.
This presentation introduced the Talus mobile application for use in the creation of a biological profile from human skeletal remains. The goal of Talus is to provide a mobile web application (accessible via smartphone browser) and a native mobile app (downloaded through iTunes or Google Play) that consolidates the desired information and makes it easily accessible and portable. Talus allows easy access to measurements, formulae, and images from the most commonly used methods for estimating aspects of the biological profile. Ease of access streamlines the data collection process and increases an osteologist’s efficiency in the field and in the lab. The integration of traditional osteological methods with contemporary, user-friendly digital platforms is important to continued growth in human osteology.
The current release of Talus compiles references for the analysis of adult remains only. Due to the high standards set for scientific testimony and peer-reviewed publishing, Talus uses only scientifically tested, widely accepted methods. All sources are cited, and permalinks to original references are provided when possible.
Julie Fleischman, Emily Niespodziewanski, Ashley Kendell, and Angela Soler. American Association of Physical Anthropologists Annual Meeting, Atlanta, GA, 2012.
This poster presented a differential diagnosis for an anomalous, bilateral non-fusion of the ischiopubic rami of a young adult female skeleton. This individual is one of 408 medieval period skeletons excavated from Mis Island, Sudan by The Sudan Archaeological Research Society and the British Museum. Fusion of the ischiopubic synchondrosis is typically complete between five and eight years of age. However, this individual is undoubtedly a young adult. The opposing surfaces of the unfused rami are rough, porous, and flared at the articular surfaces. This ossific pattern more closely resembles a pseudoarthrosis than the ridges and furrows of a typical epiphyseal surface. Given the available skeletal evidence, we propose that this bilateral anomaly of the pelvis is the result of congenitally delayed ossification, known as ischiopubic hypoplasia. It is considered a non-specific finding since it is typically associated with other syndromes or disorders (Eich et al. 1992; Sferopoulos and Tsitouridis 2003). Due to its rarity, this is a significant discovery and a unique contribution to the bioarchaeology of the region.
Last updated 2/8/16