Plant DNA in Prehistoric Coprolites: Evidence of Diet or Contamination?

Karl J. Reinhard (1), Sergio Miranda, and Alena Iñiguez (2)
    (1) School of Natural Resource Sciences, 214 Bessey Hall, University of Nebraska - Lincoln, Lincoln, NE 68588-0340
    (2) Fundação Oswaldo Cruz, Escola Nacional de Saúde Pública (ENSP), Departamento de Endemias Samuel Pessoa, Rua Leopoldo Bulhões 1480, térreo - Manguinhos, Cep 21041-210 Rio de Janeiro, RJ, Brasil

DNA from Hinds Cave coprolites dating to more than 2,000 years ago included chloroplast DNA sequences. The chloroplast sequences were interpreted as evidence of diet. We analyzed 19 Hinds Cave coprolites to evaluate the potential sources of the chloroplast DNA. Using the latest applications of phytolith analysis and pollen concetration, we determined that many of the chloroplast sequences are likely contaminants from ambient pollen. We then propose a methodology of excavation and analysis that will increase the utility of molecular methods applied to the reconstruction of diet and environment in ancient times from coprolites.