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Premise: Bryophytes form a major component of terrestrial plant biomass, structuring ecological communities in all biomes. Our understanding of the evolutionary history of hornworts, liverworts, and mosses has been significantly reshaped by inferences from molecular data, which have highlighted extensive homoplasy in various traits and repeated bursts of diversification. However, the timing of key events in the phylogeny, patterns, and processes of diversification across bryophytes remain unclear. Methods: Using the GoFlag probe set, we sequenced 405 exons representing 228 nuclear genes for 531 species from 52 of the 54 orders of bryophytes. We inferred the species phylogeny from gene tree analyses using concatenated and coalescence approaches, assessed gene conflict, and estimated the timing of divergences based on 29 fossil calibrations. Results: The phylogeny resolves many relationships across the bryophytes, enabling us to resurrect five liverwort orders and recognize three more and propose 10 new orders of mosses. Most orders originated in the Jurassic and diversified in the Cretaceous or later. The phylogenomic data also highlight topological conflict in parts of the tree, suggesting complex processes of diversification that cannot be adequately captured in a single gene‐tree topology. Conclusions: We sampled hundreds of loci across a broad phylogenetic spectrum spanning at least 450 Ma of evolution; these data resolved many of the critical nodes of the diversification of bryophytes. The data also highlight the need to explore the mechanisms underlying the phylogenetic ambiguity at specific nodes. The phylogenomic data provide an expandable framework toward reconstructing a comprehensive phylogeny of this important group of plants. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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.

Simple Summary: Biological taxonomic research deals with the grouping of organisms into entities that reflect their evolutionary history and relationships. In the species-rich plant genus Astragalus, the systematic grouping of many species changed several times during recent decades, which indicates problems in correctly recognizing relationships based on morphological characteristics. Here, we analyzed the relationships of Astragalus species from Iran and neighboring countries based on DNA sequences from three different loci. We found that species traditionally classified into two different sections of Astragalus occur intermingled in our phylogenetic trees instead of forming clear groups reflecting their taxonomic units. In addition, species thought to be only distantly related to the target species were found in this cluster. From this, we conclude that the currently used circumscription of taxonomic entities for these Astragalus species is false and should be abandoned. The reasons behind the the systematic classification problems of Astragalus include independent, parallel evolution or the loss of characteristics that were assumed to be unique and used to define certain systematic units. Thus, it is necessary to analyze the relationships of many Astragalus species to (i) identify traits useful for taxonomic classification and (ii) to understand the ecological and habitat differences driving their fast speciation. The Astragalus subgenus Hypoglottis Bunge, which consists of several sections, is one of the taxonomically most complicated groups in the genus. The Astragalus section Stereothrix Bunge belongs to this subgenus and is a significant element of the Irano-Turanian floristic region. A molecular phylogenetic analysis of this section and its closely related taxa using nuclear ribosomal DNA internal transcribed spacers (ITS) and external transcribed spacer (ETS) regions as well as plastid matK sequences were conducted. Parsimony analyses and Bayesian phylogenetic inference revealed that the section is not monophyletic in its current form, as some taxa belonging to closely related sections such as Hypoglottidei DC. and the Malacothrix Bunge group within the sect. Stereothrix render it paraphyletic. Moreover, species groups belonging to sect. Stereothrix are placed in different clades within the phylogenetic tree of subgenus Hypoglottis, which indicates polyphyly, i.e., multiple independent origins of taxa placed in the sect. Stereothrix. Molecular dating of the group estimated an age of 3.62 (1.73–5.62) My for this assemblage with the major diversification events happening during the last 2 My. Many species groups separated only within the last 0.5 to 1 My. Based on morphological and molecular data, we discuss the phylogenetic relationships of the groups and synonymy of species. In addition, the included taxa of sect. Hypoglottidei are not monophyletic and include species belonging to sects. Hololeuce, Koelziana, Malacothrix, Onobrychoideae, and Ornithodpodium group within the sect. Stereothrix taxa. We conclude that only an analysis including all groups and nearly all species of the sections within the Hypoglottis clade can finally result in an new evolutionary-based system for these taxa. [ABSTRACT FROM AUTHOR]

Late Cenozoic climate change led to the progressive aridification of Australia over the past 15 million years. This gradual biome turnover fundamentally changed Australia's ecosystems, opening new niches and prompting diversification of plants and animals. One example are termites of the Australian Amitermes group (AAG), consisting of the Australian Amitermes and affiliated genera. Although the most speciose and diverse higher termite group in Australia, little is known about its evolutionary history. We used ancestral range reconstruction and diversification analyses to illuminate 1) phylogenetic relationships of the AAG, 2) biogeographical processes leading to the current continent‐wide distribution and 3) timing and pattern of diversification in the context of late Cenozoic climate change. By estimating the largest time‐calibrated phylogeny for this group to date, we demonstrate monophyly of the AAG and confirm that their ancestor arrived in Australia ~11–10 million years ago (Mya) from Southeast Asia. Ancestral range reconstruction indicates that Australia's monsoon region was the launching point for a continental radiation shaped by dispersal and within‐biome speciation rather than vicariance. We found that multiple arid‐zone species diversified from mesic and tropical ancestors in the Plio‐Pleistocene, but also observed diversification in the opposite direction. Finally, we show that diversification steadily increased from ~8 to 9 Mya during the 'Hill Gap' and accelerated from ~4 Mya in concert with major ecological change during the Pliocene. Consistent with rapid diversification, species accumulation then slowed down into the present, likely caused by progressive niche saturation. This study provides a stepping stone for predicting future responses of Australia's termite fauna in the face of human‐mediated climate change. [ABSTRACT FROM AUTHOR]

Premise: The Cactaceae of northwestern Mexico and the southwestern United States constitute a major component of the angiosperm biodiversity of the region. The Mammilloid clade, (Cactaceae, tribe Cacteae), composed of the genera Cochemiea, Coryphantha, Cumarinia, Mammillaria, and Pelecyphora is especially species rich. We sought to understand the timing, geographical and climate influences correlated with expansion of the Mammilloid clade, through the Sonoran Desert into Baja California. Methods: We reconstructed the historical biogeography of the Mammilloid clade, using Bayesian and maximum likelihood methods, based on a strongly supported molecular phylogeny. We also estimated divergence times, the timing of emergence of key characters, and diversification rates and rate shifts of the Mammilloid clade. Results: We found that the most recent common ancestor of Cochemiea arrived in the Cape region of Baja California from the Sonoran Desert region approximately 5 million years ago, coinciding with the timing of peninsular rifting from the mainland, suggesting dispersal and vicariance as causes of species richness and endemism. The diversification rate for Cochemiea is estimated to be approximately 12 times that of the mean background diversification rate for angiosperms. Divergence time estimation shows that many of the extant taxa in Cochemiea and Baja California Mammillaria emerged from common ancestors 1 million to 200,000 years ago, having a mid‐Pleistocene origin. Conclusions: Cochemiea and Mammillaria of the Baja California region are examples of recent, rapid diversification. Geological and climatic forces at multiple spatial and temporal scales are correlated with the western distributions of the Mammilloid clade. [ABSTRACT FROM AUTHOR]

The small-eared shrew genus Cryptotis is the third largest in the family Soricidae and occurs in North, Central, and northern South America. In Mexico and Central and South America, most species inhabit geographically isolated moist, montane habitats at middle and high elevations in a typical sky-island pattern. The 49 recognized species have been partitioned into as many as six species groups based on morphological and molecular phylogenetic studies. The relationships among these species groups are poorly resolved, and their evolutionary histories, including migration patterns and locomotor adaptations, remain unclear. Herein, we provide a new phylogeny incorporating complete mitochondrial genomes (mitogenomes) and supermatrix approach. We compared different evolutionary scenarios using approximately unbiased (AU), Kishino-Hasegawa (KH), and Shimodaira-Hasegawa (SH) statistical tests. The phylogenetic hypothesis based on mitogenomes revealed novel relationships supporting a basal position for the Cryptotis parvusgroup in the genus, and a close relationship between C. gracilis and one clade of the C. thomasi-group. The former relationship is consistent with the least derived humerus morphology and northern distribution of the species. The latter relationship implies multiple migrations between Central and South America. The lack of fine resolution for the species group relationships may be due partly to the lack of taxon sampling. In contrast, multi-approach analyses suggest that the unresolved relationships may be a result of rapid diversification during the early stages of Cryptotis evolution. [ABSTRACT FROM AUTHOR]

Abstract Background The aragonite shelled, planktonic gastropod family Atlantidae (shelled heteropods) is likely to be one of the first groups to be impacted by imminent ocean changes, including ocean warming and ocean acidification. With a fossil record spanning at least 100 Ma, atlantids have experienced and survived global-scale ocean changes and extinction events in the past. However, the diversification patterns and tempo of evolution in this family are largely unknown. Results Based on a concatenated maximum likelihood phylogeny of three genes (cytochrome c oxidase subunit 1 mitochondrial DNA, 28S and 18S ribosomal rRNA) we show that the three extant genera of the family Atlantidae, Atlanta, Protatlanta and Oxygyrus, form monophyletic groups. The genus Atlanta is split into two groups, one exhibiting smaller, well ornamented shells, and the other having larger, less ornamented shells. The fossil record, in combination with a fossil-calibrated phylogeny, suggests that large scale atlantid extinction was accompanied by considerable and rapid diversification over the last 25 Ma, potentially driven by vicariance events. Conclusions Now confronted with a rapidly changing modern ocean, the ability of atlantids to survive past global change crises gives some optimism that they may be able to persist through the Anthropocene.

The Astragalus subgenus Hypoglottis Bunge, which consists of several sections, is one of the taxonomically most complicated groups in the genus. The Astragalus section Stereothrix Bunge belongs to this subgenus and is a significant element of the Irano-Turanian floristic region. A molecular phylogenetic analysis of this section and its closely related taxa using nuclear ribosomal DNA internal transcribed spacers (ITS) and external transcribed spacer (ETS) regions as well as plastid matK sequences were conducted. Parsimony analyses and Bayesian phylogenetic inference revealed that the section is not monophyletic in its current form, as some taxa belonging to closely related sections such as Hypoglottidei DC. and the Malacothrix Bunge group within the sect. Stereothrix render it paraphyletic. Moreover, species groups belonging to sect. Stereothrix are placed in different clades within the phylogenetic tree of subgenus Hypoglottis, which indicates polyphyly, i.e., multiple independent origins of taxa placed in the sect. Stereothrix. Molecular dating of the group estimated an age of 3.62 (1.73–5.62) My for this assemblage with the major diversification events happening during the last 2 My. Many species groups separated only within the last 0.5 to 1 My. Based on morphological and molecular data, we discuss the phylogenetic relationships of the groups and synonymy of species. In addition, the included taxa of sect. Hypoglottidei are not monophyletic and include species belonging to sects. Hololeuce, Koelziana, Malacothrix, Onobrychoideae, and Ornithodpodium group within the sect. Stereothrix taxa. We conclude that only an analysis including all groups and nearly all species of the sections within the Hypoglottis clade can finally result in an new evolutionary-based system for these taxa.

The relative importance of introgression for diversification has long been a highly disputed topic in speciation research and remains an open question despite the great attention it has received over the past decade. Gene flow leaves traces in the genome similar to those created by incomplete lineage sorting (ILS), and identification and quantification of gene flow in the presence of ILS is challenging and requires knowledge about the true phylogenetic relationship among the species. We use whole nuclear, plastid, and organellar genomes from 12 species in the rapidly radiated, ecologically diverse, actively hybridizing genus of peatmoss (Sphagnum) to reconstruct the species phylogeny and quantify introgression using a suite of phylogenomic methods. We found extensive phylogenetic discordance among nuclear and organellar phylogenies, as well as across the nuclear genome and the nodes in the species tree, best explained by extensive ILS following the rapid radiation of the genus rather than by postspeciation introgression. Our analyses support the idea of ancient introgression among the ancestral lineages followed by ILS, whereas recent gene flow among the species is highly restricted despite widespread interspecific hybridization known in the group. Our results contribute to phylogenomic understanding of how speciation proceeds in rapidly radiated, actively hybridizing species groups, and demonstrate that employing a combination of diverse phylogenomic methods can facilitate untangling complex phylogenetic patterns created by ILS and introgression. [ABSTRACT FROM AUTHOR]

UnlabelledPremise of the studyWe report 11 primer sets for nine single-copy nuclear genes in Streptanthus and other Thelypodieae (Brassicaceae) and their utility at tribal-level and species-level phylogenetics in this poorly resolved group. •Methods and resultsWe selected regions based on a cross-referenced matrix of previous studies and public Brassica expressed sequence tags. To design primers, we used alignments of low-depth-coverage Illumina sequencing of genomic DNA for two species of Brassica mapped onto Arabidopsis thaliana. We report several primer combinations for five regions that consistently amplified a single band and yielded high-quality sequences for at least 70% of the species assayed, and for four additional regions whose utility might be clade specific. •ConclusionsOur primers will be useful in improving resolution at shallow depths across the Thelypodieae, and likely in other Brassicaceae.

Arid soil habitats are challenging for sedentary and slow-growing lichens because the integrity of the substrate can easily be disturbed by natural forces, e.g., wind and flood. Yet, adaptation into such habitat types occurred multiple times in lichens that may be associated with specific morphological and ecological adaptations. We studied the genetic and chemical diversity of the lichen-forming fungal genus Xanthoparmelia in Western Australia, where it is abundant in both arid and temperate ecoregions occurring on both soil and rock substrates. We found frequent evolutionary transitions among substrate types and between arid and temperate habitats. However, specific chemical phenotypes were not associated with different habitat and substrate types, and the level of phenotypic (the composition of secondary metabolites) divergence was not correlated with the level of genetic divergence among taxa. The study closes by discussing the importance of arid soil habitats for evolutionary diversification in the hyperdiverse genus Xanthoparmelia.

The climate-driven species pump hypothesis has been supported in a number of phylogeographic studies of alpine species. Climate-driven shifts in distribution, coupled with rapid demographic change, have led to strong genetic drift and lineage diversification. Although the species pump has been linked to rapid speciation in a number of studies, few studies have demonstrated that ecological divergence accompanies rapid speciation. Here we examine genetic, morphological and physiological variation in members of the ground beetle taxon Nippononebria , to test three competing hypotheses of evolutionary diversification: isolation and incomplete lineage sorting (no speciation), recent speciation without ecological divergence, or recent speciation with ecological divergence into alpine habitats. Genetic data are consistent with recent divergence, with major lineages forming in the last million years. A species tree analysis, in conjunction with morphological divergence in male reproductive traits, support the formation of three recognized Nippononebria taxa. Furthermore, both morphological and physiological traits demonstrate ecological divergence in alpine lineages, with convergent shifts in body shape and thermal tolerance breadth. This provides strong evidence that the climate-driven species pump can generate ecological novelty, though it is argued that spatial scale may be a key determinant of broader patterns of macroevolution in alpine communities. [ABSTRACT FROM AUTHOR]

[Display omitted] • None of the currently proposed sections from Camellia was monophyletic. • Gene tree discordance is prevalent in the backbone of Camellia. • Rapid diversification might be one of the possible causes of gene tree discordance of Camellia. • Selective pressure analysis indicated that integrating all orthologous genes provided improved phylogenetic resolution of the species tree of Camellia. Gene tree discordance is a significant legacy of biological evolution. Multiple factors can result in incongruence among genes, such as introgression, incomplete lineage sorting (ILS), gene duplication or loss. Resolving the background of gene tree discordance is a critical way to uncover the process of species diversification. Camellia , the largest genus in Theaceae, has controversial taxonomy and systematics due in part to a complex evolutionary history. We used 60 transcriptomes of 55 species, which represented 15 sections of Camellia to investigate its phylogeny and the possible causes of gene tree discordance. We conducted gene tree discordance analysis based on 1,617 orthologous low-copy nuclear genes, primarily using coalescent species trees and polytomy tests to distinguish hard and soft conflict. A selective pressure analysis was also performed to assess the impact of selection on phylogenetic topology reconstruction. Our results detected different levels of gene tree discordance in the backbone of Camellia , and recovered rapid diversification as one of the possible causes of gene tree discordance. Furthermore, we confirmed that none of the currently proposed sections of Camellia was monophyletic. Comparisons among datasets partitioned under different selective pressure regimes showed that integrating all orthologous genes provided the best phylogenetic resolution of the species tree of Camellia. The findings of this study reveal rapid diversification as a major source of gene tree discordance in Camellia and will facilitate future investigation of reticulate relationships at the species level in this important plant genus. [ABSTRACT FROM AUTHOR]

The Irano-Turanian floristic region spans a topographically complex and climatically continental territory, which has served as a source of xerophytic taxa for neighboring regions and is represented by a high percent of endemics. Yet, a comprehensive picture of the abiotic and biotic factors that have driven diversification within this biota remains to be established due to the scarcity of phylogenetic studies. Acantholimon is an important component of the subalpine steppe flora of the Irano-Turanian region, containing c. 200 cushion-forming sub-shrubby pungent-leaved species. Our recent molecular phylogenetic study has led to enlarging the circumscription of this genus to include eight mono- or oligospecific genera lacking the characteristic life-form and leaves. Using the same molecular phylogeny, here we investigate the tempo and mode of diversification as well as the biogeographic patterns in this genus, to test the hypothesis that a combination of key morphological innovations and abiotic factors is behind Acantholimon high species diversity. Molecular dating analysis indicates that Acantholimon s.l. started to diversify between the Late Miocene and the Pliocene and the biogeographic analysis points to an Eastern Iran–Afghanistan origin. Macroevolutionary models support the hypothesis that the high diversity of the genus is explained by accelerated diversification rates in two clades associated with the appearance of morphological key innovations such as a cushion life-form and pungent leaves; this would have favored the colonization of water-stressed, substrate-poor mountainous habitats along the newly uplifted IT mountains during the Mio-Pliocene. Given the apparent similarity of mountain habitats for most species of Acantholimon , we hypothesize that its current high species diversity responds to a scenario of non-adaptive radiation fueled by allopatric speciation rather than evolutionary radiation driven by ecological opportunity. Similar scenarios might underlie the high diversity of other speciose genera in the topographically complex Irano-Turanian landscape, though this remains to be tested with fine-grained distribution and climatic data. [ABSTRACT FROM AUTHOR]

High-throughput sequencing is helping biologists to overcome the difficulties of inferring the phylogenies of recently diverged taxa. The present study analyzes the phylogenetic signal of genomic regions with different inheritance patterns using genome skimming and dd RAD-seq in a species-rich Andean genus ( Diplostephium) and its allies., We analyzed the complete nuclear ribosomal cistron, the complete chloroplast genome, a partial mitochondrial genome, and a nuclear-dd RAD matrix separately with phylogenetic methods. We applied several approaches to understand the causes of incongruence among datasets, including simulations and the detection of introgression using the D-statistic ( ABBA- BABA test)., We found significant incongruence among the nuclear, chloroplast, and mitochondrial phylogenies. The strong signal of hybridization found by simulations and the D-statistic among genera and inside the main clades of Diplostephium indicate reticulate evolution as a main cause of phylogenetic incongruence., Our results add evidence for a major role of reticulate evolution in events of rapid diversification. Hybridization and introgression confound chloroplast and mitochondrial phylogenies in relation to the species tree as a result of the uniparental inheritance of these genomic regions. Practical implications regarding the prevalence of hybridization are discussed in relation to the phylogenetic method. [ABSTRACT FROM AUTHOR]

Oceanic archipelagoes, by their young origin and isolation, provide privileged settings to study the origin and diversification of species. Here, we study the anyphaenid spider genus Philisca , endemic to the Valdivian temperate rainforest, which includes species living both on the mainland as well as on the Robison Crusoe Island in the Juan Fernández archipelago. Anyphaenids, as many spiders, are potentially good colonizers due their ability for ballooning, an airborne dispersal mediated by strands of silk that are caught in the wind. We use a molecular approach to estimate both the phylogenetic relationships and the timeframe of species diversification of Philisca , with the aim to infer its evolutionary history. We further estimate the rates of speciation on both the insular and continental Philisca species and score the microhabitat used by each species and their sizes as a proxy to evaluate ecological niche diversification within the island. Most analyses support the monophyly of Philisca , with the exclusion of Philisca tripunctata . Our results reveal colonization from a single lineage that postdated the origin of the island, followed by rapid (∼2 Ma) diversification. The ancestral microhabitat was most likely leaf-dwelling but we identify two independent microhabitat shifts. Our data provides evidence that Philisca has undergone an adaptive radiation on the Robison Crusoe Island. [ABSTRACT FROM AUTHOR]

A general procedure for the rapid diversification of peptide scaffolds is described. A one-pot click reaction between a peptide-alkyne and a series of in situ generated aryl/alkyl azides affords novel N1-substituted triazole peptidomimetics. This transformation is of broad scope, operates under mild conditions, and is parallel chemical synthesis compatible. [ABSTRACT FROM AUTHOR]

Ptilotus (Amaranthaceae) is an Australian genus with over 100 species, most of which occur in arid Western Australia. Ptilotus has been a taxonomically difficult genus; despite rigorous morphological studies into the genus over many years, previous workers have found it difficult to delimit infrageneric groups due to inconsistent morphological variation. With the goal to establish a phylogenetic framework for the genus, 100 taxa were sampled, including 87 Ptilotus spp., and the ITS nrDNA and matK cpDNA were sequenced. The phylogeny was reconstructed using Bayesian, maximum likelihood and maximum parsimony analyses on separate and concatenated datasets. Morphological characters were assessed and compared to clades on the phylogeny to identify synapomorphies and aid in the construction of an infrageneric classification. A diversification rate analysis was used to identify rate shifts in speciation across the phylogeny. Four major clades of the monophyletic Ptilotus were resolved, three small clades together comprising 27% of sampled taxa and a large, diverse clade comprising the remaining 73%. Four floral synapomorphies were identified as uniquely occurring within the latter, although none were common to all taxa in the clade. The diversification rate analysis identified a probable rate shift at the base of Ptilotus, indicating that the genus may have undergone a rapid diversification early in its evolution. This rapid diversification provides a plausible explanation for the lack of consistent variation in morphology among the major clades. [ABSTRACT FROM AUTHOR]

The article discusses the study that examines potential resolution of relationships within Valerianaceae, Dipsacales, through several of Conserved Ortholog Set II (COSII) markers, and compares performance and variability to internal transcribed spacer (ITS) and other chloroplast markers. Topics discussed include nucleotide characters added by low-copy nuclear genes (LCNG) but no phylogenetic information provided for relationship resolution, and several LCNG to increase phylogenetic signal.

Despite substantial investigations into Oryza phylogeny and evolution, reliable estimates of the divergence times and ancestral effective population sizes of major lineages in Oryza are challenging., We sampled sequences of 106 single-copy nuclear genes from all six diploid genomes of Oryza to investigate the divergence times through extensive relaxed molecular clock analyses and estimated the ancestral effective population sizes using maximum likelihood and Bayesian methods., We estimated that Oryza originated in the middle Miocene ( c. 13-15 million years ago; Ma) and obtained an explicit time frame for two rapid diversifications in this genus. The first diversification involving the extant F-/ G-genomes and possibly the extinct H-/ J-/ K-genomes occurred in the middle Miocene immediately after (within < 1 Myr) the origin of Oryza. The second giving rise to the A-/ B-/ C-genomes happened c. 5-6 Ma. We found that ancestral effective population sizes were much larger than those of extant species in Oryza., We suggest that the climate fluctuations during the period from the middle Miocene to Pliocene may have contributed to the two rapid diversifications of Oryza species. Such information helps better understand the evolutionary history of Oryza and provides further insights into the pattern and mechanism of diversification in plants in general. [ABSTRACT FROM AUTHOR]

Abstract: Several recent studies have suggested that a substantial portion of today’s plant diversity in the Neotropics has resulted from the dispersal of taxa into that region rather than vicariance, but more data are needed to substantiate this claim. Guatteria (Annonaceae) is, with 265 species, the third largest genus of Neotropical trees after Inga (Fabaceae) and Ocotea (Lauraceae), and its widespread distribution and frequent occurrence makes the genus an excellent model taxon to study diversification patterns. This study reconstructed the phylogeny of Guatteria and inferred three major biogeographical events in the history of the genus: (1) a trans-oceanic Miocene migration from Central into South America before the closing of the Isthmus of Panama; (2) a major diversification of the lineage within South America; and (3) several migrations of South American lineages back into Central America via the closed Panamanian land bridge. Therefore, Guatteria is not an Amazonian centred-genus sensu Gentry but a major Miocene diversification that followed its dispersal into South America. This study provides further evidence that migration into the Neotropics was an important factor in the historical assembly of its biodiversity. Furthermore, it is shown that phylogenetic patterns are comparable to those found in Ocotea and Inga and that a closer comparison of these genera is desirable. [Copyright &y& Elsevier]

Abstract: Phylogenetic relationships of members of the subfamily Poeciliinae (Cyprinodontiformes) are investigated to test alternate hypotheses of diversification resulting from the assembly of the Central America and the Caribbean from the Cretaceous period onwards. We use 4333 aligned base pairs of mitochondrial DNA and 1549 aligned base pairs of nuclear DNA from 55 samples representing 48 ingroup and seven outgroup species to test this hypothesis. Mitochondrial genes analyzed include those encoding the 12S and 16S ribosomal RNAs; transfer RNAs coding for valine, leucine, isoleucine, glutamine, methionine, tryptophan, alanine, asparagine, cysteine and tyrosine; and complete cytochrome b and NADH dehydrogenase subunit I and II; nuclear gene analyzed included the third exon of the recombination activation gene 1 (RAG1). Analyses of combined mtDNA and nuclear DNA data sets result in a well-supported phylogenetic hypothesis. This hypothesis is in conflict with the classical taxonomic assignment of genera into tribes and phylogenetic hypotheses based on the taxonomy; however, the molecular hypothesis defines nine clades that are geographically restricted and consistent with the geological evolution of Central America and the Caribbean. Our analyses support multiple colonization events of Middle America followed by a mix of vicariance and dispersal events. [Copyright &y& Elsevier]

Thymelaea is a Mediterranean genus belonging to a primarily tropical and subtropical family. This genus is here presented as a particular case on which the hypothesis of an in situ evolution of the Mediterranean flora from a Tertiary subtropical stock can be phylogenetically tested. To better understand the evolutionary history of Thymelaea, molecular phylogenies based on ITS (rDNA) sequences are estimated. Phylogenetic analyses strongly support the monophyly of Thymelaea and the sister position of Daphne. Unexpected relationships between sequences of T. granatensis, T. pubescens and T. sanamunda are found and explained as a case of cryptic nuclear introgression. Phylogenetic analyses also reveal the polyphyletic character of Diarthron, sensu Tan, suggesting that Dendrostellera and Stelleropsis should be reinstated as independent genera. Based on the resulting phylogenetic hypothesis and using statistical tests it is suggested that Thymelaea experienced an initial rapid diversification. Time estimates for the origin and radiation of Thymelaea based on independent sources of evidence—paleontological, paleoclimatic and paleogeographic data, on one hand, and ITS substitution rates reported for other angiosperm groups, on the other—give strikingly similar results. The early radiation of Thymelaea is inferred to have occurred in the Upper Miocene, after this lineage diverged from that of Daphne in the Lower or Middle Miocene. Both evolutionary events are related to the overall climatic deterioration (declining temperature and increasing dryness) registered throughout the Miocene in Eurasia. The rapid and extensive diversification of Thymelaea is placed in the Iberian Peninsula or here and in the neighbouring North African territory. [ABSTRACT FROM AUTHOR]

Abstract: The biologically interesting ant–plant association, myrmecophytism, occurs in ca. 140 of the 11,000 species and 22 of the 630 genera of the coffee family (Rubiaceae). These myrmecophytic Rubiaceae species are predominantly distributed in Southeast Asia, especially the Malesian region, with comparatively few species in mainland Africa and the Neotropics. The mostly Southeast Asian genus Neonauclea s.s is one of the three Rubiaceae genera with extensive radiation of myrmecophytes and also the most speciose genus of the tribe Naucleeae s.l. We perform parsimony phylogenetic analyses of Neonauclea s.s., previously resolved as paraphyletic, and its allied genera using both ETS and ITS sequencing data to test: (1) the paraphyly of Neonauclea s.s.; (2) the phylogenetic relationships within the Ludekia–Myrmeconauclea–Neonauclea complex; and (3) the evolution of myrmecophytism within the complex. The earlier proposed paraphyly of Neonauclea s.s. appears to be the result of the combined effects of parallel substitutions in Metadina trichotoma and the sampled ITS putative pseudogenes of Neonauclea longipedunculata and losses of some synapomorphies of Neonauclea s.s. in the latter. The analyses present strong support for the monophyly of Myrmeconauclea and Neonauclea s.s. and their sister-group relationships. Our findings additionally favor the hypothesis of multiple origins of myrmecophytism in the Bornean Neonauclea, which have independently been exploited by at least three Cladomyrma ant species. Furthermore, we interpret the low levels of variation in both the ETS and ITS sequences as indication of a recent and rapid radiation for Neonauclea s.s. (with 65 species) and a recent and slow radiation for Myrmeconauclea (with three species). We argue that the rapid diversification of Neonauclea s.s. is partly associated with the nature of its fruits and its ability to colonize a wide range of habitats. We postulate that both ecological and geographical events may have been responsible for the radiation of the non-myrmecophytic Neonauclea species. Finally, we argue that the acquisition of the pseudo-multiple fruits and long-tailed seeds has allowed Myrmeconauclea to specialize on rheophytic habitats but its narrow ecological tolerance may have hindered its speciation. [Copyright &y& Elsevier]

Phylogenetic relationships of a subset of Aphanius fish comprising central Anatolia, Turkey, are investigated to test the hypothesis of geographic speciation driven by early Pliocene orogenic events in spite of morphological similarity. We use 3434 aligned base pairs of mitochondrial DNA from 42 samples representing 36 populations of three species and six outgroup species to test this hypothesis. Genes analyzed include those encoding the 12S and 16S ribosomal RNAs; transfer RNAs coding for valine, leucine, isoleucine, glutamine, methionine, tryptophan, alanine, asparagine, cysteine, and tyrosine; and complete NADH dehydrogenase subunits I and II. Distance based minimum evolution and maximum-likelihood analyses identify six well-supported clades consisting of Aphanius danfordii, Aphanius sp. aff danfordii, and four clades of Aphanius anatoliae. Parsimony analysis results in 462 equally parsimonious trees, all of which contain the six well supported clades identified in the other analyses. Our phylogenetic results are supported by hybridization studies (Villwock, 1964), and by the geological history of Anatolia. Phylogenetic relationships among the six clades are only weakly supported, however, and differ among analytical methods. We therefore test and subsequently reject the hypothesis of simultaneous diversification among the six central Anatolian clades. However, our analyses do not identify any internodes that are significantly better supported than expected by chance alone. Therefore, although bifurcating branching order is hypothesized to underlie this radiation, the exact branching order is difficult to estimate with confidence. [ABSTRACT FROM AUTHOR]

Premise of the study: We report 11 primer sets for nine single-copy nuclear genes in Streptanthus and other Thelypodieae (Brassicaceae) and their utility at tribal-level and species-level phylogenetics in this poorly resolved group. Methods and Results: We selected regions based on a cross-referenced matrix of previous studies and public Brassica expressed sequence tags. To design primers, we used alignments of low-depth-coverage Illumina sequencing of genomic DNA for two species of Brassica mapped onto Arabidopsis thaliana. We report several primer combinations for five regions that consistently amplified a single band and yielded high-quality sequences for at least 70% of the species assayed, and for four additional regions whose utility might be clade specific. Conclusions: Our primers will be useful in improving resolution at shallow depths across the Thelypodieae, and likely in other Brassicaceae.

The small-eared shrew genus Cryptotis is the third largest in the family Soricidae and occurs in North, Central, and northern South America. In Mexico and Central and South America, most species inhabit geographically isolated moist, montane habitats at middle and high elevations in a typical sky-island pattern. The 49 recognized species have been partitioned into as many as six species groups based on morphological and molecular phylogenetic studies. The relationships among these species groups are poorly resolved, and their evolutionary histories, including migration patterns and locomotor adaptations, remain unclear. Herein, we provide a new phylogeny incorporating complete mitochondrial genomes (mitogenomes) and supermatrix approach. We compared different evolutionary scenarios using approximately unbiased (AU), Kishino-Hasegawa (KH), and Shimodaira-Hasegawa (SH) statistical tests. The phylogenetic hypothesis based on mitogenomes revealed novel relationships supporting a basal position for the Cryptotis parvus -group in the genus, and a close relationship between C. gracilis and one clade of the C. thomasi -group. The former relationship is consistent with the least derived humerus morphology and northern distribution of the species. The latter relationship implies multiple migrations between Central and South America. The lack of fine resolution for the species group relationships may be due partly to the lack of taxon sampling. In contrast, multi-approach analyses suggest that the unresolved relationships may be a result of rapid diversification during the early stages of Cryptotis evolution.

• Genotyping-by-sequencing (GBS) is widely employed in phylogenomics. • We employ GBS to resolve relationships within a recalcitrant orchid species complex. • About 50% of GBS loci recovered lack phylogenetic informativeness (PI) • The PI of the 42 most informative GBS loci is comparable with that of nrITS. • Phylogenomics of GBS datasets recircumscribes six prior taxa as only three species. Poor morphological and molecular differentiation in recently diversified lineages is a widespread phenomenon in plants. Phylogenetic relationships within such species complexes are often difficult to resolve because of the low variability in traditional molecular loci. Furthermore, biological phenomena responsible for topological incongruence such as Incomplete Lineage Sorting (ILS) and hybridisation complicate the resolution of phylogenetic relationships among closely related taxa. In this study, we employ a Genotyping-by-sequencing (GBS) approach to disentangle evolutionary relationships within a species complex belonging to the Neotropical orchid genus Cycnoches. This complex includes seven taxa distributed through Central America and the Colombian Chocó, and is nested within a clade estimated to have first diversified in the early Quaternary. Previous phylogenies inferred from few loci failed to provide support for internal relationships within the complex. Our Neighbour-net and coalescent-based analyses inferred from ca. 13,000 GBS loci obtained from 31 individuals belonging to six of the seven traditionally accepted Cycnoches taxa provided a robust phylogeny for this group. The genus Cycnoches includes three main clades that are further supported by morphological traits and geographic distributions. Similarly, a topology reconstructed through maximum likelihood (ML) inference of concatenated GBS loci produced results that are comparable with those reconstructed through coalescence and network-based methods. Our comparative phylogenetic informativeness analyses suggest that the low support evident in the ML phylogeny might be attributed to the abundance of uninformative GBS loci, which can account for up to 50% of the total number of loci recovered. The phylogenomic framework provided here, as well as morphological evidence and geographical patterns, suggest that the six entities previously thought to be different species or subspecies might actually represent only three distinct segregates. We further discuss the limited phylogenetic informativeness found in our GBS approach and its utility to disentangle relationships within recent and rapidly evolving species complexes. Our study is the first to demonstrate the utility of GBS data to reconstruct relationships within young (~2 Ma) Neotropical plant clades, opening new avenues for studies of species complexes that populate the species-rich orchid family. [ABSTRACT FROM AUTHOR]