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Several methods for determining a numerical distance between languages have been proposed in the literature. In this thesis I implement one of them, the ALINE distance, and develop a methodology for comparing its results with other language distance metrics. I then compare it with a leading distance metric, the LDND distance, proposed by the ASJP project.

Tumour development has long been recognised as an evolutionary process during which cells accumulate mutations and evolve into a mix of genetically distinct cell subpopulations. The resulting genetic intra-tumour heterogeneity poses a major challenge to cancer therapy, as it increases the chance of drug resistance. To study tumour evolution in more detail, reliable approaches to infer the life histories of tumours are needed. This dissertation focuses on computational methods for inferring trees of tumour evolution from single-cell and multi-sample sequencing data. Recent advances in single-cell sequencing technologies have promised to reveal tumour heterogeneity at a much higher resolution, but single-cell sequencing data is inherently noisy, making it unsuitable for analysis with classic phylogenetic methods. The first part of the dissertation describes OncoNEM, a novel probabilistic method to infer clonal lineage trees from noisy single nucleotide variants of single cells. Simulation studies are used to validate the method and to compare its performance to that of other methods. Finally, OncoNEM is applied in two case studies. In the second part of the dissertation, a comprehensive collection of existing multi-sample approaches is used to infer the phylogenies of metastatic breast cancers from ten patients. In particular, shallow whole-genome, whole exome and targeted deep sequencing data are analysed. The inference methods comprise copy number and point mutation based approaches, as well as a method that utilises a combination of the two. To improve the copy number based inference, a novel allele-specific multi-sample segmentation algorithm is presented. The results are compared across methods and data types to assess the reliability of the different methods. In summary, this thesis presents substantial methodological advances to understand tumour evolution from genomic profiles of single cells or related bulk samples.

Comprendre l'émergence des patrons de richesse biologique sur Terre intéresse les écologues et les biologistes de l'évolution depuis des décennies. La diversité en un lieu résulte d'une combinaison de processus liés à la diversification, à la dispersion et au temps. Afin d’évaluer le rôle relatif de ces différents facteurs pour mieux comprendre comment les patrons de diversité se sont mis en place, nous utilisons ici les méthodes les plus récentes basées sur des phylogénies moléculaires. Dans une première partie, nous nous sommes intéressés au gradient latitudinal de diversité des mammifères: le fait qu'il y ait plus d'espèces dans les régions tropicales que dans les régions tempérées. Pour les mammifères, nous montrons que dans les tropiques, la spéciation est plus forte, et l'extinction plus faible que dans les zones tempérées. Chez les carnivores, cependant, nous montrons que le gradient latitudinal de diversité pourrait être indépendant des taux de diversification, mais plutôt expliqué par une dispersion forte des zones tempérées vers les zones tropicales. Dans une deuxième partie, nous nous sommes intéressés à l'identification de facteurs intrinsèques et extrinsèques pouvant jouer un rôle dans la diversification des lignées. Nous avons choisi d'étudier l'impact de la migration sur la diversification des oiseaux et l'impact de la température sur la diversification des mammifères. Dans une dernière partie, et dans le contexte du réchauffement climatique actuel, nous nous sommes interrogés sur la façon d'utiliser les outils phylogénétiques pour conserver la biodiversité. / Understanding how specific richness is distributed on Earth has been a priority for ecologists and evolutionary biologists for decades. Species richness in a given place results from a combination of processes linked to diversification rates, dispersal rates, and time. In order to evaluate the relative role of these different factors and gain a better understanding of how biodiversity patterns have been shaped, we use up-to-date methodologies, based on molecular phylogenies. The first part concerns the latitudinal diversity gradient, that is how species richness decreases from the tropics to the temperate regions. For mammals, we show that speciation is higher and extinction lower in the tropics than in temperate regions. For Carnivora, however, we show that the latitudinal diversity gradient could be independent from diversification rates, and rather explained by high rates of dispersal from temperate to tropical regions. The second part is focused on the identification of intrinsic and extrinsic factors that might play a role in the diversification of lineages. We study the impact of migration on bird diversification and the impact of temperature on mammal diversification. Finally, we investigate if and how phylogenetic inference tools can be useful for the conservation of biodiversity in a changing world.

Gene evolution is important in several areas, not least the understanding of thehuman body. Since the time of Darwin, researchers have visualized evolution withrooted binary trees. Hence, genes evolve constrained to how species have evolvedand that relationship is interesting to understand and explore. To solve this, onemethod is to infer the gene tree into the species tree, a so called reconciliation, butvisualizing reconciled trees with classical binary trees often results in clutteredvisualizations that quickly become difficult to understand. Therefore, in this thesisI present a new visualization method, Genvo, for reconciled phylogenies, and definea simple tree layout algorithm. I also present a problem characterization for thedomain-specific tasks, performed when working with gene evolution visualizations.A prototype of Genvo is then studied in a small pair analytics study, where fivepairs of master students tested the developed a prototype of Genvo. The results areanalyzed compared to a workshop with three participants, all with prior knowledgein the field of gene evolution. The analysis indicates a faster understanding of thegene data in Genvo, most likely through the pre-attentive features. / Att förstå geners evolution är relevant för flertalet områden, inte minst för attutforska den mänskliga kroppen. Ända sedan Darwin har forskare visualiseratevolution med hjälp av rotade binära träd. Dock utvecklas gener begränsat till hurdess arter utvecklats, och denna relation är av intresse att förstå och utforska. Attgöra en sammanslagning av ett gen-träd med sitt art-träd (reconciliation) är ett sättatt visualisera relationen, men lösningen blir ofta väldigt rörig och svårförståelig.Därför presenterar jag i detta examensarbete Genvo, ett reconciliation programsom använder en simpel träd-layout-algoritm för att visualisera geners evolution irelation till arters evolution i 3D. Jag presenterar även en gedigen problemkarakteriseringför de uppgifter forskarna utför när de jobbar med dagensvisualiseringsverktyg. En prototyp av Genvo testades sedan i en pairanalytics studie, med en testgrupp bestående av fem par. Studien är sedan jämfördmed en workshop där tre testpersoner, med tidigare erfarenhet, jobbade medsamma uppgifter. Analysen av studiernas resultat tyder på en snabbare förståelseav datan när användarna använde sig av Genvo.

<p>This thesis focuses on phylogenetic and taxonomic studies of Catenulida (Platyhelminthes). Catenulida is a group of microscopic free-living worms mainly found in freshwater habitats. The Swedish catenulid fauna was previously virtually unknown. The taxonomy of Catenulida is difficult because of the paucity of good morphological characters, which makes species identification extremely difficult. </p><p>Molecular phylogenies are inferred from DNA sequences. Based on two molecular markers, 18S rDNA and 28S rDNA, the phylogenetic position of Catenulida has now been well established as the sister group to the rest of the flatworms, Rhabditophora. Within Catenulida there is a basal split between two major clades: Retronectidae + Catenulidae and Stenostomidae. The hypothesis of the marine Retronectidae as the sister group of the limnic Catenulida is rejected. </p><p>Four molecular markers, 18S rDNA, 28S rDNA, ITS-5.8S and CO1, are used as a backbone to infer phylogeny and to generate hypotheses about species delimitation in Catenulida using parsimony jackknifing and Bayesian analysis. <i>Anokkostenostomum</i> comes out non-monophyletic, and <i>Suomina</i> nested within <i>Catenula</i>, so two new synonymies are proposed: <i>Stenostomum</i> Schmidt, 1848 (<i>Anokkostenostomum</i> Noreña et al. 2005) and <i>Catenula</i> Duges, 1832 (<i>Suomina</i> Marcus, 1945) are proposed. </p><p>A first report on Swedish freshwater Catenulida are given. A total of 13 species are reported from Sweden. Four of them, all belonging to the taxon <i>Stenostomum</i> are new to science:<i> S. gotlandense</i> n.sp.; <i>S. handoelense</i> n.sp.; <i>S. heebuktense</i> n.sp. and <i>S. steveoi</i> n.sp.</p>

This thesis focuses on phylogenetic and taxonomic studies of Catenulida (Platyhelminthes). Catenulida is a group of microscopic free-living worms mainly found in freshwater habitats. The Swedish catenulid fauna was previously virtually unknown. The taxonomy of Catenulida is difficult because of the paucity of good morphological characters, which makes species identification extremely difficult. Molecular phylogenies are inferred from DNA sequences. Based on two molecular markers, 18S rDNA and 28S rDNA, the phylogenetic position of Catenulida has now been well established as the sister group to the rest of the flatworms, Rhabditophora. Within Catenulida there is a basal split between two major clades: Retronectidae + Catenulidae and Stenostomidae. The hypothesis of the marine Retronectidae as the sister group of the limnic Catenulida is rejected. Four molecular markers, 18S rDNA, 28S rDNA, ITS-5.8S and CO1, are used as a backbone to infer phylogeny and to generate hypotheses about species delimitation in Catenulida using parsimony jackknifing and Bayesian analysis. Anokkostenostomum comes out non-monophyletic, and Suomina nested within Catenula, so two new synonymies are proposed: Stenostomum Schmidt, 1848 (Anokkostenostomum Noreña et al. 2005) and Catenula Duges, 1832 (Suomina Marcus, 1945) are proposed. A first report on Swedish freshwater Catenulida are given. A total of 13 species are reported from Sweden. Four of them, all belonging to the taxon Stenostomum are new to science: S. gotlandense n.sp.; S. handoelense n.sp.; S. heebuktense n.sp. and S. steveoi n.sp.

<p> Two studies are presented in this thesis. First part is about the origin of tRNA genes in Trypanosoma and Leishmania. These organisms have special mitochondrial DNA, termed kinetoplast DNA (kDNA), which is unique in its structure and function. kDNA is a massive network which is composed of thousands of connected DNA circles. Unlike most other mitochondrial genomes, there is no gene encoding tRNAs in their kDNAs. So all the tRNAs used in mitochondria must be encoded on nuclear genes and transported from the cytoplasm into the mitochondria. So our question of interest is where the tRNA genes in their nucleus come from. We carry out phylogenetic analysis of these genes and the corresponding ones in bacteria, mitochondria and eukaryotic nuclei. There is no evidence indicating gene transfer from mitochondria to nucleus on the basis of this analysis. These results are consistent with the simplest hypothesis, i.e. that all tRNA genes of Trypanosoma and Leishmania have the same origin as nuclear genes of other eukaryotes.</p> <p> The second part is about the comparison of eukaryote phylogenies obtained from mitochondrial rRNA and protein sequences. We carried out phylogenetic analysis for the species which have complete mitochondrial genomes by using both concatenated mitochondrial rRNA and protein sequences. We got phylogenies for three groups, fungi/metazoan, plant/algae and stramenopile/alveolate group. The analysis is useful for the further study of position of the genetic code changes and the mechanisms involved.</p> / Thesis / Master of Science (MSc)

Les années 2000 ont vu l'apparition des technologies de séquençage haut-débit permettant de faire chuter le coût en temps et argent du séquençage du génome complet et ouvrant la perspective à des analyses de la phylogénie des espèces à l'échelle de génome entiers. Dans cette optique des méthodes pour l'inférence de l'histoire évolutive de l'ordre de marqueurs génomiques le long d'un phylogénie ont été développées. Cependant, les assemblages d'une majorité des grands génomes d'eucaryotes demeurent incomplètement résolues et ne permettent donc pas, en tant que tel, leur exploitation pour la reconstruction de l'histoire évolutive de l'ordre des gènes de ces espèces. C'est dans ce contexte que nous avons développé l'algorithme adseq qui permet de conjointement reconstruire l'histoire évolutive de l'ordre de gènes en considérant la fragmentation des génomes actuels et améliorant l'assemblage de ceux-ci par génomique comparative / The early 2000s saw the emergence of high-throughput sequencing technologies that would bring down the time and cost of sequencing the entire genome and opening the perspective to whole genome-scale species phylogeny. In this perspective, methods for the inference of evolutionary history of the order of genomic markers along a phylogeny have been developed. However, assemblies of a majority of the large eukaryotic genomes remain incompletely resolved and therefore do not, as such, allow their exploitation for the reconstruction of evolutionary history of the order of the genes of these species. It is in this context that we have developed the algorithm ADseq which allows to jointly reconstruct the evolutionary history of the order of genes by considering the fragmentation of the extant genomes and improve the assembly of these by comparative genomics