The evolution of mesic biomes: insights from an ancient lineage of arachnids

Danilo Harms

    Research output: ThesisDoctoral Thesis

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    Abstract

    [Truncated] I investigated the evolutionary history of pseudoscorpions in the family
    Pseudotyrannochthoniidae from global to local scales, using molecular sequence data
    from samples spanning the full spectrum of morphological diversity and geographic
    distributions. I combined phylogenetic reconstruction, molecular dating, distributionand
    environmental niche modelling with population genetics and taxonomy to unravel
    the evolutionary history of this fauna.
    This is an ancient lineage with origins in the Triassic-Jurassic on the supercontinent
    Pangaea. Although the phylogeny reflects the split of this gigantic landmass into
    Laurasia (Northern) and Gondwana (Southern), cladogeneses within continents are
    often older than tectonic separation, indicating that diversification has been caused by
    factors other than tectonic rifting.
    The Australian fauna is polyphyletic and falls into five distinct genetic lineages: a) two
    monotypic lineages from caves in Tasmania, b) an ’eastern’ lineage widespread in
    mesic habitats along the east coast and in southeastern Australia, c) a ‘southeastern’
    lineage from alpine habitats and caves, and d) a ‘southwestern’ lineage. There are
    ancient links: two groups from caves in Tasmania nest with forms from South America,
    consistent with long-term persistence of Gondwanan lineages in buffered habitats.
    Primary diversification of the remaining lineages coincides with periods of drastic
    climate change during the Mio-Pliocene in Australia that lead to widespread
    contraction and fragmentation of mesic habits.
    Original languageEnglish
    QualificationDoctor of Philosophy
    Publication statusUnpublished - 2014

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