The largest genus within the Phyllanthaceae family is a group called Phyllanthus L. Recent studies have shown, that Phyllanthus is paraphyletic with the genera Glochidion, Breynia and Synostemon... Show moreThe largest genus within the Phyllanthaceae family is a group called Phyllanthus L. Recent studies have shown, that Phyllanthus is paraphyletic with the genera Glochidion, Breynia and Synostemon nested within it. In this thesis, I study the evolution and systematics of Phyllanthus and how to solve the apparent paraphyly. First we explore past morphological subgroups to come to a subdivision, which was tested using molecular phylogenetics. Several species of Phyllanthus are also used in traditional medicine and by utilizing the living collections of the Hortus botanicus Leiden, we tested for antibacterial and antifungal bioactivity. The phylogeny resulting from this study is used to study the historical biogeography and diversification of the tribe and to propose a new classification where Phyllanthus is separated into several smaller genera. Show less
The explosive radiation and diversification of the advanced snakes (superfamily Colubroidea) was associated with changes in all aspects of the shared venom system. Morphological changes included... Show moreThe explosive radiation and diversification of the advanced snakes (superfamily Colubroidea) was associated with changes in all aspects of the shared venom system. Morphological changes included the partitioning of the mixed ancestral glands into two discrete glands devoted for production of venom ormucous respectively, as well as changes in the location, size and structural elements of the venom-delivering teeth. Evidence also exists for homology among venom gland toxins expressed across the advanced snakes. However, despite the evolutionary novelty of snake venoms, in-depth toxin molecular evolutionary history reconstructions have been mostly limited to those types present in only two front-fanged snake families, Elapidae and Viperidae. To have a broader understanding of toxins shared among extant snakes, here we first sequenced the transcriptomes of eight taxonomically diverse rear-fanged species and four key viperid species and analysed major toxin types shared across the advanced snakes. Show less
Taxonomy as a science has accumulated data and knowledge for more than 250 years. The quality and usefulness of the facts recorded in taxonomic literature has greatly improved from the early... Show moreTaxonomy as a science has accumulated data and knowledge for more than 250 years. The quality and usefulness of the facts recorded in taxonomic literature has greatly improved from the early descriptive texts to the modern data-rich, hypothesis-driven works. Our work illustrates the application of some of the “e-taxonomic” tools and the “New Taxonomy” thinking explored in the introduction. Here, we analyzed specimen data contained in legacy taxonomic literature in Chapters 2 and 3—to observe species distribution of one spider group and genital evolution, respectively—and also explored an integrative perspective that involves describing new taxa and testing phylogenetic hypotheses using molecular and morphological data, as done in Chapter 4 and 5. Show less
Balsaminaceae is a diverse plant family characterized by a huge floral morphological diversity. Its classification has changed many times throughout the taxonomic history of the group, owing to... Show moreBalsaminaceae is a diverse plant family characterized by a huge floral morphological diversity. Its classification has changed many times throughout the taxonomic history of the group, owing to the emphasis on particular diagnostic characters. This suggests that patterns of character evolution are labile and do not contain much phylogenetic signal. This appears particularly prevalent among floral characters, suggesting that floral evolution and pollination ecology may be important drivers of diversification in the family. Further complications in taxonomy arise from the fact that one of the two genera of the family, Impatiens, has a very large number of species, and that it is distributed across several continents. This has led to a lack of taxonomic effort, especially those regions where very few studies have been done, despite large species diversity. In this thesis, I filled particular gaps in knowledge of Balsaminaceae, focusing on issues related to the Southeast Asian region, including the taxonomic revision of this family in Myanmar (Chapter 2-4), molecular phylogeny and morphological character evolution of Impatiens sect. Semeiocardium (Chapter 5), comparative pollination biology of 7 sympatric Impatiens species in Thailand (Chapter 6), and evolution of corolla symmetry and pollination system of this family (Chapter 7). Show less
Natural zebra finch song contains heterogeneity in the relative distribution of element types across 13 populations worldwide, but compared between individuals it contains relatively little... Show moreNatural zebra finch song contains heterogeneity in the relative distribution of element types across 13 populations worldwide, but compared between individuals it contains relatively little structural constraints or rules in the order of elements. In contrast, from a perception point of view, zebra finches are able to detect differences in song structure and are able to learn rules to generalize these regularities to new element types in some instances, a hallmark of human language. This ability might seem conflicting with the absences of clear structural rules in their own natural songs, but it might be that these rule learning/detection mechanisms operate in a more general cognitive context, which has also been suggested for some mechanisms found in human artificial language learning. Show less
This thesis comprises elementary work on the evolution of ageing. The issue of ageing, and especially of starvation resistance, has been approached from both the environmental and the genetic sides... Show moreThis thesis comprises elementary work on the evolution of ageing. The issue of ageing, and especially of starvation resistance, has been approached from both the environmental and the genetic sides that are of relevance to the issue. Therewith, this study has a broad orientation, varying from ecophysiology to selection experiments, mutant analysis and sate of the art microarray gene expression analysis. All this work was performed on Drosophila melnogaster, the fruit fly, and was put in an integrative context with human ageing. Show less
