Computational Biology Commons^™

Aim We investigate the directionality of mainland-to-island dispersals, focusing on a case study of an African-Malagasy bat genus, Triaenops (Hipposideridae). Taxa include T. persicus from east Africa and three Triaenops species from Madagascar (T. auritus, T. furculus, and T. rufus). The evolution of this bat family considerably post-dated the tectonic division of Madagascar from Africa, excluding vicariance as a viable hypothesis. Therefore, we consider three biogeographical scenarios to explain these species’ current ranges: (A) a single dispersal from Africa to Madagascar with subsequent speciation of the Malagasy species; (B) multiple, unidirectional dispersals from Africa to Madagascar resulting in multiple, independent …

Incomplete lineage sorting can genetically link populations long after they have diverged, and will exert a more powerful influence on larger populations. The effects of this stochastic process can easily be confounded with those of gene flow, potentially leading to inaccurate estimates of dispersal capabilities or erroneous designation of evolutionarily significant units (ESUs). We have used phylogenetic, population genetic, and coalescent methods to examine genetic structuring in large populations of a widely dispersing bat species and to test hypotheses concerning the influences of coalescent stochasticity vs. gene flow. The Mexican free-tailed bat, Tadarida brasiliensis mexicana, exhibits variation in both migra- …