Why collect DNA samples from people of African descent living in Charleston today?
We were awarded funding from the National Geographic Society to assess the genetic diversity of the 36 individuals buried near Anson Street. This research traced their ancestral roots in Africa and sought to determine if they are related to each other. We chose to engage the community in this DNA research by offering 80 people of African descent free DNA tests, providing participants with the opportunity to learn about their genetic history. Documentary records containing historical information about individual or family identities are often incomplete or missing due processes of enslavement, leaving open questions regarding ancestry and genealogy for people of African descent. Genetics can help recover some of this lost history by illuminating biological connections to African source populations.
Participants were able to see where their mtDNA or maternal lineage traces back to in Africa - or wherever - and similarly where their paternal lineage (Y-chromosome) originated. The autosomal SNP (Single-nucleotide polymorphisms) data allows people to see where all of their ancestors from both mother's and father's sides of the family come from. The different geographic components of their SNPs will indicate varying "amounts" of ancestry from different regions of Africa or perhaps also Europe, the Americas and other places, depending on the nature of their family trees. Here, we are ascertaining what their genomes tell us about their long genealogical histories.
What will we do?
In May 2018, our colleagues, Dr. Theodore Schurr and Ms. Raquel Fleskes, at the University of Pennsylvania, collected 30 DNA samples from living individuals of African descent. In July and August 2018, College of Charleston student, Adeyemi Oduwole, analyzed this material at the University of Pennsylvania, with the support of the National Geographic Society. The results of the analysis of modern DNA variation provides an initial view of genetic diversity in Charleston that can be compared with that obtained from the Anson Street burials and enabled community members to learn about their genetic ancestry. Dr. Ofunniyin and Joanna Gilmore collected 50 more DNA samples from living individuals in September 2018, which were analyzed at the University of Pennsylvania through Fall 2018. Mitochondrial DNA (which reflects maternal ancestry) and autosomal DNA (which reflects bi-parental ancestry) was analyzed using the GenoChip 2.0 testing kit. Our goals were as follows:
Examine the maternal, paternal, and bi-parental ancestries of African descended persons whose ancestors were brought to North America in the trans-Atlantic slave trade. The genetic data will be compared to those of reference populations, and used to evaluate participant’s biological connections to Africa.
Characterize levels of genetic diversity in contemporary African Americans living in Charleston to illuminate its history as a ‘gateway’ city.
Compare the ancestry and diversity of the contemporary Charleston individuals with that of the Anson Street individuals to explore continuity or changes in genetic diversity over time. We expect that the contemporary individuals will have higher levels of diversity in comparison to the archaeological individuals due to 200 years of population movement into the city, but that the two groups will exhibit similar patterns of genetic ancestry due to shared demographic histories.
All DNA testing results will be shared with participants in full.
Any public reporting of these findings will be made such that participant identities are anonymized.