Meyer, Britta Silke. A multi-marker perspective on the evolutionary history of East African cichlid fishes. 2015, PhD Thesis, University of Basel, Faculty of Science.
Restricted to Repository staff only until 1 May 2017.
Official URL: http://edoc.unibas.ch/diss/DissB_11245
In my thesis I mainly aimed to generate a solid phylogenetic framework for the cichlid tribes of Lake Tanganyika and hence to get insights to macroevolutionary processes. I developed a broad range of primers and applied next generation sequencing methods, resulting in the most comprehensive sequence-based multi-marker set for Lake Tanganyikan cichlids so far. Further I applied phylogenetic inferences and other methods based on the theory of molecular evolution to phylogeographic and other evolutionary questions (e.g. gene diversity).
The first two chapters of this thesis were driven by the question if more information from different genes would help to resolve the phylogenetic relationship of the major tribes within Lake Tanganyika. Based on the resulting dataset we could propose new hypotheses for the evolutionary history of the East African cichlids.
In the third chapter we report the occurrence of a new cichlid species, found in Lake Tanganyika. Using two nuclear and two mitochondrial markers and conducting different phylogenetic analyses, we detected its genetic affiliation to the haplochromine cichlids of the Lake Victoria superflock. We hypothesize that faunal exchange across in East African watersheds and, hence, between isolated ichthyofaunas, is more common than previously thought.
In the fourth chapter I contributed to the study of the molecular basis of the egg spots, which are a novel phenotypic color trait within the most species-rich lineage of the haplochromines. To investigate the underlying genetics of the egg spots it was crucial to have a proper phylogenetic hypothesis at hand. To this end, I generated a new phylogeny of the haplochromines, thus providing a solid basis for the assumptions of the trait emergence and consequently the experiments.
In the last chapter I present ongoing work, in which we explore the covariations of trophic morphology, trophic level, diet, body shape, macro-parasitism and MHC genes to investigate the contribution of parasite-mediated selection in this adaptive radiation. We showed that the trophic-morphological axis of diversification in Lake Tanganyika cichlids is strongly correlated with infection levels of metazoan macroparasites. We further detect correlation between these parasites and MHC constitution. This gives insights to the potential influence of parasitism and immunogenetic adaptations to the Lake Tanganyika cichlid radiation.
|Committee Members:||Pfenninger, Markus|
|Faculties and Departments:||05 Faculty of Science > Departement Umweltwissenschaften > Zoologisches Institut > Evolutionary Biology (Salzburger)|
|Bibsysno:||Link to catalogue|
|Number of Pages:||179 S.|
|Last Modified:||30 Jun 2016 10:57|
|Deposited On:||12 Jun 2015 08:30|
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