The findings, published online today (Thursday, July 24) by the journal Science, at the Science Express website, challenges the prevailing theory of microbial biodiversity.
It is well accepted in evolutionary science that species of animals and plants are more closely related when they are geographically near each other. When it comes to the tiny world of microbes, however, most scientists believe that different evolutionary rules apply.
"The current dogma has been that, for microbes, what determines diversity is not geographic distance but specific environments," said John Taylor, professor of plant and microbial biology at UC Berkeley's College of Natural Resources and the head of the lab where the study was conducted. "The motto for microbes has been, 'Everything is everywhere, but the environment selects.' "
To test this theory, Rachel Whitaker, a UC Berkeley graduate student in Taylor's lab and lead author of the paper, trekked around the globe - by helicopter in some remote areas - to collect samples of a microbe called Sulfolobus islandicus, which thrives in the extreme environments of geothermal hot springs and volcanic vents. Sulfolobus microbes belong to the domain archaea - discovered in the 1970s - and can withstand highly acidic conditions and temperatures as high as 180 degrees Fahrenheit.
The samples were collected from the Mutnovsky Volcano and the Uzon Caldera-Geyser Valley region on the Kamchatka Peninsula in eastern Russia, the Lassen Volcanic and Yellowstone national parks in North America, and the volcanic region of western Iceland.
The researchers' analysis also includes a large portion of previously collected Sulfolobus samples that were provided by co-author Dennis Grogan, associate professor of bio
Contact: Sarah Yang
University of California - Berkeley