BLOWIN' IN THE WIND, ROLLIN' ON A RIVER: CAN BACTERIA CONTROL THEIR DISPERSAL, DISTRIBUTION, AND POPULATION STRUCTURE?

J.V. McArthur. Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina 29802

Bacteria are everywhere and they have been getting there longer than all other organisms combined. Should we expect patterns in the dispersal or population structure of these seemingly cosmopolitan panmictic organisms? The answer is that although bacteria are everywhere not all bacteria are. Ecologists still continue to lump bacteria into a single taxonomic unit and thus mask their unique and fascinating patterns in nature. Furthermore, there are intriguing observations that suggest that bacteria partially control their dispersal from waves, rivers, and terrestrial environments by affecting large scale physical processes. Interlaced on these large scale processes are patterns in bacterial distribution and structure that are clearly the results of environmental selection. Patterns are expressed at the community and population. The distribution of bacterial species and their genes are not necessarily congruent. Bacterial genes may have different distributions from the organisms that house them. These genes seem to control their own distribution. Bacteria use other organisms (including macroinvertebrates) to maintain their distribution, often affecting the behavior and even the sex of the macro-organisms involved. 3.8 billion years ago bacteria came into being…they are still with us today. Perhaps by studying the most ancient creatures we can better understand processes acting on higher organisms.