Analysis of Post-Cranial Traits for the Assessment of Biological Distance among Temporally Distinct New World Populations of African Descent

This investigation examines change in post-cranial osteometric markers in temporally distinct New World populations of African ancestry: Newton Plantation series (17th-19th century Barbados; N = 16); two subsamples from the Hamann-Todd (HT) series (U.S.) based on birth year, 1865-1900 (N = 66) and 1901-1915 (N = 62); and the Forensic Databank Collection (FDB) (20th century U.S.; N = 137). It was anticipated that individuals from Newton would exhibit less admixture than those from H-T or FDB. They were also predicted to demonstrate greater skeletal robusticity due to mechanical loading. Additionally, it was expected that stature would increase over time due to better nutrition and healthcare. Nineteen measurements were taken on the os coxae, femur, and tibia. Crural and platymetric indices were calculated to assess admixture. Stature and robusticity were utilized to evaluate environmental variation. Statistical methods included linear regression, one-way ANOVA, and Principal Component Analysis (PCA). Platymeric index means for all groups were in the range of African Americans. Crural index indicated a temporal trend toward European values in both sexes. Surprisingly, robusticity was increasing rather than decreasing over time, with greater robusticity ratios seen in females. Similar workloads, better nutrition, and weight gain likely contributed to this. Stature also showed a temporal increase for both males and females, most likely due to better nutrition. PCA indicated that most measurements clustered positively over time, with transverse measurements at joints and bone lengths having the most notable correlations. These findings support the project hypotheses and demonstrate the value of using analysis of post-cranial remains to explore the African American experience