Progress has brought new information to bear on the long-debated question of what exactly constitutes a bacterial species. It has also clarified the role of random events in the distribution of such species: randomness appears to be a substantial, although not all-powerful, influence.

The newest techniques can analyze specific functional capabilities of bacteria, such as their ability to metabolize particular molecules. Moreover, some techniques can analyze multiple capabilities in parallel. These are being combined with accurate and sensitive measurement techniques. Such research is yielding new understanding of how microbial populations shift in response to environmental change, a question that is likely to loom larger as freshwater becomes a more limiting resource for human populations.

After noon EST on February 1, the full text of the article will be available for free download through the copy of this Press Release available at http://www.aibs.org/bioscience-press-releases/

BioScience is the monthly journal of the American Institute of Biological Sciences (AIBS). BioScience publishes commentary and peer-reviewed articles covering a wide range of biological fields, with a focus on "Organisms from Molecules to the Environment." The journal has been published since 1964. AIBS is an umbrella organization for professional scientific societies and organizations that are involved with biology. It represents some 200 member societies and organizations with a combined membership of about 250,000.

The complete list of research articles in the February 2008 issue of BioScience is as follows:

Progress in the Ecological Genetics and Biodiversity of Freshwater Bacteria.
Jürg B. Logue, Helmut Bürgmann, and Christopher T. Robinson

The Green Algal Underground: Evolutionary Secrets of Desert Cells.
Zoe G. Cardon, Dennis W. Gray, and Louise A. Lewis.

The Demise of Fire and "Mesophication" of Forests in the Eastern United States.
Gregory J. Nowacki and Marc D. Abrams.

Beyond Urban Legends: An Emerging Framework of Urban Ecology, as Illustrated by the Baltimore Ecosystem Study.
Steward T. A. Pickett and colleagues

Plant Diversity in the Human Diet: Weak Phylogenetic Signal Indicates Breadth.
Serban Proches, John R. U. Wilson, Jana C. Vamosi, and David M. Richardson

Assessment of Research Performance in Biology: How Well Do Peer Review and Bibliometry Correlate?
Barry G. Lovegrove and Stephen D. Johnson.

Rotenone: An Essential but Demonized Tool for Assessing Marine Fish Diversity.
D. Ross Robertson and William F. Smith-Vaniz.