Disjunct distributions during glacial and interglacial periods in mountain butterflies: Erebia epiphron as an example

Over several decades, the distribution patterns and evolution of alpine disjunct species has become an increasingly discussed subject. Large scale genetic analysis has allowed the resolution of the past range changes and intraspecific evolution of many species, in Europe especially of Mediterranean origin. However, the phylogeographic structures of species with arctic-alpine disjunct distribution patterns are relatively poorly studied. The existing phylogeographic analysis (mostly of alpine plant species) supports disjunct distributions during glacial as well as post-glacial periods for a number of species. However, several questions still remain unresolved and we therefore analysed the Mountain Ringlet Erebia epiphron as a model for such alpine disjunct species. We found strong differentiation into five different lineages supporting five differentiation centres: (i) the eastern Pyrenees, (ii) the mountain ranges between the central Pyrenees and south-western Alps, (iii, iv) two areas along the southern Alps margin and (v) the northern Alps margin. We propose that these patterns evolved due to the humidity requirements of this species, which did not allow survival in the dry glacial steppes, but along the margins of the wetter glaciated high mountain ranges.     

Do different dispersal capacities influence the biogeography of the western Palearctic dragonflies (Odonata)?

The biogeography of the western Palearctic has been intensively studied for more than a century. Recent advances in genetics have allowed the testing of old theories based on distribution patterns, although these analyses are obviously restricted to a reduced number of specific genetic data sets. On the other hand, an increased knowledge on the distributions of species and advances in computer capacities have allowed more detailed biogeographical analyses based on species presence/absence. In the present study, we selected the Odonata as the study group. For all 162 species native to the western Palearctic, we compiled their respective presence or absence in 97 predefined biogeographical regions. Using cluster analyses and principal component analyses, both based on Jaccard similarity coefficients, we analysed the differentiation among these regions and species. In subsequent analyses, the data set was reduced to the Zygoptera, Anisoptera, and the western Palearctic endemics. All analyses consistently showed different faunal regions and faunal elements. In particular, the (1) western and (2) eastern Mediterranean; (3) Central and (4) Northern Europe; and (5) the British Isles were invariably found in all cases. Although the two major Mediterranean regions were characterized by several endemic faunal elements, Northern Europe and the British Isles lacked such elements, but were characterized by faunal compositions strongly deviating from the rest of the western Palearctic region. Moderate differences between Zygoptera and Anisoptera existed, with the latter more clearly redrawing the Mediterranean refuge areas, whereas the former reflected to a greater extent the postglacial expansion patterns from these regions. In general, our findings underline the old biogeographical theories, but refine especially our understanding of the Atlanto‐ and Ponto‐Mediterranean region. Central Europe, comprising the area with the highest species numbers of our whole study region, unravels as a crossroad of postglacial immigrations, but might also represent a region of in situ glacial survival. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 177–195.     

Evolution of the Madrean–Tethyan disjunctions and the North and South American amphitropical disjunctions in plants

Abstract The present paper reviews advances in the study of two major intercontinental disjunct biogeographic patterns: (i) between Eurasian and western North American deserts with the Mediterranean climate (the Madrean–Tethyan disjunctions); and (ii) between the temperate regions of North and South America (the amphitropical disjunctions). Both disjunct patterns have multiple times of origin. The amphitropical disjunctions have largely resulted from long‐distance dispersal, primarily from the Miocene to the Holocene, with available data indicating that most lineages dispersed from North to South America. Results of recent studies on the Mediterranean disjuncts between the deserts of Eurasia and western North America support the multiple modes of origin and are mostly consistent with hypotheses of long‐distance dispersal and the North Atlantic migration. Axelrod's Madrean–Tethyan hypothesis, which implies vicariance between the two regions in the early Tertiary, has been favored by a few studies. The Beringian migration corridor for semiarid taxa is also supported in some cases.     

Evolution of the Madrean-Tethyan disjunctions and the North and South American amphitropical disjunctions in plants

The present paper reviews advances in the study of two major intercontinental disjunct biogeographic patterns： （i） between Eurasian and western North American deserts with the Mediterranean climate （the Madrean- Tethyan disjunctions）; and （ii） between the temperate regions of North and South America （the amphitropical disjunctions）. Both disjunct patterns have multiple times of origin. The amphitropical disjunctions have largely resulted from long-distance dispersal, primarily from the Miocene to the Holocene, with available data indicating that most lineages dispersed from North to South America. Results of recent studies on the Mediterranean disjuncts between the deserts of Eurasia and western North America support the multiple modes of origin and are mostly consistent with hypotheses of long-distance dispersal and the North Atlantic migration. Axelrod＇s Madrean-Tethyan hypothesis, which implies vicariance between the two regions in the early Tertiary, has been favored by a few studies. The Beringian migration corridor for semiarid taxa is also supported in some cases.     

A tale of North and South America: time and mode of dispersal of the amphitropical genus Munroa (Poaceae,Chloridoideae)

Plant disjunctions have provided some of the most intriguing distribution patterns historically addressed by biogeographers. We evaluated the three hypotheses that have been postulated to explain these patterns [vicariance, stepping‐stone dispersal and long‐distance dispersal (LDD)] using Munroa, an American genus of grasses with six species and a disjunct distribution between the desert regions of North and South America. The ages of clades, cytology, ancestral characters and areas of distribution were investigated in order to establish relationships among species, to determine the time of divergence of the genus and its main lineages, and to understand further the biogeographical and evolutionary history of this genus. Bayesian inference recovered the North American M. pulchella as sister species to the rest. Molecular dating and ancestral area analyses suggest that Munroa originated in North America in the late Miocene–Pliocene (7.2 Mya; 8.2–6.5 Mya). Based on these results, we postulate that two dispersal events modelled the current distribution patterns of Munroa: the first from North to South America (7.2 Mya; 8.2–6.5 Mya) and the second (1.8 Mya; 2–0.8 Mya) from South to North America. Arid conditions of the late Miocene–Pliocene in the Neogene and Quaternary climatic oscillations in North America and South America were probably advantageous for the establishment of populations of Munroa. We did not find any relationship between ploidy and dispersal events, and our ancestral character analyses suggest that shifts associated with dispersal and seedling establishment, such as habit, reproductive system, disarticulation of rachilla, and shape and texture of the glume, have been important in these species reaching new areas. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 110–125.     

Galápagos and Californian sea lions are separate species: Genetic analysis of the genus Zalophus and its implications for conservation management

The climatic cycles with subsequent glacial and intergalcial periods have had a great impact on the distribution and evolution of species. Using genetic analytical tools considerably increased our understanding of these processes. In this review I therefore give an overview of the molecular biogeography of Europe. For means of simplification, I distinguish between three major biogeographical entities: (i) "Mediterranean" with Mediterranean differentiation and dispersal centres, (ii) "Continental" with extra-Mediterranean centres and (iii) "Alpine" and/or "Arctic" with recent alpine and/or arctic distribution patterns. These different molecular biogeographical patterns are presented using actual examples. Many "Mediterranean" species are differentiated into three major European genetic lineages, which are due to glacial isolation in the three major Mediterranean peninsulas. Postglacial expansion in this group of species is mostly influenced by the barriers of the Pyrenees and the Alps with four resulting main patterns of postglacial range expansions. However, some cases are known with less than one genetic lineage per Mediterranean peninsula on the one hand, and others with a considerable genetic substructure within each of the Mediterranean peninsulas, Asia Minor and the Maghreb. These structures within the Mediterranean sub-centres are often rather strong and in several cases even predate the Pleistocene. For the "Continental" species, it could be shown that the formerly supposed postglacial spread from eastern Palearctic expansion centres is mostly not applicable. Quite the contrary, most of these species apparently had extra-Mediterranean centres of survival in Europe with special importance of the perialpine regions, the Carpathian Basin and parts of the Balkan Peninsula. In the group of "Alpine" and/or "Arctic" species, several molecular biogeographical patterns have been found, which support and improve the postulates based on distribution patterns and pollen records. Thus, genetic studies support the strong linkage between southwestern Alps and Pyrenees, northeastern Alps and Carpathians as well as southeastern Alps and the Dinaric mountain systems, hereby allowing conclusions on the glacial distribution patterns of these species. Furthermore, genetic analyses of arctic-alpine disjunct species support their broad distribution in the periglacial areas at least during the last glacial period. The detailed understanding of the different phylogeographical structures is essential for the management of the different evolutionary significant units of species and the conservation of their entire genetic diversity. Furthermore, the distribution of genetic diversity due to biogeographical reasons helps understanding the differing regional vulnerabilities of extant populations.     

Bipolar distributions in vascular plants: A review

Bipolar disjunct distributions are a fascinating biogeographic pattern exhibited by about 30 vascular plants, whose populations reach very high latitudes in the northern and southern hemispheres. In this review, we first propose a new framework for the definition of bipolar disjunctions and then reformulate a list of guiding principles to consider how to study bipolar species. Vicariance and convergent evolution hypotheses have been argued to explain the origin of this fragmented distribution pattern, but we show here that they can be rejected for all bipolar species, except for Carex microglochin. Instead, human introduction and dispersal (either direct or by mountain‐hopping)—facilitated by standard and nonstandard vectors—are the most likely explanations for the origin of bipolar plant disjunctions. Successful establishment after dispersal is key for colonization of the disjunct areas and appear to be related to both intrinsic (e.g., self‐compatibility) and extrinsic (mutualistic and antagonistic interactions) characteristics. Most studies on plant bipolar disjunctions have been conducted in Carex (Cyperaceae), the genus of vascular plants with the largest number of bipolar species. We found a predominant north‐to‐south direction of dispersal, with an estimated time of diversification in agreement with major cooling events during the Pliocene and Pleistocene. Bipolar Carex species do not seem to depend on specialized traits for long‐distance dispersal and could have dispersed through one or multiple stochastic events, with birds as the most likely dispersal vector.     

Decades-long phylogeographic issues: complex historical processes and ecological factors on genetic structure of alpine plants in the Japanese Archipelago

Mountain regions are important places for biodiversity, where organisms could persist throughout prolonged periods and accumulate genetic divergence as well as promote speciation. Roles of mountains for biodiversity have been exclusively discussed in regions that have specifically diverse species or covered with ice-sheets during the Pleistocene glacial periods, whereas the importance of mountainous regions in East Asia has been less disputed. High mountains in the Japanese Archipelago, located at the eastern edge of the Eurasia continent, have one of southernmost populations of alpine and arctic-alpine plants that are also distributed in the northern Pacific and/or the circumarctic regions. Phylogeographic studies on the Japanese alpine plants have excluded their possible ephemeral occurrence during the current warm period, and rather, suggest persistence of alpine plants throughout several cycles of climate changes in the Pleistocene on high mountains in central Honshu, the main island of the Japanese Archipelago. In this review, I look through decade long phylogeographic studies and show complicated patterns of range dynamics of Japanese alpine plants. In addition, I note recent findings of genetic relationships of Japanese populations of alpine and/or arctic-alpine plants with those in northern regions and their possible ecological divergence in the Japanese Archipelago. Taken together, I provide several issues for understanding historical processes that established distribution of alpine plants following climate changes as well as their diversification and propose importance of Japanese populations of alpine plants on biodiversity in alpine communities across broader range, especially in the northern Pacific region.

     

Is it really you,Orthotrichum acuminatum? Ascertaining a new case of intercontinental disjunction in mosses

Intercontinental disjunct distributions are a main issue in current biogeography. Bryophytes usually have broad distribution ranges and therefore constitute an interesting subject of study in this context. During recent fieldwork in western North America and eastern Africa, we found new populations of a moss morphologically similar to Orthotrichum acuminatum. So far this species has been considered to be one of the most typical epiphytic mosses of the Mediterranean Basin. The new findings raise some puzzling questions. Do these new populations belong to cryptic species or do they belong to O. acuminatum, a species which then has a multiple‐continent disjunct range? In the latter case, how could such an intercontinental disjunction be explained? To answer these questions, an integrative study involving morphological and molecular approaches was conducted. Morphological results reveal that Californian and Ethiopian samples fall within the variability of those from the Mediterranean Basin. Similarly, phylogenetic analyses confirm the monophyly of these populations, showing that O. acuminatum is one of the few moss species with a distribution comprising the western Nearctic, the western Palaearctic and Palaeotropical eastern Africa. Pending a further genetic and phylogeographical study to support or reject the hypothesis, a process of long‐distance dispersal (LDD) is hypothesized to explain this distribution and the origin of the species is suggested to be the Mediterranean Basin, from where diaspores of the species may have migrated to California and Ethiopia. The spore release process in O. acuminatum is revisited to support the LDD hypothesis, © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2016, 180 , 30–49.     

Origin of the disjunct distribution of flower colour polymorphism within Limonium wrightii (Plumbaginaceae) in the Ryukyu Archipelago

The sea lavender, Limonium wrightii , has six morphs of flower colour variation. The geographical distribution of flower colour morphs is disjunct; the distribution of the pink flower morph is divided into two subregions, and that of the yellow flower morph intervenes between them. The present study aimed to examine the origin of this apparent distribution pattern of flower colour in L. wrightii . Two main hypotheses (i.e. past dispersal events and phenotypic changes by natural selection and/or stochastic processes) have been proposed to account for the origin of leapfrog distribution patterns. To determine which hypothesis was applicable, we conducted a molecular phylogenetic analysis using sequence variation in chloroplast DNA (three regions of intergenic spacers, trnG - trnfM , trnV - trnM , and psbA-trnH ). We sequenced 58 accessions of L. wrightii frin 28 islands in the Ryukyu Archipelago and the Izu-Ogasawara Islands, located south of the Japanese mainland, and 12 accessions of four congeneric species. Within L. wrightii , we obtained four lineages of ten haplotypes. These lineages and haplotypes did not correlate with the different flower colours. These results indicate that the formation processes of populations are complex. The haplotypes of the pink flower morph did not show a sister relationship between the two disjunct subregions, indicating that the disjunct populations of the pink flower morphs are unlikely to share the pink flower colour as a result of common ancestry. We conclude that the observed leapfrog distribution pattern is caused by natural selection and/or stochastic processes.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 709–717.     

Intercontinental Mediterranean disjunct mosses: morphological and molecular patterns

This study focused on three species that occur disjunctly between western North America and the Mediterranean region of southern Europe, northern Africa, and western Asia, forming the so-called Madrean-Tethyan distribution pattern. Quantitative morphological characters were measured in New and Old World plants to find any subtle phenotypic differentiation between the disjunct populations. Sequences from the nuclear ribosomal internal transcribed spacer region were obtained from the same populations to assess differentiation at the molecular level and to compare molecular diversity with patterns of morphological similarity among plants. Little or no morphological differentiation existed between New and Old World plants in any of the species, but internal transcribed spacer (ITS) sequences revealed some phylogeographic structure. Patterns of morphological similarity in all three species were incongruent with phylogeographic structure revealed by sequence data. New World populations were more variable than Old World populations at the molecular level in the three species. Despite some evidence for differentiation between disjunct plants, no plausible mutation rate would date the divergence at ≥20 million years ago (MYA), as implied by the Madrean-Tethyan hypothesis. Recent long-distance dispersal is a more likely explanation for intercontinental disjunctions in these species.     

Phylogeographical study of the alpine plant Cassiope lycopodioides (Ericaceae) suggests a range connection between the Japanese archipelago and Beringia during the Pleistocene

Given that East Asia is located south‐west of Beringia and was less glaciated during the Pleistocene, species at higher latitudes were able to expand their range in this region during climate cooling. Although southward migration is an inevitable colonization process, the biogeographical history of the disjunct ranges of higher‐latitude species in East Asia has been investigated less extensively. Here, we assess whether their disjunct distributions in the Japanese archipelago connected sufficiently with Beringia or persisted in isolation following their establishment. Sequences of nine nuclear loci were determined for Cassiope lycopodioides (Ericaceae) from the Japanese archipelago as well as its surrounding areas, Kamchatka and Alaska. According to the geographical pattern of genetic diversity, the northern populations from Kamchatka to the northern part of the Japanese archipelago were similar genetically and were differentiated from populations in central Japan. Our study suggested that the distribution of C. lycopodioides was connected between the northern part of the Japanese archipelago and south‐western Beringia due to Pleistocene climate cooling. Conversely, central Japan harboured a disjunct range after its establishment. These inferences suggest that widespread range expansion in northern East Asia was plausible for species distributed in Beringia. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 497–509.     

HISTORICAL BIOGEOGRAPHY OF THE HOLARCTIC: AREA RELATIONSHIPS, ANCESTRAL AREAS, AND DISPERSAL OF NON-MARINE ANIMALS

Abstract — Based on published phylogenies for 73 groups of Holarctic non-marine animals, interrelationships between the four Holarctic infraregions (western and eastern Nearctic, western and eastern Palearctic) are examined. The study includes analysis of resolved area cladograms, ancestral areas and dispersal indicated by cladistic subordinateness. Area relationships reflecting present continental configurations (Nearctic vs. Palearctic) dominate the material to the extent that one might speak of a general Holarctic area pattern. Paleocontinental (western Nearctic+eastern Palearctic, western Palearctic+eastern Nearctic) and disjunct patterns are relatively more frequent among groups of higher taxonomic rank. The western Nearctic seems to have played a bigger role than the other infraregions as a center of origin. Two computer programs for constructing resolved area cladograms, viz., COMPONENT 1.5 and COMPONENT 2.0, are compared. The three standard assumptions for biogeographical analysis are compared and arguments are presented in favour of Assumption 0.     

Unveiling the factors shaping the distribution of widely distributed alpine vertebrates,using multi-scale ecological niche modelling of the bat <Emphasis Type="Italic">Plecotus macrobullaris</Emphasis>

Several alpine vertebrates share a distribution pattern that extends across the South-western Palearctic but is limited to the main mountain massifs. Although they are usually regarded as cold-adapted species, the range of many alpine vertebrates also includes relatively warm areas, suggesting that factors beyond climatic conditions may be driving their distribution. In this work we first recognize the species belonging to the mentioned biogeographic group and, based on the environmental niche analysis of Plecotus macrobullaris, we identify and characterize the environmental factors constraining their ranges. Distribution overlap analysis of 504 European vertebrates was done using the Sorensen Similarity Index, and we identified four birds and one mammal that share the distribution with P. macrobullaris. We generated 135 environmental niche models including different variable combinations and regularization values for P. macrobullaris at two different scales and resolutions. After selecting the best models, we observed that topographic variables outperformed climatic predictors, and the abruptness of the landscape showed better predictive ability than elevation. The best explanatory climatic variable was mean summer temperature, which showed that P. macrobullaris is able to cope with mean temperature ranges spanning up to 16C. The models showed that the distribution of P. macrobullaris is mainly shaped by topographic factors that provide rock-abundant and open-space habitats rather than climatic determinants, and that the species is not a cold-adapted, but rather a cold-tolerant eurithermic organism. P. macrobullaris shares its distribution pattern as well as several ecological features with five other alpine vertebrates, suggesting that the conclusions obtained from this study might be extensible to them. We concluded that rock-dwelling and open-space foraging vertebrates with broad temperature tolerance are the best candidates to show wide alpine distribution in the Western Palearctic.     

Floristic biodiversity and history of African arid regions

The phytochorological patterns of the arid flora of Africa are discussed on various levels. The arid regions of the African continent are linked by a large number of taxa with disjunct distribution. Analysis of these disjunct patterns supports the hypothesis of fragmentation of a once continuous arid belt running from the Namib desert region to the Western Sahara via East Africa. The flora of the arid regions of Southern Africa shows regular patterns, e.g. identical fragmentation of distribution areas of several taxa on an infrafamilial or infrageneric level, allowing formulation of a hypothesis concerning the sequence of differentiation steps during formation of the floras. Very interesting patterns can be attributed to effects of the last glaciation. For example, disjunct distribution patterns in the Namib region can be interpreted as a result of survival of palaeotropical taxa in warm refuge areas during the last glaciation.     

中国阿勒泰地区鸟类物种编目、丰富度格局和区系组成

中国阿勒泰地区位于新疆北部, 与哈萨克斯坦、俄罗斯、蒙古国交界, 该区包含阿尔泰山及山前荒漠和绿洲, 属于全球200个生物多样性最丰富和最具代表性生态区之一的阿尔泰-萨彦岭生物热点地区。阿勒泰地区生境多样, 鸟类物种资源丰富。尽管以往曾在阿勒泰地区进行过一些鸟类调查, 但对于该地区不同景观和生境类型中鸟类物种丰富度和分布尚无详尽报道。本文通过2013-2016年在中国境内阿尔泰山及山前平原地区对不同生境类型中的鸟类进行实地调查, 并总结文献资料及观鸟爱好者的记录数据, 重新整理了阿勒泰地区鸟类名录及地理分布, 分析了鸟类的物种组成、区系成分; 通过鸟类分布位点数据, 选取气候、土地覆被类型、人类足迹指数及地形共4类环境因子作为自变量建立MaxEnt生态位模型, 通过模拟77种鸟类的适宜分布区并叠加分布图层, 获得了阿勒泰地区的鸟类物种丰富度分布格局。结果表明: 阿勒泰共记录鸟类344种, 隶属19目55科149属, 其中雀形目163种。在垂直海拔带上, 鸟类物种数分别为高山裸岩带24种, 高山草甸带35种, 山地森林草原带172种, 低山灌木带130种, 荒漠草原带84种, 平原绿洲带173种, 以及各海拔带的湿地与水域生境中水鸟92种; 在区系成分上, 以北方型鸟类为主(170种, 占49.4%), 其次为广布种(93种, 占27.0%)。阿尔泰山地的鸟类区系呈现出西伯利亚动物区系特征, 山前平原地区呈现蒙新区分布特征, 因此, 阿勒泰地区动物地理区系属于古北界欧洲-西伯利亚亚界阿尔泰-萨彦岭区阿尔泰亚区; 山前平原地区属于古北界中亚亚界蒙新区西部荒漠亚区。MaxEnt模型推测阿勒泰地区山前平原绿洲地区、山地森林草原带和低山灌木带具有较高的鸟类物种丰富度, 尤其是额尔齐斯河流域下游的绿洲带宽阔, 鸟类物种丰富, 而高山区和荒漠生境中鸟类物种相对较少。模型预测的结果与实际调查情况相符。阿勒泰地区应采用生态友好的经济发展策略, 加强对乔木和灌木的保护, 这有助于维持较高的鸟类物种多样性。此外, 降低生境破碎化不仅对该地区物种保护有重要作用, 也对维持阿尔泰-萨彦岭生物热点地区的山地鸟类多样性有重要意义。     

Lineage specific evolution of an alternative social strategy in Tetramorium ants (Hymenoptera: Formicidae)

The western Palearctic ant, Tetramorium moravicum , is the only species of the large genus known to display two alternative social strategies: macrogyny-monoygyny (characterized by one large queen per colony) and microgyny-polygyny (multiple small queens per colony). The microgyne colonies of this ant are confined to the westernmost part of its distribution area and occasionally co-occur with macrogyne colonies. We investigated phylogenetic and geographical patterns in relation to social strategy by analysing 1031 bp of the mitochondrial cytochrome c oxidase subunit I gene of T. moravicum from the entire known species range. Phylogenetic analyses revealed two clear-cut lineages coinciding with the eastern and western populations, which probably were separated after the late Quaternary glacial periods. Geographical distance analysis suggested allopatric fragmentation of the two lineages. We hypothesize that the two lineages colonized Central Europe postglacially from two directions. The current distribution gap of 500 km between the tip of the eastern lineage, in the Czech Republic, Austria and Hungary, and the western lineage, in Germany, was confirmed by hierarchical population analysis. Macrogyny-monogyny probably was the original condition in T. moravicum ; the alternative strategy of microgyny-polygyny may have evolved at the tip of the western lineage, as recently as the early Holocene.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 247–255.     

Southern isolation and northern long‐distance dispersal shaped the phylogeography of the widespread,but highly disjunct,European high mountain plant Artemisia eriantha (Asteraceae)

We investigated the range dynamics of Artemisia eriantha, a widespread, but rare, mountain plant with a highly disjunct distribution in the European Alpine System. We focused on testing the roles of vicariance and long‐distance dispersal in shaping the current distribution of the species. To this end, we collected AFLP and plastid DNA sequence data for 17 populations covering the entire distributional range of the species. Strong phylogeographical structure was found in both datasets. AFLP data suggested that almost all populations were genetically strongly differentiated, with 58% of the overall genetic variation partitioned among populations. Bayesian clustering identified five groups of populations: Balkans, Pyrenees, Central Apennines, one southwestern Alpine population and a Widespread cluster (eastern Pyrenees, Alps, Carpathians). Major groups were supported by neighbor‐joining and NeighbourNet analyses. Fourteen plastid haplotypes were found constituting five strongly distinct lineages: Alps plus Pyrenees, Apennines, Balkans, southern Carpathians, and a Widespread group (eastern Pyrenees, northern Carpathians, Mt. Olympus). Plastid DNA data suggested that A. eriantha colonized the European Alpine System in a westward direction. Although, in southern Europe, vicariant differentiation among the Iberian, Italian and Balkan Peninsulas predominated, thus highlighting their importance as glacial refugia for alpine species, in temperate mountain ranges, long‐distance dispersal prevailed. This study emphasizes that currently highly disjunct distributions can be shaped by both vicariance and long‐distance dispersal, although their relative importance may be geographically structured along, for instance, latitude, as in A. eriantha. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 174 , 214–226.     

Disjunct,highly divergent genetic lineages within two rare Eremophila (Scrophulariaceae: Myoporeae) species in a biodiversity hotspot: implications for taxonomy and conservation

Effective conservation management should target appropriate conservation units, but evolutionarily and genetically divergent lineages within nominal taxa are often unrecognized. The south‐western Australian biodiversity hotspot may harbour many cryptic taxa, as it contains many plant species with naturally fragmented population distributions. Using microsatellite markers, we tested the hypothesis that disjunct population groups in the rare species Eremophila microtheca and E. rostrata (Scrophulariaceae: Myoporeae) are highly genetically divergent and represent separate evolutionarily significant units (ESUs). Chromosome counts indicated that all individuals assessed were diploid (2n = 36). Genetic differentiation among disjunct population groups was highly significant (P < 0.001) for both E. microtheca (F_ST = 0.301–0.383; D_est = 0.756–0.774) and E. rostrata (F_ST = 0.325–0.346; D_est = 0.628–0.660), and was similar to their differentiation from allied species. These results, including high incidences of private alleles, suggest historical divergence among cryptic taxa within E. microtheca and E. rostrata. Population groups in E. rostrata have recently been taxonomically recognized as two subspecies. Our study suggests that E. microtheca should also be reassessed as two taxa or considered as two ESUs, and the southern occurrence should be listed as Critically Endangered. We suggest a precautionary approach for flora in this and similar landscapes, whereby historically wide geographical disjunctions are assumed to indicate separate units for conservation. © 2014 State of Western Australia. Botanical Journal of the Linnean Society © 2014 The Linnean Society of London, 2015, 177 , 96–111.     

Born migrators: Historical biogeography of the cosmopolitan family Cannabaceae

Dispersal scenarios have been favored over tectonic vicariance as an explanation for disjunct distributions in many plant taxa during the last two decades. However, this argument has been insufficiently addressed in cosmopolitan groups showing disjunct patterns in both the temperate and tropical regions. In this study, we used the Cannabaceae, an angiosperm family distributed in tropical and temperate regions of both the New World and the Old World, to explore the role of dispersal in shaping disjunct patterns and species diversification of cosmopolitan plants. We reconstructed the phylogenetic relationships of all 10 genera and 75 species of Cannabaceae (ca. 64.1% of recognized species) based on eight DNA regions. Based on fossil calibrations, we estimated the divergence times and net diversification rates. We further inferred the ancestral geographical ranges with several models and compared the fitness of different models. The Cannabaceae and most genera were strongly supported as monophyletic except for the Parasponia being embedded within the Trema. The Celtis were resolved into two strongly supported clades primarily corresponding to temperate and tropical regions. We inferred that the Cannabaceae originated at ca. 93 Ma, and that subsequent rampant and widespread dispersals shaped the intercontinentally disjunct distribution of the Cannabaceae. Dispersal coincides with adaptation to drier and colder climate in the Northern Hemisphere, or humid and warm climate in the tropical regions, followed by rapid species diversification. This study advances our understanding as to the formation of distribution patterns and species diversification of a plant family with tropical to temperate disjunct distributions.