Ancestral Character State Reconstruction Research Articles

Phylogeny, character evolution and historical biogeography of Scurrulinae (Loranthaceae): new insights into the circumscription of the genus Taxillus

BackgroundExploring the relationship between parasitic plants and answering taxonomic questions is still challenging. The subtribe Scurrulinae (Loranthaceae), which has a wide distribution in Asia and Africa, provides an excellent example to illuminate this scenario. Using a comprehensive taxon sampling of the subtribe, this study focuses on infer the phylogenetic relationships within Scurrulinae, investigate the phylogeny and biogeography of the subtribe, and establish a phylogenetically-based classification incorporating both molecular and morphological evidence. We conducted phylogenetic, historical biogeography, and ancestral character state reconstruction analyses of Scurrulinae based on the sequences of six DNA regions from 89 individuals to represent all five tribes of the Loranthaceae and the dataset from eleven morphological characters.ResultsThe results strongly support the non-monophyletic of Scurrulinae, with Phyllodesmis recognized as a separate genus from its allies Taxillus and Scurrula based on the results from molecular data and morphological character reconstruction. The mistletoe Scurrulinae originated in Asia during the Oligocene. Scurrulinae was inferred to have been widespread in Asia but did not disperse to other areas. The African species of Taxillus, T. wiensii, was confirmed to have originated in Africa from African Loranthaceae ca. 17 Ma, and evolved independently from Asian members of Taxillus.ConclusionsThis study based on comprehensive taxon sampling of the subtribe Scurrulinae, strongly supports the relationship between genera. The taxonomic treatment for Phyllodesmis was provided. The historical biogeography of mistletoe Scurrulinae was determined with origin in Asia during the Oligocene. Taxillus and Scurrula diverged during the climatic optimum in the middle Miocene. Taxillus wiensii originated in Africa from African Loranthaceae, and is an independent lineage from the Asian species of Taxillus. Diversification of Scurrulinae and the development of endemic species in Asia may have been supported by the fast-changing climate, including cooling, drying, and the progressive uplift of the high mountains in central Asia, especially during the late Pliocene and Pleistocene.

Sex chromosome turnover plays an important role in the maintenance of barriers to post-speciation introgression in willows

Abstract Almost all species in the genus Salix (willow) are dioecious and willows have variable sex-determining systems, the role of this variation in maintaining species barriers is relatively untested. We first analyzed the sex determination systems (SDS) of two species, Salix cardiophylla and Salix interior, whose positions in the Salix phylogeny make them important for understanding a sex chromosome turnover that has been detected in their relatives, and that changed the system from male (XX/XY) to female (ZW/ZZ) heterogamety. We show that both species have male heterogamety, with sex-linked regions (SLRs) on chromosome 15 (termed a 15XY system). The SLRs occupy 21.3% and 22.8% of the entire reference chromosome, respectively. By constructing phylogenetic trees, we determined the phylogenetic positions of all the species with known SDSs. Reconstruction of ancestral SDS character states revealed that the 15XY system is likely the ancestral state in willows. Turnovers of 15XY to 15ZW and 15XY to 7XY likely contributed to early speciation in Salix and gave rise to major groups of the Vetrix and Salix clades. Finally, we tested introgression among species in the phylogenetic trees based on both autosomes and SLRs separately. Frequent introgression was observed among species with 15XY, 15ZW, and 7XY on autosomes, in contrast to the SLR datasets, which showed less introgression, and in particular no gene flow between 15ZW and 7XY species. We argue that, although SDS turnovers in willow speciation may not create complete reproductive barriers, the evolution of SLRs plays important roles in preventing introgression and maintaining species boundaries.

Comparative chloroplast genomes study of five officinal Ardisia Species: Unraveling interspecific diversity and evolutionary insights in Ardisia

Ardisia S.W. (Primulaceae), naturally distributed in tropical and subtropical regions, has edible and medicinal values and is prevalent in clinical and daily use in China. More genetic information for distinct species delineation is needed to support the development and utilization of the genus Ardisia. We sequenced, annotated, and compared the chloroplast genomes of five Ardisia species: A. brunnescens, A. pusilla, A. squamulosa, A. crenata, and A. brevicaulis in this study. We found a typical quadripartite structure in all five chloroplast genomes, with lengths ranging from 155,045 to 156,943 bp. Except for A. pusilla, which lacked the ycf15 gene, the other four Ardisia species contained 114 unique genes, including 79 protein-coding genes, 30 tRNAs, and four rRNAs. In addition, the rps19 pseudogene gene was present only in A. brunnescens. Five highly variable DNA barcodes were identified for five Ardisia species, including trnT-GGU-psbD, trnT-UGU-trnL-UAA, rps4-trnT-UGU, rpl32-trnL-UAG, and rpoB-trnC-GAA. The RNA editiing sites of protein-coding genes in the five Ardisia plastome were characterized and compared, and 274 (A. crenata)-288 (A. brevicaulis) were found. The results of the phylogenetic analysis were consistent with the morphological classification. Sequence alignment and phylogenetic analysis showed that ycf15 genes were highly divergent in Primulaceae. Reconstructions of ancestral character states indicated that leaf margin morphology is critical for classifying the genus Ardisia, with a rodent-like character being the most primitive. These results provide valuable information on the taxonomy and evolution of Ardisia plants.

Molecular phylogeny of Gryllidea (Orthoptera: Ensifera) by mitochondrial genomes reveals the patterns of subapical spurs and dorsal spines on hind tibiae

Abstract The phylogeny of Gryllidea remains a controversy due to inconsistent findings from morphological and molecular studies. In order to investigate the phylogenetic relationships among subfamilies in Gryllidea, we sequenced and analyzed the mitochondrial genomes of five species from different subfamilies. Our analysis included a total of 41 mitochondrial genomes from Gryllidea, and the resulting phylogenetic trees revealed following relationship (((((Gryllidae + Oecanthidae) + Phalangopsidae) +Trigonidiidae) + Mogoplistidae) + Myrmecophilidae) + Gryllotalpidae. The phylogenetic analysis indicated that Itarinae and Landrevinae were grouped in Gryllidae, and Euscyrtinae grouped together with Podoscirtinae in Oecanthidae. We focused on the presence of subapical spurs and dorsal spines on hind tibiae for ancestral character state reconstruction. The results indicated that hind tibiae of Gryllidea exhibited multiple transitions between only subapical spurs and only dorsal spines states.

Phylogenomics and systematics of botryllid ascidians, and implications for the evolution of allorecognition

Allorecognition, the ability of an organism to distinguish kin from non-kin, or self from non-self, has been studied extensively in a group of invertebrate chordates, the colonial ascidians called botryllids (Subphylum Tunicata, Class Ascidiacea, Family Styelidae). When two conspecific botryllid colonies come in contact, there are two potential outcomes to an allorecognition reaction: fusion or rejection. The rejection outcome of allorecognition varies by species, and has been classified by type (referred to as R-Type). R-Type is defined according to how far the fusion process progresses before the rejection begins, since the rejection reaction appears as an interference of the fusion process. Here, we map the evolution of R-Types onto an extended and robust phylogeny of the botryllids. In this study, we have reconstructed the largest phylogenomic tree of botryllids, including 97 samples and more than 40 different species, and mapped on it nine of the 13 species for which the R-Type is known. Based on the R-Type known in a single outgroup species (Symplegma reptans), we infer that at least R-Type B and E-like could be ancestral to the Botrylloides/Botryllus group. However, the application of ancestral character state reconstructions does not provide conclusive results since several clades show more than one equiparsimonious R-Type state. Notably, all R-Type A species are clustered together and certainly evolved later than other R-Types. Our phylogenomic tree has been built on 177 nuclear loci and nearly all clades are well supported. Moreover, our phylogenetic analyses also take into account the results of species delimitation analyses based on the mitochondrial COI gene and of careful morphological analyses of the samples. The implementation of this integrated taxonomic approach, combining morphological as well as nuclear and mitochondrial data, has allowed the description of six new species, and the identification of a number of putative unnamed taxa. Thus, our results also demonstrate the existence of an unexplored hidden diversity within botryllids.

Comparative analyses of micro‐ and macro‐scale surface structures in the convergent evolution of rain‐harvesting behaviour in lizards

AbstractRain‐harvesting behaviour represents an adaptation for water collection that has evolved in some species of iguanian reptiles inhabiting arid environments. To date, such behaviour has been observed only in members of the families Agamidae and Phrynosomatidae. A common set of integumentary features characterizes these rain‐harvesting species, including scale surface microstructures (SSMs), capillary channels and hinge joints. The influence of variations in these features on rain‐harvesting has been a subject of discussion for many decades. Nevertheless, a comprehensive comparative study of similarities and differences between harvesting and non‐harvesting species on a broader scale remains lacking. In this study, we classify scale surface microstructures into three categories: large hexagons (SSM1), smaller nested hexagons (SSM2) and hinge pits (SSM2H). As the first two SSM types are widespread, they do not appear to be directly linked to the adaptation for rain‐harvesting. Conversely, the presence or absence of hinge pits distinguishes harvesters from non‐harvesters. Additionally, channel hierarchy, width and structure determine the effectiveness of the rain‐harvesting architecture. Only Moloch horridus exhibits distinct integumentary features in comparison to other agamids and rain‐harvesting species. Ancestral character state reconstruction suggests that rain‐harvesting behaviour was likely absent in the ancestor of Iguanians, even though overlapping scales and SSM1 were present. Our findings illustrate that rain‐harvesting species have independently converged upon similar structural solutions to address their water acquisition challenges, building upon shared pre‐existing features.

Phylogenetic reconstruction of Corydioidea (Dictyoptera: Blattodea) provides new insights on the placement of Latindiinae and supports the proposal of the new subfamily Ctenoneurinae

AbstractRepresentatives of the cockroach superfamily Corydioidea are less sampled than members of the two other cockroach superfamilies (Blaberoidea and Blattoidea) due to the difficulty of collecting them in the field, accentuated by a general lack of knowledge on their biology. Their evolutionary relationships have not yet been investigated with a relevant sampling and are therefore poorly known. Here, we assess the phylogenetic relationships of 35 Corydioidea species with mitochondrial genomes and two nuclear gene fragments. Our sampling for Corydiidae comprises Corydiinae and Euthyrrhaphinae representatives, whereas our sampling for the remaining Corydioidea includes species belonging to genera Beybienkonus Qiu, Wang and Che, Compsodes Hebard, Ctenoneura Hanitsch and Nocticola Bolívar. We further infer their divergence times with molecular dating analyses relying on five fossil calibrations. We also carry out reconstructions of ancestral character states for 11 phenotypic and one biological traits. Our results recover two major Corydioidea clades, one consisting solely of Corydiidae (except Latindiinae) and the other of all remaining Corydioidea taxa. Based on the results of phylogenetic analyses, an updated classification of extant Corydioidea is proposed, where Latindiinae Handlirsch stat.rev. and Ctenoneurinae Qiu and Che, subfam.nov. are assigned to the family Nocticolidae Bolívar sensu nov. A new genus Pseudoeupolyphaga Qiu and Che, gen.nov. is also established within Corydiinae. Both the origin of crown Corydioidea and the divergence of the two major lineages are estimated to have occurred during the Triassic–Jurassic boundary. Ancestral character state reconstruction analyses also suggest an adaptive relationship between phenotypic characteristics and habitat preferences.

Phylogenomics illuminates the phylogeny of flower weevils (Curculioninae) and reveals ten independent origins of brood-site pollination mutualism in true weevils.

Weevils are an unusually species-rich group of phytophagous insects for which there is increasing evidence of frequent involvement in brood-site pollination. This study examines phylogenetic patterns in the emergence of brood-site pollination mutualism among one of the most speciose beetle groups, the flower weevils (subfamily Curculioninae). We analysed a novel phylogenomic dataset consisting of 214 nuclear loci for 202 weevil species, with a sampling that mainly includes flower weevils as well as representatives of all major lineages of true weevils (Curculionidae). Our phylogenomic analyses establish a uniquely comprehensive phylogenetic framework for Curculioninae and provide new insights into the relationships among lineages of true weevils. Based on this phylogeny, statistical reconstruction of ancestral character states revealed at least 10 independent origins of brood-site pollination in higher weevils through transitions from ancestral associations with reproductive structures in the larval stage. Broadly, our results illuminate the unexpected frequency with which true weevils-typically specialized phytophages and hence antagonists of plants-have evolved mutualistic interactions of ecological significance that are key to both weevil and plant evolutionary fitness and thus a component of their deeply intertwined macroevolutionary success.

Phylogeny and morphological evolution of the Neotropical genus Cuspidaria (Bignonieae, Bignoniaceae): Combining high‐throughput sequencing and targeted loci data

AbstractThe combined use of high‐throughput sequencing (HTS) with targeted loci data offers an excellent opportunity to reconstruct robust and comprehensive phylogenies at fine taxonomic scales using a hybrid approach. In this study, we infer the phylogeny of Cuspidaria (Bignonieae, Bignoniaceae), a diverse clade of lianas and shrubs centered in South America's wet and dry forests. We used HTS to obtain complete or nearly complete plastome sequences of seven individuals of Cuspidaria selected to represent the main clades in the genus. This sampling strategy aimed to reconstruct relationships at deeper nodes (i.e., backbone). We also used targeted loci data obtained through Sanger sequencing to obtain sequences of two chloroplast markers (ndhF, rpl32‐trnL) and one nuclear marker (PepC) for multiple individuals of 18 out of the 21 species of Cuspidaria recognized in the most recent treatment of the genus; only C. emmonsii, C. lachnaea, and C. simplicifolia were not sampled. This broad sampling strategy aimed to test the monophyly of individual species and reconstruct fine‐scale interspecific relationships within the genus. Both datasets were analyzed separately and combined using Bayesian inference and maximum likelihood approaches. The combined dataset includes 65 individuals representing 18 previously recognized species of Cuspidaria plus outgroup taxa. The analysis of the combined dataset recovered a monophyletic Cuspidaria, excluding C. bracteata, which was nested within the outgroup and is best treated elsewhere. Ancestral character state reconstructions provided novel insights into the evolution of morphology and identified multiple putative morphological synapomorphies for key lineages of Cuspidaria. Namely, anthers curved forward was reconstructed as a potential synapomorphy for the Cuspidaria clade, whereas interpetiolar gland fields in stems and inflorescence, subulate or inconspicuous prophylls of the axillary buds, biternate leaves, actinodromous venation, calyx cupulate or spathaceous, calyx apices dentate or irregularly lobed, fruits with winged valves, and fruit midrib limited by two longitudinal ridges were reconstructed as potential synapomorphies of different clades within the genus. Other traits such as habit, tertiary venation, inflorescence type, corolla color, number of ovule series, and pollen unit were highly labile. As circumscribed here, Cuspidaria is composed of eight main clades supported by molecular data and morphological synapomorphies: Sideropogon, Tetrastichella, Cinerea, Paracarpaea, Cremastus, Blepharitheca, Saldanhaea, and Cuspidaria s.str. clades. All species are monophyletic, except for C. pulchra and C. sceptrum, which form a species complex and are best treated as a single taxon. The necessary taxonomic changes are proposed, leading to the recognition of 19 species in Cuspidaria.

Phylogenetic relationships of new taxa support repeated pelvic fin loss in mountain catfishes from southern Brazil (Siluriformes: Trichomycteridae)

The presence of paired appendages supported by endoskeleton elements is primarily shared by all gnathostomes, but secondarily lost in different lineages. Absence of pelvic fin and girdle is a condition relatively rare among trichomycterine catfishes, but a recent morphological study suggest that pelvic loss have occurred independently within the genus Cambeva. Herein we perform a molecular phylogenetic analysis encompassing all the five pelvic-less species of Cambeva, including two that are new: Cambeva podostemophila Costa, Feltrin & Katz sp. nov., which is supported by molecular and morphological data as sister to Cambeva poikilos, a species with well-developed pelvic fin and girdle; and Cambeva tourensis Costa, Feltrin & Katz sp. nov., that is sister to Cambeva flavopicta, another pelvic-less species. The ancestral character state reconstruction indicates that pelvic-fin loss occurred four times independently in Cambeva. Field observations indicated that C. podostemophila is closely associated to the podostemacean aquatic herb Podostemum rutifolium, consisting of the first record of trichomycterid–podostemacean association.

Untangling the assassin's web: Phylogeny and classification of the spider‐associated Emesine complex (Hemiptera: Reduviidae)

AbstractWeb‐building spiders are formidable predators, yet assassin bugs in the Emesine Complex (Hemiptera: Reduviidae: Emesinae, Saicinae, and Visayanocorinae) prey on spiders. The Emesine Complex comprises >1000 species and these web‐associated predatory strategies may have driven their diversification. However, lack of natural history data and a robust phylogenetic framework currently preclude tests of this hypothesis. We combine Sanger (207 taxa, 3865 bp) and high‐throughput sequencing data (15 taxa, 381 loci) to generate the first taxon‐ and data‐rich phylogeny for this group. We discover rampant paraphyly among subfamilies and tribes, necessitating revisions to the classification. We use ancestral character state reconstructions for 40 morphological characters to identify diagnostic features for a revised classification. Our new classification treats Saicinae Stål and Visayanocorinae Miller as junior synonyms of Emesinae Amyot and Serville, synonymizes the emesine tribes Ploiariolini Van Duzee and Metapterini Stål with Emesini Amyot and Serville, and recognises six tribes within Emesinae (Collartidini Wygodzinsky, Emesini, Leistarchini Stål, Oncerotrachelini trib.n., Saicini Stål stat.n., and Visayanocorini Miller stat.n.). We show that a pretarsal structure putatively involved in web‐associated behaviours evolved in the last common ancestor of Emesini, the most species‐rich clade within Emesinae, suggesting that web‐associations could be widespread in Emesinae.

Four new Solenogastres (Mollusca, Aplacophora) from the South China Sea and paraphyly of Proneomeniidae Simroth, 1893

Solenogastres and Caudofoveata (Aplacophora) remain some of the least known molluscs, despite ubiquity in the marine environment and importance in understanding molluscan evolution. The use of new morphological techniques and development of DNA barcode libraries have helped make specimen identification easier. However, for solenogasters, using histology for identification and adequate description of species remains necessary in most cases. This, together with the facts that knowledge about solenogaster species distributions is biased and that most species were described from one or very few individuals, explains why many open questions about the actual distribution, intra- and interspecific variability, etc., remain. We performed an integrative taxonomic study of eight specimens of solenogasters from the South China Sea (West Pacific Ocean) thatresulted in the identification of four new species of Proneomeniidae. Species identification and description following the established diagnostic characters were straightforward. However, phylogenetic analysis of molecular data obtained from these specimens and other members of Proneomeniidae indicate that the family is polyphyletic. We recovered representatives of two other families, Epimeniidae (Epimenia) and Strophomeniidae (Anamenia), nested within Proneomeniidae with strong support. Ancestral character state reconstruction indicates that characters commonly used in solenogaster taxonomy, such as the radula and foregut glands, may be more evolutionarily labile in this group than previously known. Therefore our work fills knowledge gaps regarding the diversity and distribution of members of this family but raises important questions about solenogaster taxonomy and systematics that should be further assessed with additional markers and broader taxon sampling. ZooBank: urn:lsid:zoobank.org:pub:BCADACD6-9AD0-442A-AD64-031BA8D88599

Character evolution of modern eupolypods supports the assignment of the fossil fern Cretacifilix fungiformis to Dryopteridaceae

The fossil fern species Cretacifilix fungiformis from mid-Cretaceous Kachin amber from Myanmar was previously assigned to eupolypod ferns for having sporangia with a vertical annulus and sporangial stalks 2–3 cells thick, along with monolete spores with a distinct perine. However, due to the insufficient documentation of character states and the unavailability of the holotype, the proposed affiliation of this fossil to derived families of eupolypods required further study. The recent discovery of additional leaf fragments of C. fungiformis from the same amber deposit enabled us to re-evaluate the relationships of this fossil taxon. Newly documented morphological evidence corroborated its placement within the eupolypod ferns. This was achieved by evaluating identifiable features present in the fossil species through an ancestral character state reconstruction utilizing a comprehensive, time-calibrated phylogeny of eupolypod ferns. Our character state reconstruction of extant eupolypod families and genera recovered morphological similarity of Cretacifilix to the closely related genera Arachniodes and Dryopteris, supporting an assignment of this fossil genus to the species-rich family Dryopteridaceae within the Polypodiineae.

Thermophilic Dehalococcoidia with unusual traits shed light on an unexpected past

Although the phylum Chloroflexota is ubiquitous, its biology and evolution are poorly understood due to limited cultivability. Here, we isolated two motile, thermophilic bacteria from hot spring sediments belonging to the genus Tepidiforma and class Dehalococcoidia within the phylum Chloroflexota. A combination of cryo-electron tomography, exometabolomics, and cultivation experiments using stable isotopes of carbon revealed three unusual traits: flagellar motility, a peptidoglycan-containing cell envelope, and heterotrophic activity on aromatics and plant-associated compounds. Outside of this genus, flagellar motility has not been observed in Chloroflexota, and peptidoglycan-containing cell envelopes have not been described in Dehalococcoidia. Although these traits are unusual among cultivated Chloroflexota and Dehalococcoidia, ancestral character state reconstructions showed flagellar motility and peptidoglycan-containing cell envelopes were ancestral within the Dehalococcoidia, and subsequently lost prior to a major adaptive radiation of Dehalococcoidia into marine environments. However, despite the predominantly vertical evolutionary histories of flagellar motility and peptidoglycan biosynthesis, the evolution of enzymes for degradation of aromatics and plant-associated compounds was predominantly horizontal and complex. Together, the presence of these unusual traits in Dehalococcoidia and their evolutionary histories raise new questions about the timing and selective forces driving their successful niche expansion into global oceans.

Chemical and evolutionary analysis of the scent gland secretions of two species of Gonyleptes Kirby, 1819 (Arachnida: Opiliones: Laniatores)

The subfamily Gonyleptinae is the second largest in Gonyleptidae, harboring over 100 species. Gonyleptinae is polyphyletic, nestled in the clade K92, and despite its richness, several species of that subfamily have not had their chemicals of the defensive secretions analyzed. Among these are Gonyleptes curticornis (Mello-Leitão, 1940) and G. horridus Kirby, 1819, the latter being particularly important, because it is the type species of the genus, which in turn names the subfamily Gonyleptinae. Gonyleptes horridus is also used in many phylogenetic analyses, be it using morphological or molecular data. The chemical study of the secretions of these two species by GC–MS and 1H NMR showed the presence of 1-(6-isopropyl-3,4-dihydro-2H-pyran-2-yl)-methylbutanone, 1-(6-isopropyl-3,4-dihydro-2H-pyran-2-yl) isobutanone and 4-methyl-1-hepten-3-one in both species. On the other hand, 4-methyl-1-hexen-3-one was observed only in G. curticornis, and 7-methyl-2-octanol is exclusive of G. horridus. All vinyl-ketones identified have already been described for Gonyleptidae. We ran an Ancestral Character State Reconstruction (ASR) analysis under three different conditions to infer the evolution of the identified compounds (based on modified characters of a previous study) and their chemical nature (multistate character, either as alkylphenol, benzoquinone or vinyl-ketone) on a modified Gonyleptidae phylogeny. Our results corroborate previous studies that alkylphenol is the ancestral most condition, changing to benzoquinone in the ancestor of Gonyleptidae or even earlier in a grassatorean ancestor depending on the analysis. Vinyl-ketones are a synapomorphy of K92. We briefly discuss character codifications and use of weights of ASR analyses of specific compounds, which were inconclusive. 1-(6-isopropyl-3,4-dihydro-2H-pyran-2-yl) isobutanone is shared by both Gonyleptes species and described for the genus Sodreana Mello-Leitão, 1922. 1-(6-(1-methyl-propyl)3,4-dihydro-2H-pyran-2yl)2-methylbutanone and 4-methyl-1-hepten-3-one are also shared by both Gonyleptes species and described for Moreiranula saprophila. From a taxonomic standpoint, combinations of specific compounds might help to diagnose supraspecific groups but given our limited sample, such decision should be taken with care and further tested. Finally, 7-methyl-2-octanol is described for the first time in Gonyleptidae, emphasizing the chemical diverse nature in the K92 clade.

Evolution of calling songs in the grasshopper subfamily Gomphocerinae (Orthoptera, Acrididae)

AbstractThe evolution of the calling songs in Gomphocerinae was evaluated via estimating a phylogenetic signal of the song characters and an ancestral character state reconstruction. Analyses of the calling songs in 80 palearctic gomphocerine species allowed us to define 24 characters describing the temporal pattern of the sound and the stridulatory leg‐movement pattern. The ancestral song of Gomphocerinae was shown to consist of numerous short echemes lasting on average 0.9 s; each echeme comprised only one syllable produced by movements of only one leg. The next step of the song evolution could be producing longer echemes or longer echeme‐sequence. Later, echeme duration again decreased, but this was accompanied by increasing of echeme or syllable complexity. The characters describing the echeme structure were found to be conservative in their evolution. By contrast, most characters of the syllable temporal structure were shown to be relatively labile and more likely under natural or sexual selection. Our study shows that the song evolution in Gomphocerinae implied not only increasing but also decreasing complexity of the syllable temporal structure.

Exploring morphological evolution in relation to habitat moisture in the moss genusFissidensusing molecular data generated from herbarium specimens

AbstractMorphological evolution in mosses has long been hypothesized to accompany shifts in microhabitats, which can be tested using comparative phylogenetics. These lines of inquiry have been developed to include target capture sequencing, which can yield phylogenomic scale data from herbarium specimens. Here, we test the relationship between taxonomically important morphological characters in the moss genusFissidens, using a 400‐locus data set generated using a target‐capture approach in tandem with a three‐locus phylogeny generated using Sanger sequencing. Phylogenetic trees generated using ASTRAL and Bayesian inference were used to test the monophyly of subgenera/sections. These trees provide the basis for ancestral character state reconstructions and phylogenetic correlation analyses for five morphological characters and characters related to the moisture habitat, scored from the literature and by specimen inspection. Many of these characters exhibit statistically significant phylogenetic signal. Significant correlations were found between the limbidium (phyllid/leaf border of the gametophyte) and habitat moisture niche breadth, which could be interpreted as the more extensive limbidium enabling species to survive across a wider variety of habitats. We also found correlations between costa anatomy, peristome morphology, and the limbidium, which could reflect the evolutionary recruitment of genetic networks from the gametophyte to the sporophyte phase. The correlation found between average habitat moisture and the sexual system indicates that dioicous and polyoicous species are more likely to be found in moist habitats and that these higher moisture levels could be particularly, reproductively advantageous to species with separate sexes.

Defining plant ecological specialists and generalists: Building a framework for identification and classification.

Specialization is a widespread but highly ambiguous and context-dependent ecological concept. This quality makes comparisons across related studies difficult and makes associated terms such as "specialist" and "generalist" scientifically obscure. Here, we present a metric-based framework to quantify specialization in 141 Quercus species using functional traits, biogeography, and species interactions. Rankings of specialization based on five metrics were used to answer questions about how specialization is used colloquially (i.e., individual species assessment by experts) and influenced by phylogenetics (Ancestral Character State Reconstruction, Automatic Shift Detection), biogeography (patterns of clustering by region and with climate), and species threat level (IUCN Red List). Metric-based ranking can be representative of specialization in a consistent and practical manner, correlating with IUCN Red List data, and the mean scores of individual expert assessments. Specialization is shown to be highly correlated with precipitation seasonality and only moderately influenced by evolutionary history. Data-deficient species were more likely to be highly specialized, and higher specialization was positively correlated with greater IUCN threat level. Frameworks for characterizing specialization and generalization can be done using metric ranking and can turn concepts that are often unclear into a definitive system. Metric-based rankings of specialization can also be used to reveal interesting insights about a clade's evolutionary history and geographic distribution when paired with the related phylogenetic and geographic data. Metric-based rankings can be applied to other systems and be a valuable tool for identifying species at risk and in need of conservation.

Trichomes’ Micromorphology and Their Evolution in Selected Species of Causonis (Vitaceae)

The Vitaceae genus Causonis is found in tropical to temperate climates from Asia to Australia, including the Pacific Islands. Rafinesque established the genus in 1930; however, Süssenguth classified it under Cayratia as a sect. Discypharia in 1953. The genus was resurrected in 2013 using morphological and genetic evidence. We herein provided insight into the diversity of trichomes’ micromorphology of selected species of this recently reinstated genus for taxonomical implication. Simple trichomes, representing non-glandular and unbranched trichomes, are only found in Causonis. Trichomes vary from straight, curved, hooked, appressed, pilose, to villous in different parts like branchlets, abaxial leaf surface, and adaxial leaf surface in different species. They also vary in the same plant from the young stage to the mature stage. Most species are pubescent when young, but a few species become nearly glabrous when they are mature. Significant variations can be observed in trichomes’ length between the species. Principal component analysis (PCA), based on the micromorphological traits, was carried out for the species delimitation. In Mesquite, ancestral character state reconstruction was used to examine evolutionary trends for trichomes on three different surfaces. The glabrous to sparsely pubescent state found on the branchlets and both leaf surfaces were found to be the ancestral state and, on the branchlets and both leaf surfaces, the villous hairs state was the derived state in the genus. The identification of Causonis species is greatly aided by trichomes morphology. Therefore, similar studies should be conducted on other Vitaceae genera to reveal the variety of trichomes found in the family.

Evolution and Biogeographic History of Rubyspot Damselflies (Hetaerininae: Calopterygidae: Odonata)

The damselflies Hetaerininae, a subfamily of Calopterygidae, comprise four genera distributed from North to South America: Hetaerina, Mnesarete, Ormenophlebia and Bryoplathanon. While several studies have focused on the intriguing behavioral and morphological modifications within Hetaerina, little of the evolutionary history of the group is well understood. Understanding the biogeographical history of Hetaerininae is further complicated by uncertainty in important geological events, such as the closure of the Central American Seaway (CAS). We generated a phylogenetic hypothesis to test the relationships and divergence times within Hetaerininae using IQtree and BEAST2 and found that Mnesarete and Ormenophlebia render Hetaerina paraphyletic. Reclassification of the genera within Hetaerininae is necessary based on our results. We also tested the fit to our dataset of two different hypotheses for the closure of CAS. Our results supported a gradual closure, starting in the Oligocene and ending in the Pliocene. Using Ancestral Character State Reconstruction, we found that the rubyspot, which is associated with higher fecundity in several species, was ancestral for Hetaerininae and subsequently lost four times. Estimates of diversification in association with the rubyspot are needed to understand the plasticity of this important character. Forest habitat was the ancestral state for Hetaerininae, with transitions to generalist species of Hetaerina found primarily in the Mesoamerican region. These results add to our understanding of the relationship between morphology, biogeography and habitat in a charismatic group of damselflies.