Disjunct Pattern Research Articles

A new species related to Pardosaatrata (Araneae, Lycosidae) from Armenia makes the distribution range of the atrata group disjunctive.

Species of wolf spiders considered in the Pardosaatrata group are surveyed, and comparative figures of all species included in the group are presented for the first time. A new species, P.armeniacasp. nov., is described from the shore of Lake Sevan (Armenia) based on both sexes. Pardosanarymica Savelyeva, 1972 from East Kazakhstan Oblast' is synonymized with the trans-Palaearctic P.atrata (Thorell, 1873). It was found that the record of P.atrata (sub P.lapponica) by Schenkel from British Columbia and reflected in the World Spider Catalog in fact refers to P.concinna (Thorell, 1877), a member of the P.lapponica group. The distribution of three species consideredin the atrata group are mapped. The discovery of P.armeniacasp. nov. has led to a re-evaluation of the distribution range, previously thought to be continuous, now showing a disjunctive pattern.

Patterns of disjunction in western hemisphere birds, amphibians, crocodilians, and mammals

ABSTRACT To assess the patterns and severity of disjunction at multiple taxonomic levels for birds, amphibians, crocodilians, and mammals in the western hemisphere, we compiled over 10,100 species ranges and analyzed each range using ERSI ArcMap (10.8.1). After identifying species ranges that were disjunct by 500 km or more, we calculated the mean distance between the disjunct range polygon and primary polygon (d) and relative disjunct area (A) and analyzed disjunction by geographic area and latitude. Birds are the most commonly disjunct taxa (19.3%), followed by mammals (6.4%) and amphibians (2.8%). According to distance and relative area, birds are more severely disjunct than amphibians and mammals. Geographically, South America is home to the largest number of disjunctions across all taxa and latitudinal trends show that disjunction varies by latitude and, coincident with species richness, peaks in the southern tropics. Similarities in disjunction patterns, particularly between mammals and amphibians, suggest that geographic factors, along with dispersal ability, play a key role in creating disjunct distributions.

Genetic Structure and Historical Dynamics of Pinus densiflora Siebold & Zucc. Populations

The study of population genetic structure and historical dynamics of species with disjunct distribution can reveal the mechanisms through with they were formed. Pinus densiflora is an essential tree species with ecological and economic value, and its natural distribution shows a disjunct pattern. Using transcriptome-level SNP data from 220 samples representing 32 naturally-distributed populations in East Asia, we investigated Pinus densiflora genetic diversity and structure, divergence time, and ancestral distribution. We identified five subpopulations which diverged approximately 2.02–1.49 million years ago, and found relatively low genetic differentiation among the three large subpopulations (SL, JH, and JK). Northeast China is the most likely origin, and its current distribution is the result of dispersal and vicariance events. It migrated southwest through the Liaodong Peninsula to the Shandong Peninsula and southeast through the Korean Peninsula to Japan. These results provide a basis for the conservation and management of P. densiflora in the future and the evolutionary study of species with similar life histories.

Molecular Phylogeny and Historical Biogeography of Goodyera R. Br. (Orchidaceae): A Case of the Vicariance Between East Asia and North America.

Understanding of intercontinental distribution in the Northern Hemisphere has attracted a lot of attention from botanists. However, although Orchidaceae is the largest group of angiosperms, biogeographical studies on the disjunctive pattern have not been sufficient for this family. Goodyera R. Br. (tribe Cranichideae, subfamily Orchidoideae, family Orchidaceae) is widely distributed in temperate and tropical regions. Although the phylogenetic relationship of Goodyera inferred from both morphological and molecular data has been conducted, the sampled taxa were mainly distributed in Asia regions that resulted in non-monophyly of this genus. In this study, the complete plastid genomes of Goodyera, generated by next-generation sequencing (NGS) technique and sampled in East Asia and North America, were used to reconstruct phylogeny and explore the historical biogeography. A total of 18 Goodyera species including seven newly sequenced species were analyzed. Based on 79 protein-coding genes, the phylogenetic analysis revealed that Goodyera could be subdivided into four subclades with high support values. The polyphyletic relationships among Goodyera taxa were confirmed, and the unclear position of G. foliosa was also resolved. The datasets that are composed of the 14 coding sequences (CDS) (matK, atpF, ndhK, accD, cemA, clpP, rpoA, rpl22, ndhF, ccsA, ndhD, ndhI, ndhA, and ycf 1) showed the same topology derived from 79 protein-coding genes. Molecular dating analyses revealed the origin of Goodyera in the mid-Miocene (15.75 Mya). Nearctic clade of Goodyera was diverged at 10.88 Mya from their most recent common ancestor (MRCA). The biogeographical reconstruction suggests that subtropical or tropical Asia is the origin of Goodyera and it has subsequently spread to temperate Asia during the Miocene. In addition, Nearctic clade is derived from East Asian species through Bering Land Bridge (BLB) during the Miocene. The speciation of Goodyera is most likely to have occurred during Miocene, and climatic and geological changes are thought to have had a part in this diversification. Our findings propose both origin and vicariance events of Goodyera for the first time and add an example for the biogeographical history of the Northern Hemisphere.

Biogeography Meets Niche Modeling: Inferring the Role of Deep Time Climate Change When Data Is Limited

Geographic range shifts are one major organism response to climate change, especially if the rate of climate change is higher than that of species adaptation. Ecological niche models (ENM) and biogeographic inferences are often used in estimating the effects of climatic oscillations on species range dynamics. ENMs can be used to track climatic suitable areas over time, but have often been limited to shallow timescales; biogeographic inference can reach greater evolutionary depth, but often lacks spatial resolution. Here, we present a simple approach that treats them as independent and complementary sources of evidence, which, when used in partnership, can be employed to reconstruct geographic range shifts over deep evolutionary timescales. For testing this, we chose two extreme African disjunctions:Camptoloma(Scrophulariaceae) andCanarina(Campanulaceae), each comprising of three species disjunctly distributed in Macaronesia and eastern/southern Africa. Using inferred ancestral ranges in tandem with preindustrial and paleoclimate ENM hindcastings, we show that the disjunct pattern was the result of fragmentation and extinction events linked to Neogene aridification cycles. Our results highlight the importance of considering temporal resolution when building ENMs for rare endemics with small population sizes and restricted climatic tolerances such asCamptoloma, for which models built on averaged monthly variables were more informative than those based on annual bioclimatic variables. Additionally, we show that biogeographic information can be used as truncation threshold criteria for building ENMs in the distant past. Our approach is suitable when there is sparse sampling on species occurrences and associated patterns of genetic variation, such as in the case of ancient endemics with widely disjunct distributions as a result of climate change.

Fossil-Informed Models Reveal a Boreotropical Origin and Divergent Evolutionary Trajectories in the Walnut Family (Juglandaceae).

Temperate woody plants in the Northern Hemisphere have long been known to exhibit high species richness in East Asia and North America and significantly lower diversity in Europe, but the causes of this pattern remain debated. Here, we quantify the roles of dispersal, niche evolution, and extinction in shaping the geographic diversity of the temperate woody plant family Juglandaceae (walnuts and their relatives). Integrating evidence from molecular, morphological, fossil, and (paleo)environmental data, we find strong support for a Boreotropical origin of the family with contrasting evolutionary trajectories between the temperate subfamily Juglandoideae and the tropical subfamily Engelhardioideae. Juglandoideae rapidly evolved frost tolerance when the global climate shifted to ice-house conditions from the Oligocene, with diversification at high latitudes especially in Europe and Asia during the Miocene. Subsequent range contraction at high latitudes and high levels of extinction in Europe driven by global cooling led to the current regional disparity in species diversity. Engelhardioideae showed temperature conservatism while adapting to increased humidity, tracking tropical climates to low latitudes since the middle Eocene with comparatively little diversification, perhaps due to high competition in the tropical zone. The biogeographic history of Juglandaceae shows that the North Atlantic land bridge and Europe played more critical roles than previously thought in linking the floras of East Asia and North America, and showcases the complex interplay among climate change, niche evolution, dispersal, and extinction that shaped the modern disjunct pattern of species richness in temperate woody plants. [Boreotropical origin; climatic niche evolution; disjunct distribution; dispersal; diversity anomaly; extinction; Juglandaceae.]

Genomic phylogeography of the White-crowned Manakin Pseudopipra pipra (Aves: Pipridae) illuminates a continental-scale radiation out of the Andes

The complex landscape history of the Neotropics has generated opportunities for population isolation and diversification that place this region among the most species-rich in the world. Detailed phylogeographic studies are required to uncover the biogeographic histories of Neotropical taxa, to identify evolutionary correlates of diversity, and to reveal patterns of genetic connectivity, disjunction, and potential differentiation among lineages from different areas of endemism. The White-crowned Manakin (Pseudopipra pipra) is a small suboscine passerine bird that is broadly distributed through the subtropical rainforests of Central America, the lower montane cloud forests of the Andes from Colombia to central Peru, the lowlands of Amazonia and the Guianas, and the Atlantic forest of southeast Brazil. Pseudopipra is currently recognized as a single, polytypic biological species. We studied the effect of the Neotropical landscape on genetic and phenotypic differentiation within this species using genomic data derived from double digest restriction site associated DNA sequencing (ddRAD), and mitochondrial DNA. Most of the genetic breakpoints we identify among populations coincide with physical barriers to gene flow previously associated with avian areas of endemism. The phylogenetic relationships among these populations imply a novel pattern of Andean origination for this group, with subsequent diversification into the Amazonian lowlands. Our analysis of genomic admixture and gene flow reveals a complex history of introgression between some western Amazonian populations. These reticulate processes confound our application of standard concatenated and coalescent phylogenetic methods and raise the question of whether a lineage in the western Napo area of endemism should be considered a hybrid species. Lastly, analysis of variation in vocal and plumage phenotypes in the context of our phylogeny supports the hypothesis that Pseudopipra is a species-complex composed of at least 8, and perhaps up to 17 distinct species which have arisen in the last ~2.5 Ma.

Historical biogeography and climatic differentiation of the Fulcaldea-Archidasyphyllum-Arnaldoa clade of Barnadesioideae (Asteraceae) suggest a Miocene, aridity-mediated Andean disjunction associated with climatic niche shifts

Disjunct clades between the southern and the tropical Andes represent a biogeographical pattern that has not been studied. One of the plant groups showing this disjunction is the clade formed by the genera Archidasyphyllum, Arnaldoa and Fulcaldea (Asteraceae, Barnadesioideae). Archidasyphyllum is distributed in central and southern Chile and adjacent Argentina and is sister to the latter two, which in turn form a clade centered in northern Peru and southern Ecuador, with one species of Fulcaldea in Bahia, Brazil. The western American clades are separated by a distance of ca. 2500 km in direct line and have no representatives through the entire arid and hyperarid regions of the Pacific deserts and the dry Puna. We hypothesized that the Neogene origin of aridity in this intervening area might be responsible for this disjunction. To address this hypothesis, we estimated divergence times and ancestral range and quantified the climatic niches of the respective clades and compared them to each other and with the intervening area. Our results suggest a Miocene split of this clade from an ancestor previously distributed in the Central Andes, where the species of this clade are currently absent. Colonization of NE Brazil by Fulcaldea may have occurred during the Pliocene. The niche analysis rejects climatic niche conservatism and the intervening area is found to be climatically different from the current ranges occupied by either clade. We suggest that the global cooling trend in the Miocene and concomitant hyperaridity in the Pacific deserts and southern Central Andean highlands played a crucial role in the formation of this disjunct pattern and that the climatic niches of each clade have subsequently shifted in different directions.

New taxa of extant and fossil primitive moths in South-East Asia and their biogeographic significance (Lepidoptera, Micropterigidae, Agathiphagidae, Lophocoronidae)

We report some surprising recent distributional range extensions of one extant genus and two more families of primitive moths discovered in amber fossils from South-east Asia which were previously only known from Australia and/or the southwestern Pacific, with the possible exception of an undescribed Siberian fossil attributed to Lophocoronidae. During entomological field work in rain forests of central Vietnam a new species of Micropterigidae was discovered. It is described herein as Aureopterix bachmaensis sp. nov. based on male and female specimens collected at light in the Bach-Ma National Park. The identification was corroborated by a molecular analysis. This is the first record of this genus in the Northern Hemisphere, previously thought to be restricted to the Australian Region (including New Caledonia). First results of investigations of Burmese amber inclusions now reveal the presence of the Australian Region families Agathiphagidae and Lophocoronidae in the Cretaceous of Asia. The fossil taxon Agathiphagama perdita gen. nov., sp. nov. is established on the basis of two females and this is assigned to Agathiphagidae. The fossil genus Acanthocorona gen. nov. is established in Lophocoronidae and includes seven species described here as A. skalskiisp. nov., A. bowangisp. nov., A. muellerisp. nov., A. kuranishiisp. nov., A. sattlerisp. nov., A. spiniferasp. nov. and A. wichardisp. nov. The new species can be distinguished by the male genitalia which are illustrated together with wing venation and other morphological characters. The disjunct ranges of these taxa are discussed in a historical biogeographic context. Vicariance and dispersal hypotheses explaining the disjunct pattern are discussed. The discovery of these new species suggests a broader ancestral range of Aureopterix, Agathiphagidae and Lophocoronidae. Their extant ranges may be regarded as remnants or relicts of a wider distribution in the Mesozoic, or at least in the case of Aureopterix they could be the results of recent or ancient dispersal processes, since the calibration of molecular splits does not so far accord with plate tectonics.

<p><strong><em>Cissus lombardiana</em></strong><strong> a new name for <em>Cissus ulmifolia</em> (Vitaceae)</strong></p>

Cissus Linnaeus (1753: 117) is the most speciose genus in the family Vitaceae and notable for its pantropical intercontinental disjunct pattern (Liu et al. 2013). According to the recent estimate, the genus is known to have 291 accepted species (POWO 2020) and it is widely distributed in tropical regions of Africa, Asia, Australia, Central and South America and Mexico (Wen 2007). The main characters delimiting Cissus from other Vitaceae genera are the well-developed, thick and undivided floral disks, tetramerous flowers, one-seeded berries, and seeds with a long and linear chalaza (Wen 2007). In South America, Cissus is represented by 64 species (Lombardi 2000, 2007, Rodrigues et al. 2014). Amongst C. ulmifolia (Baker 1871: 213) Planchon (1887: 552) that is a later homonym of an Italian fossil taxon Cissus ulmifolia Massalongo (1858: 80). While checking the literature and relevant websites for the availability of any synonyms, we found that C. allenii Croat (1977: 358) and C. serrulatifolia Williams (1962: 375) are listed as heterotypic synonyms of C. ulmifolia in Tropicos (2020) following Nelson (2010). However, C. allenii was synonymized under C. serrulatifolia by most of the workers (Govaerts 1999, Lombardi 2007, Morales 2015, POWO 2020, Raz & Zamora 2020) but C. ulmifolia was treated as a distinct species. So in order to ascertain the taxonomic status, we critically studied the protologues and digital specimens including types of these three species, we found that the characters of C. allenii are well within the range of C. serrulatifolia but C. ulmifolia differs from them by its 4-sided, distinctly winged stem (vs. stem terete, not winged or wingless in C. serrulatifolia) and the fruits ovoid or ovoid–subglobose, smooth (vs. obovoid or subpyriform, lenticellate in C. serrulatifolia). Since no other validly published legitimate name is available for this species (Lombardi 2007, Mota de Oliveira & Jansen-Jacobs 2016, POWO 2020), therefore, the authors propose Cissus lombardiana as a replacement name.

Phylogeny, Taxonomy, and Biogeography of Pterocarya (Juglandaceae).

Relict species play an important role in understanding the biogeography of intercontinental disjunctions. Pterocarya (a relict genus) is the valuable model taxon for studying the biogeography of East Asian versus southern European/West Asian disjunct patterns. This disjunction has not been as well studied as others (e.g., between Eastern Asia and North America). Several phylogenetic studies on Pterocarya have been conducted, but none have provided a satisfactory phylogenetic resolution. Here, we report the first well-resolved phylogeny of Pterocarya using restriction site-associated DNA sequencing data based on the sampling of all taxa across the entire distribution area of the genus. Taxonomic treatments were also clarified by combining morphological traits. Furthermore, fossil-calibrated phylogeny was used to explore the biogeography of Pterocarya. Our results support the existence of two sections in Pterocarya, which is in accordance with morphological taxonomy. Section Platyptera comprises three species: P. rhoifolia, P. macroptera, and P. delavayi. Section Pterocarya also comprises three species: P. fraxinifolia, P. hupehensis, and P. stenoptera. The divergence between the two sections took place during the early Miocene (20.5 Ma). The formation of the Gobi Desert and climate cooling of northern Siberia in the Middle Miocene (15.7 Ma) might have caused the split of the continuous distribution of this genus and the formation of the East Asian versus southern European/West Asian disjunct pattern. Lastly, the divergence between P. hupehensis and P. stenoptera as well as between P. rhoifolia and P. macroptera/P. delavayi (10.0 Ma) supports the late Miocene diversification hypothesis in East Asia.

Phylogenomics, biogeography, and evolution of the blue‐ or white‐fruited dogwoods (Cornus)—Insights into morphological and ecological niche divergence following intercontinental geographic isolation

AbstractThe eastern Asian (EA)–eastern North American (ENA) floristic disjunction represents a major pattern of phytogeography of the Northern Hemisphere. Despite 20 years of studies dedicated to identification of taxa that display this disjunct pattern, its origin and evolution remain an open question, especially regarding post‐isolation evolution. The blue‐ or white‐fruited dogwoods (BW) are the most species‐rich among the four major clades of Cornus L., consisting of ~35 species divided into three subgenera (subg. Yinquania, subg. Mesomora, and subg. Kraniopsis). The BW group provides an excellent example of the EA–ENA floristic disjunction for biogeographic study due to its diversity distribution centered in eastern Asia and eastern North America, yet its species relationships and delineation have remained poorly understood. In this study, we combined genome‐wide markers from RAD‐seq, morphology, fossils, and climate data to understand species relationships, biogeographic history, and ecological niche and morphological evolution. Our phylogenomic analyses with RAxML and MrBayes recovered a strongly supported and well‐resolved phylogeny of the BW group with three intercontinental disjunct clades in EA and ENA or Eurasia and North America, of which two are newly identified within subg. Kraniopsis. These analyses also recovered a potential new species but failed to resolve relationships within the C. hemsleyi–C. schindleri complex. In an effort to develop an approach to reduce computation time, analysis of different nodal age settings in treePL suggests setting a node's minimum age constraint to the lower bound of a fossil's age range to obtain similar ages to that of BEAST. Divergence time analyses with BEAST and treePL dated the BW stem back to the very Late Cretaceous and the divergence of the three subgenera in the Paleogene. By integrating fossil ages and morphology, a total evidence‐based dating approach was used in conjunction with time‐slice probabilities of dispersal under a DEC model to resolve ancestral ranges of each disjunct in the Miocene: Eurasia and ENA (disjunct 1), EA and western North America (disjunct 2), and EA (disjunct 3). The dated biogeographic history supports dispersal via the North Atlantic Land Bridge in the late Paleogene in disjunct 1 and dispersal via the Bering Land Bridge in the Miocene for disjuncts 2 and 3. Character mapping with a stochastic model in phytools and comparison of ecological niche, morphospace, and rate of evolution indicated differential divergence patterns in morphology, ecological niche, and molecules between disjunct sisters. Although morphological stasis was observed in most of the characters, evolutionary changes in growth habit and some features of leaf, flower, and fruit morphology occurred in one or both sister clades. A significant differentiation of ecological habitats in temperature, precipitation, and elevation between disjunct sisters was observed, suggesting a role of niche divergence in morphological evolution post‐isolation. The patterns of evolutionary rate between morphology and molecules varied among disjunct clades and were not always congruent between morphology and molecules, suggesting cases of non‐neutral morphological evolution driven by ecological selection. Our phylogenetic evidence and comparisons of evolutionary rate among disjunct lineages lend new insights into the formation of the diversity anomaly between EA and ENA, with particular support of an early diversification in EA. These findings, in conjunction with previous studies, again suggest that the EA–ENA disjunct floras are an assembly of lineages descended from the Mesophytic Forests that evolved from the early Paleogene “boreotropical flora” through varied evolutionary pathways across lineages.

Una reevaluación de la taxonomía de Mappia (Icacinaceae) utilizando datos ambientales

Antecedentes y Objetivos: Mappia (Icacinaceae) es un género de cuatro especies que habitan Mesoamérica y las Antillas Mayores. El más reciente análisis filogenético del género basado en datos morfológicos apoyó la existencia de un clado continental formado por Mappia longipes, M. mexicana y M. multiflora como grupo hermano de M. racemosa que se distribuye en las Antillas. El objetivo fue evaluar si datos ambientales soportan las hipótesis previas propuestas para las entidades de Mappia. Métodos: Se realizaron análisis de nicho ecológico (modelado de nicho ambiental y pruebas de divergencia/conservadurismo de nicho) y de varianza multivariado (MANOVA) para evaluar si existen otras líneas de evidencia que respalden la hipótesis morfológica previa a nivel de especie e infraespecífico. Resultados clave: Se encontró una diferenciación ecológica entre M. multiflora (sureste de México a Costa Rica) y M. racemosa (Cuba, Jamaica y Puerto Rico (Antillas Mayores)), pero no entre los taxones infraespecíficos de las Antillas (M. racemosa var. brachycarpa y M. racemosa var. racemosa). Conclusiones: Nuestro estudio aporta una importante señal de la divergencia ecológica entre especies cercanamente emparentadas, pero con patrones de distribución disyunta.

Born migrators: Historical biogeography of the cosmopolitan family Cannabaceae

AbstractDispersal 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.

Revision of Tropopterus Solier: A disjunct South American component of the Australo-Pacific Moriomorphini (Coleoptera, Carabidae)

TropopterusSolier, 1849, precinctive to southern South America, is taxonomically revised. Six new species are described:T. peckorumsp. nov.,T. robustussp. nov.,T. canaliculussp. nov.,T. trisinuatussp. nov.,T. minimucrosp. nov., andT. fieldianussp. nov.Merizodus catapileanusJeannel, 1962, is synonymized withT. montagneiSolier, 1849. Lectotypes are designated forT. montagnei,T. giraudyiSolier,T. duponcheliiSolier, andT. nitidusSolier (=T. duponchelii).Tropopterus peruvianusStraneo is noted as anomen dubium, with its identity and taxonomic placement to be substantiated via neotype designation. Phylogenetic relationships amongTropopterusspp. are hypothesized based on 37 morphological characters, the distributions of which are analyzed under the parsimony criterion, with the cladogram root established betweenTropopterusand its adelphotaxon from New South Wales, Australia. Speciation in the group has occurred predominantly at a limited geographical scale relative to the overall generic distribution, with three pairs of sister species sympatric. However phylogenetic divergence between taxa in the more northern, sclerophyllous forest characterized byNothofagus obliqua(Brisseau de Mirbel) and those occupying the Valdivian and North Patagonian Rain Forest dominated byN. dombeyi(Brisseau de Mirbel) is observed in two instances of phylogenetic history. Using specific collecting locality records, it is shown thatTropopterusbeetles have been collected syntopically and synchronically with species ofGlypholomaJeannel (Coleoptera, Staphylinidae),AnaballetusNewton, Švec & Fikáček (Coleoptera, Leiodidae),AndotypusSpangler (Coleoptera, Hydrophilidae), andNovonothrusBalogh (Acari, Oribatida). These concordant ecological occurrences document a cohesiveNothofagusforest leaf-litter community. These genera plus other Valdivian Rain Forest invertebrate taxa all exhibit an Austral disjunct biogeographical pattern that corroborates trans-Antarctic vicariance between theNothofagusforests of southern South America and Australia. Male genitalic antisymmetry is shown to be a synapomorphy ofTropopterus, though the female reproductive tract retains the plesiomorphic orientation observed in all other moriomorphine taxa.

Long-distance dispersal or postglacial contraction? Insights into disjunction between Himalaya-Hengduan Mountains and Taiwan in a cold-adapted herbaceous genus, Triplostegia.

Current disjunct patterns can result from long‐distance dispersal or postglacial contraction. We herein investigate the evolutionary history of Triplostegia to elucidate the disjunction between the Himalaya–Hengduan Mountain region (HHM) and Taiwan (TW). Genetic structure of Triplostegia was investigated for 48 populations using sequences from five chloroplast loci and the ribosomal nuclear internal transcribed spacer. Divergence time estimation, ancestral area reconstruction, and species distribution modeling (SDM) were employed to examine the biogeographic history of Triplostegia. Substantial genetic differentiation among populations from southwestern China (SW), Central China (CC), and TW was detected. Triplostegia was inferred to have originated in SW, and diversification began during the late Miocene; CC was colonized in the mid‐Pliocene, and TW was finally colonized in the early Pleistocene. SDM suggested an expansion of climatically suitable areas during the Last Glacial Maximum and range contraction during the Last interglacial in Triplostegia. Disjunction between HHM and TW in Triplostegia is most likely the consequence of topographic isolation and postglacial contraction. The potential climatic suitability areas for Triplostegia by 2070s (2061–2080) are predicted to slightly shrink and move northward. With continued global warming and human‐induced deforestation, extinction risk may increase for the cold‐adapted species, and appropriate strategies should be employed for ecosystem conservation.

The disjunct pattern of the Neotropical harvestman Discocyrtus dilatatus (Gonyleptidae) explained by climate-driven range shifts in the Quaternary: Paleodistributional and molecular evidence.

The disjunct distribution of the harvestman Discocyrtus dilatatus (Opiliones, Gonyleptidae) is used as a case study to test the hypothesis of a trans-Chaco Pleistocene paleobridge during range expansion stages. This would have temporarily connected humid regions (‘Mesopotamia’ in northeastern Argentina, and the ‘Yungas’ in the northwest, NWA) in the subtropical and temperate South American lowlands. The present study combines two independent approaches: paleodistributional reconstruction, using the Species Distribution Modeling method MaxEnt and projection onto Quaternary paleoclimates (6 kya, 21 kya, 130 kya), and phylogeographic analyses based on the cytochrome oxidase subunit I molecular marker. Models predict a maximal shrinkage during the warm Last Interglacial (130 kya), and the rise of the hypothesized paleobridge in the Last Glacial Maximum (21 kya), revealing that cold-dry stages (not warm-humid ones, as supposed) enabled the range expansion of this species. The disjunction was formed in the mid-Holocene (6 kya) and is intensified under current conditions. The median-joining network shows that NWA haplotypes are peripherally related to different Mesopotamian lineages; haplotypes from Santa Fe and Córdoba Provinces consistently occupy central positions in the network. According to the dated phylogeny, Mesopotamia-NWA expansion events would have occurred in the last glacial period, in many cases closely associated to the Last Glacial Maximum, with most divergence events occurring shortly thereafter. Only two (out of nine) NWA haplotypes are shared with Mesopotamian localities. A single, presumably relictual NWA haplotype was found to have diverged much earlier, suggesting an ancient expansion event not recoverable by the paleodistributional models. Different measures of sequence statistics, genetic diversity, population structure and history of demographic changes are provided. This research offers the first available evidence for the historical origin of NWA disjunct populations of a Mesopotamian harvestman.

Molecular systematics and historical biogeography of Maianthemum s.s.

Understanding the underlying mechanisms for the evolution of intercontinental disjunct patterns has long fascinated botanists. We present a molecular phylogenetic reconstruction of Maianthemum s.l. (including Smilacina) with a focus on Maianthemum s.s. species, which have a disjunct distribution between Eurasia and North America. Within this evolutionary framework, we clarify the systematic classification and biogeographical history of Maianthemum s.s. Data from two nuclear and five chloroplast DNA regions were analyzed using the programs PAUP*, RAxML, MrBayes, BEAST, and RASP. Our molecular phylogeny supports Maianthemum s.s. as monophyletic. Maianthemum bifolium and M. canadense are grouped according to their taxonomic species, but the accessions of M. dilatatum are divided into two well-defined groups, i.e., one comprising western North American accessions, and the other composed of northeast Asian accessions. Molecular dating and biogeographic reconstructions suggest a northeast Asian origin for Maianthemum s.s. and that a complicated pattern of divergent evolution began approximately in the late Miocene. Intercontinental disjunctions of Maianthemum s.s. in the Northern Hemisphere appear to have occurred two times during the Pliocene. Based on our results, two possible ways to treat Maianthemum s.s. species can be envisioned: (1) elevate Asian populations of M. dilatatum to specific rank; or (2) combine the three Maianthemum s.s. species into a broadly defined single species. We recommend treatment of Maianthemum s.s. as a single species. The biogeographic patterns of Maianthemum s.s. coupled with molecular dating suggest both vicariance and long-distance dispersal events as key mechanisms for diversification of the clade.

Evolution of biogeographic disjunction between eastern Asia and North America in Chamaecyparis: Insights from ecological niche models

The disjunct distribution of plants between eastern Asia (EA) and North America (NA) is one of the most well-known biogeographic patterns. However, the formation and historical process of this pattern have been long debated. Chamaecyparis is a good model to test previous hypotheses about the formation of this disjunct pattern as it contains six species disjunctly distributed in EA, western North America (WNA) and eastern North America (ENA). In this study, we applied ecological niche models to test the formation of the disjunct pattern of Chamaecyparis. The model calibrated with the EA species was able to predict the distribution of eastern NA species well, but not the western NA species. Furthermore, the eastern Asian species were shown to have higher niche overlap with the eastern North American species. The EA species were also shown to share more similar habitats with ENA species than with WNA species in the genus. Chamaecyparis species in WNA experienced a significant niche shift compared with congeneric species. Chamaecyparis had a low number of suitable regions in Europe and the middle and western NA during the Last Glacial Maximum (LGM) period, and became extinct in the former region whereas it retains residual distribution in the latter. The extirpations in western NA and Europe in response to the late Neogene and Quaternary climatic cooling and the more similar habitats between ENA and EA ultimately shaped the current intercontinental disjunct distribution of Chamaecyparis. Both current hypotheses may be also jointly applied to explain more eastern Asian and eastern North American disjunctions observed today.

Identifying and Quantifying Disjunctions at Multiple Taxonomic Levels in Western Hemisphere Mammals

I surveyed more than 1,700 Western Hemisphere mammal species ranges to identify, quantify, and examine patterns of disjunction at multiple taxonomic levels. Species that had disjunct populations (isolated by at least 500 km from other parts of the species range) were further analyzed using novel measures of disjunction by determining the distance to the disjunction and the relative area of disjunctions compared to the primary range area. Disjunction at this scale is rare (6.4 percent) in all terrestrial mammals but more common in bats (14.6 percent) than nonvolant mammals. Disjunctions are concentrated in six families, specifically Molossidae (31.5 percent disjunct), Didelphidae (24.7 percent disjunct), Felidae (28.6 percent disjunct), Vespertilionidae (15.3 percent disjunct), Emballonuridae (10.5 percent disjunct), and Phyllostomidae (10.4 percent disjunct). Geographically, 85 percent of disjunct mammal species have ranges that occur entirely or partially in South America. Geographic information systems analysis of species range maps is capable of identifying disjunct species and evaluating the severity of disjunctions. When compiled at the family level, these data suggest that species in certain families are more susceptible to disjunction. In some cases (e.g., species ranges separated by the Amazon rainforest), species-level data offer insight into the causes of disjunction. Study of species identified as disjunct in this study can inform conservation efforts by providing an opportunity to determine the characteristics that enable them to survive as isolated populations.