Postglacial recolonization at a snail's pace (Trochulus villosus): confronting competing refugia hypotheses using model selection

摘要: The localization of Last Glacial Maximum (LGM) refugia is crucial information to understand a species’ history and predict its reaction future climate changes. However, many phylogeographical studies often lack sampling designs intensive enough precisely localize these refugia. hairy land snail Trochulus villosus has small range centred on Switzerland, which could be intensively covered by 455 individuals from 52 populations. Based mitochondrial DNA sequences (COI 16S), we identified two divergent lineages with distinct geographical distributions. Bayesian skyline plots suggested that both expanded at the end LGM. To find where origin populations were located, applied principles ancestral character reconstruction candidate refugium for each mtDNA lineage: French Jura Central ice-free during Additional refugia, however, not excluded, as microsatellite analysis population subset. Modelling LGM niche T. villosus, showed suitable climatic conditions expected in inferred but potentially also nunataks alpine ice shield. In model selection approach, compared several alternative recolonization scenarios estimating Akaike criterion their respective maximum-likelihood migration rates. ‘two refugia’ scenario received far best support given distribution genetic diversity Provided fine-scale various analytical approaches are combined, it possible refine our necessary understanding species responses environmental