In this thesis I set out to further our understanding of the causes and consequences of genetic variation after colonisation events. Specifically, I focused on how historical processes shape genetic diversity and to what extent we can link colonisation history, genetic diversity, individual fitness and population viability. To achieve this, I used a combination of molecular markers, analytical tools and the common wall lizard, Podarcis muralis as a study system. I first infer the origin and genetic architecture of isolated population on islands at the range margin, in relation to mainland populations, to determine whether their current distribution and genetic structure are a result of a historical colonisation event or a more recent introduction. I then unravel the details of human-mediated introductions of P. muralis in England to further test which factors affect their genetic structure. I ask about the contribution of multiple introductions and admixture, the importance of number of founders and the year since their introduction and whether bottleneck events during primary and /or secondary introduction predict the level of genetic diversity in the non-native range. Throughout this study I obtain information on population genetic structure and composition from both native and non-native ranges. This is essential since the (complex) phylogeographic structure of P. muralis in the native range determines the distribution and structure of genetic diversity from which colonists are drawn and the details of colonisation will then reflect in the genetics of non-native populations. Lastly, I assess the consequences of colonisation on reproductive fitness and test for heterozygosity fitness correlations at the individual and population level. Overall, this thesis demonstrates why reconstructing the colonisation history is important when aiming to understand the causes and consequences of genetic variation during colonisation. This information is critical when assessing the relationship between genetic diversity and establishment success. Whether non-native populations have retained sufficient evolutionary potential to adapt to their new climate their long-term viability will be dictated by availability of suitable habitat rather than by internal population factors.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:711751 |
| Date | January 2015 |
| Creators | Michaelides, Sozor Nikos |
| Contributors | Uller, Tobias |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://ora.ox.ac.uk/objects/uuid:8d4979dd-febf-45cf-880b-eb9845f8b2be |
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