2008/01/04 by Amy Russell, Steven M. Goodman, Murray P. Cox · 2 citations
Agricultural and Biological Sciences · Environmental Science · #Bat Biology and Ecology Studies #Species Distribution and Climate Change #Wildlife Ecology and Conservation
paper · doi:10.1111/j.1365-2699.2008.01891.x
openalex publication_date 2008/01/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/05/21
Abstract 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 Malagasy lineages; or (C) early dispersal of a proto‐species from Africa to Madagascar, with later back‐dispersal of a descendant Malagasy taxon to Africa. Location East Africa, Madagascar, and the Mozambique Channel. Methods We compare the utility of phylogenetic and coalescent methodologies to address the question of directionality in a mainland‐to‐island dispersal event for recently diverged taxa. We also emphasize the application of biologically explicit demographic systems, such as the non‐equilibrium isolation‐with‐migration model. Here, these methods are applied to a four‐species haploid genetic data set, with simulation analyses being applied to validate this approach. Results Coalescent simulations favour scenario B: multiple, unidirectional dispersals from Africa to Madagascar resulting in multiple, independent Malagasy bat lineages. From coalescent dating, we estimate that the genus Triaenops was still a single taxon approximately 2.25 Ma. The most recent Africa to Madagascar dispersal occurred much more recently ( c. 660 ka), and led to the formation of the extant Malagasy species, T. rufus . Main conclusions Haploid genetic data from four species of Triaenops are statistically most consistent with multiple, unidirectional dispersals from mainland Africa to Madagascar during the late Pleistocene.