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2019, Forensic Anthropology
https://doi.org/10.5744/FA.2019.1005…
11 pages
Filipinos represent a significant contemporary demographic group globally, yet they are underrepresented in the forensic anthropological literature. Given the complex population history of the Philippines, it is important to ensure that traditional methods for assessing the biological profile are appropriate when applied to these peoples. Here we analyze the classification trends of a modern Filipino sample (n = 110) when using the Fordisc 3.1 (FD3) software. We hypothesize that Filipinos represent an admixed population drawn largely from Asian and marginally from European parental gene pools, such that FD3 will classify these individuals morphometrically into reference samples that reflect a range of European admixture, in quantities from small to large. Our results show the greatest classification into Asian reference groups (72.7%), followed by Hispanic (12.7%), Indigenous American (7.3%), African (4.5%), and European (2.7%) groups included in FD3. This general pattern did not change between males and females. Moreover, replacing the raw craniometric values with their shape variables did not significantly alter the trends already observed. These classification trends for Filipino crania provide useful information for casework interpretation in forensic laboratory practice. Our findings can help biological anthropologists to better understand the evolutionary, population historical, and statistical reasons for FD3-generated classifications. The results of our study indicate that ancestry estimation in forensic anthropology would benefit from population-focused research that gives consideration to histories of colonialism and periods of admixture.
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The study finds that 72.5% of Filipino males and 73.2% of females were classified as Asian, indicating a strong adherence to expected ancestral associations despite varied histories.
FD3 yielded a maximum total classification success of 50.6% with untransformed measurements, signifying variability in accuracy for ancestry estimates among an underrepresented group.
Nearly 10.1% of male and 17.1% of female Filipino crania were misclassified as Hispanic, emphasizing concerns regarding underlying ancestry representation.
The research utilized discriminant function analysis via Fordisc 3.1, implementing a conservative model with a maximum of nine cranial measurements to avoid overfitting.
The study highlights a complex colonial history influencing cranial morphologies and admixture patterns, suggesting unique genetic diversity that challenges typical classification frameworks.
Journal of Forensic Sciences
Ancestry assessment from the postcranial skeleton presents a significant challenge to forensic anthropologists. However, metric dimensions of the femur subtrochanteric region are believed to distinguish between individuals of Asian and non-Asian descent. This study tests the discriminatory power of subtrochanteric shape using modern samples of 128 Thai and 77 White American males. Results indicate that the samples’ platymeric index distributions are significantly different (p ≤ 0.001), with the Thai platymeric index range generally lower and the White American range generally higher. While the application of ancestry assessment methods developed from Native American subtrochanteric data results in low correct classification rates for the Thai sample (50.8–57.8%), adapting these methods to the current samples leads to better classification. The Thai data may be more useful in forensic analysis than previously published subtrochanteric data derived from Native American samples. Adapting methods to include appropriate geographic and contemporaneous populations increases the accuracy of femur subtrochanteric ancestry methods.
Journal of Forensic Sciences, 2021
Standard cranial measurements are commonly used for ancestry estimation; however, 3D digitizers have made cranial landmark data collection and geometric morphometric (GM) analyses more popular within forensic anthropology. Yet there has been little focus on which data type works best. The goal of the present research is to test the discrimination ability of standard and nonstandard craniometric measurements and data derived from GM analysis. A total of 31 cranial landmarks were used to generate 465 interlandmark distances, including a subset of 20 commonly used measurements, and to generate principal component scores from procrustes coordinates. All were subjected to discriminant function analysis to ascertain which type of data performed best for ancestry estimation of American Black and White and Hispanic males and females. The nonstandard interlandmark distances generated the highest classification rates for females (90.5%) and males (88.2%). Using nonstandard interlandmark distances over more commonly used measurements leads to better ancestry estimates for our current population structure.
Journal of applied genetics, 2004
Population data was collected for the STR loci F13AO1, FES/FPS, HUMvWA, and HUMTHO1, in three major Philippine ethnolinguistic groups and used to estimate statistical parameters for identity testing in forensic work on Filipinos. The Cebuano, Ilocano, and Pampango populations in the Philippines were studied because they are among the biggest linguistic groups in the country, thus their genotypic profiles should substantially represent those of many Filipinos. The number of alleles varied from 4 to 9 at all loci, falling within the range observed for other local and world populations. Pairwise comparisons of the allele frequency distributions showed no statistical differences among the populations. The test for linkage equilibrium showed no evidence of non-random association of alleles across the physically unlinked loci in any of the three populations. The four loci combined gave an exclusion power of > or =0.9995 and a power of paternity exclusion of 0.8859-0.9389.
Journal of forensic sciences, 2017
A common task in forensic anthropology involves the estimation of the ancestry of a decedent by comparing their skeletal morphology and measurements to skeletons of individuals from known geographic groups. However, the accuracy rates of ancestry estimation methods in actual forensic casework have rarely been studied. This article uses 99 forensic cases with identified skeletal remains to develop accuracy rates for ancestry estimations conducted by forensic anthropologists. The overall rate of correct ancestry estimation from these cases is 90.9%, which is comparable to most research-derived rates and those reported by individual practitioners. Statistical tests showed no significant difference in accuracy rates depending on examiner education level or on the estimated or identified ancestry. More recent cases showed a significantly higher accuracy rate. The incorporation of metric analyses into the ancestry estimate in these cases led to a higher accuracy rate.
Establishing ancestry from a skeleton for forensic purposes has been shown to be difficult. The purpose of this paper is to address the application of thirteen non-metric traits to estimate ancestry in three South African groups, namely White, Black and ‘‘Coloured’’. In doing so, the frequency distribution of thirteen non-metric traits among South Africans are presented; the relationship of these non-metric traits with ancestry, sex, age at death are evaluated; and Kappa statistics are utilized to assess the inter and intrarater reliability. Crania of 520 known individuals were obtained from four skeletal samples in South Africa: the Pretoria Bone Collection, the Raymond A. Dart Collection, the Kirsten Collection and the Student Bone Collection from the University of the Free State. Average age at death was 51, with an age range between 18 and 90. Thirteen commonly used non-metric traits from the face and jaw were scored; definition and illustrations were taken from Hefner [2], Bass [6] and Hauser and De Stephano [7]. Frequency distributions, ordinal regression and Cohen’s Kappa statistics were performed as a means to assess population variation and repeatability. Frequency distributions were highly variable among South Africans. Twelve of the 13 variables had a statistically significant relationship with ancestry. Sex significantly affected only one variable, inter-orbital breadth, and age at death affected two (anterior nasal spine and alveolar prognathism). The interaction of ancestry and sex independently affected three variables (nasal bone contour, nasal breadth, and interorbital breadth). Seven traits had moderate to excellent repeatability, while poor scoring consistency was noted for six variables. Difficulties in repeating several of the trait scores may require either a need for refinement of the definitions, or these character states may not adequately describe the observable morphology in the population. The application of the traditional experience-based approach for estimating ancestry in forensic case work is problematic.
In forensic anthropology ancestry assessment is conducted as part of the biological profile in an effort to identify unknown skeletonized remains. Ancestry assessment is based on human skeletal variation, whereby combinations of morphoscopic and morphometric traits of an unknown individual are correlated with a specific population group, typically on a continental level (European, Asian, and African). This field was historically connected to the highly controversial concept of race, although in more recent years ‘race’ has been abandoned for the more favorable term ‘ancestry.’ An important shift in research during the past two decades is the development and application of computer software within anthropology and, more recently, the introduction of new statistical approaches for the morphoscopic assessment of ancestry.
2006
Forensic anthropologists use the computer program FORDISC 2.0 (FD2) as an analytical tool for the determination of ancestry of unknown individuals. There are an almost endless number of measurements that can be taken on the human skeleton, yet FORDISC includes only 78 measurements for its analysis. In particular, the program will only utilize up to 24 measurements of the cranium. These 24 cranial variables are used because they require simple, relatively inexpensive instruments that most biological anthropology laboratories have (spreading and sliding calipers). Also, individuals with a basic knowledge of the anatomical landmarks can take the measurements with relative ease. Unconventional measurements of the cranium require unusual, costly instruments (such as the radiometer and coordinate caliper) and are more difficult to take. This study will examine which measurements of the human cranium provide the greatest classificatory power when constructing discriminant function formulae for the determination of ancestry and will answer the question of whether the use of variables that require more time, training, and equipment are worth the effort. Sixty five cranial measurement were taken on 155 adult human crania from three different ancestral groups: (1) African American (n = 50), (2) European American (n = 50), and (3) Coyotero Apache (n = 55). The 65 measurements were broken up into four subsets for statistical analysis: (1) FD2 (1996), (2) Howells (1973), (3) Gill (1984), and (4) All Measurements. A predictive discriminant analysis with a forward stepwise methodology of p = 0.05 to enter and p = 0.15 to remove was run using the computer software package SPSS 13.0. The analysis produced 4 sets of discriminant function formulae. The classificatory power of each set of formulae was determined by comparing the hit-rate estimation (the percent correctly classified) of each of the subsets. First, the resubstitution rate was compared to the leave-one-out (LOO) rate for each subset and then both rates were compared across all subsets. The FD2 subset had a resubstitution rate of 90.3% and LOO rate of 85.8%. The Howells subset had a resubstitution rate of 92.9% and a LOO rate of 90.3%. The Gill subset had a resubstitution rate of 63.2% and a LOO rate of 61.9%. Finally, the All Measurements subset had a resubstitution rate of 95.5% and a LOO rate of 93.5%. The non-standard measurements of the All Measurements subset performed the best and the standard FD2 measurements performed third best. Non-standard measurements incorporated in the All Measurements formulae included frontal subtense, mid-orbital breadth, bistephanic breadth, bimaxillary breadth, and molar alveolar radius. The formulae provided the best separation of the Apache group from the other two groups. Stepwise analysis showed that the use of more variables is not necessarily better, as not all of the variables were included in the final formulae. Only 12 of the 24 FD2 measurements, 12 of the 57 Howells measurements, 4 of the 6 Gill measurements, and 15 of the 65 All Measurements were used. Results show that the non-standard measurements can be useful for determining the ancestry of unknown human crania. These measurements could be especially useful for incomplete crania. It is suggested that biological anthropology laboratories purchase radiometers and coordinate calipers to record data that would be missed with spreading and sliding calipers. Standard measurements can be combined with non-standard measurements to produce more powerful discriminant function formulae for the determination of ancestry.

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Human Biology, 2018
In this study, we investigated, for the first time from a forensic anthropological perspective, the question of mixed ancestry estimation for modern Filipinos with geographic origins in the Philippines. We derived estimates of continental ancestry using craniometrics from four sources: a new documented collection of current forensic significance from the Manila North Cemetery; the Howells cranial series representing a sample of unclaimed individuals from Manila but said largely to originate from more remote areas, with dates of death before 1940; the Hanihara sample aggregated from various locations and time periods across the Philippines; and the Hanihara series capturing various local indigenous, ethnic groups that are together identified as Philippine Negrito. Parental craniometrics were selected from the Howells data set and more recently collected samples from Europe and Asia. Using unsupervised clustering, we investigated the algorithmically defined three-cluster, or trihybrid admixture, model to infer continental ancestry for each individual, reporting their relative proportions of Asian, European, and African admixture. We used similar clustering procedures to identify more complex models, with a larger number of clusters, to explore patterns of affinity between our four Philippine samples and the recently acquired samples from Vietnam, Thailand, China (Hong Kong), Japan, and Korea. These analyses give insight into the relationships between both macro- and microgeographic regions, revealing at the country level how different population dynamics—whether political, economic, historical, and/or social—structure the ancestral makeup of Asian peoples, especially in the degree of European and African admixture. From these ancestry estimates, we found that population of origin explains 38–51% of the variation in each ancestry component, and we detected significant differences among the Asian samples in their quantities of ancestry. Filipinos appear considerably admixed, as they carry almost 20% less Asian ancestry than the average quantity (90%) estimated for the other Asian groups. We also revealed substructure within our representation of modern Filipinos, such that differences in the patterns of three-way admixture exist between each of the four Philippine samples; the Manila cemetery sample had the highest level of Asian ancestry, and, as we might expect, the Negrito sample had the greatest quantity of African ancestry. We performed additional analyses that introduced craniometrics from the Howells Australo-Melanesian series, to more fully investigate their relationship to the Asian samples and to better understand the African contributions common to the Philippine Negritos especially, as well as the other Southeast Asians and the Spanish and Portuguese groups. By mapping the cluster patterns on a global scale, these analyses reveal that, with craniometries just as with genetic loci, patterns of affinity are informative of the complex history of Southeast Asia, as they suggest vestiges of migration, trade, and colonialism, as well as more recent periods of isolation, marginalization, and occupation.
American Journal of Physical Anthropology, 2020
Objectives: Probit has not been applied to ancestry estimation in forensic anthropology. The goals of this study were to: (1) evaluate the performance of probit analysis as a classification tool for ancestry estimation using ordinal data and (2) expand our current understanding of human cranial variation for an understudied population. Methods: Multivariate probit models were used to classify the ancestral affiliation of Filipino crania using morphoscopic traits. Ancestral reference populations represented Africa, Asia, and Europe in a three-group model, with the addition of Hispanics in a four-group model. Posterior probabilities across these groups were interpreted as admixture proportions of an individual. Model performance was also evaluated for individuals with missing data. Results: The overall correct classification rates for the three-group and four-group models were 72.1% and 68.6%, respectively. Filipinos classified as Asian 52.9% of the time using three ancestral reference groups and 48.6% using four groups. A large portion of Filipinos also classified as African. There were no significant differences in classification trends or accuracy rates between complete crania and crania with at least one missing variable. Conclusions: Multivariate probit models using morphoscopic traits perform well when populations are represented in both training and test samples. Probit can also accommodate individuals with missing data. Classifying Filipinos showed only moderate success. Filipinos are more phenotypically similar to Africans than the other Asian samples used here, but still affiliate most closely as Asian. Ancestry methods would benefit from including Filipinos as a reference sample given the additional variation they provide to the continental category of Asian.
Australian Journal of Forensic Sciences , 2023
Given their similar morphology and gene-flow histories, determining whether an unidentified cranium found in the Philippines is Japanese or Filipino presents a challenge. Two different analyses are undertaken. First, discriminant function (DF) analyses are applied to 295 crania using 22 measurements for distinguishing between: 1) males and females, 2) Japanese and Filipino males, and 3) Japanese and Filipino females, and 4) among four groups (Japanese males, Filipino males, Japanese females, and Filipino females). Second, a DF equation for distinguishing Japanese males and Filipino males using 173 crania and 29 measurements is introduced. In addition to being able to distinguish between Japanese and Filipino crania, this study found that seldom used cranial measurements such as simonic chord (least nasal breadth -WNB), inferior malar length (IML), and maximum malar length (XML) are influential for distinguishing between these two Asian groups. The predicted classification accuracy of DF equations from both analyses ranged from 82.0% to 93.6%. Sixty test crania for the first study and 40 for the second study maintains classification success rates between 82.0% and 93.3%. The DF equations reported in this study can be a useful initial screening tool for identifying Japanese war dead in the Philippines.
A collection of 75 modern skeletons from the Philippines has recently been created, and is being housed at the Archaeological Studies Program of the University of the Philippines, Diliman, Philippines. All individuals lived during the 20th century, and almost all died within the 21st century. These individuals were accessioned from exhumed and abandoned tombs at the Manila North Cemetery, and most have documented age and sex from tombstone inscriptions. This paper describes the first season of recovery and the collection's current demographic composition, with the future addition of more individuals to the collection expected to follow. The Philippines has an immediate need for forensic resources given its large vulnerable population, widespread diaspora, and exposure to natural disasters. Having a collection of modern Filipinos available for study is critical to the advancement of forensic anthropology and skeletal biology, especially for this heavily understudied population and region of the world.
Journal of Forensic Sciences , 2020
Traditionally, precontact Native Americans and Asian groups have been conflated for aspects of the biological profile due to their distantly shared genetic history, although this grouping remains largely unexplored. This study examines craniomorphic variability to ascertain whether Asian groups can be differentiated from each other and from Asian-derived groups using more fine-tuned models. Cranial and mandibular data for 35 nonmetric traits were recorded on precontact Native Americans (n = 150) and modern Japanese (n = 150) and Thai (n = 150) individuals. Chi-square analyses indicate that all groups exhibit statistically significant differences in most traits. Additionally, cross-validated binary logistic regression equations resulted in correct classification rates in the range of 65.0-93.3% and demonstrate that sex does not contribute to statistical models. Therefore, numerous traits provide discriminatory resolution that detects differences between the samples, thus highlighting the potential utility of nonmetric traits in identifying individuals beyond the traditional African, European, and Asian forensic ancestry groupings.
Forensic Science International, 2019
Ancestry estimation of skeletonized remains by forensic anthropologists is conducted through comparative means, and a lack of population-specific data results in possible misclassifications. This is especially germane to individuals of Latin American ancestry. Generally, each country in Latin America can trace their ancestral lineage through three main parental groups: Indigenous, European, and African. However, grouping all Latin American individuals under the broad “Hispanic” category ignores the specific genetic contributions from each parental group, which is variable and dependent on the population histories and sociocultural dynamics of each country. This study analyzes the craniometric ancestry of Hispaniola (the Dominican Republic and Haiti) using 190 cranial Computed Tomography (CT) scans (f = 103; m = 87), along with the island’s history, to explore similarities and differences between the two groups. MANOVA results indicate that 53.6% and 71.4% of the 28 cranial measurements differ between the ancestries and sexes, respectively; and intraobserver error analyses demonstrate that 85.7% of measurements from CT scans are good-excellent in reliability. Further, a total of 12 canonical discriminant function analyses produced cross-validated classification accuracies of 73.7–78.6% for females, 71.8–87.5% for males, and 72.0–77.8% for pooled sex. This study demonstrates that, despite sharing a small island, Dominican and Haitian individuals can be differentiated with a fair amount of statistical certainty, which is possible due to complex socio-cultural, -political, and -demographic factors that have produced and maintained genetic heterogeneity.
Biology Letters 5, 849-852, 2009
"Determining the ancestry of unidentified human remains is a major task for bioarchaeologists and forensic anthropologists. Here, we report an assessment of the computer program that has become the main tool for accomplishing this task. Called FORDISC, the program determines ancestry through discriminant function analysis of cranial measurements. We evaluated the utility of FORDISC with 200 specimens of known ancestry. We ran the analyses with and without the test specimen’s source population included in the program’s reference sample, and with and without specifying the sex of the test specimen. We also controlled for the possibility that the number of variables employed affects the program’s ability to attribute ancestry. The results of the analyses suggest that FORDISC’s utility in research and medico-legal contexts is limited. FORDISC will only return a correct ancestry attribution when an unidentified specimen is more or less complete, and belongs to one of the populations represented in the program’s reference samples. Even then FORDISC can be expected to classify no more than 1 per cent of specimens with confidence."
Australian Journal of Forensic Sciences, 2022
Given their similar morphology and gene-flow histories, determining whether an unidentified cranium found in the Philippines is Japanese or Filipino presents a challenge. Two different analyses are undertaken. First, discriminant function (DF) analyses are applied to 295 crania using 22 measurements for distinguishing between: 1) males and females, 2) Japanese and Filipino males, and 3) Japanese and Filipino females, and 4) among four groups (Japanese males, Filipino males, Japanese females, and Filipino females). Second, a DF equation for distinguishing Japanese males and Filipino males using 173 crania and 29 measurements is introduced. In addition to being able to distinguish between Japanese and Filipino crania, this study found that seldom used cranial measurements such as simonic chord (least nasal breadth -WNB), inferior malar length (IML), and maximum malar length (XML) are influential for distinguishing between these two Asian groups. The predicted classification accuracy of DF equations from both analyses ranged from 82.0% to 93.6%. Sixty test crania for the first study and 40 for the second study maintains classification success rates between 82.0% and 93.3%. The DF equations reported in this study can be a useful initial screening tool for identifying Japanese war dead in the Philippines.
It has been brought to the attention of the authors of Fordisc 3.1 that Hispanic samples will often misclassify as Japanese when Asian population samples are included. This study examined this problem in an effort to better document the occurrence and deduce possible causes via comparative analyses. Asian and Hispanic samples were first compared utilizing the existing samples from the University of Tennessee's Forensic Data Bank. Additional modern Japanese, Thai, and Korean samples collected by the first author that have previously not been utilized in analyses were subsequently included. Results of this study confirm frequent rates of misclassification among Hispanic and Japa-nese groups. Furthermore, a close morphological relationship is identified through further group comparisons and the addition of data used in conjunction with Fordisc samples. Similarities identified among Hispanic and Japanese crania may stem from similar population histories reflected in ancestral Native American and East Asian populations.
Forensic Science International: Genetics, 2013
A revision of an established 34 SNP forensic ancestry test has been made by swapping the underperforming rs727811 component SNP with the highly informative rs3827760 that shows a near-fixed East Asian specific allele. We collated SNP variability data for the revised SNP set in 66 reference populations from 1000 Genomes and HGDP-CEPH panels and used this as reference data to analyse four U.S. populations showing a range of admixture patterns. The U.S. Hispanics sample in particular displayed heterogeneous values of co-ancestry between European, Native American and African contributors, likely to reflect in part, the way this disparate group is defined using cultural as well as population genetic parameters. The genotyping of over 700 U.S. population samples also provided the opportunity to thoroughly gauge peak mobility variation and peak height ratios observed from routine use of the single base extension chemistry of the 34-plex test. Finally, the genotyping of the widely used DNA profiling Standard Reference Material samples plus other control DNAs completes the audit of the 34-plex assay to allow forensic practitioners to apply this test more readily in their own laboratories.