Bachelor of Arts, Mount Allison University (2000)
Master of Arts, Bryn Mawr College (2002)
Doctor of Philosophy, University of Tennessee Knoxville (2011)
Noah Rosenberg, Postdoctoral Faculty Sponsor
An enhanced computational method for age-at-death estimation based on the pubic symphysis using 3D laser scans and thin plate splines
AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY
2015; 158 (3): 431-440
The pubic symphysis is frequently used to estimate age-at-death from the adult skeleton. Assessment methods require the visual comparison of the bone morphology against age-informative characteristics that represent a series of phases. Age-at-death is then estimated from the age-range previously associated with the chosen phase. While easily executed, the "morphoscopic" process of feature-scoring and bone-to-phase-matching is known to be subjective. Studies of method and practitioner error demonstrate a need for alternative tools to quantify age-progressive change in the pubic symphysis. This article proposes a more objective, quantitative method that analyzes three-dimensional (3D) surface scans of the pubic symphysis using a thin plate spline algorithm (TPS).This algorithm models the bending of a flat plane to approximately match the surface of the bone and minimizes the bending energy required for this transformation. Known age-at-death and bending energy were used to construct a linear model to predict age from observed bending energy. This approach is tested with scans from 44 documented white male skeletons and 12 casts.The results of the surface analysis show a significant association (regression p-value = 0.0002 and coefficient of determination = 0.2270) between the minimum bending energy and age-at-death, with a root mean square error of ≈19 years.This TPS method yields estimates comparable to established methods but offers a fully integrated, objective and quantitative framework of analysis and has potential for use in archaeological and forensic casework. Am J Phys Anthropol 158:431-440, 2015. © 2015 Wiley Periodicals, Inc.
View details for DOI 10.1002/ajpa.22797
View details for Web of Science ID 000362953000007
View details for PubMedID 26173843
Modeling Bone Surface Morphology: A Fully Quantitative Method for Age-at-Death Estimation Using the Pubic Symphysis.
Journal of forensic sciences
2015; 60 (4): 835-843
The pubic symphysis is widely used in age estimation for the adult skeleton. Standard practice requires the visual comparison of surface morphology against criteria representing predefined phases and the estimation of case-specific age from an age range associated with the chosen phase. Known problems of method and observer error necessitate alternative tools to quantify age-related change in pubic morphology. This paper presents an objective, fully quantitative method for estimating age-at-death from the skeleton, which exploits a variance-based score of surface complexity computed from vertices obtained from a scanner sampling the pubic symphysis. For laser scans from 41 modern American male skeletons, this method produces results that are significantly associated with known age-at-death (RMSE = 17.15 years). Chronological age is predicted, therefore, equally well, if not, better, with this robust, objective, and fully quantitative method than with prevailing phase-aging systems. This method contributes to forensic casework by responding to medico-legal expectations for evidence standards.
View details for DOI 10.1111/1556-4029.12778
View details for PubMedID 25929827
The reality of virtual anthropology: Comparing digitizer and laser scan data collection methods for the quantitative assessment of the cranium.
American journal of physical anthropology
The use of geometric morphometry to study cranial variation has steadily grown in appeal over the past decade in biological anthropology. Publication trends suggest that the most popular methods for three-dimensional data acquisition involve landmark-based coordinate data collection using a digitizer. Newer laser scan approaches are seeing increasing use, owing to the benefits that densely sampled data offer. While both of these methods have their utility, research that investigates their compatibility is lacking. The purpose of this project is to compare, quantitatively, craniometrics collected with a digitizer against data extracted from laser scans using the same individuals and laboratory conditions.Three-dimensional (x,y,z) coordinates and traditional inter-landmark distances (ILDs) were obtained with a Microscribe digitizer and 360° color models produced from NextEngine laser scans for 38 adult crania representing five cemeteries from the ADBOU skeletal collection in Denmark. Variance-based tests were performed to evaluate the disagreement between data collected with a digitizer and from laser scan models. Consideration was given to differences among landmarks by type, between ILDs calculated from landmark coordinates, and in morphology for the cemetery populations. Further, the reliability of laser scan data collection was assessed by intra-observer error tests.Researchers should be aware of the potential error associated with the use of Types II and III landmarks and the limitations on reliability imposed by object-to-scanner placement.This project reveals how laser scans can provide a valuable digital archive of cranial material that can be reasonably exploited for the "virtual" collection of coordinates and the calculation of ILDs. Am J Phys Anthropol, 2015. © 2015 Wiley Periodicals, Inc.
View details for DOI 10.1002/ajpa.22932
View details for PubMedID 26714825
- The Myth of Race. The troubling persistence of an unscientific idea AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2015; 157 (4): 705-706
Estimation and Evidence in Forensic Anthropology: Sex and Race
AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY
2009; 139 (1): 77-90
Forensic anthropology typically uses osteological and/or dental data either to estimate characteristics of unidentified individuals or to serve as evidence in cases where there is a putative identification. In the estimation context, the problem is to describe aspects of an individual that may lead to their eventual identification, whereas in the evidentiary context, the problem is to provide the relative support for the identification. In either context, individual characteristics such as sex and race may be useful. Using a previously published forensic case (Steadman et al. (2006) Am J Phys Anthropol 131:15-26) and a large (N = 3,167) reference sample, we show that the sex of the individual can be reliably estimated using a small set of 11 craniometric variables. The likelihood ratio from sex (assuming a 1:1 sex ratio for the "population at large") is, however, relatively uninformative in "making" the identification. Similarly, the known "race" of the individual is relatively uninformative in "making" the identification, because the individual was recovered from an area where the 2000 US census provides a very homogenous picture of (self-identified) race. Of interest in this analysis is the fact that the individual, who was recovered from Eastern Iowa, classifies very clearly with [Howells 1973. Cranial Variation in Man: A Study by Multivariate Analysis of Patterns of Difference Among Recent Human Populations. Cambridge, MA: Peabody Museum of Archaeology and Ethnology; 1989. Skull Shape and the Map: Craniometric Analyses in the Dispersion of Modern Homo. Cambridge, MA: Harvard University Press]. Easter Islander sample in an analysis with uninformative priors. When the Iowa 2000 Census data on self-reported race are used for informative priors, the individual is clearly identified as "American White." This analysis shows the extreme importance of an informative prior in any forensic application.
View details for DOI 10.1002/ajpa.20934
View details for Web of Science ID 000265279700009
View details for PubMedID 19226642