@phdthesis{Treplin2006, author = {Treplin, Simone}, title = {Inference of phylogenetic relationships in passerine birds (Aves: Passeriformes) using new molecular markers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-11230}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {The aim of this study was to provide deeper insights in passerine phylogenetic relationships using new molecular markers. The monophyly of the largest avian order Passeriformes (~59\% of all living birds) and the division into its suborders suboscines and oscines are well established. Phylogenetic relationships within the group have been extremely puzzling, as most of the evolutionary lineages originated through rapid radiation. Numerous studies have hypothesised conflicting passerine phylogenies and have repeatedly stimulated further research with new markers. In the present study, I used three different approaches to contribute to the ongoing phylogenetic debate in Passeriformes. I investigated the recently introduced gene ZENK for its phylogenetic utility for passerine systematics in combination and comparison to three already established nuclear markers. My phylogenetic analyses of a comprehensive data set yielded highly resolved, consistent and strongly supported trees. I was able to show the high utility of ZENK for elucidating phylogenetic relationships within Passeriformes. For the second and third approach, I used chicken repeat 1 (CR1) retrotransposons as phylogenetic markers. I presented two specific CR1 insertions as apomorphic characters, whose presence/absence pattern significantly contributed to the resolution of a particular phylogenetic uncertainty, namely the position of the rockfowl species Picathartes spp. in the passerine tree. Based on my results, I suggest a closer relationship of these birds to crows, ravens, jays, and allies. For the third approach, I showed that CR1 sequences contain phylogenetic signal and investigated their applicability in more detail. In this context, I screened for CR1 elements in different passerine birds, used sequences of several loci to construct phylogenetic trees, and evaluated their reliability. I was able to corroborate existing hypotheses and provide strong evidence for some new hypotheses, e.g. I suggest a revision of the taxa Corvidae and Corvinae as vireos are closer related to crows, ravens, and allies. The subdivision of the Passerida into three superfamilies, Sylvioidea, Passeroidea, and Muscicapoidea was strongly supported. I found evidence for a split within Sylvioidea into two clades, one consisting of tits and the other comprising warblers, bulbuls, laughingthrushes, whitethroats, and allies. Whereas Passeridae appear to be paraphyletic, monophyly of weavers and estrild finches as a separate clade was strongly supported. The sister taxon relationships of dippers and the thrushes/flycatcher/chat assemblage was corroborated and I suggest a closer relationship of waxwings and kinglets to wrens, tree-creepers, and nuthatches.}, language = {en} } @phdthesis{Feulner2006, author = {Feulner, Philine}, title = {Adaptive radiation, speciation, and reproductive isolation in African weakly electric fish : (Genus Campylomormyrus, Mormyridae, Teleostei)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-9560}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {The ultimate aim of this study is to better understand the relevance of weak electricity in the adaptive radiation of the African mormyrid fish. The chosen model taxon, the genus Campylomormyrus, exhibits a wide diversity of electric organ discharge (EOD) waveform types. Their EOD is age, sex, and species specific and is an important character for discriminating among species that are otherwise cryptic. After having established a complementary set of molecular markers, I examined the radiation of Campylomormyrus by a combined approach of molecular data (sequence data from the mitochondrial cytochrome b and the nuclear S7 ribosomal protein gene, as well as 18 microsatellite loci, especially developed for the genus Campylomormyrus), observation of ontogeny and diversification of EOD waveform, and morphometric analysis of relevant morphological traits. I built up the first convincing phylogenetic hypothesis for the genus Campylomormyrus. Taking advantage of microsatellite data, the identified phylogenetic clades proved to be reproductively isolated biological species. This way I detected at least six species occurring in sympatry near Brazzaville/Kinshasa (Congo Basin). By combining molecular data and EOD analyses, I could show that there are three cryptic species, characterised by their own adult EOD types, hidden under a common juvenile EOD form. In addition, I confirmed that adult male EOD is species-specific and is more different among closely related species than among more distantly related ones. This result and the observation that the EOD changes with maturity suggest its function as a reproductive isolation mechanism. As a result of my morphometric shape analysis, I could assign species types to the identified reproductively isolated groups to produce a sound taxonomy of the group. Besides this, I could also identify morphological traits relevant for the divergences between the identified species. Among them, the variations I found in the shape of the trunk-like snout, suggest the presence of different trophic specializations; therefore, this trait might have been involved in the ecological radiation of the group. In conclusion, I provided a convincing scenario envisioning an adaptive radiation of weakly electric fish triggered by sexual selection via assortative mating due to differences in EOD characteristics, but caused by a divergent selection of morphological traits correlated with the feeding ecology.}, subject = {Phylogenie}, language = {en} }