UC San Diego

The application of environmental DNA (eDNA) methods in tropical environments has been limited due to assumptions of poor preservation of genomic material given drastic climate variations (high temperature, soil acidity, high precipitation). However, improvements in technologies and methods (Orlando et al 2021; Shapiro et al 2019; Rizzi et al 2012; Mumy et al 2004; Miller et al 1999) have made it possible to extract and sequence highly degraded DNA (aDNA) from some tropical environments, drastically changing our previous understanding of DNA preservation capacities. Addressing the need to reclaim material from archaeological collections, I visited the Paleogenomics lab at the University of California Santa Cruz (UCSC) and performed DNA extraction experiments on sediment samples from three archaeological sites in Borikén (Puerto Rico) - Tierras Nuevas, Cueva María de la Cruz, and Puerto del Rey - in search of the presence of aDNA, and the levels of degradation they present. The ability to extract genomic material from tropical sediments, could provide high value proxy data to inquiry past climate, migration patterns, biomonitoring, and landscape formation processes, in addition to providing mitigation strategies to deal with the ongoing curation crisis exacerbated by the colonial system.