Information Services banner Edinburgh Research Archive The University of Edinburgh crest

Edinburgh Research Archive >
Biological Sciences, School of >
Biological Sciences thesis and dissertation collection >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1842/3977

This item has been viewed 87 times in the last year. View Statistics

Files in This Item:

File Description SizeFormat
Hall2009.pdf2.43 MBAdobe PDFView/Open
Title: Experimental evolution with bacteria in complex environments
Authors: Hall, Alex R.
Supervisor(s): Colegrave, Nick
West, Stuart
Issue Date: 2009
Publisher: The University of Edinburgh
Abstract: Experiments with microbes are a powerful tool for addressing general questions in evolutionary ecology. Microbial evolution is also interesting in its own right, and often clinically relevant. I have used experimental evolution of bacteria (Pseudomonas spp.) in controlled laboratory environments to investigate the role of environmental heterogeneity in the evolution of phenotypic diversity. Some of my results provide insight on general processes, while others are specific to bacteria. (1) I have shown that variation in resource supply affects the evolution of niche breadth in complex environments containing a range of available resources, leading to a peak in phenotypic diversity at intermediate levels. (2) I have found that resource availability also affects selection against redundant phenotypic characters, which is strongest when resources are scarce. (3) Using experiments with bacteria and their protozoan predators, I have found that selection for predator resistance varies with resource supply during a model adaptive radiation. (4) I have looked at the role of periodic bottlenecks in population size in the evolution of antibiotic-resistant bacteria. My results highlight the importance of biochemical constraints specific to different resistance mutations. (5) Finally, I have shown that bacterial adaptation to novel carbon substrates affects different growth parameters simultaneously, and that the same response is seen in environments that maintain different levels of phenotypic diversity. These findings emphasize the role of environmental heterogeneity in the evolution of phenotypic diversity, but also show how ecological and genetic factors can constrain adaptation to a given niche within a heterogeneous environment.
Sponsor(s): Biotechnology and Biological Sciences Research Council (BBSRC)
Keywords: evolutionary ecology
Microbial evolution
phenotypic diversity
environmental heterogeneity
URI: http://hdl.handle.net/1842/3977
Appears in Collections:Biological Sciences thesis and dissertation collection

Items in ERA are protected by copyright, with all rights reserved, unless otherwise indicated.

 

Valid XHTML 1.0! Unless explicitly stated otherwise, all material is copyright © The University of Edinburgh 2013, and/or the original authors. Privacy and Cookies Policy