Katie McCormack

The legacy of the Transatlantic Slave Trade is evident in the diverse identities and genetic ancestries found in the Caribbean today. Beginning in the 16th century, an estimated three million enslaved African people were forcibly relocated from western and central Africa to the Americas. Although a resulting admixture of African, European, and Native American peoples has been documented, the heterogeneity of modern Caribbean populations is not reflected in national histories that exclude marginalized communities. Our study aims to document these patterns of genetic ancestry in Afro-Puerto Rican communities. Previous research on the maternal ancestry of these communities found that 68% of individuals had maternally-inherited haplotypes of African origin; however, less is known about their paternal ancestry. To this end, we used Pyrosequencing to genotype diagnostic SNPs for Y Chromosome haplogroups in 28 Afro-Puerto Rican men. Because the Y Chromosome is uniparentally inherited through men to men, this technique provides insights into the patterns of paternal ancestry in the population. The vast majority of men had African paternal ancestry while a minority had Indigenous paternal ancestry, suggesting that both African and Indigenous Caribbean men were formative in shaping contemporary Afro-Puerto Rican communities. These findings also demonstrate a complex ancestry of Afro-Puerto Ricans that is distinct from that of the general Puerto Rican populace. Additional studies will provide a fuller understanding of the interactions between populations throughout Caribbean history.

Katie McCormack is a first-year Ph.D. student in the Anthropology department at Vanderbilt University. Her research focuses on using genetic methods to answer questions related to disease and the history of colonialism in the Caribbean. She holds a B.S. in Biology and Anthropology from William & Mary.