Dissertation
Life in the city – adaptive evolution of urban eastern water dragons
University of the Sunshine Coast, Queensland
Doctor of Philosophy, University of the Sunshine Coast, Queensland
2023
DOI:
https://doi.org/10.25907/00736
Abstract
As we enter the Anthropocene, city growth is unprecedented in its magnitude and rate, therefore it is imperative that we understand the consequences of, and mechanisms by which, animals can respond to a life within the city. Using the eastern water dragon as a study species I explore the process of selection and diversification in the city.
Here, I investigate the genomic basis for urban adaptation by identifying putatively adaptative loci between eastern water dragon in city park and native riparian habitats. Further, I demonstrate that city parks exhibit a small, but unique number of loci that are likely candidates for localised selection within the city. These findings suggest that adaptive divergence between city park and native riparian habitats may occur over a finer scale matrix of environmental differences driving localised selection between city park populations.
To build on this first chapter, I demonstrate that selection is acting to drive divergence of snout-vent length and jaw width across native riparian populations that are geographically isolated and across city park populations that are geographically close yet isolated by an urban matrix. These findings suggest that local adaptation may be occurring over exceptionally small geographic and temporal scales within a single metropolis, demonstrating that city parks can act as archipelagos for the study of rapid evolution.
In the final research chapter, Chapter four, I investigate deviations from Mendelian inheritance in an urban free-living population of eastern water dragons. This refers to the preferential transmission of one allele over another at a particular locus from parents to their offspring, a process that can drive the frequency of alleles in a population. Here, I demonstrate the differential success of genotypes acting in opposing directions across three life history stages. This work suggests there is a balance of conflicting fitness advantages and opposing selection pressures across life history stages. These findings pose a potential mechanism for the maintenance of diversity within city populations, which are frequently affected by drift and small effective population sizes.
Together this work is a major step forward in understanding how city life impacts wild native vertebrate species and highlights the potential cities present for the study of fundamental questions in evolutionary biology.
Details
- Title
- Life in the city – adaptive evolution of urban eastern water dragons
- Authors
- Nicola Jackson - University of the Sunshine Coast, Queensland, School of Science, Technology and Engineering
- Contributors
- Dominique Potvin (Supervisor) - University of the Sunshine Coast, Queensland, School of Science, Technology and Engineering
- Awarding institution
- University of the Sunshine Coast, Queensland
- Degree awarded
- Doctor of Philosophy
- Publisher
- University of the Sunshine Coast, Queensland
- DOI
- 10.25907/00736
- Organisation Unit
- University of the Sunshine Coast, Queensland; School of Science, Technology and Engineering
- Language
- English
- Record Identifier
- 99704997802621
- Output Type
- Dissertation
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