Biogeography: Is everything everywhere?

Many microbial ecologists have come to believe that microbes are not infinitely mobile as was once thought. DNA studies have given a more detailed picture of microbial diversity that, argue some, demands a more nuanced view of microbial ecology. Those nuances have spawned a debate over what the DNA data actually show and how a molecular view of microbial diversity can be compared with our species-based view of plant and animal ecology. Answering those questions, in turn, will help scientists better understand the crucial role played by microbes in keeping our ecosystem livable.