The birth of an endemic species flock: demographic history of the Bellamya group (Gastropoda,Viviparidae) in Lake Malawi |
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Authors: | ROLAND SCHULTHEIß THOMAS WILKE ASLAK JØRGENSEN CHRISTIAN ALBRECHT |
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Affiliation: | 1. Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Heinrich‐Buff‐Ring 26‐32 (IFZ), D‐35392 Giessen, Germany;2. The Molecular Systematic Laboratory, The Natural History Museum of Denmark, S?lvgade 83, DK‐1307 Copenhagen K, Denmark |
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Abstract: | Changes in habitat stability may significantly shape evolutionary patterns and processes in ancient lakes. In the present study, we use a hierarchical combination of molecular phylogenetic and coalescent approaches to investigate the evolutionary history of the endemic species of the gastropod genus Bellamya in the African rift‐lake Malawi. By integrating our findings with reported palaeontological and palaeolimnological data, we demonstrate that all but one evolutionary lineage of the Pliocene Bellamya fauna in Lake Malawi became extinct. Coalescent analyses indicate that the modern radiation underwent both a sudden demographic and a spatial expansion after a genetic bottleneck. We argue that a reflooding of the lake after severe Pleistocene low stands offers a straightforward explanation for this pattern and may have triggered speciation processes in the modern endemic Bellamya radiation in Lake Malawi. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 130–143. |
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Keywords: | ancient lake biogeography extinction lake level changes parallel evolution radiation speciation |
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