XVI International Botanical Congess

Glacial ice is a natural air-sampling mechanism that entraps microorganisms. It provides a unique source of viable microorganisms and/or preserved nucleic acids that allows study of both contemporary and ancient biological diversity. Ice cores up to 140,000 years old have been examined. Some recovered nucleic acid sequences were nearly identical to those from contemporary microorganisms and viruses, while others were distant from any sequences available from current databases. Viable fungal and bacterial isolates, as well as viral RNAs, were successfully isolated from cores up to 140,000 years old, leading to the conclusion that these organisms may be released into the environment during glacial calving and melting. Such releases might impact calculated mutation rates, evolutionary rates, and gene flow, via temporal recycling of genes and genotypes. It may explain the disappearance and sudden reappearance of some microorganisms and viruses, including those that are pathogenic.