Adaptive Radiation of Niche Specialists in Experimental Microcosms

University Of Houston, Houston TX

Investigators

Abstract

The proposed research is a series of experiments that directly examine the causes of adaptive radiation and its effects on populations and communities of organisms over short and long time scales. Populations of the bacterium Escherichia coli will be used as a model system. The rapid generation time and the ability to viably store bacterial cells at -80C allow direct observation of adaptive radiation and direct comparison of ancestral and descendent individuals. Previous research has already demonstrated that adaptive radiation can occur in experimental populations of bacteria, our studies will be the first to systematically determine the effects of multiple factors (environmental and genetic) on replicated populations. Adaptive radiation is a fundamental process in the evolution of biodiversity. Many of the well-known examples of evolution are of adaptive radiation, including Darwin's Finches, Hawaiian Honeycreepers, and African cichlids. However, the factors causing and shaping adaptive radiation are only partially understood, primarily since the history of life can only be investigated indirectly. Because of this, essential information on phylogenetic history and environmental conditions is often imprecise. Species interactions are particularly difficult to study as they are neither prone to fossilization nor do they appear to have systematic effects on diversity.