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Distribution
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Gallery
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Bibliography
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Current Research Topics |
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Topic A: Neural development in Onychophora and the phylogeny of arthropods Currently there are two competing hypotheses concerning the phylogenetic relationships within the Panarthropoda. According to the Mandibulata hypothesis, myriapods (centipedes, millipedes, and allies) are the closest relatives to crustaceans and insects. Some recent analyses of molecular data, however, have challenged this traditional view and instead propose a close relationship of myriapods to chelicerates (spiders, scorpions, and allies). This concept is known as the Paradoxopoda or Myriochelata hypothesis. In order to clarify the controversy, I focus on development of the nervous system in Onychophora since they are the closest relatives of arthropods and a useful outgroup for character polarization among the panarthropods. |
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Topic B: The arthropod “head problem” Understanding the composition of the arthropod head has caused much controversy in the past and remains one of the most contentious issues in the fields of comparative morphology and developmental biology. As the closest relatives of arthropods, onychophorans play an important role in this debate. Hence, studying the anterior body region in these animals might provide helpful insights for resolving the arthropod head problem. My aim is therefore to study structure and development of the onychophoran “head” and associated structures and organs by using neurobiological, cytological and immunohistochemical techniques, in conjunction with gene expression studies, confocal laser scanning microscopy and electron microscopy. |
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Topic C: Mesoderm development in Onychophora According to the traditional Articulata hypothesis, segmentation represents a synapomorphy of the Annelida and Arthropoda. The homology hypothesis of segmentation is mainly based on serially arranged coelomic cavities and nephridia. However, this support is ambiguous since coelomic cavities are lacking and nephridia are strongly modified in adult arthropods. In the light of recent phylogenetic analyses based on molecular data, segmentation either arose convergently in annelids and arthropods or is an ancestral feature of protostomes or even bilaterians. In order to clarify the issue, more detailed studies are necessary. Among the panarthropods, onychophorans are traditionally considered to share the majority of morphological correspondences with annelids. In order to contribute to the current discussion on the evolution of segmentation, I focus on development of the mesoderm and its derivatives in Onychophora. |
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Topic D: Taxonomy, biogeography and systematics of Onychophora I am interested in life history and morphology (reproductive system, visual system, excretory system, nervous system, muscular system, locomotory system), and their implications for onychophoran phylogeny. My aim is to obtain as many characters as possible for a reliable phylogenetic reconstruction. In collaboration with other scientists, I apply molecular methods (involving both mitochondrial and nuclear gene sequences) to study the biogeography of Onychophora, which show a disjunct distribution reflecting the break-up of Gondwana. Taxonomic work involves description of new species and revision of species and sub-groups. |
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Peripatopsis balfouri (Peripatopsidae) from South Africa
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