Ancestral Area Reconstruction Research Articles

Origins of cryophilous lineages and the role of Beringia: evidence from the cosmopolitan angiosperm genus Stellaria L. (Caryophyllaceae)

Abstract The cosmopolitan angiosperm genus Stellaria L. (Caryophyllaceae) occurs across the Arctic and is most diverse in the high southern Asian mountains, including presence at the most extreme latitudinal and elevational limits of vascular plants. Using the primary fossil record and double digest restriction site-associated DNA sequencing data, we estimated divergence times of Stellaria and relatives across the Caryophyllaceae. We then used ancestral area and ancestral state reconstructions to interpret the biogeographical history of the group. We found that Stellaria originated in the Miocene and gave rise to repeated New World lineages, mostly from temperate Old World regions and probably via Bering Land Bridges. Circumboreal lineages were recovered of recent, Pleistocene origin and several might have originated in southerly mountains of both the Old World and the New World before subsequently colonizing the Arctic. Ancestral state reconstruction of inhabitance of cold vs. temperate climates and of wet vs. dry habitats revealed repeated evolutionary transitions across these extremes by members of the genus worldwide. Our study, which samples nearly all species within a diverse and cosmopolitan lineage of flowering plants, recovers a group characterized by niche lability and helps to support prior findings of temperate origins of many cryophilous plant lineages. Pre-adaptation to cold might have been a prerequisite for colonization of the Arctic.

Molecular phylogenetics and biogeography reveal the origin of cherries (Prunus subg. Cerasus, Rosaceae)

Abstract Cherries (subg. Cerasus) belong to Prunus s.l. (Rosaceae) and are widely distributed in temperate and subtropical regions of the Northern Hemisphere. Given its ornamental and edible functions, it is a hugely preferred germplasm resource for human societies. However, the interspecific phylogenetic relationships, divergence times, and routes of this subgenus remain unclear. To reveal its enigmatic and intricate evolutionary history, we newly sequenced 12 subg. Cerasus species, reconstructed the plastome phylogeny with 24 previously published subg. Cerasus species. This study supports that subg. Cerasus split into five clades, among which P. mahaleb is the basal group of subg. Cerasus; P. campanulata is genetically distantly related to P. cerasoides and is not recommended for treatment as a variety of the latter; P. subhirtella is involved in the speciation of P. yedoensis. Molecular dating and ancestral area reconstructions infer that subg. Cerasus originated in the Eastern Mediterranean–Central Asia before 11.57 Mya (95% HPD = 5.34–19.1 Mya) and subsequently spread into the Qinghai-Tibetan Plateau (QTP) and adjacent regions. The first dispersal event of modern subg. Cerasus was facilitated by ‘out-of-QTP’, colonizing North America across the Bering Land Bridge and re-dispersing into Europe from the Late Miocene to Pliocene and forming the initial distribution pattern of extant subg. Cerasus in the Pliocene; The end of the Quaternary glacial period witnessed a second dispersal event, and core subg. Cerasus population diversity flourished radially in its separate refugia during the Late Pleistocene.

New insights into infrageneric relationships of Lonicera (Caprifoliaceae) as revealed by nuclear ribosomal DNA cistron data and plastid phylogenomics

AbstractThe discontinuous geographic distribution pattern of plants in the north temperate zone has been a focus of biogeographic research, especially concerning the mechanisms behind the formation of such a pattern and the spatial and temporal evolution of this intermittent distribution pattern. Hypotheses of boreotropical origin, land bridge migration, and out‐of‐Tibet have been proposed to explain the formation of the discontinuous distribution pattern. The distribution of Lonicera shows a typical Europe–Asia–North America discontinuous distribution, which makes for a good case study to investigate the above three hypotheses. In this study, we inferred the phylogeny based on plastid genomes and a nuclear data set with broad taxon sampling, covering 83 species representing two subgenera and four sections. Both nuclear and plastid phylogenetic analyses found section Isika polyphyletic, while sections Nintooa, Isoxylosteum, and Coelxylosteum were monophyletic in subgenus Chamaecerasus. Based on the nuclear and chloroplast phylogeny, we suggest transferring Lonicera maximowiczii and Lonicera tangutica into section Nintooa. Reconstruction of ancestral areas suggests that Lonicera originated in the Qinghai–Tibetan Plateau (QTP) and/or Asia, and subsequently dispersed to other regions. The aridification of the Asian interior may have facilitated the rapid radiation of Lonicera in the region. At the same time, the uplifts of the Tibetan Plateau appear to have triggered the spread and recent rapid diversification of the genus on the QTP and adjacent areas. Overall, our results deepen the understanding of the evolutionary diversification history of Lonicera.

Understanding the diversification and functional radiation of Aporrectodea (Crassiclitellata, Lumbricidae) through molecular phylogenetics of its endemic species

The genus Aporrectodea includes some of the most conspicuous earthworm species, but its taxonomic history is among the most complex within the family Lumbricidae. Molecular phylogenetic studies have produced some advances by assigning former Aporrectodea species to other monophyletic clades and by detecting species level lineages within the cosmopolitan caliginosa-trapezoides complex. However, little attention has been devoted to endemic taxa of Aporrectodea such as Ap. rubra, Ap. arverna, Ap. gogna, Ap. balisa, Ap. velox, Ap. giardi voconca and Ap. longa ripicola. These earthworms (and additional populations of Ap. longa and Ap. nocturna) were included in a molecular phylogenetic framework in order to reconstruct the ancestral range of the genus, as well as to help understand its diversification within its native range and to perform a systematic revision. Species delimitation, ancestral area reconstruction and Bayesian inference of the phylogenetic relationships were performed using a large gene sequence (COI) dataset and a narrower dataset composed of 5 mitochondrial and nuclear markers. Phylogenetic position and species delimitation indicated that Ap. giardi voconca and Ap. longa ripicola constitute species-level entities not closely related to Ap. giardi or Ap. longa, and they were thus redescribed as Aporrectodea voconca stat. nov. and Aporrectodea ripicola stat. nov. Ancestral area reconstruction enabled location of the origin of Aporrectodea in the Auvergne-Rhône-Alps, in Southeastern France. The study findings provide some insight into the evolution of functional traits in this ecologically successful genus. Ap. rubra and Ap. arverna (small, reddish, epigeic/epianecic) and Ap. gogna (very large, dark, anecic) were recovered as the earliest branching taxa, suggesting a complex evolution of functional traits within this genus.

Unity in diversity: morphological and genetic variability, integrative systematics, and phylogeography of the widespread nudibranch mollusc Onchidoris muricata

Onchidoris muricata (Gastropoda: Nudibranchia: Onchidorididae) is a well-known nudibranch species, which has a wide amphiboreal range confirmed by molecular data. However, O. muricata shows a high degree of variation in external morphology among distant populations, which may indicate the presence of cryptic diversity within this species. There are also two closely related species with an unconfirmed taxonomic status, which were recently described from the northwestern Pacific based on morphological data. In this paper we study the taxonomic status and population structure of O. muricata based on an integrative approach combining morphological and molecular data and using O. muricata as a model we explore issues of boreal marine fauna connectivity and glaciation-driven isolation. The external morphology, spicule composition, and features of the buccal armature and the reproductive system were studied using light microscopy, scanning electron microscopy and mCT scan technology. The molecular study included various population genetic analyses as well as divergence time estimation and ancestral area reconstruction analyses. Onchidoris muricata represents a true amphiboreal species, which shows a high degree of heterogeneity in morphological characters, especially in the radular morphology and in features of the reproductive system. Our new data question the validity of the North-West Pacific species O. macropompa and O. pavli as the morphology of both these species fall within the phenotypic diversity of O. muricata. Although our sampling does not include the type localities of these two species, the observed morphological variability in O. muricata and the lack of molecular data for the North Pacific species O. macropompa and O. pavli suggest the latter two species are in fact part of O. muricata morphological diversity. Phylogeographic analyses indicate a genetic separation of the North Pacific and North Atlantic-Arctic populations of O. muricata, suggesting restricted gene flow between these areas. We show that this divergence may be a result of glacial cycles during the late Pleistocene, which were a key factor in the reduction of gene flow across the Arctic Ocean. Our molecular results also suggest that the White Sea population experienced a bottleneck event during the last Glacial Maximum.

Plastome phylogenomics reveals an early Pliocene North- and Central America colonization by long-distance dispersal from South America of a highly diverse bromeliad lineage.

Understanding the spatial and temporal frameworks of species diversification is fundamental in evolutionary biology. Assessing the geographic origin and dispersal history of highly diverse lineages of rapid diversification can be hindered by the lack of appropriately sampled, resolved, and strongly supported phylogenetic contexts. The use of currently available cost-efficient sequencing strategies allows for the generation of a substantial amount of sequence data for dense taxonomic samplings, which together with well-curated geographic information and biogeographic models allow us to formally test the mode and tempo of dispersal events occurring in quick succession. Here, we assess the spatial and temporal frameworks for the origin and dispersal history of the expanded clade K, a highly diverse Tillandsia subgenus Tillandsia (Bromeliaceae, Poales) lineage hypothesized to have undergone a rapid radiation across the Neotropics. We assembled full plastomes from Hyb-Seq data for a dense taxon sampling of the expanded clade K plus a careful selection of outgroup species and used them to estimate a time- calibrated phylogenetic framework. This dated phylogenetic hypothesis was then used to perform biogeographic model tests and ancestral area reconstructions based on a comprehensive compilation of geographic information. The expanded clade K colonized North and Central America, specifically the Mexican transition zone and the Mesoamerican dominion, by long-distance dispersal from South America at least 4.86 Mya, when most of the Mexican highlands were already formed. Several dispersal events occurred subsequently northward to the southern Nearctic region, eastward to the Caribbean, and southward to the Pacific dominion during the last 2.8 Mya, a period characterized by pronounced climate fluctuations, derived from glacial-interglacial climate oscillations, and substantial volcanic activity, mainly in the Trans-Mexican Volcanic Belt. Our taxon sampling design allowed us to calibrate for the first time several nodes, not only within the expanded clade K focal group but also in other Tillandsioideae lineages. We expect that this dated phylogenetic framework will facilitate future macroevolutionary studies and provide reference age estimates to perform secondary calibrations for other Tillandsioideae lineages.

Target sequence capture data shed light on the deeper evolutionary relationships of subgenus Chamaecerasus in Lonicera (Caprifoliaceae)

The genus Lonicera L. is widely distributed in the north temperate zone and is well-known for its high species richness and morphological diversity. Previous studies have suggested that many sections of Lonicera are not monophyletic and phylogenetic relationships within the genus are still poorly resolved. In this study, we sampled 37 accessions of Lonicera, covering four sections of subgenus Chamaecerasus plus six outgroup taxa, to recover the main clades of Lonicera based on sequences of nuclear loci generated by target enrichment and cpDNA from genome skimming. We found extensive cytonuclear discordance across the subgenus. Both nuclear and plastid phylogenetic analyses supported subgenus Chamaecerasus sister to subgenus Lonicera. Within subgenus Chamaecerasus, sections Isika and Nintooa were each polyphyletic. Based on the nuclear and chloroplast phylogenies, we propose to merge Lonicera korolkowii into section Coeloxylosteum and Lonicera caerulea into section Nintooa. In addition, Lonicera is estimated to have originated in the mid Oligocene (26.45 Ma). The stem age of section Nintooa was estimated to be 17.09 Ma (95% HPD: 13.30–24.45). The stem age of subgenus Lonicera was estimated to be 16.35 Ma (95% HPD: 14.12–23.66). Ancestral area reconstruction analyses indicate that subgenus Chamaecerasus originated in East Asia and Central Asia. In addition, sections Coeloxylosteum and Nintooa originated in East Asia, with subsequent dispersals into other areas. The aridification of the Asian interior likely promoted the rapid radiation of sections Coeloxylosteum and Nintooa within this region. Moreover, our biogeographic analysis fully supports the Bering and the North Atlantic Land Bridge hypotheses for the intercontinental migrations in the Northern Hemisphere. Overall, this study provides new insights into the taxonomically complex lineages of subgenus Chamaecerasus and the process of speciation.

Insights into the evolutionary history of Diestramimini cave crickets (Orthoptera, Rhaphidophoridae)

AbstractDiestramimini is one of the two tribes of Aemodogryllinae and is mainly distributed in southern China and Southeast Asia. The intergeneric phylogenetic relationship and historical biogeography of this tribe remain unclear. Here, we present the first phylogenetic and biogeographical analyses of Diestramimini based on three mitochondrial (COI, 12S rRNA and 16S rRNA) and two nuclear (18S rRNA and 28S rRNA) gene fragments. The molecular phylogenetic inference strongly supports the monophyly of Diestramimini and recovers the sister‐group relationship between Diestramima + Tamdaotettix and Arboramima + Gigantettix. A new genus, Bidiestramima Zhu & Shi gen. n., is established and recovered as sister to all the remaining genera of Diestramimini. Moreover, a new species Bidiestramima hekouensis Zhu & Shi gen. et sp. n. is described. Mimadiestra is recovered as paraphyletic, and thus, we propose two new combinations based on the combination of morphological and molecular evidence: Bidiestramima dicha comb. n. and Tamdaotettix (Laotettix) gracilus comb. n. Divergence time estimation and reconstruction of ancestral areas indicate that Diestramimini in China may have originated from Southern Yunnan and Guangxi during the mid‐Oligocene and had two separate evolutionary routes. The diversification of Diestramimini has been driven by several dispersal and vicariance events since the Miocene, linked to the uplift of the Himalaya–Tibetan Plateau, the formation of the monsoon and climate fluctuations.

Origin and diversification of a Himalayan orchid genus Pleione

Pleione is an orchid endemically distributed in high mountain areas across the Hengduan Mountains (HDM), Himalayas, Southeast Asia and South of China. The unique flower shapes, rich colors and immense medicinal importance of Pleione are valuable ornamental and economic resources. However, the phylogenetic relationships and evolutionary history of the genus have not yet been comprehensively resolved. Here, the evolutionary history of Pleione was investigated using single-copy gene single nucleotide polymorphisms and chloroplast genome datasets. The data revealed that Pleione could be divided into five clades. Discordance in topology between the two phylogenetic trees and network and D-statistic analyses indicated the occurrence of reticulate evolution in the genus. The evolution could be attributed to introgression and incomplete lineage sorting. Ancestral area reconstruction suggested that Pleione was originated from the HDM. Uplifting of the HDM drove rapid diversification by creating conditions favoring rapid speciation. This coincided with two periods of consolidation of the Asian monsoon climate, which caused the first rapid diversification of Pleione from 8.87 to 7.83 Mya, and a second rapid diversification started at around 4.05 Mya to Pleistocene. The interaction between Pleione and climate changes, especially the monsoons, led to the current distribution pattern and shaped the dormancy characteristic of the different clades. In addition to revealing the evolutionary relationship of Pleione with orogeny and climate changes, the findings of this study provide insights into the speciation and diversification mechanisms of plants in the East Asian flora.

Herodotools: An R package to integrate macroevolution, biogeography and community ecology

AbstractAimSpeciation, extinction and historical dispersal are the ultimate factors generating and maintaining biodiversity. However, methods of macroevolution used to detect historical processes usually ignore the variation of macroevolutionary processes at scales finer than entire regions. Likewise, biogeography and community ecology often ignore deep‐time evolutionary processes. To overcome this problem, it is necessary to integrate data from ancestral state reconstructions, current species distributions and biogeographical regionalization. Herodotools is an R package designed to perform this integration.LocationGlobal application, with an example from Neotropics.Major taxa studiedAny taxa, with an example from small rodents (genus Akodon and subfamily Sigmodontinae).MethodsHerodotools streamline analyses of historical biogeography, including regionalization, calculation of assemblage age, lineage in situ diversification and community phylogenetic metrics, merging species occurrence with macroevolutionary methods of ancestral area and trait reconstruction. The main functions of our R package are presented with toy examples and by analysing the historical biogeography of small rodent assemblages in the Neotropics.ResultsOur package can integrate methods from biogeography, macroevolution and community ecology, allowing us to downscale the effects of historical processes and calculate important historical variables (e.g., age of assemblages, in situ diversification, phylogenetic regionalization, phylogenetic transition zones, metrics of trait macroevolutionary dynamics and new metrics of phylogenetic diversity and endemism) in different scales, from entire regions to communities of co‐occurrent species.Main ConclusionsHerodotools is the first platform to streamline the analysis of historical biogeography, enabling a better understanding of historical processes at different levels of organization, from local assemblages to entire biogeographical regions and incorporating macroevolutionary models in commonly used community phylogenetic metrics. This integration bridges the gap between macroevolutionary, biogeography and community ecology methods.

Still Many to Be Named: An Integrative Analysis of the Genus Dendronotus (Gastropoda: Nudibranchia) in the North Pacific Revealed Seven New Species

In this paper, we report on the discovery of the hidden biodiversity of the genus Dendronotus (Gastropoda: Nudibranchia) in bathyal areas of the North Pacific (the Sea of Okhotsk and the Kuril Islands). We also test different scenarios of Dendronotus expansion to deeper waters. An integrative analysis was implemented based on morphological data (light microscopy and SEM) and molecular data, which included molecular phylogenetic analysis of four markers (COI, 16S, H3, and 28S), molecular species delimitation analyses, and ancestral area reconstruction. Our results indicated the presence of seven species new to science, five of which are described herein. The phylogenetic reconstructions show that these new species are members of different Dendronotus lineages. Ancestral area reconstruction indicates the shallow-water origin of the genus, while the invasion of deep waters occurs independently multiple times.

Phylogeny, biogeography, and character evolution of the genus Sophora s.l. (Fabaceae, Papilionoideae)

The papilionoid legume genus Sophora (Fabaceae) exhibits a worldwide distribution, but a phylogenetic framework to understand the evolution of this group is lacking to date. Previous studies have demonstrated that Sophora is not monophyletic and might include Ammodendron, Ammothamnus, and Echinosophora, but the relationships among these four genera (defined as Sophora s.l.) are unclear. Here we used a nuclear DNA dataset (ETS, ITS, SQD1) and a plastid DNA dataset (matK, rbcL, rpl32-trnL, trnL-F) of 654 accession sequences to reconstruct the phylogenetic relationships, estimate the divergence times and ancestral range of Sophora s.l., and infer the evolution of chromosome number and morphological characteristics. Our major aim was to reconstruct phylogenetic relationships to test monophyly and elucidate relationships within the genus. Our results indicated that Ammodendron, Ammothamnus, and Echinosophora are embedded within Sophora s.s. and that nine well-supported clades can be recognized within comprise Sophora s.l. Ancestral character state estimation revealed that the most recent common ancestor of Sophora s.l. was a deciduous shrub that lacks rhizome spines and has unwinged legumes. Divergence times estimation and ancestral area reconstruction showed that Sophora s.l. originated in Central Asia and/or adjacent Southeast China in the early Oligocene (ca. 31 Mya) and dispersed from these regions into East and South Asia’s adjacent areas and North America via the Bering land bridge. The analyses also supported a South American origin for S. sect. Edwardsia, which experienced rapid radiation with its major lineages diversifying over a relatively narrow timescale (8 Mya).

Biogeography of the Sunda Shelf revisited: Insights from Macaranga section Pruinosae (Euphorbiaceae)

The Southeast Asian region of Sundaland is among the world’s major biodiversity hotspots. The region’s biodiversity coupled with its complex and dynamic geographic and climatic histories makes it an ideal region to study the various factors that determine the diversification and distribution patterns of tropical biota. Here we investigate the biogeographic patterns in the partly myrmecophyticMacarangasectionPruinosaeto reveal some of the factors that play a role in determining the distribution of biota in Sundaland. We used single nucleotide polymorphisms (SNP) data derived from GBS, a next generation sequencing technique, in maximum likelihood and cluster analyses to determine phylogenetic relationships and population structures within this taxonomic section. Bayesian inference based on secondary calibration points and ancestral area reconstruction analyses were performed to infer spatial–temporal origins of the major lineages in the section. The results from these analyses were further substantiated using nuclear microsatellite data obtained from a broader sample set of two widely distributed species within the section:Macaranga giganteaandMacaranga pruinosa. Phylogenetic and cluster analyses reveal four well-defined, discrete species groups within sectionPruinosae, all of which but one originated in Borneo with the crown node dated at 3.58 mya. Biogeographic patterns within the species reveal a biogeographic barrier between east and west Sundaland besides bringing to light the role played by various geological factors, especially the Crocker Range, on Borneo. Patterns also reveal a biogeographic barrier between the Bangka/Belitung islands and Sumatra for ant-free, swamp-adapted species. This study provides evidence that geographic barriers, edaphic conditions, and ecological adaptations are tightly linked and that their mutual interaction determines the diversification and distribution of species.

The role of landscape evolution in the genetic diversification of a stream fish Sarcocheilichthys parvus from Southern China.

Sarcocheilichthys parvus (Cypriniformes: Gobionidae) is a stream fish which is endemic to sub-tropical coastal drainages in southern China, thus offering a valuable model for understanding how genetic divergence arises in stream-adapting freshwater fishes in this region. Using the mitochondrial Cyt b gene, integrative analyses of phylogeny, population demography, and ancestral area and paleo-drainage reconstructions are carried out to explicitly explore the role of landscape evolution in genetic diversification of S. parvus. The time-calibrated phylogeny of S. parvus indicates the splitting of two major lineages (A and B) at ∼3.66Ma. Lineage A inhabits the Poyang Lake sub-drainage of the middle Yangtze River, Han River and Pearl River, and can be split into two sub-lineages (A-I and A-II), where sub-lineage A-II can be further sub-divided into three infra-sub-lineages (A-IIa, A-IIb and A-IIc). Except for the infra-sub-lineage A-IIc, which is restricted to the Han River and Pearl River, the other sub-lineages and infra-sub-lineages live exclusively in the Poyang Lake sub-drainage. Lineage B lives in the lower Yangtze River, Qiantang River, Jiaojiang River and Ou River, displaying close genetic relationships among the drainages. Rapid population expansion has occurred since the Late Pleistocene. Our findings indicate that the splitting of lineages A and B could be attributed to geographic isolation due to the Zhe-Min Uplift, acting as a biogeographic barrier before the late Early Pleistocene. Furthermore, the strong genetic divergence within Lineage A could be explained by the isolation role of the Nanling Mountains and Poyang Lake acting as an ecological barrier; while the lack of phylogenetic structure within Lineage B may have been the result of paleo-drainage connections or episodic freshwater connections during the eustatic low stand of sea level in the late Middle-Late Pleistocene.

Time-calibrated phylogenies reveal mediterranean and pre-mediterranean origin of the thermophilous vegetation of the Canary Islands.

The Canary Islands have strong floristic affinities with the Mediterranean Basin. One of the most characteristic and diverse vegetation belts of the archipelago is the thermophilous woodland (between 200 and 900 m.a.s.l.). This thermophilous plant community consists of many non-endemic species shared with the Mediterranean Floristic Region together with Canarian endemic species. Consequently, phytogeographic studies have historically proposed the hypothesis of an origin of the Canarian thermophilous species following the establishment of the summer-dry mediterranean climate in the Mediterranean Basin around 2.8 million years ago. Time-calibrated phylogenies for 39 plant groups including Canarian thermophilous species were primarily analysed to infer colonization times. In particular, we used 26 previously published phylogenies together with 13 new time-calibrated phylogenies (including newly generated plastid and nuclear DNA sequence data) to assess whether the time interval between stem and crown ages of Canarian thermophilous lineages postdates 2.8 Ma. For lineages postdating this time threshold, we additionally conducted ancestral area reconstructions to infer the potential source area for colonization. A total of 43 Canarian thermophilous lineages were identified from 39 plant groups. Both mediterranean (16) and pre-mediterranean (9) plant lineages were found. However, we failed to determine the temporal origin for 18 lineages because a stem-crown time interval overlaps with the 2.8-Ma threshold. The spatial origin of thermophilous lineages was also heterogeneous, including ancestral areas from the Mediterranean Basin (nine) and other regions (six). Our findings reveal an unexpectedly heterogeneous origin of the Canarian thermophilous species in terms of colonization times and mainland source areas. A substantial proportion of the lineages arrived in the Canaries before the summer-dry climate was established in the Mediterranean Basin. The complex temporal and geographic origin of Canarian thermophilous species challenges the view of the Canary Islands (and Madeira) as a subregion within the Mediterranean Floristic Region.

Evolutionary relationships of mitogenomes in a recently radiated Old World avian family

Environmentally heterogeneous mountains provide opportunities for rapid diversification and speciation. The family Prunellidae (accentors) is a group of birds comprising primarily mountain specialists that have recently radiated across the Palearctic region. This rapid diversification poses challenges to resolving their phylogeny. Herein we sequenced the complete mitogenomes and estimated the phylogeny using all 12 (including 28 individuals) currently recognized species of Prunellidae. We reconstructed the mitochondrial genome phylogeny using 13 protein-coding genes of 12 species and 2 Eurasian Tree Sparrows (Passer montanus). Phylogenetic relationships were estimated using a suite of analyses: maximum likelihood, maximum parsimony and the coalescent-based SVDquartets. Divergence times were estimated by implementing a Bayesian relaxed clock model in BEAST2. Based on the BEAST time-calibrated tree, we implemented an ancestral area reconstruction using RASP v.4.3. Our phylogenies based on the maximum likelihood, maximum parsimony and SVDquartets approaches support a clade of large-sized accentors (subgenus Laiscopus) to be sister to all other accentors with small size (subgenus Prunella). In addition, the trees also support the sister relationship of P. immaculata and P. rubeculoides ​+ ​P.atrogularis with 100% bootstrap support, but the relationships among the remaining eight species in the Prunella clade are poorly resolved. These species cluster in different positions in the three phylogenetic trees and the nodes are often poorly supported. The five nodes separating the seven species diverged simultaneously within less than half million years (i.e., between 2.71 and 3.15 million years ago), suggesting that the recent radiation is likely responsible for rampant incomplete lineage sorting and gene tree conflicts. Ancestral area reconstruction indicates a central Palearctic region origin for Prunellidae. Our study highlights that whole mitochondrial genome phylogeny can resolve major lineages within Prunellidae but is not sufficient to fully resolve the relationship among the species in the Prunella clade that almost simultaneously diversify during a short time period. Our results emphasize the challenge to reconstruct reliable phylogenetic relationship in a group of recently radiated species.

Phylogeography and Genetic Structure of the Bush Cricket Decma fissa (Orthoptera, Tettigoniidae) in Southern China.

Decma fissa is the most widely distributed species of the genus Decma occuring in southern China. This study presents the first phylogeographic work of D. fissa based on COI, Cytb and ITS sequence. We examined genetic diversity with ITS and mitochondrial sequence respectively, and phylogenetic work was based on the mitochondrial data. A high-level genetic diversity was revealed based on mitochondrial data but a low-level diversity was shown with ITS sequence. For the mitochondrial data, divergence time analysis displayed five lineages. Based on the Mantel test, geographic and genetic distances among D. fissa populations revealed a significant positive correlation. Bayesian skyline plot (BSP) analyses implied that none of three major lineages of D. fissa was seemingly affected by the last glacial maximum (LGM, 0.015-0.025 Mya). Ecological niche modeling was used to predict the distribution of D. fissa in four periods (LGM, Mid-Holocene, current and 2070) in China. Analysis of the ancestral area reconstruction indicated that D. fissa occurred in the South China area.

Origin, evolution and systematics of the genusPoecilimon(Orthoptera: Tettigoniidae)—An outburst of diversification in the Aegean area

AbstractOur study focuses on the origin, dispersal patterns, evolutionary strategies and systematics ofPoecilimon, the largest bush‐cricket genus in the Palaearctic with over 150 taxa described. We employ phylogenetic and divergence time estimation analyses based on multilocus sequence data (ND2 + COI + 12 S + 16 S + ITS+28 S), perform ancestral area reconstruction, and track the evolution of behavioural (evolution of sound communication) and morpho‐physiological traits (body size and shape, and spermatophore size) in this genus. Based on our results, we propose a revised systematics ofPoecilimon, including description of a new species,P. nivalissp. n., and hypothesize three stages in the evolution ofPoecilimon. (1) In the early evolution of the genus in Tortonian, when open dry habitats appeared in the Eastern Mediterranean, diversification rates were low and speciation was possibly induced by vicariance and habitat fragmentation; physiology and morphology during this period retained their ancestral states but the evolution of main lineages may have been accompanied by behavioural specializations. (2) Climate cooling and aridification during the Messinian induced dispersals and adaptation to new habitats, followed by physiological and behavioural adaptations; major clades formed or started diversifying. (3) Starting at the end of Messinian and continuing through the Plio‐ and Pleistocene, a few dispersal events from Anatolia to the Balkans took place and climatic oscillations were followed by allo‐ and parapatric divergence of habitat specialists, while ecological adaptations enhanced song diversity and led to morpho‐physiological changes.

Diversification of Amazonian spiny tree rats in genus Makalata (Rodentia, Echimyidae): Cryptic diversity, geographic structure and drivers of speciation.

Amazonian mammal diversity is exceptionally high, yet new taxonomic discoveries continue to be made and many questions remain for understanding its diversification through time and space. Here we investigate the diversification of spiny rats in the genus Makalata, whose species are strongly associated with seasonally flooded forests, watercourses and flooded islands. We use a biogeographical approach based on a mitochondrial cytochrome b gene through divergence time estimation and reconstruction of ancestral areas and events. Our findings indicate an ancient origin of Makalata for the Guiana Shield and Eastern Amazonia as ancestral area. A first cladogenetic event led to a phylogeographic break into two broader clades of Makalata through dispersal, implying a pattern of western/Eastern Amazonian clades coinciding with the Purus Arch (middle Miocene). Most of subclades we infer originated between the late Pliocene to the early Pleistocene, with few recent exceptions in the early Pliocene through dispersal and vicariant events. The hypothesis of rivers as dispersal barriers is not corroborated for Makalata, as expected for mammalian species associated with seasonally flooded environments. We identify two key events for the expansion and diversification of Makalata species: the presence of geologically stable areas in the Guiana and Brazilian shields and the transition from lacustrine conditions in western Amazonia (Acre system) to a river system, with the establishment of the Amazon River transcontinental system and its tributaries. Our results are congruent with older geological scenarios for the Amazon basin formation (Miocene), but we do not discard the influence of recent dynamics on some speciation events and, mainly, on phylogeographic structuring processes.

A reappraisal of the phylogeny and historical biogeography of Sparganium (Typhaceae) using complete chloroplast genomes

BackgroundSparganium (Typhaceae) is a widespread temperate genus of ecologically important aquatic plants. Previous reconstructions of the phylogenetic relationships among Sparganium species are incompletely resolved partly because they were based on molecular markers comprising < 7,000 bp. Here, we sequenced and assembled the complete chloroplast genomes from 19 Sparganium samples representing 15 putative species and three putative subspecies in order to explore chloroplast genome evolution in this genus, clarify taxonomic lineages, estimate the divergence times of Sparganium species, and reconstruct aspects of the biogeographic history of the genus.ResultsThe 19 chloroplast genomes shared a conserved genome structure, gene content, and gene order. Our phylogenomic analysis presented a well-resolved phylogeny with robust support for most clades. Non-monophyly was revealed in three species: S. erectum, S. eurycarpum, and S. stoloniferum. Divergence time estimates suggest that the two subgenera of Sparganium split from each other ca. 30.67 Ma in the middle Oligocene. The subgenus Xanthosparganium diversified in the late Oligocene and Miocene, while the subgenus Sparganium diversified in the late Pliocene and Pleistocene. Ancestral area reconstruction suggested that the two subgenera may have originated in East Eurasia and North America.ConclusionThe non-monophyletic nature of three putative species underscores the necessity of taxonomic revision for Sparganium: S. stoloniferum subsp. choui may be more appropriately identified as S. choui, and subspecies of S. erectum may be in fact distinct species. The estimated diversification times of the two subgenera correspond to their species and nucleotide diversities. The likely ancestral area for most of subgenus Xanthosparganium was East Eurasia and North America from where it dispersed into West Eurasia and Australia. Most of subgenus Sparganium likely originated in North America and then dispersed into Eurasia. Our study demonstrates some of the ways in which complete chloroplast genome sequences can provide new insights into the evolution, phylogeny, and biogeography of the genus Sparganium.