Is the Gibraltar Strait a barrier to gene flow for the bat Myotis myotis (Chiroptera: Vespertilionidae (original) (raw)
Related papers
Journal of Biogeography, 2010
Aim We investigate the population genetic structure of the Maghrebian bat, Myotis punicus, between the mainland and islands to assess the island colonization pattern and current gene flow between nearby islands and within the mainland.Location North Africa and the Mediterranean islands of Corsica and Sardinia.Methods We sequenced part of the control region (HVII) of 79 bats across 11 colonies. The phylogeographical pattern was assessed by analysing molecular diversity indices, examining differentiation among populations and estimating divergence time. In addition, we genotyped 182 bats across 10 colonies at seven microsatellite loci. We used analysis of molecular variance and a Bayesian approach to infer nuclear population structure. Finally, we estimated sex-specific dispersal between Corsica and Sardinia.Results Mitochondrial analyses indicated that colonies between Corsica, Sardinia and North Africa are highly differentiated. Within islands there was no difference between colonies, while at the continental level Moroccan and Tunisian populations were highly differentiated. Analyses with seven microsatellite loci showed a similar pattern. The sole difference was the lack of nuclear differentiation between populations in North Africa, suggesting a male-biased dispersal over the continental area. The divergence time of Sardinian and Corsican populations was estimated to date back to the early and mid-Pleistocene.Main conclusions Island colonization by the Maghrebian bats seems to have occurred in a stepping-stone manner and certainly pre-dated human colonization. Currently, open water seems to prevent exchange of bats between the two islands, despite their ability to fly and the narrowness of the strait of Bonifacio. Corsican and Sardinian populations are thus currently isolated from any continental gene pool and must therefore be considered as different evolutionarily significant units (ESU).
Heredity, 2009
The meridional serotine bat Eptesicus isabellinus is found in North Africa and the Iberian Peninsula. We analyzed the genetic structure of E. isabellinus at two different geographic scales to reveal the historical and ecological patterns that have shaped its populations. The role of the Straits of Gibraltar as an isolating barrier between African and Iberian populations is evaluated and the degree of genetic structure and female-mediated gene flow was assessed at a local scale between neighboring colonies. Populations of E. isabellinus from Iberia and northern Morocco show little genetic divergence and share mtDNA haplotypes, indicating that the Straits of Gibraltar are neither an impediment to dispersal nor a cause of genetic differentiation. Our results also suggest that E. isabellinus may have dispersed from western Andalusia into northern Morocco after the last glacial period. At a smaller geographic scale, the colonies studied showed high variation in genetic variability and structure, indicating that no female-mediated gene flow is present. This pattern is consistent with a described pattern of independent endemic viral circulation of the bat rabies virus EBLV-1, which was found when studying rabies dynamics in the same serotine bat colonies.
2010
a bstract. The azorean bat (Nyctalus azoreum), the only endemic mammal of the azores archipelago (Portugal), diverged recently from its mainland relative, the leisler's bat (N. leisleri). although the two species are phenotypically very different, mtDNa studies detected very low genetic divergence between them, which could question the validity of the species status of N. azoreum. in order to assess the genetic variability in each species and check for present levels of gene flow between the two taxa, eight microsatellite loci were genotyped and analysed. The results indicated lower genetic diversity in the insular species. Many unshared alleles were found between the two species and no evidence of migrants, which provides strong support against any contemporary gene flow between them. The species status of the azorean bat is discussed in the light of the cohesion species concept, and we conclude that it is an isolated species with a high conservation value.
Molecular Phylogenetics and Evolution, 2004
Long-eared bats of the genus Plecotus are widespread and common over most of the western Palaearctic. Based on recent molecular evidence, they proved to represent a complex of several cryptic species, with three new species being described from Europe in 2002. Evolutionary relationships among the different lineages are still fragmentary because of the limited geographic coverage of previous studies. Here we analyze Plecotus mitochondrial DNA sequences from the entire Mediterranean region and Atlantic Islands. Phylogenetic reconstructions group these western Palaearctic Plecotus into two major clades which split at least 5 Myr ago and that are each subdivided into further subgroups. An Ôauritus groupÕ includes the traditional P. auritus species and its sister taxon P. macrobullaris ( ¼ P. alpinus) plus related specimens from the Middle East. P. auritus and P. macrobullaris have broadly overlapping distributions in Europe, although the latter is apparently more restricted to mountain ranges. The other major clade, the Ôaustriacus group,Õ includes the European species P. austriacus and at least two other related taxa from North Africa (including P. teneriffae from the Canary Islands), the Balkans and Anatolia (P. kolombatovici). The sister species of this Ôaustriacus groupÕ is P. balensis, an Ethiopian endemic. Phylogenetic reconstructions further suggest that P. austriacus reached Madeira during its relatively recent westwards expansion through Europe, while the Canary Islands were colonized by a North African ancestor. Although colonization of the two groups of Atlantic Islands by Plecotus bats followed very distinct routes, neither involved lineages from the Ôauritus group.Õ Furthermore, the Strait of Gibraltar perfectly segregates the distinct lineages, which confirms its key role as a geographic barrier. This study also stresses the biogeographical importance of the Mediterranean region, and particularly of North Africa, in understanding the evolution of the western Palaearctic biotas.
The Iberian contribution to cryptic diversity in European bats
Acta Chiropterologica, 2006
We investigate the contribution of the Iberian bat fauna to the cryptic diversity in Europe using mitochondrial (cytb and ND1) and nuclear (RAG2) DNA sequences. For each of the 28 bat species known for Iberia, samples covering a wide geographic range within Spain were compared to samples from the rest of Europe. In this general screening, almost 20% of the Iberian species showed important mitochondrial discontinuities (K2P distance values > 5%) either within the Iberian or between Iberian and other European samples. Within Eptesicus serotinus and Myotis nattereri, levels of genetic divergence between lineages exceeded 16%, indicating that these taxa represent a complex of several biological species. Other well-differentiated lineages (K2P distances between 5-10%) appeared within Hypsugo savii, Pipistrellus kuhlii and Plecotus auritus, suggesting the existence of further cryptic diversity. Most unsuspected lineages seem restricted to Iberia, although two have crossed the Pyrenees to reach, at least, Switzerland.
Estuarine Coastal and Shelf Science, 2015
Previous population genetic studies on the Mediterranean mussel Mytilus galloprovincialis have shown the existence of two well differentiated sets of populations around Southern European coasts, one Atlantic and another Mediterranean. Those two population pools are kept apart by the Almería e Oran Oceanographic Front (AOOF), an oceanographic discontinuity acting either as a cause of such differentiation or simply as a means of maintaining two historically differentiated gene pools. The role of the Gibraltar Strait at shaping mussel larval flow entering the Alboran Sea has been much less addressed, especially regarding mussel swarms inhabiting the northern coast of Morocco. The present study applies seven microsatellite markers to describing the genetic status of northern Moroccan populations of M. galloprovincialis and their relationship with the two well-characterized mussel gene pools from southern Europe. We show that the Atlantic Iberia gene pool extending continuously from the Cantabrian Sea (NE Iberia) to the Alboran Sea (SE Iberia) up to the AOOF is well differentiated from the Atlantic Moroccan mussel. Either an oceanographic barrier or a limited larval dispersal or both, are required to explain this unexpected intercontinental differentiation regarding previous studies on this species. Populations from Atlantic Morocco conformed to a single gene pool (F ST ± SD ¼ 0.012 ± 0.007) as opposed to the reported latitudinal barrier to gene flow at Cape Ghir in western Morocco. Additionally, a significant restriction to gene flow was observed between Atlantic Morocco and Alboran Morocco (F ST ± SD ¼ 0.038 ± 0.010) in contrast to the reported mussel genetic continuity along the Iberian coast up to AOOF. Three major mussel gene pools appear to meet at this crossroads between continents and between seas, namely, a Mediterranean European subpopulation, an Atlantic Iberia subpopulation including the Alboran Sea, and an Atlantic Morocco subpopulation. Knowledge on genetic patterns across species around the biogeographical breakpoints of Gibraltar and AOOF allows a better understanding of the complexity of dispersal patterns at this crossroads between continents.
Journal of Biogeography
Aim The role of glacial refugia in the biogeographical patterns in the Western Palaearctic region has been widely discussed, but many questions remain unresolved. We examined the biogeography, genetic diversity, spatial distribution and evolutionary history of the Myotis nattereri bat species complex to investigate the presence of multiple refugia and the persistence of Quaternary differentiation between and within Mediterranean refugia in a flying mammal. Location Western Palaearctic region (central and southern Europe and north-western Maghreb). Methods We analysed three mitochondrial fragments (cytochrome b, NADH dehydrogenase subunit 1 and the control region; 1570 bp) from 136 individuals of the M. nattereri complex sampled from 87 different localities using a range of phylogenetic techniques. Divergences among clades were also dated using a Bayesian coalescence approach. Results Phylogenetic analyses identified four main lineages, coincident with the four cryptic species recently described. Each species is further subdivided into well-supported lineages with evident geographical structure. Estimates of genetic diversity and polymorphism were very high for the majority of subclades, with the exception of M. nattereri s.s. Main conclusions The M. nattereri bat complex comprises four species whose distributions in the Western Palaearctic correspond to four main glacial refugia (Iberia, Italy, Balkans and Morocco). These species are the result of long-term isolation (remarkable in a flying mammal) over several glacial cycles. The Balkan species expanded into central Europe in a rapid recolonization process. Both the Iberian and Italian peninsulas show a clear pattern of refugia-within-refugia in their genetic structuring, with a deeply differentiated southern Italian clade. Morocco shows two markedly differentiated lineages, probably separated by the Atlas Mountains. The legacy of Pleistocene cycles is evident in both the speciation and the intraspecific diversification events. "
Genetica, 2007
We used three mitochondrial DNA fragments with different substitution rates (ND1, Cyt b and the CR) to infer phylogenetic relationships among six species of the genus Nyctalus, and compare levels of genetic divergence between the insular, vulnerable Nyctalus azoreum and its continental counterpart to assess the origins of the Azorean bat. The larger species found throughout the Palaearctic region (N. lasiopterus, N. aviator and N. noctula) share a unique chromosome formula (2n = 42) and form a monophyletic clade in our reconstructions. Nyctalus plancyi (= velutinus), a Chinese taxon with 2n = 36 chromosomes, is sometimes included in N. noctula, but is genetically very divergent from the latter and deserves full species status. All Cyt b and CR haplotypes of N. azoreum are closely related and only found in the Azores archipelago, but when compared to continental sequences of N. leisleri, levels of mtDNA divergence are unusually low for mammalian species. This contrasts with the high level of differentiation that N. azoreum has attained in its morphology, ecology, and echolocation calls, suggesting a recent split followed by fast evolutionary change. The molecular data suggest that N. azoreum originated from a European population of N. leisleri, and that the colonisation of the Azores occurred at the end of the Pleistocene. The Madeiran populations of N. leisleri also appear to have a European origin, whereas those of the Canary Islands probably came from North Africa. In spite of its recent origin and low genetic divergence, the Azorean bat is well differentiated and consequently represents a unique evolutionary unit with great conservation value.
Environmental margin and island evolution in Middle Eastern populations of the Egyptian fruit bat
Here, we present a study of the population genetic architecture and microevolution of the Egyptian fruit bat (Rousettus aegyptiacus) at the environmental margins in the Middle East using mitochondrial sequences and nuclear microsatellites. In contrast to the rather homogenous population structure typical of cave-dwelling bats in climax tropical ecosystems, a relatively pronounced isolation by distance and population diversification was observed. The evolution of this pattern could be ascribed to the complicated demographic history at higher latitudes related to the range margin fragmentation and complex geomorphology of the studied area. Lineages from East Africa and Arabia show divergent positions. Within the northwestern unit, the most marked pattern of the microsatellite data set is connected with insularity, as demonstrated by the separate status of populations from Saharan oases and Cyprus. These demes also exhibit a reduction in genetic variability, which is presumably connected with founder effects, drift and other potential factors related to island evolution as site-specific selection. Genetic clustering indicates a semipermeability of the desert barriers in the Sahara and Arabian Peninsula and a corridor role of the Nile Valley. The results emphasize the role of the island environment in restricting the gene flow in megabats, which is also corroborated by biogeographic patterns within the family, and suggests the possibility of nascent island speciation on Cyprus. Demographic analyses suggest that the colonization of the region was connected to the spread of agricultural plants; therefore, the peripatric processes described above might be because of or strengthened by anthropogenic changes in the environment.