"Exploration of this newly discovered 'rare biosphere' could become a major field of marine biology."
Says Dr. Sogin: "We know we're going through global change and micro organisms are vital to our survival. What we do not know is the role of low-abundance microbial populations that have persisted over large evolutionary time scales. We need to understand their diversity and how they work, to anticipate which species can be expected to adapt and how quickly, and to grasp how such other forces as competition and resource availability drive evolutionary change."
Possible Roles of Rare Microbes in Nature
While a small number of different kinds of bacteria dominated all samples studied, thousands of low-abundance populations represented an overwhelming majority of the novel diversity. Dr. Sogin says: "The most intriguing immediate questions are: How and why do these many different populations of low abundance organisms exist at all; why are they still here?"
"It's possible these rare organisms are present in high numbers at some locations and their low abundance at other sites is a consequence of diffusion and dispersal. However we believe they must have some importance to the marine ecosystem and can theorize a couple of possible roles."
One is that they are keystone life forms micro organisms that exist in low numbers but have some important function within the community, producing perhaps some essential compound.
Alternatively, these rare, low-abundance organisms, which are less prone to predation and direct competition with dominant species, may exist throughout the oceans. If environmental change precludes the growth of dominant populations, members of the rar
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Contact: Terry Collins
terrycollins@rogers.com
416-538-8712
Census of Marine Life
31-Jul-2006