6-way DFA A combined correct classification of 63% was obtained in a six-way DFA for sex and ancestry using 10 stepwise-selected variables. Black females classified 76% correctly, black males classified 74% correctly, coloured females classified 24% correctly, coloured males classified 41% correctly, white females classified 69% correctly, and white males classified 66% correctly (Tables 3 and 4; Figure 3). White males and females are distinct. They misclassify within the opposite-sex but same ancestry group and rarely into black or coloured groups. South African black males and females misclassify first into the opposite-sex but same ancestry group, then into the same-sex but another ancestry (coloured) group. South Africans coloured males and female exhibit considerably lower correct classification accuracies and present with a different classification pattern than either white or black South Africans. Coloured males and females first misclassified into the same-sex but different ancestry (black) group, the coloured males misclassified as black females and coloured females misclassify as coloured males. Coloured females misclassified into the same-sex but different ancestry (black) more often than they correctly classified as themselves. ? ? ? ? Craniometric assessment of modern 20 century black, white and coloured* South Africans th L'Abbé EN , Kenyhercz MW , Stull KE , Ousley SD 1 2 1 3 1 2 Department of Anatomy, University of Pretoria, Private Bag x323, 0007, Arcadia, South Africa Department of Anthropology, University of Alaska, Fairbanks, USA 3 Department of Applied Forensic Sciences, Mercyhurst University, 501 E. 38th St. Erie, PA 16546 Introduction All human populations are relative, are often regionally specific, and all are qualified in numerous ways Historical circumstances, which contribute to cultural/social behavior, are catalysts for mitigating, or prohibiting, gene flow and subsequently morphological expression. This research addresses human variation in modern South Africans as well as the impact of forced segregation on cranial plasticity in different ancestral populations occupying the same geographic space. From 1913 to 1983, approximately 60 segregation Acts concerning race; employment; education; land tenure and geography; marriage; political representation; and state security were implemented to control and to govern the ethnically diverse country of South Africa. Of importance to the social and physical separation of groups, The Mixed Marriages Act No 55 and the Immorality Act No 21 were passed in 1949 and 1950, respectively, and prohibited marriage or sexual acts between white and black persons. In 1950, Population Registration Act No 30 empowered the 1951 census bureau to racially classify every South African into four groups: “Native/Bantu” (Black); Coloured , White, and Asian. In 1966, over 12-million race classifications appeared into the national population register. Once classified, the Group Areas Act of 1950 defined where the above-mentioned population groups could reside in the country. As illustrated in the following quote, racial segregation essentially determined a person's access to education; livelihood; marriage partners; and geography. If permitted to “colour change” to a more “superior” group, a person's social condition tremendously improved; this is reflected in Figure 1 in which a newspaper article outlines the colour chameleons of 1985. In total 702 Coloureds turned white; 249 blacks turned Coloured; but . In 1991, The Population Registration Act was repealed, but 22 years later, the social and physical legacy of Apartheid remains, and continually affects social behavior within the population. While no longer mandatory under the constitution, self-classification is requested of all South Africans, and is often equated to employment and educational opportunities. Today, approximately 80% of the population self- identifies as black; 9% coloured; 8% white; and 3% Indian. 1,2 3 “Those classified as whites were guaranteed a lifetime of privilege. As members of a supposedly inferior race, “Coloureds” were consigned to lower positions on the scale of economic and political opportunity. But they were considered superior to “Natives” who were almost all relegated to lives of exploitation, poverty and hardship” (Apartheid Museum, Johannesburg, South Africa) no blacks became whites and no whites became black Aim Materials and Methods The purpose of this study was to use craniometrics and discriminant function analysis (DFA) to evaluate ancestral variation and sexual dimorphism among white, black, and coloured groups as a mean to explain current variation and to more accurately estimate ancestry among unidentified persons in the country. ? ? ? A total of 351 crania of black (49 F, 110 M); white (45 F, 64 M); and coloured (29 F, 54 M) groups were used from the Pretoria Bone (University of Pretoria), Raymond A. Dart (University of Witwatersrand), and Kirsten (Stellenbosch University) skeletal collections in South Africa. All groups are of known age, sex and self-identified ancestry. Exclusion criteria included: (1) persons younger than 18 years of age; (2) macroscopic pathology, ante- and post-mortem fractures, as this does not represent normal variation; and (3) extensive ante- mortem tooth loss (less than 6 teeth remaining), as tooth loss and alveolar resorption can change facial shape . Seventy-seven standard landmarks on the face, vault and cranial base were digitized with a MicroScribe G2 to generate various linear measures, fractures, angles, and subtenses. 3 Skull was used to record the data and all dimensions were stored in Advantage Data Architect versions 9.0. Discriminant function analysis was employed and South African groups were tested against themselves to test classification accuracies. All accuracies were cross-validated. 4 5 6 ? Results 3-way DFA In a three-way DFA for ancestry using 11 stepwise-selected variables, 82% classified correctly using cross-validation, indicating significant differences between D among all groups (Tables 1 and 2, Figure 2). Black South Africans classified 80% correctly, coloureds classified 84% correctly, and whites classified 83% correctly. Black South Africans misclassified as a coloured group but rarely as a white group. Coloured South Africans occasionally misclassified as either white or black groups. Whites South Africans misclassified more frequently as a coloured group than as a black group. 2 ? ? ? Discussion and Conclusion Despite strong separation of these groups in a three-way DFA, classification accuracies are lowered when the groups are split into sex and ancestry, particularly for coloured and black groups. This may be attributed to higher heterogeneity and lower sexual dimorphism than in the white groups. Misclassification patterns for white and black South Africans are similar and is likely associated with reduced cranial sexual dimorphism within each ancestry group. L’Abbe et al. (in print) demonstrated that white and black South Africans had lower cranial sexual dimorphism than their North American counterparts 7. Coloured groups do not follow the above-mentioned patterns and are more likely to misclassify as black South Africans than as each other. No clear discrimination is made between males and females of these two groups, possibly due to greater similarities among themselves than to white male or female South Africans. The tendency to split groups into white and non-white clusters was also noted in observations on nasal aperture shapes among South Africans 8. White and black South Africans show roughly the same level of homogeneity and can be easily separated while coloureds are highly heterogeneous. The social-political pressures of maintaining “within one’s race group” were much stronger amongst the white South African than any other governmental imposed communities; a fact which may lead to their distinct morphological features. A clear understanding of human variation of self-identified South African groups is required so that existing standards can be modified and anthropological work within the country can be brought on par with international standards. References 1. Spradley MK, Jantz RL, Robinson A, Peccerelli F. 2008. Demographic change and forensic identification: problem in metric identification of Hispanic skeletons. Journal of Forensic Science 53(1): 21-8. 2. Ousley SD, L’Abbé EN. Craniometric variation in South Africans and American Blacks. Proceedings of the 62nd Annual Meeting of the American Academy of Forensic Sciences 16:377 3. Adhikari, M. 2005. Contending approaches to coloured identity and the history of the coloured people of South Africa. History Compass 3:1-6. 4. Reichs, K.M., Huber, C.D., Lipping, W.R. & Tangl, S. (2011).Atrophy of the residual alveolar ridge following tooth loss in an historical population. Oral Diseases. 17:33-44. 5. Howells, WW. 1973. Cranial Variation in Man: A study by multivariate analysis of patterns of difference among recent human populations. Boston, Harvard University Press. Pp. 163 – 190. 6. Ousley, S.D. (2004). 3SkullVersion 2.1.111P. (Computer software). 7. L’Abbé EN, Kenyhercz, MW, Stull, KE, Keough, N, Nawrocki, N.Application of Fordisc 3.0 to explore differences among crania of North American and South African blacks and whites. Journal of Forensic Science (In print for 2013). 8. McDowell JL, L’Abbé EN, Kenyhercz MW. 2012. Morphometric comparison of nasal aperture shapes among modern South Africans. Proceedings of the 64th Annual Meeting of the American Academy of Forensic Sciences 18:363. *Coloured refers to a social group primarily from the Western Cape who are descendants of slaves brought from Indonesia, India, Malaysia and Asia and who mixed with Europeans and the indigenous Khoi and San. 3 Table 1. Discriminant function results using 11 Forward Wilks selected variables: WRB, SIS, NDA, PAF, ZYB, OCC, DKB, NLH, NLB, DKS, FRS Into Group From Group Total Number B C W Percent Correct B 159 127 29 3 79.9 C 83 4 70 9 84.3 W 109 6 13 90 82.6 Total Correct: 287 out of 351 (81.8%) Cross-validated Table 2. Mahalanobis D Distance Matrix. All distances significant at p<0.001 2 Group B C W B - 7.80 13.58 C 7.80 - 8.74 W 13.58 8.74 - Figure 1. Social Chameleons of Apartheid - 4 . 0 - 2 . 0 0 . 0 2 . 0 4 . 0 C a n 1 ( 6 7 . 8 % ) - 4 . 0 - 2 . 0 0 . 0 2 . 0 4 . 0 C a n 2 ( 3 2 . 2 % ) W C B Figure 2. Canonical variates plot of the discriminant function between ancestral groups accounting for 100% of the variation. Table 3. Discriminant function results using 10 Forward Wilks selected variables: BNL, PAF, SIS, NDA, ZYB, DKB, FOL, MDH, OBB, ZOR Into Group From Group Total Number BF BM CF CM WF WM Percent Correct BF 49 37 6 5 0 1 0 75.5 BM 110 12 81 0 9 4 4 73.6 CF 29 15 1 7 4 2 0 24.1 CM 54 8 10 6 22 3 5 40.7 WF 45 4 0 1 2 31 7 68.9 WM 64 1 3 0 6 12 42 65.6 Total Correct: 220 out of 351 (62.7%) Cross-validated. - 2 . 0 0 . 0 2 . 0 4 . 0 C a n 1 ( 5 3 . 9 % ) - 4 . 0 - 2 . 0 0 . 0 2 . 0 C a n 2 ( 3 0 . 1 % ) W M W F C M C F B M B F Figure 3. Canonical variates plot of the discriminant function between ancestral groups accounting for 84% of the variation. Table 4. Mahalanobis D Distance Matrix. All distances significant at p<0.001 2 From Group BF BM CF CM WF WM BF - 4.13 2.11 3.94 8.46 10.7 BM 4.13 - 7.88 3.77 12.8 9.52 CF 2.11 7.88 - 2.92 8.44 12.8 CM 3.94 3.77 2.92 - 7.64 6.92 WF 8.46 12.8 8.44 7.64 - 4.47 WM 10.7 9.52 12.8 6.92 4.47 -