2009/05/13 by Roland Schultheiß, Bert Van Bocxlaer, Thomas Wilke +1 · 2 citations
Environmental Science · Agricultural and Biological Sciences · #Aquatic Invertebrate Ecology and Behavior #Mollusks and Parasites Studies #Isotope Analysis in Ecology
paper · doi:10.1098/rspb.2009.0467
openalex publication_date 2009/05/13 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Studies on environmental changes provide important insights into modes of speciation, into the (adaptive) reoccupation of ecological niches and into species turnover. Against this background, we here examine the history of the gastropod genus Lanistes in the African Rift Lake Malawi, guided by four general evolutionary scenarios, and compare it with patterns reported from other endemic Malawian rift taxa. Based on an integrated approach using a mitochondrial DNA phylogeny and a trait-specific molecular clock in combination with insights from the fossil record and palaeoenvironmental data, we demonstrate that the accumulation of extant molecular diversity in the endemic group did not start before approximately 600,000 years ago from a single lineage. Fossils of the genus from the Malawi Rift, however, are over one million years older. We argue that severe drops in the lake level of Lake Malawi in the Pleistocene offer a potential explanation for this pattern. Our results also challenge previously established phylogenetic relationships within the genus by revealing parallel evolution and providing evidence that the endemic Lanistes species are not restricted to the lake proper but are present throughout the Malawi Rift.