New insights on postglacial colonization in western Europe: the phylogeography of the Leisler's bat (Nyctalus leisleri)

Abstract

Despite recent advances in the understanding of the interplay between a dynamic physical environment and phylogeography in Europe, the origins of contemporary Irish biota remain uncertain. Current thinking is that Ireland was colonized post-glacially from southern European refugia, following the end of the last glacial maximum (LGM), some 20 000 years BP. The Leisler's bat (Nyctalus leisleri), one of the few native Irish mammal species, is widely distributed throughout Europe but, with the exception of Ireland, is generally rare and considered vulnerable. We investigate the origins and phylogeographic relationships of Irish populations in relation to those across Europe, including the closely related species N. azoreum. We use a combination of approaches, including mitochondrial and nuclear DNA markers, in addition to approximate Bayesian computation and palaeo-climatic species distribution modelling. Molecular analyses revealed two distinct and diverse European mitochondrial DNA lineages, which probably diverged in separate glacial refugia. A western lineage, restricted to Ireland, Britain and the Azores, comprises Irish and British N. leisleri and N. azoreum specimens; an eastern lineage is distributed throughout mainland Europe. Palaeo-climatic projections indicate suitable habitats during the LGM, including known glacial refugia, in addition to potential novel cryptic refugia along the western fringe of Europe. These results may be applicable to populations of many species.

Species distribution modeling and molecular markers suggest longitudinal range shifts and cryptic northern refugia of the typical calcareous grassland species Hippocrepis comosa (horseshoe vetch)

“…Beyond climatic parameters, it is uncertain whether this land masses provided the proper calcareous substrates for H. comosa and therefore could have served as refugia. Otherwise several studies including flora and fauna (Boston, Montgomery, Hynes, & Prodohl, ; Ohlemüller, Huntley, Normand, & Svenning, ; Svenning, Normand, & Kageyama, ) are supporting the existence of these north western potential refugia.…”

Molecular markers provide evidence for a broad‐fronted recolonisation of the widespread calcareous grassland species Sanguisorba minor from southern and cryptic northern refugia

“…; Boston et al . ). Altogether, species have shown individual responses to climate change, depending on different dispersal abilities, refugia locations and post‐glacial migration trajectories (Stewart et al .…”

Genetic origin and dispersal of the invasive soybean aphid inferred from population genetic analysis and approximate Bayesian computation

“…The ABC, as implemented in the DIYABC 2.1.0 program (Cornuet et al 2014), was used to compare different competing scenarios to describe the ancestral populations of the soybean aphid as well as the dispersal routes. This method does not calculate the exact likelihoods, making it efficient for complex population genetic models such as those underlying biological invasions or population colonizations (Cornille et al 2012;Dilmaghani et al 2012;Zhang et al 2014;Boston et al 2015). The approach simulates the datasets for different predefined scenarios and compares the summary statistics of these with the summary statistics of the observed data, estimating the posterior probabilities of competing scenarios and posterior distributions of the demographic parameters under a given scenario (Cornuet et al 2014).…”