Chapter 31 : A Glimpse into Microevolution in Nature

Abstract:

It is a known fact that bacteria (and archaea) are genetically, phylogenetically, and physiologically very diverse. Microbial microevolution has been and is still being analyzed in very elegant laboratory experiments in which microbes are allowed to mutate, adapt, and evolve in test tubes under very stringent and therefore reproducible and adjustable conditions. The "Evolution Canyon" (EC) system in Israel turned out to be a suitable sampling place for such microevolutionary studies. For more than 20 years, adaptation and speciation of macroorganisms have been explored in EC, with Drosophila flies and wild barley being two of the most prominent model organisms. Compared to proteins and genomes, the cell membrane is hardly in the focus of mainstream research. The potential research topics appear to be endless. The author focuses on addressing some of these issues, and expects that comparative genome sequence comparisons will soon aid one in understanding how these evolutionary changes are implemented on the molecular level of genes and their expression. It is perhaps too naïve to expect that the observed traits indeed evolved precisely in those sites from where the Bacillus simplex bacteria have been isolated, taking into account that there are probably thousands of such east-west-directed canyons on the globe and that sporulating bacteria like bacilli easily migrate with the wind from continent to continent. But most probably, such sharp microclimatic contrasts in immediate proximity reinforce within-species evolutionary splits, and therefore EC represents a beautiful site to study microevolution in natural habitats.