RESUMO
The extraordinary diversification of beetles on Earth is a textbook example of adaptive evolution. Yet, the tempo and drivers of this super-radiation remain largely unclear. Here, we address this problem by investigating macroevolutionary dynamics in darkling beetles (Coleoptera: Tenebrionidae), one of the most ecomorphologically diverse beetle families (with over 30,000 species). Using multiple genomic datasets and analytical approaches, we resolve the long-standing inconsistency over deep relationships in the family. In conjunction with a landmark-based dataset of body shape morphology, we show that the evolutionary history of darkling beetles is marked by ancient rapid radiations, frequent ecological transitions, and rapid bursts of morphological diversification. On a global scale, our analyses uncovered a significant pulse of phenotypic diversification proximal to the Cretaceous-Palaeogene (K/Pg) mass extinction and convergence of body shape associated with recurrent ecological specializations. On a regional scale, two major Australasian radiations, the Adeliini and the Heleine clade, exhibited contrasting patterns of ecomorphological diversification, representing phylogenetic niche conservatism versus adaptive radiation. Our findings align with the Simpsonian model of adaptive evolution across the macroevolutionary landscape and highlight a significant role of ecological opportunity in driving the immense ecomorphological diversity in a hyperdiverse beetle group.
Assuntos
Evolução Biológica , Besouros , Filogenia , Animais , Besouros/genética , Besouros/anatomia & histologia , Besouros/fisiologia , Adaptação BiológicaRESUMO
We describe three new genera of cynipid oak gall wasps from the Nearctic: Burnettweldia Pujade-Villar, Melika Nicholls, gen. nov., Nichollsiella Melika, Pujade-Villar Stone, gen. nov., and Disholandricus Melika, Pujade-Villar Nicholls, gen. nov. (Hymenoptera: Cynipidae: Cynipini). Burnettweldia includes five species, B. californicordazi Cuesta-Porta, Melika Pujade-Villar, sp. nov., B. conalis (Weld), comb. nov., B. corallina (Bassett), comb. nov., B. plumbella (Kinsey), comb. nov., B. washingtonensis (Gillette), comb. nov.. Nichollsiella includes three species, N. arizonica (Cockerell), comb. nov., N. sulcata (Ashmead), comb. nov., and N. puigi Melika, Cuesta-Porta Pujade-Villar, sp. nov.. Disholandricus includes four species, D. chrysolepidis (Ashmead), comb. nov., D. lasius (Ashmead), comb. nov., D. reniformis (McCracken Egbert), comb. nov., D. truckeensis (Ashmead), comb. nov. The genus Paracraspis Weld, comb. rev. is re-established with three species, P. guadaloupensis (Fullaway), P. insolens (Weld), and P. patelloides (Trotter). Descriptions, re-descriptions, diagnoses, keys to genera and species are given, including data on DNA sequences, biology, phenology and distribution.
Assuntos
Tumores de Planta/parasitologia , Quercus , Vespas/classificação , Distribuição Animal , AnimaisRESUMO
PREMISE: Targeted enrichment methods facilitate sequencing of hundreds of nuclear loci to enhance phylogenetic resolution and elucidate why some parts of the "tree of life" are difficult (if not impossible) to resolve. The mimosoid legumes are a prominent pantropical clade of ~3300 species of woody angiosperms for which previous phylogenies have shown extensive lack of resolution, especially among the species-rich and taxonomically challenging ingoids. METHODS: We generated transcriptomes to select low-copy nuclear genes, enrich these via hybrid capture for representative species of most mimosoid genera, and analyze the resulting data using de novo assembly and various phylogenomic tools for species tree inference. We also evaluate gene tree support and conflict for key internodes and use phylogenetic network analysis to investigate phylogenetic signal across the ingoids. RESULTS: Our selection of 964 nuclear genes greatly improves phylogenetic resolution across the mimosoid phylogeny and shows that the ingoid clade can be resolved into several well-supported clades. However, nearly all loci show lack of phylogenetic signal for some of the deeper internodes within the ingoids. CONCLUSIONS: Lack of resolution in the ingoid clade is most likely the result of hyperfast diversification, potentially causing a hard polytomy of six or seven lineages. The gene set for targeted sequencing presented here offers great potential to further enhance the phylogeny of mimosoids and the wider Caesalpinioideae with denser taxon sampling, to provide a framework for taxonomic reclassification, and to study the ingoid radiation.
Assuntos
Fabaceae , Radiação , Evolução Biológica , Núcleo Celular/genética , Fabaceae/genética , FilogeniaRESUMO
Coevolutionary theory has long predicted that the arms race between plants and herbivores is a major driver of host selection and diversification. At a local scale, plant defenses contribute significantly to the structure of herbivore assemblages and the high alpha diversity of plants in tropical rain forests. However, the general importance of plant defenses in host associations and divergence at regional scales remains unclear. Here, we examine the role of plant defensive traits and phylogeny in the evolution of host range and species divergence in leaf-feeding sawflies of the family Argidae associated with Neotropical trees in the genus Inga throughout the Amazon, the Guiana Shield and Panama. Our analyses show that the phylogenies of both the sawfly herbivores and their Inga hosts are congruent, and that sawflies radiated at approximately the same time, or more recently than their Inga hosts. Analyses controlling for phylogenetic effects show that the evolution of host use in the sawflies associated with Inga is better correlated with Inga chemistry than with Inga phylogeny, suggesting a pattern of delayed host tracking closely tied to host chemistry. Finally, phylogenetic analyses show that sister species of Inga-sawflies are dispersed across the Neotropics, suggesting a role for allopatric divergence and vicariance in Inga diversification. These results are consistent with the idea that host defensive traits play a key role not only in structuring the herbivore assemblages at a single site, but also in the processes shaping host association and species divergence at a regional scale.
RESUMO
Communities of insect herbivores and their natural enemies are rich and ecologically crucial components of terrestrial biodiversity. Understanding the processes that promote their origin and maintenance is thus of considerable interest. One major proposed mechanism is ecological speciation through host-associated differentiation (HAD), the divergence of a polyphagous species first into ecological host races and eventually into more specialized daughter species. The rich chalcid parasitoid communities attacking cynipid oak gall wasp hosts are structured by multiple host traits, including food plant taxon, host gall phenology, and gall structure. Here, we ask whether the same traits structure genetic diversity within supposedly generalist parasitoid morphospecies. We use mitochondrial DNA sequences and microsatellite genotypes to quantify HAD for Megastigmus (Bootanomyia) dorsalis, a complex of two apparently generalist cryptic parasitoid species attacking oak galls. Ancient Balkan refugial populations showed phenological separation between the cryptic species, one primarily attacking spring galls, and the other mainly attacking autumn galls. The spring species also contained host races specializing on galls developing on different host-plant lineages (sections Cerris vs. Quercus) within the oak genus Quercus. These results indicate more significant host-associated structuring within oak gall parasitoid communities than previously thought and support ecological theory predicting the evolution of specialist lineages within generalist parasitoids. In contrast, UK populations of the autumn cryptic species associated with both native and recently invading oak gall wasps showed no evidence of population differentiation, implying rapid recruitment of native parasitoid populations onto invading hosts, and hence potential for natural biological control. This is of significance given recent rapid range expansion of the economically damaging chestnut gall wasp, Dryocosmus kuriphilus, in Europe.
RESUMO
AIMS: To identify a typology of heavier drinking styles in Great Britain and to identify socio-demographic trends in the typology over the period 1978-2010. METHODS: We applied multiple correspondence analysis and agglomerative hierarchical clustering to beverage-specific quantity-frequency measures of alcohol consumption in the repeated cross-sectional General Lifestyle Survey of Great Britain, 1978-2010. The cluster analysis focuses on the 60,043 adult respondents over this period reporting average drinking levels above the UK Government guidelines. We projected sex, age, income, education, socio-economic status and tobacco consumption variables onto the clusters to inspect socio-demographic trends in heavier drinking. RESULTS: We identified four stable clusters of heavier drinking: (a) high volume beer; (b) beer and spirit combination; (c) all beverage and (d) wine and spirit only. The socio-demographic characteristics of the clusters were distinct from both each other and the general population. However, all clusters had higher median incomes and higher smoking rates than the population. Increases in the prevalence of heavier drinking were driven by a 5-fold increase in the contribution of the female-dominated, wine and spirit only cluster. CONCLUSIONS: Recent changes in per capita alcohol consumption in Great Britain occurred within the context of a stable typology of heavier drinking styles and shifting socio-demographics. Identifying these trends is essential to better understand how drinking cultures develop over time and where potentially problematic drinking styles may emerge. Our findings suggest that careful attention to patterns and cultures of consumption is more important than relying on headline consumption data, for both understanding drinking behaviours and targeting interventions. SHORT SUMMARY: This analysis of alcohol consumption survey data identifies four styles of heavier drinking in Great Britain, which remain unchanged over the period 1978-2010. The socio-demographic characteristics of the drinking styles are distinct from both each other and the general population, with increased participation of female and older drinkers over time.
Assuntos
Alcoolismo/epidemiologia , Adulto , Fatores Etários , Consumo de Bebidas Alcoólicas/epidemiologia , Bebidas Alcoólicas/estatística & dados numéricos , Análise por Conglomerados , Estudos Transversais , Feminino , Humanos , Renda , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Fumar/epidemiologia , Classe Social , Fatores Socioeconômicos , Inquéritos e Questionários , Reino Unido/epidemiologiaRESUMO
BACKGROUND: Internationally, studies show that similar levels of alcohol consumption in deprived communities (vs. more affluent) result in higher levels of alcohol-related ill health. Hypotheses to explain this alcohol harm paradox include deprived drinkers: suffering greater combined health challenges (e.g. smoking, obesity) which exacerbate effects of alcohol harms; exhibiting more harmful consumption patterns (e.g. bingeing); having a history of more harmful consumption; and disproportionately under-reporting consumption. We use a bespoke national survey to assess each of these hypotheses. METHODS: A national telephone survey designed to test this alcohol harm paradox was undertaken (May 2013 to April 2014) with English adults (n = 6015). Deprivation was assigned by area of residence. Questions examined factors including: current and historic drinking patterns; combined health challenges (smoking, diet, exercise and body mass); and under-reported consumption (enhanced questioning on atypical/special occasion drinking). For each factor, analyses examined differences between deprived and more affluent individuals controlled for total alcohol consumption. RESULTS: Independent of total consumption, deprived drinkers were more likely to smoke, be overweight and report poor diet and exercise. Consequently, deprived increased risk drinkers (male >168-400 g, female >112-280 g alcohol/week) were >10 times more likely than non-deprived counterparts to drink in a behavioural syndrome combining smoking, excess weight and poor diet/exercise. Differences by deprivation were significant but less marked in higher risk drinkers (male >400 g, female >280 g alcohol/week). Current binge drinking was associated with deprivation independently of total consumption and a history of bingeing was also associated with deprivation in lower and increased risk drinkers. CONCLUSIONS: Deprived increased/higher drinkers are more likely than affluent counterparts to consume alcohol as part of a suite of health challenging behaviours including smoking, excess weight and poor diet/exercise. Together these can have multiplicative effects on risks of wholly (e.g. alcoholic liver disease) and partly (e.g. cancers) alcohol-related conditions. More binge drinking in deprived individuals will also increase risks of injury and heart disease despite total alcohol consumption not differing from affluent counterparts. Public health messages on how smoking, poor diet/exercise and bingeing escalate health risks associated with alcohol are needed, especially in deprived communities, as their absence will contribute to health inequalities.
Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Transtornos Relacionados ao Uso de Álcool/complicações , Comportamentos Relacionados com a Saúde , Saúde , Estilo de Vida , Classe Social , Adolescente , Adulto , Idoso , Intoxicação Alcoólica/complicações , Alcoolismo/complicações , Consumo Excessivo de Bebidas Alcoólicas/complicações , Estudos Transversais , Feminino , Humanos , Hepatopatias Alcoólicas/etiologia , Masculino , Pessoa de Meia-Idade , Características de Residência , Fatores de Risco , Fumar , Inquéritos e Questionários , Adulto JovemRESUMO
A new genus of cynipid oak gallwasp-Cyclocynips Melika, Tang, & Sinclair (Hymenoptera: Cynipidae: Cynipini), with two new species--C. uberis and C. tumorvirgae--reared from galls on oaks of the Quercus subgenus Cyclobalanopsis is described from Taiwan. Descriptions of asexual generation adults and their diagnostic characters are presented. The likelihood of yet undiscovered sexual generations and the evolution of host-plant associations in these species are discussed.
Assuntos
Himenópteros/classificação , Doenças das Plantas/parasitologia , Quercus/parasitologia , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Feminino , Especificidade de Hospedeiro , Himenópteros/anatomia & histologia , Himenópteros/genética , Himenópteros/fisiologia , Tamanho do Órgão , TaiwanRESUMO
Several lines of evidence point to a role for noncoding RNA in transcriptional repression by Polycomb group (PcG) proteins, but the precise mechanism remains unclear. Here we show that human MOV10, a putative RNA helicase previously implicated in post-transcriptional gene silencing, co-purifies and interacts with components of Polycomb-repressive complex 1 (PRC1) from human cells. Endogenous human MOV10 is mostly nuclear, and a proportion associates with chromatin in an RNA-dependent manner. Small hairpin RNA (shRNA)-mediated knockdown of MOV10 in human fibroblasts leads to the upregulation of the INK4a tumor suppressor, a known target of PcG-mediated repression, accompanied by the dissociation of PRC1 proteins from the locus and a reduction in trimethylation of histone H3 on Lys27 (H3K27me3). As well as prompting reassessment of MOV10's role in other settings, our findings suggest that it is directly involved in transcriptional silencing by PcG complexes.
Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/genética , Inativação Gênica , RNA Helicases/metabolismo , Proteínas Repressoras/metabolismo , Linhagem Celular , Células Cultivadas , Cromatina/metabolismo , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Fibroblastos/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Complexo Repressor Polycomb 1 , Proteínas do Grupo Polycomb , RNA Helicases/genéticaRESUMO
Misexpression of Polycomb repressive complex 1 (PRC1) components in human cells profoundly influences the onset of cellular senescence by modulating transcription of the INK4a tumor suppressor gene. Using tandem affinity purification, we find that CBX7 and CBX8, two Polycomb (Pc) homologs that repress INK4a, both participate in PRC1-like complexes with at least two Posterior sex combs (Psc) proteins, MEL18 and BMI1. Each complex contains a single representative of the Pc and Psc families. In primary human fibroblasts, CBX7, CBX8, MEL18 and BMI1 are present at the INK4a locus and shRNA-mediated knockdown of any one of these components results in de-repression of INK4a and proliferative arrest. Sequential chromatin immunoprecipitation (ChIP) reveals that CBX7 and CBX8 bind simultaneously to the same region of chromatin and knockdown of one of the Pc or Psc proteins results in release of the other, suggesting that the binding of PRC1 complexes is interdependent. Our findings provide the first evidence that a single gene can be regulated by several distinct PRC1 complexes and raise important questions about their configuration and relative functions.