The evolution of sensory divergence in the context of limited gene flow in the bumblebee bat

Abstract

The sensory drive theory of speciation predicts that populations of the same species inhabiting different environments can differ in sensory traits, and that this sensory difference can ultimately drive speciation. However, even in the best-known examples of sensory ecology driven speciation, it is uncertain whether the variation in sensory traits is the cause or the consequence of a reduction in levels of gene flow. Here we show strong genetic differentiation, no gene flow and large echolocation differences between the allopatric Myanmar and Thai populations of the world's smallest mammal, Craseonycteris thonglongyai, and suggest that geographic isolation most likely preceded sensory divergence. Within the geographically continuous Thai population, we show that geographic distance has a primary role in limiting gene flow rather than echolocation divergence. In line with sensory-driven speciation models, we suggest that in C. thonglongyai, limited gene flow creates the suitable conditions that favour the evolution of sensory divergence via local adaptation.

The Roles of Taxonomy and Systematics in Bat Conservation

“…Hipposideros ridleyi E V Emballonura semicaudata semicaudata C E population (Bates et al 2001;Pereira et al 2007;Puechmaille et al 2011). These discoveries have led to changes in the dynamic of conservation for Craseonycteris, since conservation priorities are often related to species range sizes.…”

A new species of the Miniopterus schreibersii species complex (Chiroptera: Miniopteridae) from the Maghreb Region, North Africa

“…nov., especially in areas of sympatry or parapatry to identify reliable diagnostic field characters. It is not unusual to have closely related bat species showing divergence in echolocation calls (Douangboubpha et al, 2010;Ith et al, 2011;Puechmaille et al, 2011;Thong et al, 2012b) and those differences can be used to discriminate species (Walters et al, 2012). Nevertheless, our analyses of echolocation calls from a limited number of individuals tend to suggest that M. maghrebensis sp.…”

Bat Biology, Genomes, and the Bat1K Project: To Generate Chromosome-Level Genomes for All Living Bat Species

“…Bats have also been shown to be an excellent model for sensory-driven speciation [e.g., Rhinolophus philippinensis (76), Craseonycteris thonglongyai (77)]. High-quality bat genomes will enable further elucidation of the molecular basis of sensory adaptation and finally untangle the evolutionary mechanisms driving speciation (77,78).…”

“…With such genomes and tools in place, a wide range of questions that are central to current bat population biology and ecology can subsequently be addressed. These include what determines evolutionarily significant units (ESUs), what the degree of gene flow is among them, and even the dynamics of the speciation process itself (77,78,112), a critical question in bats given their dispersal ability and the high taxonomic diversity of some clades [e.g., genus Myotis, with 100+ species (145)]. These are, in turn, critical to more applied efforts, ranging from optimizing conservation strategies, for example, by focusing on ESUs at most risk or most likely to respond to efforts, to defining bat clades that represent possible high risks of cross-species pathogen outbreaks, for example, those exhibiting the greatest degree of inter-ESU, population, or even species admixture, and thus possible cross-host pathogen transmissions.…”

“…Indeed, applying a particular species concept to bats is difficult. The Biological Species concept (110) is commonly applied to mammals, but investigations of gene flow among bat species have been attempted but are not commonly performed and often rely on indirect evidence (76)(77)(78)(111)(112)(113)(114)(115). The Genetic Species concept was tested for multiple species and suggested hybridization in several cases (116).…”