At present, species are faced with a host of human-induced impacts that have already led to a loss of biodiversity and shifts in species’ ranges. Knowledge of the ecological and evolutionary processes of dynamic species’ ranges, that are either shifting or expanding, will be key to understanding the ability of species to persist and adapt during periods of environmental change. The aim of this thesis is to investigate the effects of range expansion on the genetics and evolution of species, and understand the processes that facilitate the spatial spread of populations. Using individual-based simulation models, this work demonstrates that the unique selective environment of range expansion can have a significant effect on spatial genetics and the evolution of life-history traits. It is found that the survival and spread of mutations, of various fitness effects, is influenced substantially by landscape features encountered by the expanding range. The incorporation of more specific genetic architecture shows that a substantially increased frequency of fitness peak shifts may occur on the edge of an expanding range than would arise within a stationary population. Range expansion is shown to select for increased dispersal and reproduction at the expense of competitive ability on the front of the expanding wave which results in an accelerating spread rate. The survival and spread of a population during range expansion is also affected substantially by the specific movement behaviour of individuals. The exact nature of suitable habitat, in terms of the number of suitable habitat patches and level of fragmentation, will also greatly affect the ability of a population to survive and spread during a period of environmental change. These findings are synthesised within a conceptual framework that is proposed for the evolution of populations during range expansion, where a flattening of the fitness landscape leads to adaptive revolutions.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:542622 |
| Date | January 2011 |
| Creators | Burton, Olivia Jean |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=167720 |
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