Sogin, Mitchell L.; Morrison, Hilary G.; Huber, Julie A.; Welsch, David Mark; Huse, Susan M.; Neal, Phillip R.; Arrieta, Jesus M.; Herndl, Gerhard J.

Proceedings of the National Academy of Sciences of the United States of America (2006), 103(32), 12115-12120 CODEN: PNASA6; ISSN: 0027-8424. English.

The evolution of marine microbes over billions of years predicts microbial community composition should be much greater than published ests. of a few thousand distinct types of microbes/L seawater. By adopting a massively parallel tag sequencing strategy, the authors showed deep water mass bacterial communities in the North Atlantic and diffuse flow hydrothermal vents are 1-2 orders of magnitude more complex than previously reported for any microbial environment. A relatively small number of different populations dominated all samples, but thousands of low-abundance populations accounted for most of the observed phylogenetic diversity. This rare biosphere is very ancient and may represent a nearly inexhaustible source of genomic innovation. Members of the rare biosphere are highly divergent from each other and, at different times in earth history, may have profoundly affected planetary processes.