Doctoral Dissertation Research: Morphological biodistances as indicators of slave trade migration histories in the African Diaspora

Millions of people were displaced due to slave trade during the 15th – 19th centuries. These systems profoundly influenced population dynamics as enslaved people were transported thousands of miles from their homes and experienced restricted social life and mobility in enslavement. This doctoral dissertation project examines skeletal morphology of these enslaved people and their descendants to understand how certain biological groups formed and changed over time, explores gene flow and other evolutionary processes that may explain how the biological variation is distributed, and investigates patterns of biological relatedness that may not be reflected in historic migration data.

The project supports the doctoral training of a student from an underrepresented group in science, a multi-point research collaboration, outreach with community members, and student mentoring. The project also develops curricula and seminars in collaboration with the University of Florida’s College Reach Out Program to increase postsecondary admission and completion for students from groups historically underrepresented in STEM research.

This project’s theoretical framework is rooted in stochastic microevolutionary expectations and diaspora studies. Microevolutionary processes such as population stratification are inferred from the premise that gene flow, rather than natural selection, is the main influence on observed biological patterns. Further, interpretations gleaned from the project derive from slave trade history, where European nations directly influenced the gene flow of the diaspora populations that formed across the Atlantic.

The project asks two central questions: (1) What African and Afro-descendant diaspora groups show high biological relatedness as estimated by cranial morphology, and how do these data identify evidence of gene flow not otherwise described by historical migration data? and, (2) Given the social and legal restrictions that created physical separation among enslaved persons, do diaspora groups show stronger evidence of population stratification and genetic isolation than African groups? To investigate these questions, this project applies geometric morphometric methods to collect 3D landmarks from adult human cranial remains and uses these data to statistically analyze within-group and between-group variation in cranial morphology.

Data will be collected from twenty-one sites, comprising cranial remains of 805 adult African descendants. These samples represent a variety of regions.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.