Genetic diversity of sexual and parthenogenetic soil living arthropods (Collembola) in Europe: colonization patterns, pre-glacial diversifications and founder effects
Large parts of northern and central Europe were covered by ice sheets and permafrost due to climate changes in Europe during the last ice age (2.7 million to 11.7 kya). Plant and animal species had to adapt to lower temperatures, retreated to warmer areas in the south or went extinct. Once, after th...
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| Other Authors: | , , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | German |
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2016
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| Online Access: | http://hdl.handle.net/11858/00-1735-0000-0028-8712-C https://doi.org/10.53846/goediss-5584 https://nbn-resolving.org/urn:nbn:de:gbv:7-11858/00-1735-0000-0028-8712-C-6 |
| Summary: | Large parts of northern and central Europe were covered by ice sheets and permafrost due to climate changes in Europe during the last ice age (2.7 million to 11.7 kya). Plant and animal species had to adapt to lower temperatures, retreated to warmer areas in the south or went extinct. Once, after the Last Glacial Maximum (LGM, 26.5 kya to 19 kya) higher temperatures induced ice free habitats and these new habitats could be recolonized from different refugia. Collembola are one of the most abundant soil living decomposer animals and play a major role in aboveground - belowground interactions. Surprisingly, little is known about genetic and phylogeographic patterns, dispersal routes and anthropogenic influences of sexual and parthenogenetic reproducing European Collembola species, neglecting one important part of the global biodiversity, the belowground system. This thesis focuses on genetic patterns of four Collembola species with different reproductive modes and overlapping ecology across Europe. Collembola existed millions of years in stable habitats, as Eocene fossils show only little variation to extant taxa. In contrast, Cenozoic and Quaternary climatic changes reduced diversity and changed genetic structure of above living animals and plants. In Chapter 2 I investigated the phylogeographic patterns of three common species of Collembola (Ceratophysella denticulata, Folsomia quadrioculata and Isotomiella minor) at a pan-European scale to identify glacial refuges and post-glacial colonization patterns with three genetic markers to cover different time scales. Results suggested density dependent processes for the establishment of new populations, as genetic diversity was high between but low within populations. This founder-takes-it-all principle is common in animal and plant species and suggests that only few early colonizing individuals founded the populations which grew and expanded rapidly. Arrival and invasion of other alleles into these populations was prevented by competition. Surprisingly and in ... |
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