Heliosperma (nom. cons prop.) comprises 15—20 taxa, most of them endemic to the Balkan Peninsula. DNA sequences from the chloroplast (rps16 intron, psbE-petG spacer) and the nuclear genome (ITS and four putatively unlinked RNA polymerase genes) are used to elucidate phylogenetic relationships within Heliosperma, and its position within Sileneae. Three main lineages are found within Heliosperma: Heliosperma alpestre, H. macranthum and the H. pusillum-clade. The relationships among the lineages differ between the plastid and the nuclear trees. Relative dates are used to discriminate among inter- and intralineage processes causing such incongruences, and ancient homoploid hybridisation is the most likely explanation. The chloroplast data strongly support two, geographically correlated clades in the H. pusillum-group, whereas the relationships appear poorly resolved by the ITS data, when analysed under a phylogenetic tree model. However, a network analysis finds a geographic structuring similar to that in the chloroplast data. Ancient vicariant divergence followed by hybridisation events best explains the observed pattern. The morphological and taxonomical diversity in the H. pusillum-group is possibly ecology-induced, and is not correlated with the molecular data. Phylogenetic patterns regarding the origin of Heliosperma are complicated, probably influenced by reticulate and sorting events. At least two ancient lineages have been involved in its evolution, one most closely related to Viscaria/Atocion and the other to Eudianthe/Petrocoptis. Atocion and Viscaria are sister genera, most species-rich on the Balkans, and including six/three species. Phylogenies do not support their traditional classification, and provide a framework for a taxonomic revision. Atocion compactum is found in three different positions in the chloroplast tree, and in a single clade in the nuclear gene trees. Using relative dates we demonstrate that hybridisation with subsequent chloroplast capture is a feasible explanation for the pattern observed. This, and other observed reticulate patterns, highlights the importance of hybridisation in plant evolution.

The duplication of genes followed by selection is perhaps the most prominent way in which molecular biological systems gain multiplicity, diversity and functional complexity in evolution. Whole genome duplications (WGDs) therefore have the potential of generating an extraordinary amount of evolutionary innovation. It is now accepted that the vertebrate lineage has gone through two rounds of WGD in its early stages, after the divergence of invertebrate chordates and before the emergence of jawed vertebrates. These basal vertebrate WGDs are called 2R for two rounds of whole genome duplication. An additional WGD called 3R occurred early in the evolution of teleost fishes, before the radiation of this species-rich group. This thesis describes the evolution of several endocrine and neuronal gene families in relation to the vertebrate WGDs, through a comparative genomic approach including both phylogenetic analyses and chromosomal location data across a wide range of vertebrate taxa. These results show that numerous endocrine gene families have expanded in 2R and in several cases also in 3R. These include the gene families of oxytocin and vasopressin receptors (OT/VP-R), somatostatin receptors (SSTR) and insulin-like growth factor binding proteins (IGFBP). For the OT/VP-R and SSTR families, previously undescribed subtypes were identified. The protein hormone family that includes growth hormone (GH), prolactin (PRL) and somatolactin (SL) acquired a new PRL gene in 2R, however the origins of GH, PRL and SL likely predate 2R. The corresponding family of receptors diversified during different time periods through a combination of local duplications and 3R. Neuronal gene families of the visual system have also expanded in 2R and 3R. The results presented here demonstrate that the vertebrate repertoire of visual opsin genes arose in 2R as part of chromosomal blocks that also include the OT/VP-R genes. The gene families including the transducin alpha, beta and gamma subunits also arose in 2R, hinting at the importance of these events in the diversification and specialization of phototransduction cascades for rods and cones. Thus, the whole genome duplications have been important contributors to the evolution of both vision and endocrine regulation in the vertebrates.

Black grouse (Tetrao tetrix) is a bird species with a lek mating system found in the Palearctic boreal taiga. It is assumed that it has a continuous distribution along Scandinavia and Siberia, whereas in Central Europe it has declined during the last decades. The primary objective of this thesis was to obtain a deeper understanding of the history, systematic classification and the genetic structure of black grouse on different geographical scales using microsatellites and control region mtDNA sequences (CR). I determined how much the mating system, habitat fragmentation and historical population processes have influenced the partitioning of genetic diversity in this species. Phylogeographical results are consistent with a demographic population expansion, and the patterns of postglacial dispersal suggest that a glacial refugium was located somewhere in central Asia, and from there black grouse spread out to Europe following the retreat of glacial ice sheets. I suggest that the two European black grouse subspecies, T. t. Tetrix and T. t. britannicus correspond to only one subspecies: T. t. tetrix, and that this lineage has diverged from T.t. viridanus, a subspecies found in Kazakhstan. The British population is significantly divergent from the remaining Eurasian samples for microsatellites but it is not for mtDNA. Therefore, they should regard as a separate Management Unit and not as a subspecies. Furthermore, British black grouse occur in three independent genetic units, corresponding to Wales, northern England/southern Scotland and northern Scotland. There was also genetic structure within Sweden. Habitat fragmentation is the main cause of population genetic structure in southern Swedish black grouse. In contrast, low levels of genetic differentiation and high connectivity were found in northern Sweden due to female-biased dispersal. On a finer geographical scale, I found genetic differences between leks due to a mixture of related and unrelated individuals within leks. However, mean relatedness values hardly differed from zero. Some leks were similar to one another and I interpret this as a result of variation in local reproductive success and philopatry. These factors would cause genetic structuring but this by itself would not reveal that kin selection is operating within black grouse leks.