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
Individual Identifiability Predicts Population Identifiability in Forensic Microsatellite Markers.
2016; 26 (7): 935-942
Highly polymorphic genetic markers with significant potential for distinguishing individual identity are used as a standard tool in forensic testing [1, 2]. At the same time, population-genetic studies have suggested that genetically diverse markers with high individual identifiability also confer information about genetic ancestry [3-6]. The dual influence of polymorphism levels on ancestry inference and forensic desirability suggests that forensically useful marker sets with high levels of individual identifiability might also possess substantial ancestry information. We study a standard forensic marker set-the 13 CODIS loci used in the United States and elsewhere [2, 7-9]-together with 779 additional microsatellites , using direct population structure inference to test whether markers with substantial individual identifiability also produce considerable information about ancestry. Despite having been selected for individual identification and not for ancestry inference , the CODIS markers generate nontrivial model-based clustering patterns similar to those of other sets of 13 tetranucleotide microsatellites. Although the CODIS markers have relatively low values of the FST divergence statistic, their high heterozygosities produce greater ancestry inference potential than is possessed by less heterozygous marker sets. More generally, we observe that marker sets with greater individual identifiability also tend toward greater population identifiability. We conclude that population identifiability regularly follows as a byproduct of the use of highly polymorphic forensic markers. Our findings have implications for the design of new forensic marker sets and for evaluations of the extent to which individual characteristics beyond identification might be predicted from current and future forensic data.
View details for DOI 10.1016/j.cub.2016.01.065
View details for PubMedID 26996508
Population inference from contemporary American craniometrics.
American journal of physical anthropology
This analysis delivers a composite picture of population structure, admixture, ancestry variation, and personal identity in the United States, as observed through the lens of forensic anthropological casework and modern skeletal collections. It tests the applicability of the probabilistic clustering methods commonly used in human population genetics for the analysis of continuous, cranial measurement data, to improve population inference for admixed individuals without prior knowledge of sample origins.The unsupervised model-based clustering methods of finite mixture analysis are used here to reveal latent population structure and generate admixture proportions for craniofacial measurements from the Forensic Anthropology Data Bank (FDB). Craniometric estimates of ancestry are also generated under a three contributor model, sourcing parental reference populations from the Howells Craniometric Dataset. Tests of association are made among the coefficients of cluster memberships and the demographic information documented for each individual in the FDB. Clustering results are contextualized within the framework of conventional approaches to population structure analysis and individual ancestry estimation to discuss method compatibility.The findings reported here for contemporary American craniometrics are in agreement with the expected patterns of intergroup relationships, geographic origins and results from published genetic analyses.Population inference methods that allow for the model-bound estimation of admixture and ancestry proportions from craniometric data not only enable parallel-skeletal and genetic-analyses but they are also shown to be more informative than those methods that perform hard classifications using externally-imposed categories or seek to explain gross variation by low-dimensional projections. Am J Phys Anthropol, 2016. © 2016 Wiley Periodicals, Inc.
View details for DOI 10.1002/ajpa.22959
View details for PubMedID 26892285
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
2016; 160 (1): 148-155
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
Better together: Thinking anthropologically about genetics.
American journal of physical anthropology
What are the effects that genetics has had on Anthropological research and how can we think anthropologically about Genetics? Just as genetic data have encouraged new hypotheses about human phenotypic variation, evolutionary history, population interaction, and environmental effects, so too has Anthropology offered to genetic studies a new interpretive locus in its history and perspective. This introduction examines how the fields of Anthropology and Genetics have arrived at a crucial moment at which their interaction requires careful examination and critical reflection. The papers discussed here exemplify how we may engage in such a trans-disciplinary conversation. They speak to the future of thoughtful interaction between genetic and anthropological literature and seek a new integration that embodies the holism of the human biological sciences.
View details for DOI 10.1002/ajpa.23022
View details for PubMedID 27312265
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
- The Myth of Race. The troubling persistence of an unscientific idea (Book Review) AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2015; 157 (4): 705-706
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 Web of Science ID 000359262900001
View details for PubMedID 25929827
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