The 89th Annual Meeting of the American Association of Physical Anthropologists (2020)

Whole mitochondrial sequences reveal substantial heterogeneity within African descendants in the Caribbean


1Anthropology, Vanderbilt University, 2Vanderbilt Genetics Institute, Vanderbilt University

April 18, 2020 , Platinum Ballroom Add to calendar

The Caribbean took in an estimated 3 million enslaved African peoples during the Transatlantic Slave Trade (TAST). Puerto Rico specifically received about 16,000 of these individuals. Despite the relatively small number of enslaved people that were brought to Puerto Rico, there are gaps in knowledge about the impacts of the TAST on all aspects of island life. To this end, we consider mitochondrial diversity of Afro-Puerto Ricans (AfPRs) in order to comment on the demographic histories of AfPRs and other African descendants in the Americas. Building from our previous work, we expanded our sample size from 31 to 53 whole mitochondrial DNA sequences and compared them to data from various African and American populations. While 32% of the sample belonged to Indigenous American or Eurasian haplogroups, most individuals, 68%, belonged to a sub-Saharan African L type haplogroup. Of the L-types, 6% belonged to L0, 33% to L1, and 28% to L2 and 33% to L3. We used Fisher Freeman analysis to compare haplogroup distributions between Afro-Puerto Ricans and comparative populations with African descent. We found significant differences between AfPRs and comparative groups from US Americans (NHB), Kenya (LWK), Nigeria (YRI), and Haiti (p<0.05); while the remaining comparisons were not significantly different. Summary statistics indicated increased levels of nucleotide (>0.003) and gene diversity (>0.991), with the additional AfPR samples. Analysis of whole mitochondrial sequences from Afro- Puerto Ricans illustrates genetic diversity that is characteristic of African-descended populations, yet highlights heterogeneity among populations within the African Diaspora.


Slides/Poster (pdf)