Similar Traits Research Articles

Effects of Rice Root Development and Rhizosphere Soil on Methane Emission in Paddy Fields

Paddy fields are important anthropogenic emission sources of methane (CH4). However, it is not clear how rice root development and rhizosphere soil properties affect CH4 emissions. Therefore, we selected rice varieties with similar growth periods but different root traits in the local area. We measured CH4 emission fluxes, cumulative CH4 emissions, root dry weight, root length, and the dissolved organic carbon (DOC), microbial biomass carbon (MBC), redox potential (Eh), ammonium nitrogen (NH4+–N), and nitrate nitrogen (NO3−–N) contents in rhizosphere soil. Methanogens and methanotrophs are crucial factors influencing CH4 emissions; thus, their abundance and community composition were also assessed. The result showed that CH4 fluxes of each rice variety reached the peak at tillering stage and jointing-booting stage. The CH4 emissions in tillering stage were the largest in each growth period. CH4 emissions had negative correlations with root length, root dry weight, Eh NO3−–N, methanotroph abundance, and the pmoA/mcrA ratio, and positive correlations with NH4+–N, MBC, DOC, and methanogen abundance. Path analysis confirmed methanogens and methanotrophs as direct influences on CH4 emissions. Root development and rhizosphere soil properties affect CH4 emissions indirectly through these microbes. This study suggests that choosing rice varieties with good root systems and managing the rhizosphere soil can effectively reduce CH4 emissions.

Effect of Plant Identity in Wheat Mixtures on English Grain Aphid (Sitobion avenae) Control

ABSTRACTField experiments have demonstrated that wheat mixtures differ in their ability to regulate aphid populations. To further investigate the effectiveness of wheat mixtures (Triticum aestivum and Triticum turgidum) in controlling aphids, we conducted both laboratory and greenhouse experiments. Specifically, we assessed the associational resistance of two wheat mixtures (Florence‐Aurora with Forment, Florence‐Aurora with Montcada), and their respective monocultures, in different stages of the aphid host selection process. We analysed aphid acceptance rate, population growth, and load under different wheat treatments. Additionally, we characterised wheat aboveground biomass and nitrogen content as important functional traits for aphid resistant. Aphid acceptance decreased in plants of cv. Forment when exposed to volatiles from undamaged Florence‐Aurora plants, whereas the other tested combinations tested had no effect. Aphids performed differently in the two mixtures: Florence‐Aurora mixed with Forment significantly reduced aphid population growth and load compared to the monocultures, whereas the combination of Florence‐Aurora with Montcada wheat had no effect on aphid performance. The plant–plant interactions also modified the analysed traits. Nitrogen content of Florence‐Aurora wheat plants was reduced when mixed with Forment wheat, which may explain the lower aphid load observed in plants of cv. Florence‐Aurora when mixed with plants of cv. Forment. However, mixing wheats with similar aboveground biomass resulted in an increase in the average biomass of plants of both cultivars which could have led to a higher aphid population. The data supports the idea of right neighbour, as the benefits of wheat mixtures for aphid control were determined by the identity of the combined plants (or species). Finally, our results suggest that associating wheats with different traits may promote facilitative interactions, which in turn enhances associational resistance, whereas the combination of wheats with similar traits may result in competitive interactions that may hinder aphid control benefits.

Rhythmic qualities of jazz improvisation predict performer identity and style in source-separated audio recordings.

Great musicians have a unique style and, with training, humans can learn to distinguish between these styles. What differences between performers enable us to make such judgements? We investigate this question by building a machine learning model that predicts performer identity from data extracted automatically from an audio recording. Such a model could be trained on all kinds of musical features, but here we focus specifically on rhythm, which (unlike harmony, melody and timbre) is relevant for any musical instrument. We demonstrate that a supervised learning model trained solely on rhythmic features extracted from 300 recordings of 10 jazz pianists correctly identified the performer in 59% of cases, six times better than chance. The most important features related to a performer's 'feel' (ensemble synchronization) and 'complexity' (information density). Further analysis revealed two clusters of performers, with those in the same cluster sharing similar rhythmic traits, and that the rhythmic style of each musician changed relatively little over the duration of their career. Our findings highlight the possibility that artificial intelligence can perform performer identification tasks normally reserved for experts. Links to each recording and the corresponding predictions are available on an interactive map to support future work in stylometry.

Exploring Ganoderma lucidum: morphology, cultivation and market potential.

Ganoderma lucidum, known as the "mushroom of immortality," is a white rot fungus renowned for its medicinal properties, attributed to its bioactive compounds. Although species with similar morphological traits to G. lucidum are found across the globe, precise identification is made possible through DNA barcoding and molecular phylogenetic analysis. Global cultivation and wild harvesting of G. lucidum are both done in response to the growing market needs. Artificial cultivation is typically performed on sawdust, but other woody substrates and the wood log method are also employed. This cultivation leverages the fungus's ecological role in converting industrial and agricultural solid wastes into biomass, thereby producing functional food and potential pharmaceutical sources. The review consolidates research on various aspects of, including cultivation methods (sawdust, agricultural waste, wood logs, and submerged fermentation), and the current global market conditions.

Molecular-based characterization and bioengineering of Sorghum bicolor to enhance iron deficiency tolerance in iron-limiting calcareous soils.

Plant biomass can significantly contribute to alternative energy sources. Sorghum bicolor is a promising plant for producing energy, but is susceptible to iron deficiency, which inhibits its cultivation in iron-limiting calcareous soils. The molecular basis for the susceptibility of sorghum to iron deficiency remains unclear. Here, we explored the sorghum genome to identify genes involved in iron uptake and translocation. Iron deficiency-responsive gene expression was comparable to that in other graminaceous plants. A nicotianamine synthase gene, SbNAS1, was induced in response to iron deficiency, and SbNAS1 showed enzyme activity. Sorghum secreted 2'-deoxymugineic acid and other phytosiderophores under iron deficiency, but their levels were relatively low. Intercropping of sorghum with barley or rice rescued iron deficiency symptoms of sorghum. To produce bioengineered sorghum with enhanced tolerance to iron deficiency, we introduced four cassettes into sorghum: 35S promoter-OsIRO2 for activation of iron acquisition-related gene expression, SbIRT1 promoter-Refre1/372 for enhanced ferric-chelate reductase activity, and barley IDS3, and HvNAS1 genomic fragments for enhanced production of phytosiderophores and nicotianamine. The resultant single sorghum line exhibited enhanced secretion of phytosiderophores, increased ferric-chelate reductase activity, and improved iron uptake and leaf greenness compared with non-transformants under iron-limiting conditions. Similar traits were also conferred to rice by introducing the four cassettes. Moreover, these rice lines showed similar or better tolerance in calcareous soils and increased grain iron accumulation compared with previous rice lines carrying two or three comparable cassettes. These results provide a molecular basis for the bioengineering of sorghum tolerant of low iron availability in calcareous soils.

Large invasive herbaceous plants decrease the taxonomic, functional and phylogenetic diversity of birds via their reproductive traits

Abstract Birds are among the organisms most impacted by plant invasions, the effects of which are particularly conspicuous during the breeding season. Birds can incorrectly assess the suitability of large, invasive hogweeds Heracleum sp. in south‐eastern Poland when selecting nesting sites early in spring when the developing invaders do not yet differ substantially in form from the rest of the vegetation. One would expect lower bird breeding success in areas with invasive hogweeds. Furthermore, this may shift bird community composition towards species with filtered traits, which may then be reflected in various measures of diversity. To assess these expectations, we conducted bird surveys at 74 sites, arranged as 37 pairs (with invasive Heracleum vs. control). The presence of Heracleum was associated with lower bird taxonomic and phylogenetic diversity. Functional richness (calculated based on species' reproductive traits) was also lower at sites with these invaders. The species detected at Heracleum sites were characterised by traits associated with rapid breeding, for example, small clutches, short incubation periods and short fledging periods. We show that the bird community at sites with hogweeds became less diverse and composed of random species sharing similar reproductive traits. Bird communities with low diversity at Heracleum sites tended to exhibit a common trait syndrome. These patterns provide insights into the mechanisms of how invasive plants may lead to the loss of some traits and species in bird communities. Read the free Plain Language Summary for this article on the Journal blog.

Convergent reductive evolution in bee-associated lactic acid bacteria.

Distantly related organisms may evolve similar traits when exposed to similar environments or engaging in certain lifestyles. Several members of the Lactobacillaceae [lactic acid bacteria (LAB)] family are frequently isolated from the floral niche, mostly from bees and flowers. In some floral LAB species (henceforth referred to as bee-associated LAB), distinctive genomic (e.g., genome reduction) and phenotypic (e.g., preference for fructose over glucose or fructophily) features were recently documented. These features are found across distantly related species, raising the hypothesis that specific genomic and phenotypic traits evolved convergently during adaptation to the floral environment. To test this hypothesis, we examined representative genomes of 369 species of bee-associated and non-bee-associated LAB. Phylogenomic analysis unveiled seven independent ecological shifts toward the bee environment in LAB. In these species, we observed significant reductions of genome size, gene repertoire, and GC content. Using machine leaning, we could distinguish bee-associated from non-bee-associated species with 94% accuracy, based on the absence of genes involved in metabolism, osmotic stress, or DNA repair. Moreover, we found that the most important genes for the machine learning classifier were seemingly lost, independently, in multiple bee-associated lineages. One of these genes, acetaldehyde-alcohol dehydrogenase (adhE), encodes a bifunctional aldehyde-alcohol dehydrogenase which has been associated with the evolution of fructophily, a rare phenotypic trait that is pervasive across bee-associated LAB species. These results suggest that the independent evolution of distinctive phenotypes in bee-associated LAB has been largely driven by independent losses of the same sets of genes.IMPORTANCESeveral LAB species are intimately associated with bees and exhibit unique biochemical properties with potential for food applications and honeybee health. Using a machine learning-based approach, our study shows that adaptation of LAB to the bee environment was accompanied by a distinctive genomic trajectory deeply shaped by gene loss. Several of these gene losses occurred independently in distantly related species and are linked to some of their unique biotechnologically relevant traits, such as the preference for fructose over glucose (fructophily). This study underscores the potential of machine learning in identifying fingerprints of adaptation and detecting instances of convergent evolution. Furthermore, it sheds light onto the genomic and phenotypic particularities of bee-associated bacteria, thereby deepening the understanding of their positive impact on honeybee health.

The effects of environmental heterogeneity on the morphological similarity of toothed-leafed red oak species (Acutifoliae; <i>Quercus</i>) in Mexico and Central America

Background: In plants, environmental gradients can promote similar morphophysiological traits in species that inhabit areas with similar climatic conditions. Here, to evaluate possible causes of morphological similarity, we analyzed leaf morphological and functional variation in toothed-leaf oaks and its relationships with environmental and geographic variables. Hypotheses: We expected that species with a greater degree of environmental overlap would exhibit similar leaf morphology, and those with a broader range of environmental tolerance would exhibit greater leaf morphological variation. Studied species: Acutifoliae group (Fagaceae, Quercus) Study sites and dates: Leaf samples were collected from adult trees distributed in diverse forest types between 495 and 2,566 meters above sea level (m asl) in Mexico and Guatemala. Methods: We compared patterns of leaf variation in a total of 2,934 leaves from 640 individuals corresponding to 68 populations of ten oak species using univariate and multivariate analyses. We also characterized the environmental conditions where each of the species occurred using the available geographical records and bioclimatic variables. Results: We found morphological overlap in leaf traits in oak species occurring in similar climatic environments. Additionally, oak species with a greater range of environmental distributions showed greater leaf shape morphological variation. Conclusions: The environment influenced the generation of similar leaf morphologies among oak species despite geographical distance and phylogenetic relationships.

Elevational patterns of bird alpha and beta diversity in Haba Snow Mountain, Southwestern China: Implication for conservation

Understanding environmental patterns of species diversity is essential for nature reserve planning and biodiversity conservation. In this study, we explored the birds’ alpha and beta diversity along the elevational gradients in Haba Snow Mountain Nature Reserve (hereafter, HBSM), a global biodiversity hotspot, and studied which environmental factor is the main driver in explaining alpha and beta diversity patterns. Our results indicated that taxonomic, functional, and phylogenetic alpha diversity consistently exhibited hump-shaped patterns with similar peaks. After controlling for species richness, both functional and phylogenetic alpha diversity increased with elevation, and the peaks at 3400–3700 m. Mean pairwise functional distance remained nearly constant along the elevation band, whereas mean pairwise phylogenetic distance shown hump-shaped pattern, and the predicted MPD peaked at the fifth band (3100–3400 m a.s.l). The functional and phylogenetic structure of bird communities in HBSM were more clustered along the elevation gradients, suggesting environmental filtering likely drove the assembly processes. Additionally, primary productivity (NDVI and/or habitat heterogeneity) and/or precipitation were robust predictors of variation in most diversity metrics. For multiple-site beta diversity, we observed that high turnover component in taxonomic, functional, and phylogenetic dimensions, indicating distinct bird assemblages across various elevational bands. In pairwise beta diversity, the spatial turnover of taxonomic and phylogenetic aspects was higher than nestedness, revealing species replacement occurs relatively frequently between evolutionarily related species with similar niche and functional traits. Overall, our findings highlight the importance of considering both different dimensions and multifaceted diversity when assessing elevational patterns of bird diversity. This study also provides valuable insights into the structuring mechanisms of bird communities and informs conservation planning along elevational gradients in HBSM, and offers a comprehensive case on species richness along elevational gradients.

Assessing shell morphology in freshwater mussels (Mollusca: Bivalvia: Unionidae) from the Maâden River, Tunisia: Insights from geometric morphometrics and shape descriptors

Identifying freshwater mussel species within the Unionidae family can be challenging due to systematic confusion. This study investigates shell shapes to identify four sympatric species of freshwater mussels (Potamida littoralis, Unio durieui, U. gibbus, and U. ravoisieri) in the Maâden river (northern Tunisia) using two morphological approaches: global shape descriptors and geometric morphometrics of shell contours. The results revealed significant differences in global shape descriptors among the species. More in-depth analyses showed distinct shape variations, with P. littoralis and U. gibbus significantly differing from U. durieui and U. ravoisieri across most descriptors. Notably, U. durieui and U. ravoisieri exhibited similar shape traits, differing primarily in roundness, characterized by low circularity and high ellipticity. Principal Component Analyses depicted substantial morphological variance, with Procrustes data requiring the first two components to fully elucidate dispersion. Linear Discriminant Analysis revealed effective discrimination among species, with an accuracy rate of over 74 % in classifying individuals into their respective populations across both approaches. Geospatial analyses indicated varying influences of latitude, longitude, and altitude on shell morphology among species. Latitude had noteworthy impacts on P. littoralis, approaching significance for shape descriptors and Procrustes data. Conversely, U. durieui and U. gibbus displayed minimal geographic influence on shell morphology, while U. ravoisieri showed significant variations across these parameters. This study highlights the distinct morphological differences among sympatric mussel species in northern Tunisia, providing valuable insights for conservation efforts, especially for species vulnerable to climate change.

Effective prevention of early resignation of newly graduated nurses: a transactional analysis

BackgroundNew employees often exhibit stress reactions to changes in their environment and some of these may result in resignations. Employees in medical institutions are no exceptions. Considering the shortage of nurses in Japan, countermeasures are needed against the resignation of newly graduated nurses. Many studies have indicated that multifaced factors affect the resignation of newly graduated nurses. Even though individual characteristics are important factors in this regard, training and support for newly graduated nurses do not focus on the nurses’ characteristics. The purpose of this study is to examine the characteristics influencing the early resignation of newly graduated nurses and suggest ways to support them and prevent their early resignation based on their characteristics.MethodsWith the approval of the Ethics Committee, various characteristics of 353 newly graduated nurses (personality, interpersonal relationships, trait anxiety, nurse orientation, desire to be a nurse, and self-proclaimed academic ability) were assessed using a transactional analysis, the State-Trait Anxiety Inventory, and self-reporting numerical rating scales. The characteristics of those who resigned within 1 year (case group) and those who did not (control group) were compared using chi-square test and logistic regression analysis.ResultsOur sample of 353 participants included 32 nurses from the case group and 304 nurses from the control group. Most participants showed similar personality traits. However, the control group had a significantly lower percentage with negative self, strong trait anxiety, negative self and strong trait anxiety, and low orientation compared to the case group. Our logistic regression analysis showed that strong trait anxiety and low nurse orientation are significantly related with the early resignation of nurses.ConclusionsThe early resignation of newly graduated nurses may be prevented by understanding their characteristics at the time of gaining employment and implementing early intervention programs, such as education programs to reduce anxiety, and helping those with strong trait anxiety and low nurse orientation to find meaning in work.

Adaptation to space conditions of novel bacterial species isolated from the International Space Station revealed by functional gene annotations and comparative genome analysis

BackgroundThe extreme environment of the International Space Station (ISS) puts selective pressure on microorganisms unintentionally introduced during its 20+ years of service as a low-orbit science platform and human habitat. Such pressure leads to the development of new features not found in the Earth-bound relatives, which enable them to adapt to unfavorable conditions.ResultsIn this study, we generated the functional annotation of the genomes of five newly identified species of Gram-positive bacteria, four of which are non-spore-forming and one spore-forming, all isolated from the ISS. Using a deep-learning based tool—deepFRI—we were able to functionally annotate close to 100% of protein-coding genes in all studied species, overcoming other annotation tools. Our comparative genomic analysis highlights common characteristics across all five species and specific genetic traits that appear unique to these ISS microorganisms. Proteome analysis mirrored these genomic patterns, revealing similar traits. The collective annotations suggest adaptations to life in space, including the management of hypoosmotic stress related to microgravity via mechanosensitive channel proteins, increased DNA repair activity to counteract heightened radiation exposure, and the presence of mobile genetic elements enhancing metabolism. In addition, our findings suggest the evolution of certain genetic traits indicative of potential pathogenic capabilities, such as small molecule and peptide synthesis and ATP-dependent transporters. These traits, exclusive to the ISS microorganisms, further substantiate previous reports explaining why microbes exposed to space conditions demonstrate enhanced antibiotic resistance and pathogenicity.ConclusionOur findings indicate that the microorganisms isolated from ISS we studied have adapted to life in space. Evidence such as mechanosensitive channel proteins, increased DNA repair activity, as well as metallopeptidases and novel S-layer oxidoreductases suggest a convergent adaptation among these diverse microorganisms, potentially complementing one another within the context of the microbiome. The common genes that facilitate adaptation to the ISS environment may enable bioproduction of essential biomolecules need during future space missions, or serve as potential drug targets, if these microorganisms pose health risks.17AcJHQ5oWAqHhb9n7GQHSVideo

Incorporating functional traits with habitat maps: patterns of diversity in coastal benthic assemblages

Benthic species assemblages are groups of species that co-occur on the seafloor. Linking assemblages to physical environmental features allows for understanding and predicting their spatial distribution. Species identity and abundance are commonly quantified using a taxonomic approach to assess benthic diversity, yet functional traits that describe the behavior, life history, and morphology of a species may be equally or more important. Here, we investigate the biodiversity of five benthic species assemblages in relation to their habitat and environmental conditions in an Ecologically and Biologically Significant Area (EBSA) along Canada’s east coast, using both a taxonomic approach and biological traits analysis. Random Forest regression was applied to map spatial patterns of functional and taxonomic diversity metrics, including richness, Shannon index, and Rao’s quadratic entropy. We evaluate discrepancies between related taxonomic and trait measures, and the community-weighted mean of trait data was calculated to characterize each assemblage. Taxonomic and functional richness – representing the number of species and the species community volume in the trait space, respectively – showed similar spatial patterns. However, when considering diversity, which also accounts for the relative abundance and differences among species or traits, these patterns diverged. Taxonomically different assemblages exhibited similar trait compositions for two assemblages, indicating potential trait equivalencies, while one assemblage exhibited traits potentially indicating sensitivity to human activity. The taxonomic and functional metrics of richness and diversity were low close to the coast, which could be indicative of disturbance. Consideration of functional metrics can support spatial planning and prioritization for management and conservation efforts by assessing the sensitivity of traits to different stressors.

The importance of belonging: Interactions between individual and structural risk factors for youth‐disengagement

AbstractAre disengagement risks lower when youths are surrounded by others with similar risk traits? Applying theoretical perspectives of belonging and residential context, this study examines interactional effects between individual and structural risk factors for youth‐disengagement. From registry data of 590,085 Norwegians aged 16–24, the study finds less disengagement among youths in municipalities where an above‐average rate of individuals shared individual risk‐traits of immigrant background, young parenthood, and not completing high school. Youths with parents on social welfare had an increased risk of disengagement in municipalities with above average rates of people on social welfare. Sex‐stratified analysis reveals that men and women benefit from belonging to different risk‐groups. In challenging the prevailing segmented approach to individual and structural risk factors for youth‐disengagement, the findings demonstrate the need for continued examination of gender, belonging and residential context as theoretical perspectives.

Estimating the Effective Size of European Wolf Populations.

Molecular methods are routinely used to estimate the effective size of populations (N e). However, underlying model assumptions are frequently violated to an unknown extent. Although simulations can detect sources of bias and help to adjust sampling strategies and analyses methods, additional information from empirical data can also be used to calibrate methods and improve molecular N e estimation methods. Here, we take advantage of long-term genetic and ecological monitoring data of the grey wolf (Canis lupus) in Germany, and detailed population genetic studies in Poland, Spain and Portugal to improve N e estimation strategies in this species, and species with similar life history traits. We first calculated N e from average lifetime reproductive success and detailed census data from the German population, which served as a baseline to compare to molecular estimates based on linkage disequilibrium and sibship frequency. This yielded a robust N e/N c estimation that we used to calibrate molecular estimates of German, Polish and Iberian wolf populations. The linkage disequilibrium method was strongly influenced by spatial genetic structure, much more than the sibship frequency method. When N e was estimated in local neighbourhoods, both methods yielded comparable results. Estimates of the metapopulation effective size seemed to correspond generally well with the sum of the estimates of local neighbourhoods. Overall, we found that the number of packs is a good proxy of the effective population size. Using this as a rule of thumb, we evaluated for all European wolf populations the N e 500 indicator and concluded that half of the European wolf populations do not yet fulfil this criterion.

Evaluation of the Spike Diversity of Seven Hexaploid Wheat Species and an Artificial Amphidiploid Using a Quadrangle Model Obtained from 2D Images

The spike shape and morphometric characteristics are among the key characteristics of cultivated cereals, being associated with their productivity. These traits are often used for the plant taxonomy and authenticity of hexaploid wheat species. Manual measurement of spike characteristics is tedious and not precise. Recently, the authors of this study developed a method for wheat spike morphometry utilizing 2D image analysis. Here, this method is applied to study variations in spike size and shape for 190 plants of seven hexaploid (2n = 6x = 42) species and one artificial amphidiploid of wheat. Five manually estimated spike traits and 26 traits obtained from digital image analysis were analyzed. Image-based traits describe the characteristics of the base, center and apex of the spike and common parameters (circularity, roundness, perimeter, etc.). Estimates of similar traits by manual measurement and image analysis were shown to be highly correlated, suggesting the practical importance of digital spike phenotyping. The utility of spike traits for classification into types (spelt, normal and compact) and species or amphidiploid is shown. It is also demonstrated that the estimates obtained made it possible to identify the spike characteristics differing significantly between species or between accessions within the same species. The present work suggests the usefulness of wheat spike shape analysis using an approach based on characteristics obtained by digital image analysis.

Non-darwinian theories of biological evolution

The article presents material related to evolutionary theories such as Berg’s nomogenesis, Kimura’s theory of neutral evolution, and neo-Lamarckism, the content of which is opposed to Darwin’s doctrine of natural selection as a leading factor in biological evolution. Nomogenesis, a hypothesis according to which the evolution of organisms is based on internal laws. The general thesis of Berg’s worldview was that evolution occurs naturally, in accordance with a pre-existing – pre-established – law of development. The neutral theory of molecular evolution was put forward by Motoo Kimura. It argues that the vast majority of mutations at the molecular level are neutral in nature with respect to the action of natural selection. Thus, the theory of neutral evolution contradicted Darwinism, pointing to the fixation of neutral mutations in the population without the participation of natural selection. Neo-Lamarckism is a combination of three heterogeneous trends in evolutionary doctrine. Despite the fact that neo-Lamarckists have deviated from the basic postulates of Lamarck, most of their concepts contain two provisions that correspond to Lamarck's laws. The first is the recognition of adequate variability that occurs under the direct or indirect influence of the environment and creates well-acquired adaptive traits. The second is the inheritance of similar traits in individual life.

Assortativity in sympatric speciation and species classification

We investigate the role of assortative mating in speciation using the sympatric model of Derrida and Higgs. The model explores the idea that genetic differences create incompatibilities between individuals, preventing mating if the number of such differences is too large. Speciation, however, only happens in this mating system if the number of genes is large. Here we show that speciation with small genome sizes can occur if assortative mating is introduced. In our model individuals are represented by three chromosomes: one responsible for reproductive compatibility, one for coding the trait on which assortativity will operate, and a neutral chromosome. Reproduction is possible if individuals are genetically similar with respect to the first chromosome, but among these compatible mating partners, the one with the most similar trait coded by the second chromosome is selected. We show that this type of assortativity facilitates speciation, which can happen with a small number of genes in the first chromosome. Species, classified according to reproductive isolation, dictated by the first chromosome, can display different traits values, as measured by the second and the third chromosomes. Therefore, species can also be identified based on similarity of the neutral trait, which works as a proxy for reproductive isolation.

Quantitative eco-anatomical analysis reveals distinctive stem traits of six Cannabis sativa cultivars in Rif Mountains (Northern Morocco)

Cannabis sativa stands out as an important crop with significant socioeconomic importance in the Rif Mountains of North Morocco. Recently the number of new cultivars developed in this region has gradually increased for different purposes. In this current study, we delve into the eco-anatomical characteristics of stems across six of the most prevalent Cannabis sativa cultivars in Morocco: ‘Avocat’, ‘Beldiya’, ‘Critical Plus’, ‘Industriel’, ‘Khardala’, and ‘Mexicana’. The investigation encompasses the measurement and analysis of six key eco-anatomical traits: plant height, stem diameter, vessel size, vessel density, number of vessels joined in radial files, and coefficient of hydraulic conductivity. Our aim is to elucidate the variations among these cultivars and underscore their agricultural and ecological relevance. Through anatomical examinations of stem cross-sections, our findings reveal notable disparities and distinctive features among the cultivars. The ‘Khardala’ cultivar exhibits the highest values across most measured eco-anatomical traits, while ‘Beldiya’ and ‘Mexicana’ show similar trait values, particularly with low stem diameter and vessel density. In contrast, ‘Industriel’ stands out with the lowest vessel size and highest vessel density. ‘Critical Plus’ and ‘Avocat’ closely resemble ‘Khardala’ in vessel size and stem diameter. Regarding hydraulic conductivity, ‘Khardala’ ranks highest, followed by ‘Avocat’ and ‘Critical Plus’, while ‘Industriel’ registers the lowest. Our findings underscore increased water demand and uptake potential in ‘Khardala’, ‘Critical Plus’, and ‘Avocat’, contrasting with ‘Industriel’, ‘Beldiya’, and ‘Mexicana’. Anatomical diversity among Cannabis cultivars in our study likely stems from genetic lineage and ecological adaptation.

Co‐occurrence in snake and lizard sister species is unrelated to major ecomorphological traits

AbstractEnvironmental factors and interspecific interactions, such as competition and facilitation, can shape species' geographic ranges. Here, we tested the relationship between geographic range overlap of squamate sister species, and their divergence in body size, diel activity, and microhabitat use. Competition theory predicts that sister species with similar traits will overlap less geographically than sister pairs with dissimilar traits. However, similar distributions may present similar selective pressures and favour similar adaptations, such that habitat filtering may result in species with more similar traits in sympatry. Across 1434 sister species contrasts, we found little relationship between range overlap and niche divergence. In some models, the divergence in body size and microhabitat use marginally increased with sympatry, while in other models, sympatric sisters had similar activity times. However, the low R‐squared values of almost all these models lend only weak support to predictions from competition or habitat filtering theories. Sympatric sister species within the same biome showed more similar activity times than expected, lending some support to habitat filtering. Niche divergence in allopatry or sympatry, as calculated using a multi‐trait dissimilarity index, did not show a phylogenetic signal, and niches of sister species from different squamate clades did not deviate significantly from the null expectation. Overall, niche divergence or convergence, across the axes we explored, is not a prerequisite for regional species co‐occurrence. We suggest here that the lack of consistent support for either limiting similarity or habitat filtering may reflect that both these forces act as transient phenomena. More fine‐grained analyses, in space and time, would be needed to detect their fingerprints. Thus, coexistence in the face of competition can arise due to various evolutionary and biogeographic mechanisms, acting concurrently or asynchronously.