Diet-breadth analysis in the american southwest: metabarcoding method with coprolites

Molecular analysis of coprolites is proposed as new means of studying bio-archaeological remains that aids in the ability to capture diet breadth from past populations. This research utilizes the targeted PCR method, known as metabarcoding, to study dietary elements preserved in the coprolites from three greater Southwest sites. The Illumina MiSeq technology was used to sequence the samples after multiple rounds of targeted PCR using two primers (16s and 12s) proven successful for taxonomic identification with animal DNA and one primer specific to plant DNA (Rias et al 2011). The sequencing data was then run through two different bioinformatics pipelines that yielded varied results. The molecular analysis of coprolites did not yield any sequences of maize DNA; however, presence of maize in the control soil samples suggest an error in the amplification of processed and digested maize. The use of the 16s and 12s primers successfully added to the knowledge of our understanding of diet breadth for the three selected sites--and furthermore for the greater Southwest. The use of the plant specific primer was not as insightful as previously conducted microremains analysis; however, one of the two bioinformatics approaches yielded at least one sample with significant confidence of cacao DNA--potentially some of the earliest diet in the region (Crown and Hurst 2008).