A novel commensal proxy for tracing indigenous interaction in the Ceramic Age Lesser Antilles, Caribbean: Ancient mitochondrial DNA of Agouti (Dasyprocta sp.)

The agouti (Dasyprocta sp.) was one of the many commensal species humans translocated to the Caribbean from South America as early as ca. A.D. 500. Their widespread archaeological presence in the Lesser Antilles, including on Carriacou, Grenada, makes them valuable proxies for reconstructing pre-Columbian human interactions between the islands and continent. This study applies a genetic commensal model to agouti, a novel commensal proxy offering an ideal opportunity for commensal research. Mitochondrial DNA (mtDNA) was extracted from archaeological agouti bones from seven sites across the Lesser Antilles. Of 30 tested, 26 specimens (Sabazan (n = 5) and Grand Bay (n = 19) on Carriacou, Macabou (n = 1) on Martinique, and BK77 Grand Case (n = 1) on Saint Martin) were successfully amplified. Analysis shows that archaeological sequences belong to Dasyprocta leporina and relate to a single continental clade, likely from northern South America or Trinidad. This is the first study to provide genetic evidence for species identification of archaeological Caribbean agouti. Results provide new data informing continental and Caribbean agouti population structure and offer insight into the origin and dissemination of agouti in the Caribbean. Agouti appear to have rapidly established viable, reproducing populations on Carriacou around ca. A.D. 400/600, but the population status on other islands is unclear. This study contributes to the ongoing discussion regarding the relationships between humans and continental translocates in the Caribbean and emphasizes the potential of the commensal model for the global study of ancient translocations and island interactions. Analytic findings are significant for the archaeological, ecological, and genetic study of the Caribbean and South America, prompting the need for continued study of Caribbean commensals and additional sampling focusing on pre-Columbian agouti from coastal South America. Results highlight the potential of the commensal model for the global study of ancient translocations and island interactions. This study also brings to light new data for both pre-Columbian and modern agouti, informing upon the Caribbean agouti’s taxonomic classification and population structure in the Caribbean and South America. Finally, results have implications for Caribbean ecology, refining the timing of potential ecological repercussions brought on by translocates in the islands.