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Summary Mate limitation in small populations can reduce reproductive fitness, hinder population growth, and increase extinction risk. Mate limitation is exacerbated in self‐incompatible (SI) taxa, where shared S‐alleles further restrict mating. Theory suggests genetic drift as a predictor of mate limitation and the breakdown of SI systems. We tested this prediction by evaluating mate availability and S‐allele number in populations of a tetraploid herb with gametophytic SI (GSI) spanning a range of effective population sizes. We performed controlled crosses in 13 populations of Argentina anserina to quantify mate availability and S‐allele diversity, which were compared with simulations of tetraploid populations with GSI. We further evaluated mechanisms at the pollen–pistil interface contributing to outcross failure and leakiness in self‐recognition. Mate availability declined in small populations, and closely fit tetraploid GSI population genetic models where maternal plants receive pollen with diverse S‐alleles generated through tetrasomic inheritance. The failure to arrest self‐pollen in the style was common in some populations. Specifically, leaky SI was more common in small populations with low mate availability, where it explained higher seed production in natural populations. The restriction of leaky self‐recognition to the smallest populations is consistent with mate limitation as a pressure driving the breakdown of self‐incompatibility. [ABSTRACT FROM AUTHOR]

Sexual compatibility in the Basidiomycota is governed by genetic identity at one or two loci, resulting in compatibility systems called bipolar and tetrapolar. The loci are known as HD and P/R, encoding homeodomain transcription factors and pheromone precursors and receptors, respectively. Bipolarity is known to evolve either by linkage of the two loci or by loss of mating-type determination of either the HD or the P/R locus. The ancestor to basidiomycete fungi is thought to have been tetrapolar, and many transitions to bipolarity have been described in different lineages. In the diverse genus Marasmius (Agaricales), both compatibility systems are found, and the system has been shown to follow the infrageneric sections of the genus, suggesting a single origin of bipolarity. Here, we tested this hypothesis using a comprehensive phylogenetic framework and investigated the mode by which bipolarity has evolved in this group. We utilized available genomic data and marker sequences to investigate evolution of sexual compatibility in Marasmius and allied genera. By generating a concatenated multilocus phylogeny, we found support for a single transition to known bipolarity within Marasmius. Furthermore, utilizing genomic data of the bipolar species Marasmius oreades, we found that the HD and P/R loci likely have remained unlinked through this transition. By comparing nucleotide diversity at the HD and P/R loci in Ma. oreades, we show that the HD locus has retained high diversity, and thus likely the function of determining sexual identity, as similarly in other bipolar mushroom-forming fungi. Finally, we describe the genomic architecture of the MAT loci of species of both sexual compatibility systems in Marasmiaceae and related families. [ABSTRACT FROM AUTHOR]

The mating system of non-native plant populations plays a role in determining the colonizing success following introduction into locations outside of the native distribution. For plant species capable of mixed-mating, both selfing and outcrossing can be advantageous and promote the establishment, persistence, and spread of newly arrived populations. To investigate how mating systems may contribute to the invasion process we estimated mating system parameters in perennial populations of the model plant species, Mimulus guttatus from its native range (West coast USA), non-native populations that are established but have not become invasive (East coast USA, >50 years), and populations in invasive regions (UK >200 years). Studies that include mating system data across the continuum of the invasion process are rare, thus here we utilize molecular markers to estimate outcrossing rates (t), inbreeding coefficients (F), and inbreeding depression in native, naturalized, and invasive populations. Overall, we found support for the persistence of mixed-mating across populations, variability in the relationship between outcrossing rates and inbreeding depression across populations, and evidence for the bridgehead process, where non-native populations may be the sources for the further establishment or reinforcement of additional non-native populations. The methodology we deployed had its own assumptions and sampling design constraints, that contributed to the variation in the parameter estimates. All M. guttatus populations likely rely on selfing through both within clone, and within flower and plant mating in addition to vegetative propagation. The results underscore the importance of introduction history in determining the role of both sexual and asexual reproduction in the successful establishment of a plant species outside its native range. [ABSTRACT FROM AUTHOR]

Sexual reproduction with alternative generations in a life cycle is an important feature in eukaryotic evolution. Partial selfing can regulate the efficacy of purging deleterious alleles in the gametophyte phase and the masking effect in heterozygotes in the sporophyte phase. Here, we develop a new theory to analyze how selfing shapes fixation of a mutant allele that is expressed in the gametophyte or the sporophyte phase only or in two phases. In an infinitely large population, we analyze a critical selfing rate beyond which the mutant allele tends to be fixed under equilibrium between irreversible mutation and selection effects. The critical selfing rate varies with genes expressed in alternative phases. In a finite population with partial self-fertilization, we apply Wright's method to calculate the fixation probability of the mutant allele under flux equilibrium among irreversible mutation, selection, and drift effects and compare it with the fixation probability derived from diffusion model under equilibrium between selection and drift effects. Selfing facilitates fixation of the deleterious allele expressed in the gametophyte phase only but impedes fixation of the deleterious allele expressed in the sporophyte phase only. Selfing facilitates or impedes fixation of the deleterious allele expressed in two phases, depending upon how phase variation in selection occurs in a life cycle. The overall results help to understand the adaptive strategy that sexual reproductive plant species evolve through the joint effects of partial selfing and alternative generations in a life cycle. [ABSTRACT FROM AUTHOR]

Background/Objectives: Systems of reproduction differ with respect to the magnitude of neutral genetic diversity maintained in a population. In particular, the partitioning of reproductive organisms into mating types and regular inbreeding have long been recognized as key factors that influence effective population number. Here, a range of reproductive systems are compared with respect to the maintenance of neutral genetic diversity. This study addresses full gonochorism, full hermaphroditism, androdioecy (male and hermaphroditic reproductives), and gynodioecy (female and hermaphroditic reproductives). Methods: Coalescence theory is used to determine the level of diversity maintained under each mating system considered. Results: For each mating system, the nature of the dependence of the level of neutral diversity on inbreeding depression, sex-specific viability, and other factors is described. In particular, the models account for the effects of sex-specific viability on the evolutionarily stable sex ratio and the collective contribution of each mating type (sex) to the offspring generation. Conclusions: Within the context of conservation biology, population genetic and quantitative genetic theory has addressed the determination of the target minimum effective population size. In contrast, this study proposes and explores a summary statistic (a ratio of effective numbers) as a means of characterizing the context in which evolution occurs. [ABSTRACT FROM AUTHOR]

Life cycles with a prolonged haploid phase are thought to be correlated with greater rates of selfing and asexual reproduction. In red algae, recent population genetic studies have aimed to test this prediction but have mostly focused on marine species with separate sexes. We characterized the reproductive system of the obligately monoicous (i.e., hermaphroditic) freshwater red alga Batrachospermum gelatinosum and predicted that we would find genetic signatures of uniparental reproduction because of its haploid‐diploid life cycle. We sampled 18 sites and genotyped 311 gametophytes with 10 polymorphic microsatellite loci to describe the reproductive system. Genotypic richness was low (<0.5) and pareto β values (describing clonal membership) were <0.7 for most sites. In taxa with separate sexes, these patterns are typically indicative of asexual reproduction. However, the genetic consequences of selfing in monoicous gametophytes are indistinguishable from those caused by asexual processes. Since we sampled gametophytes and have not yet genotyped the chantransia (i.e., the diploid phase), we interpreted low diversity as a signature of intragametophytic selfing. Additionally, to understand the factors that drive selfing, we tested latitude and several other environmental variables, but none was significantly correlated with the genetic variation we observed. Nevertheless, future studies should genotype the chantransia to measure observed heterozygosity among other summary statistics to disentangle the effects of selfing versus asexual reproduction. Together, these data, coupled with further characterization of abiotic factors that influence population genetic patterns, will allow us to test potential drivers of reproductive system evolution. [ABSTRACT FROM AUTHOR]

The mating system of plants is predicted to modify the role of pollinators in driving floral evolution by influencing trait-fitness relationships and plant reproductive success. However, these effects have not been well documented for mixed-mating system species. We experimentally manipulated the pollination environment separately for individuals in mixed- (including selfing and outcrossing) and outcrossing-mating systems within a natural population of Primula chungensis to address whether pollinator-mediated selection on three floral traits differed between the two mating systems. The three traits included the flowering start, number of flowers and corolla tube length, which influenced the pollinator attractiveness as well as per-visit efficiency. On average, plants in mixed-mating systems produced more flowers with longer corolla tubes. In the open-pollinated treatment, plants from mixed-mating systems produced more seeds than did plants from outcrossing systems. Hand pollination increased seed production for plants with an outcrossing-mating system. The pollen limitation for plants with an outcrossing-mating system was three times greater than that for plants with mixed-mating systems. Pollinator-mediated selection on flowering start and corolla tube length differed between the two mating systems. Pollinators mediated selection for an earlier flowering start and longer corolla tubes for plants with an outcrossing-mating system. However, selective pressure from pollinators was not observed on any trait in plants with mixed-mating systems. The results suggest that the occurrence and magnitude of pollinator-mediated selection can strongly depend on the mating systems of target plants. [ABSTRACT FROM AUTHOR]

Within‐flower self‐pollination should be the major source of self‐fertilization in mixed‐mating species that present single or few flowers simultaneously. It is also an often unmeasured source of selfing in species with many flowers open simultaneously. In self‐compatible species in which pistil and stamen numbers vary, the rate of within‐flower selfing should depend on the number of pistils and stamens, the timing of flowering and the morphology of subsidiary floral traits. The intensity and direction of selection on these traits should thus also depend on the level of inbreeding depression.Here, we measured the dependence of the within‐flower selfing rate on floral sex allocation, phenology, petal length and floral stalk height in a population of the perennial herb Pulsatilla alpina (Ranunculaceae) in which most individuals had single flowers. We estimated inbreeding depression in the population by comparing inbreeding coefficients between parents and seed progeny using microsatellite markers. We then estimated selection on the measured traits via female reproductive success at the flower level and compared our estimates with a hypothetical scenario in which inbreeding depression was assumed to be absent.Inbreeding depression was estimated to be severe (0.95). The within‐flower selfing rate varied widely among flowers and depended positively on stamen number and negatively on pistil number and flowering date, supporting the predictions of a mass‐action model. The dependence of the selfing rate on the measured floral traits consistently predicted (non‐linear) patterns of selection under high inbreeding depression that were distinct from those under a hypothetical scenario of no inbreeding depression.Synthesis. While previous research has emphasized the importance of mass‐action mating on selfing among flowers of plants with large floral displays, our results demonstrate its importance for selfing within individual flowers. They also demonstrate the importance of accounting for both the selfing rate and inbreeding depression when inferring selection on floral and other traits via female fitness. [ABSTRACT FROM AUTHOR]

This study describes a compact method for determining joint probabilities of identity-by-state (IBS) within and between loci in populations evolving under genetic drift, crossing-over, mutation, and regular inbreeding (partial self-fertilization). Analogues of classical indices of associations among loci arise as functions of these joint identities. This coalescence-based analysis indicates that multi-locus associations reflect simultaneous coalescence events across loci. Measures of association depend on genetic diversity rather than allelic frequencies, as do linkage disequilibrium and its relatives. Scaled indices designed to show monotonic dependence on rates of crossing-over, inbreeding, and mutation may prove useful for interpreting patterns of genome-scale variation. [ABSTRACT FROM AUTHOR]

Context: Resupination is the movement of developing buds that leads to a vertical inversion of the flowers at an angle of 180°. Chamaecrista nictitans exhibits two anther sizes, and nonresupinate and resupinate flowers in the same individual, which is known as monomorphic resupinate dimorphy. Aims: We aimed to investigate the influence of monomorphic resupinate dimorphy upon pollen deposition on pollinators, capture by the stigma and on plant reproduction, using three populations of C. nictitans from NE Brazil as a model. Methods: We assessed the floral biology, the proportion of nonresupinate and resupinate flowers in the populations, dynamics of pollen transfer between floral morphs, and the plant's reproductive system. Key results: All flowers have two anther sizes with similar pollen viability. The proportion of nonresupinate:resupinate flowers was 3:1 in all populations. The bee Florilegus (Euflorilegus) sp. was the only pollinator observed and had pollen of both flower morphs deposited on the underside part of the thorax and abdomen. The stigma of nonresupinate flowers received pollen from the pollinators' underside of the abdomen, whereas the stigma of resupinate flowers received pollen from the pollinators' underside of the thorax. The species is self-compatible but does not set fruits by spontaneous self-pollination. Therefore, natural fruit set had resulted from both intramorph- and intermorph-pollination in the same or in different individuals. Conclusions: Both flower types have a similar pattern of pollen deposition on the pollinator's body (underside of the abdomen and thorax) and only differ in relation to areas of pollen capture by the stigma (underside of the abdomen or underside of thorax). Implications: The monomorphic resupinate dimorphy observed here improves the area of pollen deposition by the anthers on pollinator's body and makes the capture of pollen by stigma sectored in the different floral types, similar to what is observed in other species presenting floral polymorphisms. Resupination is the movement of floral buds that leads to flowers turning upside down. We tested the reproductive functioning of this characteristic in the native legume Chamaecrista nictitans and found that it causes pollen to be deposited in particular portions of pollinators' bodies, improving pollination. Image by Natan Messias Almeida and Paulo Estêvão Araújo Vilaça Júnior. [ABSTRACT FROM AUTHOR]

We present a case of extended sperm storage in a female red-tailed phascogale (Phascogale calura) during a trial reintroduction in 2022. Parentage reported by single nucleotide polymorphism genotyping revealed the father of one litter had died approximately 50 days before the litter was born. The recorded gestation period for red-tailed phascogales is 28–32 days. Our record indicates sperm storage and/or diapause of up to 15–27 days, at least double the previously recorded sperm storage duration in this species. Sperm storage is common in dasyurid species and has been recorded for up to 8 days in red-tailed phascogales (Phascogale calura). We present a case where sperm storage has occurred for 15–27 days in a free-living translocated red-tailed phascogale. Our result is the longest sperm storage period recorded to-date in dasyurid species. [ABSTRACT FROM AUTHOR]

Context: Knowledge of the reproductive biology of plants is fundamental for conservation, especially of the ones with a limited distribution. Aims: The sexual reproduction of the small-ranged Passiflora chrysophylla Chod. was studied. Methods: Controlled pollinations were performed to assess the breeding system, whereas floral traits and visitors (identity, frequency, activity on the flowers, dimensions and pollen load) were analysed to assess the pollination mechanism. Key results: Self-compatibility was partial. Anthesis was matinal. The odour emitted by the corona was sweet, whereas the odour emitted by the persistent sepals and bracts was similar to that of the leaves. Contrasting concentric circular reward guides were present in the visible and UV spectra. Nectar concentration was high, the volume increased throughout anthesis and, if removed, nectar was replenished only once during the flower lifespan. Style movements towards the anthers determined male and hermaphroditic phases in most of the flowers; in a few flowers (smaller, scented and nectarless), styles remained apart from the anthers, thus constituting a functionally andromonecious and deceptive automimicry system. The bees Ptiloglossa sp., Thygater analis and Xylocopa augusti acted as pollinators, whereas ants, butterflies and beetles were nectar or pollen thieves and florivores. Conclusions: P. chrysophylla is melittophilous and pollinators increase reproductive success. Implications: Pollination biology of P. chrysophylla , reported for the first time, would contribute to conservation management of this species with restricted distribution. The pollination of the tiny passion vine Passiflora chrysophylla , a small-ranged species from the southern hemisphere, has been studied for the first time. Its sexual reproduction and, consequently, its genetic variability, is partially dependant on native bees, mainly crepuscular ones, to which it offers highly concentrated nectar during the morning. Its floral biology is similar to that of its close relative P. foetida , which is widespread, even invasive, and provides useful information in case of conservation needs. Photograph by P. I. Picca. [ABSTRACT FROM AUTHOR]

Mating systems, influenced by the social and ecological environment and individual attributes, are fundamental components of animal social organisation, impacting behaviour, animal distribution, ecosystem processes, individual reproductive success, and population dynamics. Bats are of particular interest for studies of mating systems as they are thought to exhibit a greater diversity in mating systems than any other mammalian order, and thus make great models for improving our fundamental understanding of causes and consequences of social organisation. Here, we review the current knowledge of bat mating systems. Our analyses show that research on bat mating systems has not kept pace with research on bats in general and that traditional typologies do not accommodate the mating system of several species. Therefore, we propose an alternative, functional framework to categorise mating systems of bats and by extension of other taxa. We argue that mating systems can be classified according to a male reproductive skew continuum, with an increasing skew from monogamy to true lekking. We include an additional category of lek‐like mating system along the continuum to account for previous trans‐categorical cases that have the appearance of resource defence but are functionally akin to a lek. The new framework has a total of seven categories: promiscuity, monogamy, female defence polygyny, resource defence polygyny, a lek‐like mating system, exploded classical lek, and clustered classical lek. Applying this framework to bats reveals that lek mating systems are more prevalent in bats than previously recognised. It is our aim that this review and the proposed framework provide a greater understanding of bat mating systems particularly and provoke research into the factors that shape mating systems across animal taxa more generally. [ABSTRACT FROM AUTHOR]

Summary: Shifts in pollinator occurrence and their pollen transport effectiveness drive the evolution of mating systems in flowering plants. Understanding the genomic basis of these changes is essential for predicting the persistence of a species under environmental changes. We investigated the genomic changes in Brassica rapa over nine generations of pollination by hoverflies associated with rapid morphological evolution toward the selfing syndrome.We combined a genotyping‐by‐sequencing (GBS) approach with a genome‐wide association study (GWAS) to identify candidate genes, and assessed their functional role in the observed morphological changes by studying mutations of orthologous genes in the model plant Arabidopsis thaliana.We found 31 candidate genes involved in a wide range of functions from DNA/RNA binding to transport. Our functional assessment of orthologous genes in A. thaliana revealed that two of the identified genes in B. rapa are involved in regulating the size of floral organs. We found a protein kinase superfamily protein involved in petal width, an important trait in plant attractiveness to pollinators. Moreover, we found a histone lysine methyltransferase (HKMT) associated with stamen length.Altogether, our study shows that hoverfly pollination leads to rapid evolution toward the selfing syndrome mediated by polygenic changes. [ABSTRACT FROM AUTHOR]

Social competition for resources is widespread among animals. Females of many species compete for foraging resources through interference competition, which is a behavioural interaction between animals that reduces an individual's access to shared resources. In addition to competition from other females, females also often face harassment from males during and after the breeding season. The female competition hypothesis predicts that female-initiated aggression associated with foraging competition increases as a function of group size, but we expected this effect to be more pronounced in higher quality foraging habitat. The male harassment hypothesis predicts that male harassment of females should also increase as a function of group size as well as a function of the ratio of males to other group members. Here, we tested the female competition and male harassment hypotheses for caribou (Rangifer tarandus) within the context of variation in the social environment (i.e., group size and sex ratio) and the physical environment (i.e., variation in habitat quality). We conducted focal observations of caribou on Fogo Island, Newfoundland, over three years and quantified aggressive social interactions in different habitat types to test our hypotheses. Specifically, we took advantage of natural variation in caribou behaviour in our system and observed caribou foraging in an enhanced habitat (i.e., recreational sports complex field) and natural habitat (i.e., lichen barrens). We found limited support for the female competition hypothesis, possibly because of females' propensity to increase foraging rates in enhanced habitats. By contrast, we found strong support for the male harassment hypothesis, where males increase the frequency of harassment as group size increased. Our results suggest costs of grouping for female caribou in the post-rut time period may be related to the presence of males potentially seeking mating opportunities. [ABSTRACT FROM AUTHOR]

Studies of reproductive biology and resources availability to floral visitors by plant species are important to understand the plant-pollinator interactions that drive species adaptation. We aim to understand the relationship between reproduction mechanisms of Deuterocohnia meziana (Bromeliaceae) and pollinators. The species occurs in Bolivia and Paraguay, and it is the only species of the genus found in Brazil, where it is restricted to ironstone outcrops. These areas are currently threatened by the iron mining industry. Additionally, they face risks from fire occurrence and grazing by cattle. We analyzed the floral biology, reproductive system, phenology, and pollination ecology of a natural population of Deuterocohnia meziana, from ironstone outcrops in Brazil. The species exhibits diurnal anthesis, with stigma receptive throughout anthesis, and 77% of pollen viability. Deuterocohnia meziana produces relatively large amounts of nectar, especially early in the morning (32.8 ± 9.4 μl), with a mean sugar concentration of 23.5 (± 3.2) ºBrix. It is self-incompatible with a peak flowering occurring in August (dry season), although flowers are observed continuously throughout the year. The species exhibits two types of inflorescences, young and mature, among which an average of 13.1 and 3.6 flowers open per day, respectively. Hummingbirds and bees are the effective pollinators, although butterflies and ants also visit D. meziana flowers. The species is reliant on exogenous pollen and pollinators for fruit set. The continuous conservation of D. meziana populations and their communities is essential for preserving plant-pollinator mutualism and the floral community adapted to ironstone outcrops. [ABSTRACT FROM AUTHOR]

The mating system of non-native plant populations plays a role in determining the colonizing success following introduction into locations outside of the native distribution. For plant species capable of mixed-mating, both selfing and outcrossing can be advantageous and promote the establishment, persistence, and spread of newly arrived populations. To investigate how mating systems may contribute to the invasion process we estimated mating system parameters in perennial populations of the model plant species, Mimulus guttatus from its native range (West coast USA), non-native populations that are established but have not become invasive (East coast USA, >50 years), and populations in invasive regions (UK >200 years). Studies that include mating system data across the continuum of the invasion process are rare, thus here we utilize molecular markers to estimate outcrossing rates (t), inbreeding coefficients (F), and inbreeding depression in native, naturalized, and invasive populations. Overall, we found support for the persistence of mixed-mating across populations, variability in the relationship between outcrossing rates and inbreeding depression across populations, and evidence for the bridgehead process, where non-native populations may be the sources for the further establishment or reinforcement of additional non-native populations. The methodology we deployed had its own assumptions and sampling design constraints, that contributed to the variation in the parameter estimates. All M. guttatus populations likely rely on selfing through both within clone, and within flower and plant mating in addition to vegetative propagation. The results underscore the importance of introduction history in determining the role of both sexual and asexual reproduction in the successful establishment of a plant species outside its native range.

Inbreeding depression (ID) is a major selective force during mating system evolution primarily contributed by highly to partially recessive deleterious mutations. Theories suggest that transient genetic association with fitness alleles can be important in affecting the evolution of alleles that modify the selfing rate during its sweep. Nevertheless, empirical tests often focus on the pre- existing genetic association between selfing rate and ID maintained under mutation--selection balance. Therefore, how this standing genetic association is affected by key factors and its impacts on the evolution of selfing remain unclear. I show that as the selection coefficient of deleterious mutations increases, the association between selfing rate and ID declines from positive to negative. These results predict that association between selfing and ID tends to be negative in populations with low selfing rates, while positive in highly selfing populations. Using population genetic and quantitative genetic models, I show that standing genetic associations between selfing rate and fitness alleles can significantly impact the evolution of the mean selfing rate of a population. I present better metrics of population-level ID, which can be calculated based on the correlation coefficient between individual selfing rate and the fitness of selfed and outcrossed offspring. [ABSTRACT FROM AUTHOR]

The distribution of the resources needed by females for reproduction affects their dispersion in space and time, which in turn influences the number of females a male can defend. When males provide parental care they in turn become a resource for females, and influence where females choose to breed. Combined, these factors explain a preponderance of monogamous and (to a lesser extent) polygynous mating systems in birds. However, less frequently observed mating systems in birds remain harder to explain. Here, we analyse the home ranges of male Eclectus parrots (Eclectus roratus) to investigate how their use of space facilitates an unusual polygynandrous mating system (where multiple males mate with multiple females). Female Eclectus parrots in the rainforests of northern Queensland, Australia, have limited movements. They remain at their nest trees for most of the year and rely on multiple wide-ranging males to bring them their food. We used light aircraft and VHF transmitters to track the movements of four male Eclectus parrots during the breeding season. We combined data on home range size with molecular analyses of a larger sample of breeding birds. Our analyses demonstrate that male home ranges overlap with each other and encompass multiple (3–14) trees with nesting females. We show that some males divide their time between, and gain reproductive success with, females up to 7 km apart. Our tracking and molecular data offer insights into how polygynandrous mating systems relate to space use among males and females. [ABSTRACT FROM AUTHOR]

Runs of homozygosity (ROHs) are indicative of elevated homozygosity and inbreeding due to mating of closely related individuals. Self-fertilization can be a major source of inbreeding which elevates genome-wide homozygosity and thus should also create long ROHs. While ROHs are frequently used to understand inbreeding in the context of conservation and selective breeding, as well as for consanguinity of populations and their demographic history, it remains unclear how ROH characteristics are altered by selfing and if this confounds expected signatures of inbreeding due to demographic change. Using simulations, we study the impact of the mode of reproduction and demographic history on ROHs. We apply random forests to identify unique characteristics of ROHs, indicative of different sources of inbreeding. We pinpoint distinct features of ROHs that can be used to better characterize the type of inbreeding the population was subjected to and to predict outcrossing rates and complex demographic histories. Using additional simulations and four empirical datasets, two from highly selfing species and two from mixed-maters, we predict the selfing rate and validate our estimations. We find that self-fertilization rates are successfully identified even with complex demography. Population genetic summary statistics improve algorithm accuracy particularly in the presence of additional inbreeding, e.g. from population bottlenecks. Our findings highlight the importance of ROHs in disentangling confounding factors related to various sources of inbreeding and demonstrate situations where such sources cannot be differentiated. Additionally, our random forest models provide a novel tool to the community for inferring selfing rates using genomic data. [ABSTRACT FROM AUTHOR]

The restoration of diverse self‐sustaining ecosystems requires re‐establishment of functional interactions among species. For plant communities, pollinators are usually essential for pollination, seed set and seed quality. A common assumption in ecological restoration for plants pollinated by animals is one of 'build it and they will come', which is rarely tested. Beyond seed set, there may be negative genetic consequences for seed quality if pollinators and their behaviour do not reflect those in reference populations.Here, we conduct an ecological genetic assessment of seed quality via mating system parameters in Lambertia multiflora (Proteaceae), a species dependent on nectar‐feeding birds for pollination. Four populations of L. multiflora in disturbed sites that were rehabilitated following mineral sands mining were compared with four native reference populations, near Eneabba, Western Australia. In each population, approximately 10 offspring from each of 10 maternal plants were genotyped with 11 highly polymorphic microsatellite markers.From these data, genetic diversity and mating system parameters were assessed, and found to be equivalent across all populations. Mean allelic diversity and heterozygosity across loci were very high. All populations were completely outcrossing with no bi‐parental inbreeding. Mean correlated paternity, sibship and effective population size estimates for restored and natural populations were not significantly different and reflected uniformly high paternal diversity and wide outcrossing. Equivalent genetic results for restored and natural reference populations indicate successful restitution of bird‐pollinator services for L. multiflora in these post‐mining rehabilitation sites.Synthesis and applications. Reviewing our results with other published studies to date suggests a resilience of bird‐pollinator services in restored plant communities. These findings provide some reassurance to restoration practitioners working in these global south systems where bird pollination is a feature, at least for similar landscape scenarios. Our study also highlights the global contribution of ecological genetics to the objective assessment of functional species interactions in ecological restoration, an increasingly important goal of land managers and regulators seeking to improve restoration standards. [ABSTRACT FROM AUTHOR]

Premise: Evolution of cross‐pollination efficiency depends on the genetic variation of flower traits, the pollen vector, and flower trait matching between pollen donors and recipients. Trait matching has been almost unexplored among nonheterostylous species, and we examined whether the match of anther length in pollen donors and stigma length in pollen recipients influences the efficiency of cross‐pollination. To explore potential constraints for evolutionary response, we also quantified genetic variation and covariation among sepal length, petal length and width, stamen length, style length, and herkogamy. Methods: We created 58 experimental arrays of Turnera velutina that varied in the extent of mismatch in the position of anthers and stigmas between single‐flowered plants. Genetic variation and correlations among flower traits were estimated under greenhouse conditions. Results: Style length, but not herkogamy, influenced the efficiency of cross‐pollination. Plants with stamen length that matched the style length of other plants were more efficient pollen donors, whereas those with the style protruding above the stamens of other plants were more efficient pollen recipients. Significant broad‐sense heritability (0.22 > hB2 < 0.42) and moderate genetic correlations (0.33 > r < 0.85) among floral traits were detected. Conclusions: Our results demonstrated that anther‐stigma mismatch between flowers contributed to variation in the efficiency of cross‐pollination. The genetic correlations between stamen length and other floral traits suggests that any change in cross‐pollination efficiency would be driven by changes in style rather than in stamen length. [ABSTRACT FROM AUTHOR]

Inbreeding is thought to be a key adverse factor impacting the genetic quality of seeds in seed production populations and the inbreeding degree (i.e., selfing or outcrossing rate) of seed production populations have been extensively assessed through mating system analysis. The adverse effect of inbreeding on seed quality traits in seed production populations under open-pollination conditions has not yet been clearly described. In this study, the open-pollinated seeds were collected from 26 mother trees in a 58-year-old seed tree stand. Three seed quality traits, including thousand-seed weight (TSW), germination rate (GR), and germination potential (GP), were measured, and the seeds from eight of 26 families with significant differences in seed quality traits were genotyped through twelve microsatellite markers. In addition, the seeds and sprouts (germinated seeds) from six families were genotyped to reveal the effect of inbreeding on seed germination. The three seed quality traits significantly differed among families (p < 0.001). The multilocus outcrossing rate (tm = 0.889) and single-locus outcrossing rate (ts = 0.648) of overall seeds indicated apparent selfing (11.1%) and biparental inbreeding (24.0%). The outcrossing rate in the sprout group (tm = 0.919, ts = 0.788) was higher than that in the seed group (tm = 0.833, ts = 0.646), and the difference in ts between groups was different from zero under the 95% confidence interval (0.024–0.260), suggesting that inbreeding negatively affected seed germination. Linear regression demonstrated that TSW was positively correlated with tm and ts, while GR was negatively related to tm−ts and positively related to ts, implying that seed mass (development) was probably more affected by self-fertilization, but germination capacity was more influenced by biparental inbreeding. The inbreeding depression (ID) of TSW was estimated to be 26.3% with a 0.1 decrease in tm, while that of GR was estimated to be 8.4% with a 0.1 decrease in ts. These results suggest that the IDs during seed development and the germination stage of Masson pine were nonignorable and that more attention to outcrossing rate should be paid to the establishment and management of Masson pine seed production. [ABSTRACT FROM AUTHOR]

Roupala montana var. brasiliensis is a timber tree species native to the Cerrado and Atlantic Forest areas of Brazil. The wood was exploited for international markets, but there is no information on the conservation status of its natural populations, nor on other key aspects, such as mating system, gene flow, and inbreeding depression, essential for the species' sustainable management and conservation. We report the first study of any Roupala species to apply a validated set of species-specific microsatellite markers to genotype adults, juveniles, and seedlings, and analyse genetic diversity, inbreeding, effective population size, and mating system. We studied four populations of the species in areas of mixed Ombrophilous forest with different disturbance levels (undisturbed to strongly disturbed) in southern Brazil. The species occurs at low frequency in the study forests, but the populations are genetically diverse without significant differences in genetic diversity levels related to disturbance. The study also indicated resistance to the severe fragmentation associated with low density of individuals, with a stable mating system showing preferential outcrossing, with some inbreeding (tm ≈ 0.83, F > 0.165). Despite being spatially isolated from each other, the populations are not reproductively isolated, receiving immigrant pollen from long distances, although there was no evidence of gene flow into the populations via seeds. Seedlings from self-fertilization show low levels of inbreeding depression, which may reflect earlier pre-germination selection events. There was loss of allelic wealth in the younger cohorts, which may be a warning of the fragility of the genetic diversity detected in populations. We consider the implications of the results for the development of ex and in situ conservation and tree improvement programs. [ABSTRACT FROM AUTHOR]

Sex is a crucial process that has molecular, genetic, cellular, organismal, and population‐level consequences for eukaryotic evolution. Eukaryotic life cycles are composed of alternating haploid and diploid phases but are constrained by the need to accommodate the phenotypes of these different phases. Critical gaps in our understanding of evolutionary drivers of the diversity in algae life cycles include how selection acts to stabilize and change features of the life cycle. Moreover, most eukaryotes are partially clonal, engaging in both sexual and asexual reproduction. Yet, our understanding of the variation in their reproductive systems is largely based on sexual reproduction in animals or angiosperms. The relative balance of sexual versus asexual reproduction not only controls but also is in turn controlled by standing genetic variability, thereby shaping evolutionary trajectories. Thus, we must quantitatively assess the consequences of the variation in life cycles on reproductive systems. Algae are a polyphyletic group spread across many of the major eukaryotic lineages, providing powerful models by which to resolve this knowledge gap. There is, however, an alarming lack of data about the population genetics of most algae and, therefore, the relative frequency of sexual versus asexual processes. For many algae, the occurrence of sexual reproduction is unknown, observations have been lost in overlooked papers, or data on population genetics do not yet exist. This greatly restricts our ability to forecast the consequences of climate change on algal populations inhabiting terrestrial, aquatic, and marine ecosystems. This perspective summarizes our extant knowledge and provides some future directions to pursue broadly across micro‐ and macroalgal species. [ABSTRACT FROM AUTHOR]

Background and aims: In the Atacama Desert certain plant species can be found in small and isolated areas, limited to regions with water availability. The degree of connectivity within and between these natural populations depends on their pollen and seed dispersal abilities, as well as on the barriers imposed by the landscape. Prosopis flexuosa is a species of high economic and ecological importance included in the algarrobo Conservation and Management program. The main objective of this work is to analyze the genetic variability and mating system of P. flexuosa in the Atacama Desert. M&M: Genetic diversity parameters as well as the mating system were evaluated in a natural population (Quillagua) based on microsatellite molecular markers. The hierarchical distribution of genetic variance and kinship coefficients were analyzed. Results: The results indicate high levels of genetic diversity (HE = 0.67-0.65; Ar = 3.8- 3.7), high outcrossing rates (t m = 0.97, t s = 0.85), low biparental inbreeding (11.6%) and multiple paternity. The proportion of full sibs decreases when considering seeds from the same or different pods (89→16%). Only the variance between families is significant (p < 0.001) and mean kinships estimated show that progenies within families are not only constituted by half sibs. Conclusions: The results are discussed and related to the limited pollen and seed dispersal and their implication for the management of this resource. The study of the mating system parameters of this Chilean desert population suggests that the low population density and the environment fragmentation would not be influencing their mating capacity. [ABSTRACT FROM AUTHOR]

Premise: The ability to self‐fertilize is predicted to provide an advantage in colonization because a single individual can reproduce and establish a next generation in a new location regardless of the density of mates. While there is theoretical and correlative support for this idea, the strength of mate limitation as a selective agent has not yet been delineated from other factors that can also select for self‐fertilization in colonization of new habitats. We used known mating‐system variation in the American bellflower (Campanula americana) to explore how plants' ability to self‐fertilize can mitigate density‐dependent reproduction and impact colonization success. Methods: We created experimental populations of single individuals or a small number of plants to emulate isolated colonization events. These populations were composed of plants that differed in their ability to self‐fertilize. We compared pollen limitation of the single individuals to that of small populations. Results: Experimental populations of plants that readily self‐fertilize produced consistent seed numbers regardless of population size, whereas plants with lower ability to self‐fertilize had density‐dependent reproduction with greater seed production in small populations than in populations composed of a single individual. Conclusions: We experimentally isolated the effect of mate limitation in colonization and found that it can select for increased self‐fertilization. We show the benefit of self‐fertilization in colonization, which helps to explain geographic patterns of self‐fertilization and shows support for Baker's law, a long‐held hypothesis in the field of mating‐system evolution. [ABSTRACT FROM AUTHOR]

Revealing the relationship between the mating system (i.e., the outcrossing/inbreeding degree) and the fitness of seeds in tree species under wild conditions is essential for understanding the ecological adaptability and evolutionary stability of the species. This study collected open-pollinated seeds from seven wild populations of Pinus yunnanensis var. tenuifolia that exhibited fragmentation in the Nanpan–Hongshui River basin, an ecologically fragile area in China. The seeds and sprouts (germinated seeds) from 20 families were genotyped (24 seeds and 24 sprouts per family) using twelve microsatellite loci to reveal the genetic diversity, mating status, and effect of inbreeding on the three seed quality indicators (thousand-seed weight, germination rate, and germination potential). The three seed quality indicators differed significantly between families (p < 0.001). Higher values of genetic diversity (except the observed heterozygosity) were observed in the sprout group than those in the seed group. Families from different populations showed a notable genetic differentiation (Φst = 0.12), and a large part of families from the common populations had a high degree of coancestry, which signified that the current habitat fragmentation is limiting gene flow between populations. High levels of outcrossing rates (tm) were observed in both the seed group (tm = 0.974) and the sprout group (tm = 0.978), indicating that a low proportion of seeds were self-fertilized. Although there was a slightly higher single outcrossing rate (ts = 0.888) and a lower proportion of biparental inbreeding (tm − ts = 0.077) in sprouts compared to the seeds (ts = 0.871, tm − ts = 0.091), indicating that a part of inbred seeds were purged during the germination stage, curve fitting between the outcrossing rate and seed quality indicators showed that a certain degree of biparental inbreeding (ts between 0.89 and 0.91 and tm − ts between 0.09 and 0.11) did have a positive effect on seed germination ability. This highlights that excessive inbreeding or outbreeding seems to be unfavorable to seed viability. The peculiar relationship between seed viability and the mating system in P. yunnanensis var. tenuifolia was likely an evolutionary consequence of a trade-off between the nature of mixed mating and its specific ecological niche. [ABSTRACT FROM AUTHOR]

Males and females often have different roles in reproduction, although the origin of these differences has remained controversial. Explaining the enigmatic reversed sex roles where males sacrifice their mating potential and provide full parental care is a particularly long-standing challenge in evolutionary biology. While most studies focused on ecological factors as the drivers of sex roles, recent research highlights the significance of social factors such as the adult sex ratio. To disentangle these propositions, here, we investigate the additive and interactive effects of several ecological and social factors on sex role variation using shorebirds (sandpipers, plovers, and allies) as model organisms that provide the full spectrum of sex role variation including some of the best-known examples of sex-role reversal. Our results consistently show that social factors play a prominent role in driving sex roles. Importantly, we show that reversed sex roles are associated with both male-skewed adult sex ratios and high breeding densities. Furthermore, phylogenetic path analyses provide general support for sex ratios driving sex role variations rather than being a consequence of sex roles. Together, these important results open future research directions by showing that different mating opportunities of males and females play a major role in generating the evolutionary diversity of sex roles, mating system, and parental care. [ABSTRACT FROM AUTHOR]

In species with resource-defense mating systems (such as most temperate-breeding songbirds), male dispersal is often considered to be limited in both frequency and spatial extent. When dispersal occurs within a breeding season, the favored explanation is ecological resource tracking. In contrast, movements of male birds associated with temporary emigration, such as polyterritoriality (i.e., defense of an additional location after attracting a female in the initial territory), are usually attributed to mate searching. We suggest that male dispersal and polyterritoriality are functionally related and that mate searching may be a unifying hypothesis for predicting the within-season movements of male songbirds. Here, we test three key predictions derived from this hypothesis in Wood Warblers (Phylloscopus sibilatrix). We collected data on the spatial behavior of 107 males between 2017 and 2019 and related male movements to a new territory (in both a dispersal and a polyterritorial context) to mating potential in the current territory. Most males dispersed from their territories within days or weeks after failing to attract a female, despite occupying territories in apparently suitable habitat. Probability of polyterritoriality by paired males increased after the peak fertile period of their mate. Males never dispersed following nest predation if the female remained to renest. Thus, our data are consistent with the hypothesis that both movement types are functionally related to mate searching. [ABSTRACT FROM AUTHOR]

Premise of research. Reinforcement is the process through which prezygotic reproductive barriers evolve in sympatry owing to selection against hybridization between co-occurring, closely related species. The role of self-fertilization in reinforcement and reproductive isolation is uncertain, in part because its efficiency as a barrier against heterospecific mating can depend on the timing of autonomous selfing. Methodology. To investigate whether increased autonomous selfing has evolved as a mechanism for reinforcement, we compared Phlox cuspidata populations across their native Texas range using both estimates of genetic diversity and experimental manipulation with morphological measurements. Specifically, we investigated patterns of variation in floral traits and timing of selfing between individuals from allopatric populations of P. cuspidata and from populations sympatric with the closely related species Phlox drummondii. Pivotal results. We infer intermediate rates of selfing across field-collected individuals with no significant difference between allopatric and sympatric populations. Among greenhouse-grown plants, we find no differences in timing of selfing or other floral traits, including anther dehiscence timing, anther-stigma distance, autonomous selfing rate, and self-seed count, between allopatric and sympatric populations. However, our statistical analyses indicate that P. cuspidata individuals sympatric with P. drummondii seem to have generally larger flowers compared with allopatric individuals. Conclusions. Despite strong evidence of costly hybridization with P. drummondii , we find no evidence of trait divergence due to reinforcement in P. cuspidata. Although we document nearly complete autonomous self-seed set in the greenhouse, estimates of selfing rates from genetic data imply that realized selfing is much lower in nature, suggesting an opportunity for reinforcing selection to act on this trait. [ABSTRACT FROM AUTHOR]

Morphological variation of body size and appendages is defined as polymorphism and may be associated with important structures linked to the sexual selection process. Some studies have suggested an expressive heterochely (i.e., dissimilar chelipeds) in the male adult phase of the semi-terrestrial crab Ucides cordatus , an important decapod species of mangrove systems from the western Atlantic. Here, the morphology, size, and growth pattern of male chelipeds in U. cordatus from the Brazilian coast were examined to test for polymorphism, considering that adult males usually develop one ornamented and hypertrophied cheliped. Two cheliped morphs were detected in U. cordatus males: chelipeds can be either homochelous or heterochelous and both morphotypes occur from the juvenile to adult phase. The higher frequencies of heterochelous males in larger size classes (71%: ⩾51 mm CW) and homochelous males in smaller ones (56%: <51 mm CW) confirmed that the prevalence of each morph is also associated with the ontogeny in males. The ornamentation of both morphs mainly differed in the dentition of cutting edges, but it was similar in the presence and position of tubercles. Adult crabs with homochelous and heterochelous chelipeds reached a similar body size, but their major chelipeds were significantly different in size and growth pattern. The presence of both cheliped morphs suggests the existence of distinct functions in this species, associated with feeding habits and behavioral displays (sexual / agonistic interactions). Our results indicate that more than one morph can participate in the reproductive process in species with mating systems (e.g., explosive breeding) allowing for this, as in the subfamily Ucidinae. [ABSTRACT FROM AUTHOR]

We describe the details of the mating behavior of the Japanese badger, Meles anakuma, using camera trapping. Similar to other mustelid species, the females copulated with multiple males (mean = 3.0). Repeated mounting with the same male was observed, occurring 3.4 times on average. The average duration of the mounting bout was approximately 70 min, which was much longer than that observed for the congener M. meles. Following the initial mounting bout, males constructed a rest site by gathering fallen leaves and branches close to the female sett. Males rested at these sites between mounting bouts, likely to guard their mates from rival males. The mating pairs displayed a preference for returning to the same location for copulatory activities, which resulted in the dispersal of fallen leaves and surface soil disturbance. We found that some males restored the copulation site by covering it with leaves, soil, and branches after all mating behaviors were completed. This action prevented rival males from locating females, especially if they relied on olfactory cues from the copulation sites. Our study reveals interspecific differences in mating behavior within Meles and the relationship between social systems and mating behavior. Digital video images related to this article are available at http://www.momo-p.com/showdetail-e.php?movieid=momo240213ma01a, http://www.momo-p.com/showdetail-e.php?movieid=momo240213ma02a, http://www.momo-p.com/showdetail-e.php?movieid=momo240213ma04a, http://www.momo-p.com/showdetail-e.php?movieid=momo240213ma05a, and http://www.momo-p.com/showdetail-e.php?movieid=momo240213ma06a. [ABSTRACT FROM AUTHOR]

The cost of reproduction is well studied in females but only recently have the costs of mating been investigated in males. Research suggests that males allocate resources between subsequent mating events, resulting in differential success across mating bouts. Selection should favor allocation strategies that match the likelihood of successive matings. The complexity of the system, however, suggests that one fixed strategy is unlikely to be universally favored and thus I predict that genetic variation for different allocation strategies will be segregating in natural populations. To test this, I measured several components of reproductive performance in eight inbred genotypes of Drosophila melanogaster across three sequential mating events. As predicted, there was genetic variation for how previous experience affected a male's reproductive performance for both the proportion of matings that produced offspring and the proportion of offspring sired (P1). Some genotypes had the highest success in their first matings and declined in successive matings while other genotypes did best in later matings. Mating experience had consistent effects across genotypes on fertility and induced refractoriness to remating. On average, virgin matings produced the highest fertility and third matings most effectively induced refractoriness. Genotype also had a significant effect on fertility. These results have important implications for understanding how selection may be acting on males when there is variation in the likelihood of multiple mating events and could affect the evolution of male allocation strategies in the face of perceived competitors. [ABSTRACT FROM AUTHOR]

Quantifying the relative strength of isolating barriers is a major focus of research on plant speciation. Contrasting life histories and mating systems have the potential to limit gene exchange between closely related populations growing in sympatry. However, few studies have quantified reproductive isolating barriers between conspecific annual and perennial populations and their contributions to total reproductive isolation (RI). Incarvillea sinensis Lam. (Bignoniaceae) is an insect‐pollinated herb with largely allopatric annual and perennial populations that differ in mating systems. The perennial populations are primarily outcrossing whereas annual populations are predominantly selfing. At a rare sympatric site in northern China we estimated prezygotic and postzygotic barriers to gene exchange between annual and perennial plants and found complete RI between the two life histories. Annuals exhibited significantly higher ecogeographic isolation than perennials whereas perennials experienced more isolation through pollen–pistil interactions than annuals. Crosses between annuals and perennials demonstrated that postzygotic barriers influencing fruit and seed formation, F1 germination and survival were negligible for annuals but played a small role for perennials. However, F1 hybrids of crosses between annuals and perennials produced no pollen and their ovules were largely sterile. Our study provides insight into the relative importance of prezygotic and postzygotic isolating barriers between closely related annual and perennial populations of I. sinensis and some of these barriers could have been involved with speciation. Annuals and perennials of I. sinensis represent two biological species and thus deserve to be recognized as distinct taxonomic species. [ABSTRACT FROM AUTHOR]

Keteleeria davidiana var. calcarea is an endangered plant endemic to China. It is mainly distributed in the karst areas of the Guangxi and Guizhou Provinces. It is characterized by small populations and intermittent distribution. This study aimed to explore the genetic diversity and mating system of wild populations of Keteleeria davidiana var. calcarea in fragmented habitats. To achieve this, we genotyped 46 maternal trees and 214 progenies from four fragmented populations of Keteleeria davidiana var. calcarea using nine pairs of microsatellite primers. The genetic diversity of Keteleeria davidiana var. calcarea (Ho = 0.68, He = 0.63) was lower than that of the species overall but higher than that of other Keteleeria plants. The incidence of unbiased expected heterozygosity (uHe) and allelic richness (Ar) was higher in the maternal generation than in the progeny. This suggests that the genetic diversity of the progeny was lower than that of the maternal generation. Keteleeria davidiana var. calcarea is divided into four populations, but there is significant genetic exchange between the populations according to STRUCTURE and gene flow analyses. The multilocus mating system analysis (MLTR) results indicate that the multilocus outcrossing rate (tm) was 0.902, the single-locus outcrossing rate (ts) was 0.606, the bimaternal inbreeding coefficient (tm-ts) was 0.295, and the coefficient of inbreeding depression(δ) was 0.904. These results suggest a certain degree of selfing and inbreeding in Keteleeria davidiana var. calcarea. To prevent problems associated with inbreeding and conserve the genetic diversity of Keteleeria davidiana var. calcarea, we recommend establishing seed gardens, using artificial pollination, and employing asexual propagation techniques for conservation intervention. [ABSTRACT FROM AUTHOR]

The West Indian sweetpotato weevil, Euscepes postfasciatus, a serious pest of sweet potatoes, is being eradicated by sterile insect technique (SIT) in the south-western islands of Japan. Information on the diurnal movement of the target pests on host plants and where mating and egg-laying behavior occurs on the host is important for the application of SIT, which eradicates the target pest through mating of released sterile males and wild females. However, little such information is available on this species. In this study, male and female adults were released on host plants to examine the diurnal distribution on seedlings according to sex, as well as the sites where mounting behavior and egg laying occurs. The results showed that females left the host plant more frequently at night, whereas males were more likely to remain on the host plant at night. Both males and females stayed on the nodes of the host plant during the daytime. Mounting behavior also tended to occur more often at nodes. Furthermore, compared to unmated females, mated females stayed at the vertical top of the seedlings. However, it was found that eggs were often laid close to the roots rather than at the top of the vertical stems, even when the seedlings were placed upside down. The results of previous studies and this study will be discussed from the perspective of the application of SIT against E. postfasciatus. [ABSTRACT FROM AUTHOR]

Abstract Mating systems, influenced by the social and ecological environment and individual attributes, are fundamental components of animal social organisation, impacting behaviour, animal distribution, ecosystem processes, individual reproductive success, and population dynamics. Bats are of particular interest for studies of mating systems as they are thought to exhibit a greater diversity in mating systems than any other mammalian order, and thus make great models for improving our fundamental understanding of causes and consequences of social organisation. Here, we review the current knowledge of bat mating systems. Our analyses show that research on bat mating systems has not kept pace with research on bats in general and that traditional typologies do not accommodate the mating system of several species. Therefore, we propose an alternative, functional framework to categorise mating systems of bats and by extension of other taxa. We argue that mating systems can be classified according to a male reproductive skew continuum, with an increasing skew from monogamy to true lekking. We include an additional category of lek‐like mating system along the continuum to account for previous trans‐categorical cases that have the appearance of resource defence but are functionally akin to a lek. The new framework has a total of seven categories: promiscuity, monogamy, female defence polygyny, resource defence polygyny, a lek‐like mating system, exploded classical lek, and clustered classical lek. Applying this framework to bats reveals that lek mating systems are more prevalent in bats than previously recognised. It is our aim that this review and the proposed framework provide a greater understanding of bat mating systems particularly and provoke research into the factors that shape mating systems across animal taxa more generally.

Summary: Plant–pollinator interactions evolved early in the angiosperm radiation. Ongoing environmental changes are however leading to pollinator declines that may cause pollen limitation to plants and change the evolutionary pressures shaping plant mating systems.We used resurrection ecology methodology to contrast ancestors and contemporary descendants in four natural populations of the field pansy (Viola arvensis) in the Paris region (France), a depauperate pollinator environment. We combine population genetics analysis, phenotypic measurements and behavioural tests on a common garden experiment.Population genetics analysis reveals 27% increase in realized selfing rates in the field during this period. We documented trait evolution towards smaller and less conspicuous corollas, reduced nectar production and reduced attractiveness to bumblebees, with these trait shifts convergent across the four studied populations.We demonstrate the rapid evolution of a selfing syndrome in the four studied plant populations, associated with a weakening of the interactions with pollinators over the last three decades. This study demonstrates that plant mating systems can evolve rapidly in natural populations in the face of ongoing environmental changes. The rapid evolution towards a selfing syndrome may in turn further accelerate pollinator declines, in an eco‐evolutionary feedback loop with broader implications to natural ecosystems. See also the Commentary on this article by Kelly, 242: 331–332. [ABSTRACT FROM AUTHOR]

The evolution of sexual size dimorphism (SSD) is a long‐standing topic in evolutionary biology, but there is little agreement on the extent to which SSD is driven by the different selective forces. While sexual selection and fecundity selection have traditionally been proposed as the two leading hypotheses, SSD may also result from natural selection through mechanisms such as sexual niche divergence, which might have reduced resource competition between sexes.Here, we revisited the niche divergence hypothesis by testing the relationship between the sexual overlap in diet and SSD of 56 bird species using phylogenetic comparative analyses. We then assessed how SSD variation relates to the three main hypotheses: sexual selection, fecundity selection, and sexual niche divergence using phylogenetic generalized least squares (PGLS). Then, we compared sexual selection, fecundity selection and niche divergence selection as SSD drivers through phylogenetic confirmatory path analyses to disentangle the possible causal evolutionary relationships between SSD and the three hypotheses.Phylogenetic generalized least squares showed that SSD was negatively correlated with diet overlap, that is, the greater the difference in body size between males and females, the less diet overlap. As predicted by sexual selection theory, the difference in body size between sexes was higher in polygynous species. Confirmatory phylogenetic path analyses suggested that the most likely evolutionary path might include the mating system as a main driver in SSD and niche divergence as a result of SSD. We found no evidence of a role of fecundity selection in the evolution of female‐biased SSD.Our study provides evidence that sexual selection has likely been the main cause of SSD and that dietary divergence is likely an indirect effect of SSD. [ABSTRACT FROM AUTHOR]

Males and females often exhibit different behaviours during mate acquisition, pair‐bonding and parenting, and a convenient label to characterize these behaviours is sex role. The diverse roles that male and female shorebirds (plovers, sandpipers and allies) exhibit in mating and parenting have played a key role in advancing mainstream theories in avian ecology and behavioural biology including sexual selection, sexual conflict and parental cooperation. Recent advances in shorebird research have also highlighted the significance of the social environment in driving sex role behaviours by linking the adult sex ratio with breeding behaviour and population demography. Here we review the key advances in sex role research using shorebirds as an ecological model system. We identify knowledge gaps and argue that shorebirds have untapped potential to accelerate diverse research fields including evolutionary genomics, movement ecology, social networks and environmental changes. Future studies of sex roles will benefit from individual‐based monitoring using advanced tracking technologies, and from multi‐team collaborations that are facilitated by standardized data collection methodologies across different species in the field. These advances will not only contribute to our understanding of reproductive strategies, but they will also have knock‐on effects on predicting population resilience to environmental changes and on prioritizing species for conservation. [ABSTRACT FROM AUTHOR]

Introgression is pervasive across the tree of life but varies across taxa, geography, and genomic regions. However, the factors modulating this variation and how they may be affected by global change are not well understood. Here, we used 200 genomes and a 15-y site-specific environmental dataset to investigate the effects of environmental variation and mating system divergence on the magnitude of introgression between a recently diverged outcrosser-selfer pair of annual plants in the genus Clarkia. These sister taxa diverged very recently and subsequently came into secondary sympatry where they form replicated contact zones. Consistent with observations of other outcrosser-selfer pairs, we found that introgression was asymmetric between taxa, with substantially more introgression from the selfer to the outcrosser. This asymmetry was caused by a bias in the direction of initial F1 hybrid formation and subsequent backcrossing. We also found extensive variation in the outcrosser's admixture proportion among contact zones, which was predicted nearly entirely by interannual variance in spring precipitation. Greater fluctuations in spring precipitation resulted in higher admixture proportions, likely mediated by the effects of spring precipitation on the expression of traits that determine premating reproductive isolation. Climate-driven hybridization dynamics may be particularly affected by global change, potentially reshaping species boundaries and adaptation to novel environments. [ABSTRACT FROM AUTHOR]

Theory predicts that organisms should diversify their offspring when faced with a stressful environment. This prediction has received empirical support across diverse groups of organisms and stressors. For example, when encountered by Caenorhabditis elegans during early development, food limitation (a common environmental stressor) induces the nematodes to arrest in a developmental stage called dauer and to increase their propensity to outcross when they are subsequently provided with food and enabled to develop to maturity. Here we tested whether food limitation first encountered during late development/early adulthood can also induce increased outcrossing propensity in C. elegans. Previously well‐fed C. elegans increased their propensity to outcross when challenged with food limitation during the final larval stage of development and into early adulthood, relative to continuously well‐fed (control) nematodes. Our results thus support previous research demonstrating that the stress of food limitation can induce increased outcrossing propensity in C. elegans. Furthermore, our results expand on previous work by showing that food limitation can still increase outcrossing propensity even when it is not encountered until late development, and this can occur independently of the developmental and gene expression changes associated with dauer. Caenorhabditis elegans increase their propensity to outcross in response to food limitation encountered during late development. [ABSTRACT FROM AUTHOR]

Numerous empirical studies have witnessed an increase in meiotic recombination rate in response to physiological stress imposed by unfavorable environmental conditions. Thus, inherited plasticity in recombination rate is hypothesized to be evolutionarily advantageous in changing environments. Previous theoretical models proceeded from the assumption that organisms increase their recombination rate when the environment becomes more stressful and demonstrated the evolutionary advantage of such a form of plasticity. Here, we numerically explore a complementary scenario—when the plastic increase in recombination rate is triggered by the environmental shifts. Specifically, we assume increased recombination in individuals developing in a different environment than their parents and, optionally, also in offspring of such individuals. We show that such shift-inducible recombination is always superior when the optimal constant recombination implies an intermediate rate. Moreover, under certain conditions, plastic recombination may also appear beneficial when the optimal constant recombination is either zero or free. The advantage of plastic recombination was better predicted by the range of the population's mean fitness over the period of environmental fluctuations, compared with the geometric mean fitness. These results hold for both panmixia and partial selfing, with faster dynamics of recombination modifier alleles under selfing. We think that recombination plasticity can be acquired under the control of environmentally responsive mechanisms, such as chromatin epigenetics remodeling. [ABSTRACT FROM AUTHOR]

Close-kin mark-recapture (CKMR) is a method analogous to traditional mark-recapture but without requiring recapture of individuals. Instead, multilocus genotypes (genetic marks) are used to identify related individuals in one or more sampling occasions, which enables the opportunistic use of samples from harvested wildlife. To apply the method accurately, it is important to build appropriate CKMR models that do not violate assumptions linked to the species' and population's biology and sampling methods. In this study, we evaluated the implications of fitting overly simplistic CKMR models to populations with complex reproductive success dynamics or selective sampling. We used forward-in-time, individual-based simulations to evaluate the accuracy and precision of CKMR abundance and survival estimates in species with different longevities, mating systems, and sampling strategies. Simulated populations approximated a range of life histories among game species of North America with lethal sampling to evaluate the potential of using harvested samples to estimate population size. Our simulations show that CKMR can yield nontrivial biases in both survival and abundance estimates, unless influential life history traits and selective sampling are explicitly accounted for in the modeling framework. The number of kin pairs observed in the sample, in combination with the type of kinship used in the model (parent-offspring pairs and/or half-sibling pairs), can affect the precision and/or accuracy of the estimates. CKMR is a promising method that will likely see an increasing number of applications in the field as costs of genetic analysis continue to decline. Our work highlights the importance of applying population-specific CKMR models that consider relevant demographic parameters, individual covariates, and the protocol through which individuals were sampled. [ABSTRACT FROM AUTHOR]

Key Message: Interspecific comparison of two Paspalum species has demonstrated that mating systems (selfing and outcrossing) contribute to variation (genetically and morphologically) within species through similar but mutually exclusive processes. Mating systems play a key role in the genetic dynamics of populations. Studies show that populations of selfing plants have less genetic diversity than outcrossing plants. Yet, many such studies have ignored morphological diversity. Here, we compared the morphological and molecular diversity patterns in populations of two phylogenetically-related sexual diploids that differ in their mating system: self-sterile Paspalum indecorum and self-fertile P. pumilum. We assessed the morphological variation using 16 morpho-phenological characters and the molecular diversity using three combinations of AFLPs. We compared the morphological and molecular diversity within and among populations in each mating system. Contrary to expectations, selfers showed higher morphological variation within populations, mainly in vegetative and phenological traits, compared to outcrossers. The high morphological variation within populations of selfers led to a low differentiation among populations. At molecular level, selfing populations showed lower levels of genotypic and genetic diversity than outcrossing populations. As expected, selfers showed higher population structure than outcrossers (PhiST = 0.301 and PhiST = 0.108, respectively). Increased homozygous combinations for the same trait/locus enhance morphological variation and reduce molecular variation within populations in selfing P. pumilum. Thus, selfing outcomes are opposite when comparing morphological and molecular variation in P. pumilum. Meanwhile, pollen flow in obligate outcrossing populations of P. indecorum increases within-population molecular variation, but tends to homogenize phenotypes within-population. Pollen flow in obligate outcrossers tends to merge geographically closer populations; but isolation by distance can lead to a weak differentiation among distant populations of P. indecorum. [ABSTRACT FROM AUTHOR]

Global fruit and nut yields are affected by shortfalls in pollinator populations, and pollen limitation is most prevalent among tropical, bee-pollinated and self-incompatible plants. Macadamia is a subtropical, bee-pollinated crop in which some cultivars have been found to be highly outcrossing. We aimed to determine the extent of outcrossing and its effects on nut quality across a wide range of international macadamia cultivars in three countries. We sampled fruit from 19 macadamia cultivars across 23 sites in Australia, Brazil and South Africa. We used genotype-by-sequencing and MassARRAY methods to assign paternity to individual fruit and we assessed pollen-parent effects on nut quality. Macadamia was highly outcrossing, producing 80–100% of fruit by cross-pollination, at 17 of the 23 sites. Mixed mating (41–72% outcrossing) was identified at five sites, and low outcrossing (10%) was identified in one cultivar at one site where it was isolated from other flowering macadamia trees. Outcrossed fruit often had significantly better quality than selfed fruit, with 1.61–3.39 g higher nut-in-shell mass, 0.53–1.55 g higher kernel mass, 3.3–6.4% higher kernel recovery, and 3.0–3.5% higher oil concentration. The differences in kernel recovery equated to differences in value of USD 433–841 per ton of nut-in-shell at prices of USD 3000 per ton. In summary, macadamia cultivars were mostly highly outcrossing, and outcrossed nuts often had higher quality than selfed nuts. Growers should consider interplanting different cultivars more closely and distributing bee hives more widely to maximise cross-pollination, produce high yields, and optimise nut quality. [ABSTRACT FROM AUTHOR]

Plant reproductive ecology is one of the research hotspots in ecology. With the increasing attention paid to the conservation of plant diversity, the research on reproductive characteristics and flowering biological characteristics of more species has attracted more attention. However, plant reproduction is affected by multiple interacting factors such as pollen limitation and resource availability. Vitex negundo var. heterophylla (Franch.) Rehder (Lamiaceae) is a significant species for water and soil conservation. Previous studies have revealed its mating system by the biological characteristics of flowering and SSR markers, but its reproductive strategies remain to be further studied. We evaluated reproductive success through artificial pollination to explore the reproductive characteristics of V. negundo var. heterophylla for the first time. From the results of fruit set, there is a mixed mating system dominated by outcrossing in V. negundo var. heterophylla accompanied by self‐compatibility, and it cannot carry out autonomous selfing. Our data show the pollinator‐mediated interaction in the success of reproduction, whereas the effect of anemophily is very weak. And the seed germination rate of inbred line progenies was lower than that of hybrid progenies, which is suspected to be caused by inbreeding depression. The research will provide scientific information for the protection and conservation of V. negundo var. heterophylla from the point of view of reproduction. In sum, the results are necessary to protect animal vectors in the background of insect decline. [ABSTRACT FROM AUTHOR]