Recovery of DNA and pollen from New Zealand lake sediments

An undisturbed sediment core taken from Round Lake, Hawke's Bay, New Zealand, using a specially designed sterile sampler, has been dated by tephra analysis and radiocarbon and analysed for pollen, charcoal and DNA. It appears to cover the last ca. 3600 years. There are clear indications of Maori effects on vegetation from ca. 800 BP. DNA was extracted from the core and amplified using bacterial and a range of other PCR primers targeting human and other animal mtDNA sequences. Cloned bacterial DNA sequences from just above the Taupo tephra (dated to AD 217-247) produced 98% and 99% similarity matches with human faecal bacteria. The 98% match was to the human gut bacterial genus Prevotella. This genus can, however, be found in a range of animal (including insect) guts. Extracted DNA was matched closely to the New Zealand native fish species Gobiomorphus cotidianus. Further work is needed to establish unequivocally that no DNA movement through the profile is occurring, but these results suggest a new technique of potentially revolutionary importance for Quaternary research. (c) 2007 Elsevier Ltd and INQUA. All rights reserved.