Forthcoming in Physiological and Biochemical Zoology, a fascinating new selection of papers collects leading experimental research in evolution and artificial selection, providing insight into how organisms adapt to changing environmental conditions and fluctuations.

Dr. James Hicks, Editor in Chief of PBZ, explains the momentum behind this collection of papers: "This exciting approach experimental evolution allows scientists to investigate the fundamental mechanisms of evolution. Prior to the advent of contemporary laboratory techniques, inferences about evolution were based on observation. Now, we can study evolutionary change as it is happening, by selecting organisms that change rapidly, such as the fruit fly or E. coli. This advantage allows scientists to investigate how changes occur and how they affect an organism's individual physiology and overall community."

In the July/August 2007 issue, the first of three issues that will contain articles from the collection, Bradley S. Hughes, Alistair J. Cullum, and Albert F. Bennett (University of California, Irvine) explore the effect on E. coli of fluctuating acidity, an especially important environmental factor for the bacteria.

E. coli may spend hundreds or thousands of generations in the relatively neutral-acidity colon, with brief exposure to the extreme acidity of the stomach and modest alkalinity in the small intestine during colonization of a new host. With modern sewage handling (or mishandling), the bacteria may also experience exposure to the ocean, with a pH near 8.0, before infecting a new host.

To assess how E. coli might adapt to different environmental conditions, the researchers observed four groups of bacteria. One group was exposed to constant acidity (pH of 5.3) and another to constant alkalinity (pH of 7.8). A third group was exposed to randomly fluctuating pH levels, and the fourth was exposed to pH levels that cycled d
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Contact: Suzanne Wu
swu@press.uchicago.edu
773-834-0386
University of Chicago Press Journals
29-May-2007