Assessing the genetic landscape of a contact zone: the case of European hare in northeastern Greece

The European hare populations of the Balkan Peninsula comprise two divergent phylogenetic lineages with discrete geographical distribution slightly overlapping in the area of northeastern Greece and Bulgaria. Here we elucidate their contact zone, by defining the spatial distributional pattern of the two highly divergent groups, detecting individuals of hybrid origin, and identifying genetic barriers present in the area of their co-existence. Specimens from northeastern Greece were assayed for lineage assignment and population genetic inference based on a 511 bp fragment of mitochondrial DNA control region and allelic data from 10 microsatellite loci. Bayesian analyses on original and simulated genotypes were performed allowing for the contact zone delineation. Our results indicate high genetic diversity in both nuclear and mitochondrial DNA, strong population structure and non random spatial distribution of the differentiated gene pools. The information provided by the two types of molecular markers yielded consistent results. This study comprises a fine scale analysis of the contact zone between the two evolutionary lineages of European brown hares in northeastern Greece. Specific questions on the spatial patterns where addressed for the first time. Furthermore, hypotheses regarding the presence of hybrids were also tested. As a result, interpretive power to the diversity patterns observed today in the Balkans was added and previously overlooked aspects of the species biology were highlighted.     

Genetic structure of Eurasian badgers Meles meles (Carnivora: Mustelidae) and the colonization history of Ireland

The present study examined the contemporary genetic composition of the Eurasian badger, Meles meles, in Ireland, Britain and Western Europe, using six nuclear microsatellite loci and a 215‐bp fragment of the mitochondrial DNA control region. Significant population structure was evident within Europe (global multilocus microsatellite F_ST = 0.205, P < 0.001; global mitochondrial control region Φ_ST = 0.399, P < 0.001). Microsatellite‐based cluster analyses detected one population in Ireland, whereas badgers from Britain could be subdivided into several populations. Excluding the island populations of Ireland and Britain, badgers from Western Europe showed further structuring, with evidence of discrete Scandinavian, Central European, and Spanish populations. Mitochondrial DNA cluster analysis grouped the Irish population with Scandinavia and Spain, whereas the majority of British haplotypes grouped with those from Central Europe. The findings of the present study suggest that British and Irish badger populations colonized from different refugial areas, or that there were different waves of colonization from the source population. There are indications for the presence of an Atlantic fringe element, which has been seen in other Irish species. We discuss the results in light of the controversy about natural versus human‐mediated introductions. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??.     

Genetic differentiation of the Western Capercaillie highlights the importance of South-eastern Europe for understanding the species phylogeography

The Western Capercaillie (Tetrao urogallus L.) is a grouse species of open boreal or high altitude forests of Eurasia. It is endangered throughout most mountain range habitat areas in Europe. Two major genetically identifiable lineages of Western Capercaillie have been described to date: the southern lineage at the species' southernmost range of distribution in Europe, and the boreal lineage. We address the question of genetic differentiation of capercaillie populations from the Rhodope and Rila Mountains in Bulgaria, across the Dinaric Mountains to the Slovenian Alps. The two lineages' contact zone and resulting conservation strategies in this so-far understudied area of distribution have not been previously determined. The results of analysis of mitochondrial DNA control region sequences of 319 samples from the studied populations show that Alpine populations were composed exclusively of boreal lineage; Dinaric populations of both, but predominantly (96%) of boreal lineage; and Rhodope-Rila populations predominantly (>90%) of southern lineage individuals. The Bulgarian mountains were identified as the core area of the southern lineage, and the Dinaric Mountains as the western contact zone between both lineages in the Balkans. Bulgarian populations appeared genetically distinct from Alpine and Dinaric populations and exhibited characteristics of a long-term stationary population, suggesting that they should be considered as a glacial relict and probably a distinct subspecies. Although all of the studied populations suffered a decline in the past, the significantly lower level of genetic diversity when compared with the neighbouring Alpine and Bulgarian populations suggests that the isolated Dinaric capercaillie is particularly vulnerable to continuing population decline. The results are discussed in the context of conservation of the species in the Balkans, its principal threats and legal protection status. Potential conservation strategies should consider the existence of the two lineages and their vulnerable Dinaric contact zone and support the specificities of the populations.     

Reduced genetic variation and strong genetic population structure in the freshwater killifish Valencia letourneuxi (Valenciidae) based on nuclear and mitochondrial markers

The genetic variation of the critically endangered Corfu killifish (Valencia letourneuxi), an endemic freshwater fish species of the western Balkans, was assessed for nine populations sampled in eight water systems in western continental Greece, the Peloponnese and the Ionian Island of Corfu, using mitochondrial and microsatellite markers. The analyses were based on data from three mtDNA regions (D‐loop, COI and 16S rRNA sequences) and 14 microsatellite loci. Samples from the congeneric species Valencia hispanica and the phylogenetically closely related species Aphanius fasciatus were also used in the study as outgroups. Both the mitochondrial and the microsatellite analyses revealed three distinct population groupings associated with the geographical distribution of the populations: one southern group occupying rivers draining to the Patraikos Gulf, the second one including the populations flowing into the Amvrakikos Gulf and the third, more northern group, including the other populations from rivers in Corfu Island and Epirus flowing into the Ionian Sea. Within these groupings there is limited genetic differentiation between populations; in addition, there is reduced intrapopulation genetic variation, evidenced by low heterozygosity values, number of alleles and haplotype diversity. In terms of taxonomic implications and appropriate management actions for conservation, our data suggest that the major population groups should be regarded at least as three distinct conservation units (CUs), with translocation and restocking actions to take place only within the geographical range of the CU concerned. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 334–349.     

Phylogeography and genetic structure of the threatened Canarian Juniperus cedrus (Cupressaceae)

We used plastid sequences (trnL, trnL‐trnF, petN‐psbM and trnT‐trnL) to infer the phylogenetic relationships and inter‐island connections of the Canarian Juniperus cedrus, and AFLP fingerprints to assess its genetic diversity patterns. Maximum Likelihood, Maximum Parsimony and Bayesian methods suggest independent colonization events for the three Macaronesian junipers and support the monophyly of J. cedrus. Plastid sequences reveal a low genetic diversity (three haplotypes) and do not provide sufficient information to resolve its temporal and geographical origin. AFLPs indicate a greater isolation in J. cedrus than in other Macaronesian trees with similar distributions and dispersal syndromes. Gran Canaria harbours the least genetically diverse population, which justifies immediate conservation actions. This island and Tenerife also show independent genetic structure, meaning that genetic exchange from other islands should be avoided in eventual reinforcements. Populations from La Palma and La Gomera show the highest genetic diversity levels and number of polymorphic AFLPs, probably because a lower incidence of felling has allowed a less dramatic influence of genetic bottlenecks. We suggest that management efforts should prioritize populations from these islands to preserve the evolutionary potential of the species, but we also stress the importance of knowledge of the evolutionary history, genetic structure and ecological interactions in conservation strategies. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 376–394.     

Effect of founding events on coat colour polymorphism of Apodemus speciosus (Rodentia: Muridae) on the Izu Islands

To infer the evolutionary mechanism of phenotypic variation among isolated island populations, we investigated coat colour and genetic variation in the large Japanese field mouse (Apodemus speciosus) on the Izu Islands (Ohshima, Niijima, Kouzushima, and Miyakejima). Coat colour in the most remote population (Miyakejima) was unique and significantly darker than that in the other populations. Ohshima that is closest to the source population showed variation in coat colour within its population. Phylogeographical analyses using mitochondrial and microsatellite markers suggested that the island populations (except Kouzushima) were founded sequentially from the closest Ohshima to remote Niijima and Miyakejima during or before the penultimate interglacial period. Secondary gene flow from the source population was rare and occurred only for the closest (Ohshima) population. In addition, we found that an amino acid mutation in the Agouti signalling protein gene (Asip) was associated with coat colour variation among the island populations. The mutation was rare in the source population but completely fixed in the Miyakejima population. The phenotypic and genetic variation suggested that severe reduction of genetic variation and changes in allele frequency as a result of sequential colonization (i.e. the founder effect) had significant effects on colour polymorphism. The findings of the present study suggest that the founder effect, in addition to natural selection, facilitated the morphological changes below the species level over a relatively long time scale. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 522–535.     

Evidence of a complex phylogeographic structure in the common dormouse,Muscardinus avellanarius (Rodentia: Gliridae)

This is the first mitochondrial phylogeography of the common dormouse, Muscardinus avellanarius (Linnaeus, 1758), a hibernating rodent strictly protected in Europe (Habitat Directive, annex IV; Bern Convention, annex III). The 84 individuals of M. avellanarius, sampled throughout the distributional range of the species, have been sequenced at the mitochondrial DNA gene (cytochrome b, 704 base pairs). The results revealed two highly divergent lineages, with an ancient separation around 7.7 Mya and a genetic divergence of 7.7%. Lineage 1 occurs in Western Europe (France, Belgium, and Switzerland) and Italy, and lineage 2 occurs in Central–Northern Europe (Poland, Germany, Latvia, and Lithuania), on the Balkan Peninsula, and in Turkey. Furthermore, these two lineages are subdivided into five sublineages genetically isolated with a strong geographical association. Therefore, lineage 1 branches into two further sublineages (Western European and Italian), whereas lineage 2 contained three sublineages (Central–Northern European, Turkish, and Balkan). We observed low genetic diversity within the sublineages, in contrast to the significant level of genetic differentiation between them. The understanding of genetic population structure is essential for identifying units to be conserved. Therefore, these results may have important implications for M. avellanarius conservation. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 648–664.     

Phylogeography of a mite,Halozetes fulvus,reflects the landscape history of a young volcanic island in the sub‐Antarctic

Previous studies of the microarthropods of Marion Island, Southern Ocean, documented high mitochondrial COI (cytochrome c oxidase subunit I) haplotype diversity and significant genetic structure, which were ascribed to landscape subdivision. In this paper we revisit these ideas in light of new geomorphological evidence indicating a major lineament orientated along N26.5°E. Using the microarthropod Halozetes fulvus, we test the hypothesis that the eastern and western sides of the island show different population genetic patterns, corresponding to the previously unrecognized geological separation of these regions, and perhaps also with differences in climates across the island and further landscape complexity. Mitochondrial COI data were collected for 291 H. fulvus individuals from 30 localities across the island. Notwithstanding our sampling effort, haplotype diversity was under‐sampled as indicated by rarefaction analyses. Overall, significant genetic structure was found across the island as indicated by Φ_ST analyses. Nested clade phylogeographical analyses suggested that restricted gene flow (with isolation‐by‐distance) played a role in shaping current genetic patterns, as confirmed by Mantel tests. At the local scale, coalescent modelling revealed two different genetic patterns. The first, characterizing populations on the south‐western corner of the island, was that of low effective population size and high gene flow. The converse was found on the eastern side of Marion Island. Taken together, substantial differences in spatial genetic structure characterize H. fulvus populations across Marion Island, in keeping with the hypothesis that the complex history of the island, including the N26.5°E geological lineament, has influenced population genetic structure. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 131–145.     

Genetic diversity of Andean Polylepis (Rosaceae) woodlands and inferences regarding their fragmentation history

There is a long‐standing debate on whether the occurrence of the iconic high‐Andes Polylepis woodlands as small and isolated fragments is of natural or anthropogenic origin. We make inferences regarding the fragmentation history based on both a new population genetic study on P. besseri and a synthesis of available studies on the population genetics of Polylepis woodlands. We infer the timing of the main woodland fragmentation event by analysing: (1) the remaining levels of population genetic diversity and the relation to population size; (2) among‐population genetic differentiation; and (3) the difference in genetic diversity between the offspring and adult generation. We retrieved seven publications on the population genetics of five Polylepis spp. We did not find a relationship between population size and genetic diversity, and genetic differentiation was low compared with that reported for similar plant species. These findings do not support a history of long‐term fragmentation. The offspring showed a loss of genetic diversity and increasing differentiation compared with adults, suggesting that the main habitat fragmentation event is of relatively recent origin. For P. besseri, no significant differences were found between the adult and offspring genetic variation. We discuss the conservation and restoration consequences for this important high‐Andean genus. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172 , 544–554.     

Mitochondrial gene diversity in Cepaea– population structure, history and positive selection

Previous studies on the geographical distributions of both shell polymorphisms and mitochondrial haplotypes in Cepaea land snails have suggested varying contributions of natural selection, random genetic drift and population history to the origin and persistence of variation. We combine previous studies of polymorphism within two species of Cepaea , with new molecular data from two mitochondrial genes. The distributions of mitochondrial variants suggest that elements of population history may have been influential in creating patterns of diversity. However, some patterns of amino acid substitution that are found in a protein coding gene are also consistent with the action of diversifying selection. This suggests the possibility that in addition to stochastic processes such as repeated founder events, local extinctions and random genetic drift within a structured population, adaptive molecular change may have affected mitochondrial diversity.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 87 , 167–184.     

Phylogeography of Xiphorhynchus fuscus (Passeriformes, Dendrocolaptidae): vicariance and recent demographic expansion in southern Atlantic forest

Knowledge of the evolutionary processes that shaped a biota is important for both academic and conservation purposes. The objective of the present study is to analyse the mitochondrial genetic variation of Xiphorhynchus fuscus (Aves: Dendrocolaptidae) from the southern Atlantic forest in Brazil and Argentina, and to discuss whether the results support different hypotheses regarding the local intraspecific diversification of this species . We sequenced 575 bp of the control region of 114 specimens collected in the Brazilian states of Bahia, Minas Gerais, Rio de Janeiro, São Paulo, Paraná, and Santa Catarina, and in the province of Misiones in Argentina. We studied the population genetic structure with analysis of molecular variance and the demographic history with multiple regression analysis, coalescence simulations, and demographic tests. Xiphorhynchus fuscus presented a significant population genetic structure (Φ_st = 0.57). Three mitochondrial lineages were described, one associated with Xiphorhynchus fuscus tenuirostris and the others with Xiphorhynchus fuscus fuscus. The data did not support the primary influence of geographical barriers or rivers in the intraspecific diversification of X. fuscus in the southern Atlantic forest. Instead, the data supported the influence of isolation by geographical distance, recent vicariance events, and demographic expansions apparently related to Pleistocene and Holocene forest dynamics.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 73–84.     

Genetic diversity and phylogeography of the European roe deer: the refuge area theory revisited

The extant taxa of central and northern Europe are commonly believed to derive from Pleistocene ancestors, who moved to the north from three separate glacial refugia: the Iberian and Italian peninsulae, as well as the southern Balkans. The issue of postglacial dispersal patterns was addressed through the investigation of population structure and phylogeography of the European roe deer, Capreolus capreolus . The genetic diversity in 376 individuals representing 14 allegedly native populations across their European range was assessed, using ten autosomal microsatellite loci and restriction fragment length polymorphisms of the mitochondrial D-loop and NADH dehydrogenase 1 gene segments. Our results suggest the existence of three major genetic lineages of roe deer in Europe. One comprises populations in the south-western limit of the species' distribution (i.e. Iberia), where an internal substructure splits a northern from a southern sublineage. A second lineage includes populations of southern and eastern Europe, as well as a separate sublineage sampled in central-southern Italy, where the existence of the subspecies Capreolus c. italicus was supported. In central-northern Europe, a third lineage is present, which appeared genetically rather homogeneous, although admixed, and equally divergent from both the eastern and western lineages. Current patterns of intraspecific genetic variation suggest that postglacial recolonization routes of this cervid to northern Europe could be due to range expansion from one or more refugia in central-eastern Europe, rather than proceeding from the Mediterranean areas.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 85–100.     

Multilocus phylogeography of the Patagonian lizard complex Liolaemus kriegi (Iguania: Liolaemini)

This study presents a detailed phylogeographical analysis of one of the most conspicuous groups of lizards in northwestern Patagonia, the Liolaemus kriegi complex. This region is geographically very complex as a result of Andean orogeny and subsequent volcanism coupled with a long history of glaciations and climatic changes. For 247 individuals we sequenced one mitochondrial gene (cytochrome b) and for a subset we sequenced another mitochondrial gene [12S ribosomal RNA (12S)] and two nuclear fragments [kinesin family member 24 (KIF24) and BA3 ribosomal RNA (BA3)]. We obtained gene trees and mitochondrial and nuclear haploytpe networks, and estimated genetic distances between the main lineages and basic molecular diversity indices. We also performed spatial analysis of molecular variance (SAMOVA) and Bayesian Skyline Plot (BSP) analyses, and concordant patterns from different lines of evidence permitted delimitation of seven lineages: two described species, Liolaemus buergeri and Liolaemus tregenzai; four candidate species, Liolaemus sp. A, Liolaemus sp. B, Liolaemus sp. C, and Liolaemus sp. D; and one lineage that includes all individuals from the geographical range of Liolaemus ceii and L. kriegi, referred to as L. kriegi + L. ceii. We discuss the evolutionary processes that may contribute to the origin of these lineages and their taxonomic and conservation implications. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 256–269.     

Connectivity,small islands and large distances: the Cellana strigilis limpet complex in the Southern Ocean

The Southern Ocean contains some of the most isolated islands on Earth, and fundamental questions remain regarding their colonization and the connectivity of their coastal biotas. Here, we conduct a genetic investigation into the Cellana strigilis (limpet) complex that was originally classified based on morphological characters into six subspecies, five of which are endemic to the New Zealand (NZ) subantarctic and Chatham islands (44–52°S). Previous genetic analyses of C. strigilis from six of the seven island groups revealed two lineages with little or no within‐lineage variation. We analysed C. strigilis samples from all seven island groups using two mitochondrial (COI and 16S), one nuclear (ATPase β) and 58 loci from four randomly amplified polymorphic DNA markers (RAPDs) and confirmed the existence of two distinct lineages. The pronounced genetic structuring within each lineage and the presence of private haplotypes in individual islands are the result of little genetic connectivity and therefore very high self‐recruitment. This study supports the significance of the subantarctic islands as refugia during the last glacial maximum and adds to the knowledge of contemporary population connectivity among coastal populations of remote islands in large oceans and the distance barrier to gene flow that exists in the sea (despite its continuous medium) for most taxa.     

Enhanced colour polymorphisms in island populations of the land snail Euhadra peliomphala

Variations in visible genetic polymorphisms are assumed to decrease in populations on small islands because of intense founder effects, genetic drift and inbreeding. However, we have found evidence of a marked enhancement of colour polymorphisms within populations on small oceanic islands that were colonized from the mainland. The source populations on the mainland of the land snail Euhadra peliomphala in four oceanic islands were estimated by phylogenetic analysis of mitochondrial DNA sequences. Diversity of shell colour was higher in the island populations than in the source populations on the mainland. In addition, the shell colour morphs differed not only among populations from different islands but also between the island populations and the source populations on the mainland. By contrast, no mtDNA variations were found in any of the island populations, even though the source populations possessed high mtDNA diversity. Thus, components of colour morphs changed in the island populations after their colonization, and colour polymorphisms are enhanced in these islands despite the loss of genetic variation. The above findings suggest that ecological mechanisms such as morphological release owing to a release from competition may overcome the tendency toward reduced genetic variation in islands to enhance the colour polymorphism.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 81 , 417–425.     

Population genetic structure of rock ptarmigan in the 'sky islands' of French Pyrenees: implications for conservation

Expected consequences of global warming include habitat reduction in many cool climate species. Rock ptarmigan is a Holarctic grouse that inhabits arctic and alpine tundra. In Europe, the Pyrenean ptarmigan inhabits the southern edge of the species' range and since the last glacial maximum its habitat has been severely fragmented and is restricted to high-alpine zones or 'sky islands'. A recent study of rock ptarmigan population genetic in Europe found that the Pyrenean ptarmigan had very low genetic diversity compared with that found in the Alps and Scandinavia. Habitat fragmentation and reduced genetic diversity raises concerns about the viability of ptarmigan populations in the Pyrenees. However, information on population structuring and gene flow across the Pyrenees, which is essential for designing a sound management plan, is absent. In this study, we use seven microsatellites and mitochondrial control region sequences to investigate genetic variation and differentiation among five localities across the Pyrenees. Our analyses reveal the presence of genetic differentiation among all five localities and a significant isolation-by-distance effect that is likely the result of short dispersal distances and high natal and breeding philopatry of Pyrenean ptarmigan coupled with severe habitat fragmentation. Furthermore, analysis of molecular variance, principal component analysis and Bayesian analysis of genetic structuring identified the greatest amount of differentiation between the eastern and main parts of the Pyrenean chain separated by the Sègre Valley. Our data also show that the Canigou massif may host an isolated population and requires special conservation attention. We propose a management plan which includes the translocation of birds. If a sky island structure affects genetic divergence in rock ptarmigan, it may also affect the genetic structure of other sky island species having low dispersal abilities.     

Cryptic diversity within the endemic prehensile‐tailed gecko Urocotyledon inexpectata across the Seychelles Islands: patterns of phylogeographical structure and isolation at the multilocus level

The deciphering of the process of genetic differentiation of species with insular distributions is relevant for biogeographical and conservation reasons. Despite their importance as old gondwanic islands and part of the western Indian Ocean biodiversity hotspot, little is known about the genetic structure of taxa from the Seychelles Islands. We have examined the patterns of structure and isolation within Urocotyledon inexpectata (Reptilia: Geckkonidae), an endemic species from this archipelago. Genetic diversity was screened from populations across the archipelago for both mitochondrial and nuclear genes. Gene genealogies and model‐based inference were used to explore patterns and timings of isolation between the main lineages. High levels of genetic diversity were found for the mitochondrial and some of the nuclear markers. This species harbours at least two highly differentiated lineages, exclusively distributed across the northern and southern groups of the islands. The main split between these was dated back to the Miocene–late Pliocene, but isolation events throughout the Pliocene and Pleistocene were also inferred. Migration between groups of islands was apparently nonexistent, except for one case. The low dispersal capabilities of this species, together with the intrinsic fragmented nature of its geographical distribution, seem to have resulted in highly structured populations, despite the cyclic periods of contact between the different island groups. These populations may currently represent more than one species, making U. inexpectata another example of a morphologically cryptic lineage with deep genetic divergence within gekkonids. The observed patterns suggest a hypothetical biogeographic scenario (of a main north–south phylogeographic break) for the Seychelles that can be further tested with the exploration of the phylogeographic structure of other Seychellois taxa. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 177–191.     

Lasting through the ice age: The role of the proglacial refugia in the maintenance of genetic diversity,population growth,and high dispersal rate in a widespread freshwater crustacean

1. The severe climatic changes during the Pleistocene ice ages have shaped the genetic structure and distribution of biota in Europe. We aimed to reveal in detail the genetic diversity, geographical population structure, historical and present demography, migration patterns, and the presence of possible glacial refugia within the nominative subspecies Asellus aquaticus aquaticus.
2. We analysed DNA sequences of the mitochondrial cytochrome c oxidase subunit I gene and nuclear noncoding internal transcribed spacer II region, from populations inhabiting post-glacial Europe (from the British Isles and Scandinavia to the northern Mediterranean and Black Sea coasts).
3. The origin of the taxon, including establishment in the Dinaric Western Balkans, dates to the Middle/Late Pliocene, but most of its genetic diversity emerged during the Middle/Late Pleistocene before the Last Glacial Maximum.
4. Despite the general absence of spatial genetic structure with population growth, we discovered two different phylogeographic stories across 11 clusters revealed by a coalescent approach. Firstly, the periglacial cluster group—spatially restricted mainly to the northern Balkans, Pannonian Basin, and Pontic Region—is older and more divergent. It apparently retained a relatively stable population size during the glacial-interglacial cycles. Conversely, the proglacial cluster group—widely distributed in areas close to the glacier margins (north of the Alps, Sudetes, Carpathians) and in the Pannonian Basin—is younger and composed of closely related individuals. It originated in Pleistocene and lasted continuously through the Last Glacial Maximum in numerous high latitude refugia. This was probably due to the vast network of proglacial lakes and rivers, which played a crucial role in the maintenance of genetic diversity, population growth, and high dispersal rate.
5. The evolutionary history of A. a. aquaticus reveals unexpected patterns and is an important lesson when making predictions for other aquatic taxa. Our results suggest that we should stop perceiving the proglacial habitats as lifeless ice desert.

     

Genetic analysis of a novel invasion of Puerto Rico by an exotic constricting snake

The tropical island Puerto Rico is potentially vulnerable to invasion by some species of exotic snakes; however, until now no established populations had been reported. Here we report and genetically characterize the nascent invasion of Puerto Rico by an exotic constricting snake of the family Boidae (Boa constrictor) using mtDNA and microsatellite data. Over 150 individual B. constrictor have been removed from Mayagüez municipality since May 2011, and our results from the genetic analysis of 32 individuals suggest that this population was recently founded by individuals of one subspecies from a genetic lineage common to zoo and breeding collections, but that the potential propagule pool consists of two subspecies. We also suggest that anthropogenic long-distance dispersal within the island of Puerto Rico may be occurring from the established population, with implications for further establishment across the island. This study represents the first report of the naturalization of an invasive species of boid snake in Puerto Rico and will be important in determining mitigation strategies for this invasion as well as providing a basis for comparison to other on-going studies of invasive snakes.     

Population structure,diversity, and phylogeography in the near‐threatened Eurasian black vultures Aegypius monachus (Falconiformes; Accipitridae) in Europe: insights from microsatellite and mitochondrial DNA variation

The Eurasian black vulture (Aegypius monachus) has experienced a severe decline during the last two centuries and is globally classified as near‐threatened. This has led to the extinction of many traditional breeding areas in Europe and resulted in the present patchy distribution (Iberian and Balkan peninsulas) in the Western Palearctic. In the present study, we describe the current genetic status of the European populations using both mitochondrial cytochrome b sequences and nuclear microsatellite markers, comparing with those found in Asia (Mongolia and Caucasus region). Although, mitochondrial (mt)DNA revealed a relatively low genetic variability (haplotype diversity), no evidence of genome‐wide genetic erosion exists because nuclear diversity exhibits normal levels and strong differentiation. A highly philopatric dispersal behaviour must be invoked to explain the existence of a clear pattern that revealed by the phylogeographic analysis, which indicates a sharp East–West clinal distribution and an allopatric differentiation. The distribution of mtDNA haplotypes one in the Iberian population and two in Balkan population and the significance divergence at nuclear loci fulfill the definitions of those populations as evolutionary significant units. We discuss how management strategies should aim at the maintenance (or increase) of current genetic variability levels, suggesting that independent conservation plans are urgently required to protect these two breeding European populations from extinction. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 859–872.