Ecology and Evolution

In wild animals, glucocorticoid hormones play a key role in responses to environmental stressors and the maintenance of homeostasis, allocating energy between energy-demanding processes. Although acute rises in glucocorticoids are beneficial for short-term survival, prolonged exposure can be detrimental to reproduction and survival. Thus, understanding the factors driving glucocorticoid concentrations is crucial for understanding key processes in ecology and evolution. Here, we examined how manipulation of two environmental stressors - food availability and parasite burden, influence levels of faecal corticosterone in a wild population of wood mice (Apodemus sylvaticus). To do so, we experimentally altered nutrition via food supplementation and reduced gastrointestinal nematode infection by anthelmintic treatment, using Heligmosomoides polygyrus as an indicator of treatment efficacy. Faecal corticosterone was not found to be impacted by food supplementation or anthelminthic treatment. However, our results may be mediated by variation in resource availability or masked by other factors that affect corticosterone. For example, corticosterone declined seasonally and was higher in adult, female mice. While we expected higher food availability and lower worm burden to decrease stress, putatively higher rates of reproduction in food supplemented areas could neutralise any decreases in corticosterone associated with alleviation of food and parasite stress. Thus, alleviating stress in the wild may have unintended consequences on fitness.

O_LIBody condition is an important life history challenge that directly impacts individual fitness and is particularly important for hibernating animals, whose maintenance of adequate body fat and mass is essential for survival. C_LIO_LIIt is well documented that symbiotic microorganisms play a vital role in animal physiology and behaviour. Recent work demonstrates that gut microbes are associated with fat accumulation and obesity; Firmicutes is consistently associated with obesity while Bacteroidetes is associated with leanness both in humans and other animals. C_LIO_LIThe focus of most microbiome studies has been on human health or involved lab reared animals used as a model system. However, these microbes likely are important for individual fitness in wild populations and provide potential mechanistic insights into the adaptability and survival of wildlife. C_LIO_LIHere we test whether symbiotic microorganisms within the phyla of Firmicutes and Bacteroidetes are associated with summer mass gain in an exceptionally well-studied wild population of yellow-bellied marmots (Marmota flaviventer) by quantifying microbial abundance over five years of fecal samples (2015 - 2019) collected during their summer active season. C_LIO_LIResults show that marmots with higher mass gain rates have a greater abundance of Firmicutes. In contrast, higher abundance of Bacteroidetes was associated with lower mass gain rates, but only for marmots living in harsher environments. Similar patterns were found at the family level where Ruminococcaceae, a member of Firmicutes, was associated with higher mass gain rates, and Muribaculaceae, a member of Bacteroidetes, was associated with lower mass gain rates, and similarly in harsher environments. C_LIO_LIAlthough correlative, these results highlight the importance of symbiotic gut microbiota to mass gain in the wild, a trait associated with survival and fitness in many taxonomic groups. C_LI

Mixed mating, a reproduction strategy utilized by many plants and invertebrates, optimizes the cost to benefit ratio of a labile mating system. One type of mixed mating includes outcrossing with conspecifics and self-fertilizing ones own eggs. The mangrove rivulus fish (Kryptolebias marmoratus) is one of two vertebrates known to employ both self-fertilization (selfing) and outcrossing. Variation in rates of outcrossing and selfing within and among populations produces individuals with diverse levels of heterozygosity. I designed an experiment to explore the consequences of variable heterozygosity across four ecologically relevant conditions of salinity and water availability (10{per thousand}, 25{per thousand}, and 40{per thousand} salinity, and twice daily tide changes). I report a significant increase in mortality in the high salinity (40{per thousand}) treatment. I also report significant effects on fecundity measures with increasing heterozygosity. The odds of laying eggs decreased with increasing heterozygosity across all treatments, and the number of eggs laid decreased with increasing heterozygosity in the 10{per thousand} and 25{per thousand} treatments. Increasing heterozygosity also was associated with a reduction liver mass and body condition in all treatments. My results highlight the fitness challenges that accompany living in mangrove forests ecosystem and provide the first evidence for outbreeding depression on reproductive and condition-related traits.

Insects are the most abundant described living creatures in the world, and they play important roles in our global ecosystem. Climate change affects global biodiversity, and researchers in many fields are striving to better understand the impact of the climate crisis. One such endeavour is the study of temperature-dependent effects on insects. At present, we know little of how climate affects gene expression in insects of different sexes. Here, we took four species of fruit flies of the genus Drosophila (D. melanogaster, D. virilis, D. pseudoobscura, and D. erecta), and subjected the male and female flies of each species to three different temperatures to test their sex-specific gene expression responses. A total of 144 transcriptomic profiles of protein-coding genes and microRNAs were generated. We found that, at the same temperature, there were more male-biased than female-biased protein-coding genes and microRNAs in all four investigated drosophilid species. Interestingly, upon temperature changes, there were more differentially expressed protein-coding genes in females than in males in all four investigated species, while the microRNAs were highly species- and sex-specific. This study provides the first evidence that sex-biased protein-coding gene and microRNA expression responses to temperature change differ between insect species within the same genus, and demonstrates the complexity of sex-specific responses of insects to climate change. HighlightsO_LIAt the same temperature, protein coding gene and microRNA expression showed a greater bias towards males than towards females in all four tested insect species. C_LIO_LIIn response to increasing temperature, females of all 4 tested species exhibited more differentially expressed genes than did males, and enrichment analyses showed that they are species-specific. C_LIO_LIDifferentially expressed microRNAs did not show a conserved trend between insects upon temperature changes. C_LIO_LISex-specific gene and microRNA expression of insects in response to climate change evidently involves a complex adaptation mechanism. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=121 SRC="FIGDIR/small/591511v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@1037b18org.highwire.dtl.DTLVardef@18683f3org.highwire.dtl.DTLVardef@40dee5org.highwire.dtl.DTLVardef@e9a108_HPS_FORMAT_FIGEXP M_FIG C_FIG

The coleoid cephalopods (octopus, cuttlefish, and squid) are emerging model organisms for neuroscience, development, and evolutionary biology. Determining their sex early in life is critical for population management and controlled experiments. Here, we present a protocol to non-invasively determine the sex of multiple cephalopod species as young as 3 hours post-hatching using a skin swab and quantitative PCR (qPCR). We describe steps for designing qPCR primers, swabbing live animals, extracting DNA, running the qPCR, and analyzing the results. For complete details on the use and execution of this protocol, please refer to Rubino et al.1 HighlightsO_LISwab live cephalopods as early as 3 hours post-hatching C_LIO_LIExtract DNA from cephalopod skin swabs C_LIO_LIPerform qPCR-based sex determination C_LIO_LIDesign and validate qPCR primers for new species C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=190 SRC="FIGDIR/small/715692v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@3aa68dorg.highwire.dtl.DTLVardef@8c7e61org.highwire.dtl.DTLVardef@1bd45d9org.highwire.dtl.DTLVardef@134cc4d_HPS_FORMAT_FIGEXP M_FIG C_FIG

1O_LIThe ability to select statistical models based on how well they fit an empirical dataset is a central tenet of modern bioscience. How well this works, though, depends on how goodness-of-fit is measured. Likelihood and its derivatives (e.g. AIC) are popular and powerful tools when measuring goodness-of-fit, though inherently make assumptions about the data. One such assumption is absence of error on the x-axis (i.e. no error in the predictor). This, however, is often not correct and deviations from this assumption are often hard (or impossible) to measure. C_LIO_LIHere, we show that, when predictor error is present, goodness-of-fit as perceived using likelihood will increase with decreases in sample size, effect size, predictor error and predictor variance. This results in predictors with increased effect size, predictor variance or predictor error being punished. As a consequence, we suggest that larger effect sizes are biased against in likelihood-based model comparison. Of note: (i) this problem is exacerbated in datasets with larger samples sizes and a broader range of predictor values - typically considered desirable biological data collection; and (ii) the magnitude of this effect is non-trivial given that proxy error (caused by using correlates of a predictor rather than the predictor itself) can lead to unexpectedly high amounts of error. C_LIO_LIWe investigate the effects of our findings in an empirical dataset of wood anemone (Anemone nemorosa) first flowering date regressed against temperature. Our results show that the proxy error caused by using air temperature rather than ground temperature results in a {triangleup}AIC of around 3. We also demonstrate potential consequences for model selection procedures with autocorrelation (e.g. sliding window approaches). Via simulation we show that in the presence of predictor error AIC will favour autocorrelated, lower effect size predictors (such as those found on the edges of predictive windows), rather than the a priori specified true window. C_LIO_LIOur results suggest significant and far-reaching implications for biological inference with model selection for much of todays ecology using observational data under non-experimental conditions. We assert that no obvious, globally-applicable solution to this problem exists; and propose that quantifying predictor error is key in accurate ecological model selection going forward. C_LI

Laboratory studies are often criticized for not being representative of processes occurring in natural populations. This can be partially mitigated by using lab populations that capture large amounts of variation. Additionally, many studies addressing adaptation of organisms to their environment are done with laboratory populations, using quantitative genetics or experimental evolution methodologies. Such studies rely on populations that are either highly outbred or inbred. However, the methodology underlying the generation of such biological resources are usually not explicitly documented. Given their small size, short generation time, amenability to laboratory experimentation and knowledge of their ecological interactions, haplodiploid spider mites are becoming a widely used model organism. Here, we describe the creation of outbred populations of two species of spider mites, Tetranychus urticae and T. evansi, obtained by performing controlled crosses between individuals from field-collected populations. Subsequently, from the outbred population of T. evansi, we derived inbred lines, by performing several generations of sib-mating. These can be used to measure broad-sense heritability as well as correlations among traits. Finally, we outline an experimental evolution protocol that can be widely used in other systems. Sharing these biological resources with other laboratories and combining them with the available powerful genetic tools for T. urticae (and other species) will allow consistent and comparable studies that greatly contribute to our understanding of ecological and evolutionary processes.

Open Science (OS) comprises a variety of practices and principles that are broadly intended to improve the quality and transparency of research, and the concept is gaining traction. Since OS has multiple facets and still lacks a unifying definition, it may be interpreted quite differently among practitioners. Moreover, successfully implementing OS broadly throughout science requires a better understanding of the conditions that facilitate or hinder OS engagement, and in particular, how practitioners learn OS in the first place. We addressed these issues by surveying OS practitioners that attended a workshop hosted by the Living Norway Ecological Data Network in 2020. The survey contained scaled-response and open-ended questions, allowing for a mixed-methods approach. Out of 128 registered participants we obtained survey responses from 60 individuals. Responses indicated usage and sharing of data and code, as well as open access publications, as the OS aspects most frequently engaged with. Men and those affiliated with academic institutions reported more frequent engagement with OS than women and those with other affiliations. When it came to learning OS practices, only a minority of respondents reported having encountered OS in their own formal education. Consistent with this, a majority of respondents viewed OS as less important in their teaching than in their research and supervision. Even so, many of the respondents suggestions for what would help or hinder individual OS engagement included more knowledge, guidelines, resource availability and social and structural support; indicating that formal instruction can facilitate individual OS engagement. We suggest that the time is ripe to incorporate OS in teaching and learning, as this can yield substantial benefits to OS practitioners, student learning, and ultimately, the objectives advanced by the OS movement.

O_LIWithin-species individual variation has been gaining increased attention in ecological studies of species interactions. Yet, these studies rarely consider genetic variation and potential genetic correlations among traits. Moreover, traits beyond those associated with trophic interactions are mostly overlooked. Filling these gaps is important to fully understand the relevance of trait variation in both the ecology and evolution of species interactions. C_LIO_LIWe addressed this using inbred lines of Tetranychus cinnabarinus, a spider mite species that often engages in antagonistic interactions with its congeneric T. urticae. Specifically, we measured (a) the intrinsic growth rate and the sex ratio in the absence of food competition and reproductive interference; (b) food competition against a density gradient of con- or heterospecific competitors in absence of reproductive interference; (c) reproductive interference in absence of food competition; and (d) the body size of adult females and males. C_LIO_LIWe found significant genetic variance (i.e., broad-sense heritability) among lines for all variables except for the effect of T. cinnabarinus on its heterospecific competitor via food competition. Moreover, we showed that lines with higher intrinsic growth were more sensitive to intra- and inter-specific competition for food but exerted stronger reproductive interference on heterospecifics. In addition, the higher the proportion of sons produced by a line, the more resilient it was to reproductive interference but also the lower its growth rate. No genetic correlations were found between any variable and body size. C_LIO_LIOur results indicate that considering the genetic correlations among traits involved in both trophic and sexual interactions is key to understanding the role of individual variation in species interactions and their evolution. C_LI

Sexual selection is often assumed to elicit sexually dimorphic traits. However, most work on this assumption in tetrapod vertebrates has focused on birds. In this field experiment, we assessed relationships between both sexually dimorphic (body size, claw length) and non-dimorphic traits (forelimb stripe color, baseline corticosterone concentrations) and reproductive success in adult painted turtles to explicate the roles of these phenotypes in mate choice and the evolution of sexual dimorphism. We also modified adult sex ratios in experimental ponds to elucidate the role of biased sex ratios on reproductive success, which is a timely test of the potential threat of biased sex ratios on population persistence in a species with temperature-dependent sex determination. We found no strong influence of male phenotypes on male siring success, but female body size and baseline corticosterone concentrations predicted female clutch sizes. We find weak evidence that adult sex ratio influences male siring success, with a male-biased sex ratio producing lower male siring success than a female-biased sex ratio. This study offers evidence that female mate choice may not be an important selective force on male phenotypes, but that instead selection occurs on female phenotypes, particularly body size and corticosterone concentrations. Further, biased adult sex ratios can influence reproductive success of both sexes. Finally, the use of Kompetitive Allele Specific PCR (KASP) was highly successful in parentage analysis, which adds reptiles to the growing list of taxa successfully genotyped with this new technology. Lay SummaryFemale painted turtles arent choosy about traits of their mates. In a field experiment, we find that male traits do not predict male fitness, but key female traits (body size and stress levels) do predict female reproductive success. Further, we find weak evidence that adult sex ratio influences individual fitness in this species with environmental sex determination. Ultimately, we reject the long-assumed importance of female mate choice in this freshwater turtle.

The evolutionary potential of organisms depends on the presence of sufficient genetic variation for traits subject to selection, as well as on the genetic covariances among them. While genetic variation ultimately derives from mutation, theory predicts the depletion of genetic (co)variation under consistent directional or stabilizing selection in natural populations. We estimated and compared additive genetic (co)variances for several standard life history traits, including some for which this has never been assessed, before and after 24 generations of artificial selection on male size in the yellow dung fly Scathophaga stercoraria (Diptera: Scathophagidae) using a series of standard half-sib breeding experiments. As predicted, genetic variances (VA), heritabilities (h2) and evolvabilities (IA) of body size, development time, first clutch size, and female age at first clutch were lower after selection. As independent selection lines were crossed prior to testing, we can rule out that this reduction is due to genetic drift. In contrast to the variances, and against expectation, the additive genetic correlations between the sexes for development time and body size remained strong and positive (rA = 0.8-0.9), while the genetic correlation between these traits within the sexes tended to strengthen (but not significantly so). Our study documents that the effect of selection on genetic variance is predictable, whereas that on genetic correlations is not.

O_LIWarm ocean waters during El Nino events deplete primary productivity, with cascading effects through the food chain that profoundly affect many marine and terrestrial species, commonly increasing adult mortality and offspring starvation. With global warming, events will double and increasingly threaten the depletion or extinction of some animal populations.\nC_LIO_LIBecause adverse environments experienced during infancy generally induce reproductive deficits in adulthood, El Nino events are also expected to affect animals born during them, engendering generations of adults with reduced reproductive potential and exacerbating demographic impacts.\nC_LIO_LIWe made the first test of this idea, using the blue-footed booby, a piscivorous apex predator of the eastern tropical Pacific Ocean. Surprisingly, detailed monitoring of 18 generations over a 27-year period detected no deficits in the annual breeding success, offspring viability, lifespan or lifetime reproductive success of generations of adults born during El Nino years.\nC_LIO_LIThese results testify to remarkable developmental resilience extending across the lifespan. However, there was evidence that this resilience was supported by two mechanisms of quality control of adult generations from El Nino years.\nC_LIO_LIFirst, viability selection on nestlings and fledglings was more severe for El Nino birth cohorts than ordinary cohorts.\nC_LIO_LISecond, in El Nino years, adult boobies self-selected for breeding. There was no increase in the proportional representation of either high quality breeders or breeders in their peak years (middle-age), but there was an increase in old-young adult pairings, which in this population produce the most viable fledglings.\nC_LIO_LIThe blue-footed booby appears to be immune to the expected developmental impact of El Nino on the reproductive value of adult generations. The susceptibilities and resilience of other species need to be explored, to better predict the demographic impacts of this accelerating climatic oscillation.\nC_LI

O_LIThe rapid pace of environmental change seems to outstrip the evolutionary response rates of many species. Physiological, morphological, and behavioral plasticity alone may also not suffice to cope with environments drastic changes, potentially hindering individuals ability to adapt. Therefore, it has been proposed that social flexibility may be a powerful mechanism for fast adaptation, but empirical evidence is lacking. C_LIO_LIWe investigated the combined effects of manipulated social conditions and ambient temperature during the reproductive phase on parental care, reproductive success, and offspring performance of the burying beetle (Nicrophorus vespilloides), a facultative social breeding insect. C_LIO_LIWe conducted a mixed factorial design experiment, establishing four categories of social conditions during breeding (no-care, unifemale-care, biparenta-care, and multiple-care) alongside two thermal conditions (benign: 20{degrees}C and harsh: 23{degrees}C). Additionally, dispersed larvae produced from each of these breeding conditions were allocated to climate rooms maintained at either 20{degrees}C or 23{degrees}C for pupation. Data on brood size, brood mass, dispersed larval weight, larval development duration, body size and lifespan of newly eclosed beetles, and parental care were collected C_LIO_LIOur results showed that (1) harsh temperature and the without-care condition (i.e., no-care compared to the other three social conditions) reduced brood size, brood mass, body size of newly eclosed beetles; (2) social and ambient thermal conditions had interactive effects on dispersed larval weight, larval development duration, and newly eclosed beetles lifespan; and (3) harsh temperature reduced both individual and total parental care, whereas sociality had opposing effects: individual care decreased, but total care increased from unifemale-care to biparental-care and multiple-care conditions. C_LIO_LIOur findings shed light on the critical role of sociality in modulating the adaptive response of individuals to harsh thermal environments, one of the ecological problems exacerbated by ongoing global warming. C_LI

Madagascar exhibits extraordinarily high level of species richness and endemism, while being severely threatened by habitat loss and fragmentation (HL&F). In front of such threat to biodiversity, conservation effort can be directed, for instance, in the documentation of species that are still unknown to science, or in investigating how species respond to HL&F. The tufted-tail rats genus (Eliurus spp.) is the most speciose genus of endemic rodents in Madagascar, with 13 described species, which occupy two major habitat types: dry or humid forests. The large species diversity and association to specific habitat types make the Eliurus genus a suitable model for investigating species adaptation to new environments, as well as response to HL&F (dry vs humid). In the present study, we investigated Eliurus spp. genomic diversity across northern Madagascar, a region covered by both dry and humid fragmented forests. From the mitochondrial DNA (mtDNA) and nuclear genomic (RAD-seq) data of 124 Eliurus individuals sampled in poorly studied forests of northern Madagascar, we identified an undescribed Eliurus taxon (Eliurus sp. nova). We tested the hypothesis of a new Eliurus species using several approaches: i) DNA barcoding; ii) phylogenetic inferences; iii) species delimitation tests based on the Multi-Species Coalescent (MSC) model, iv) genealogical discordance index (gdi); v) the ad-hoc test of isolation-by-distance within versus between sister-taxa, vi) comparisons of %GC content patterns and vii) morphological analyses. All analyses support the recognition of the undescribed lineage as a distinct species. In addition, we show that Eliurus myoxinus, a species known from the dry forests of western Madagascar, is, surprisingly, found mostly in humid forests in northern Madagascar. In conclusion, we discuss the implications of such findings in the context of Eliurus species evolution and diversification, and use the distribution of northern Eliurus species as a proxy for reconstructing past changes in forest cover and vegetation type in northern Madagascar.

It is generally believed that when maternally inherited sex ratio distorters become predominant, either the host population goes extinct or nuclear suppressors evolve in the host. Here, we show an empirical case where all-female-producing Wolbachia is likely to be stably maintained at a high frequency. On an island population of the butterfly Eurema mandarina, a Wolbachia strain wFem, which makes female hosts produce all-female offspring without sibling lethality (female drive), is highly prevalent. We found that, with some fluctuations, wFem appeared to be stably maintained for at least 12 years at a high frequency, resulting in the existence of an abnormally high number of virgin females. Interestingly, comparison between sex ratios of captive individuals and sex ratios deduced from wFem frequencies suggested a plastic behavioral change of males and females in response to the shift of sex ratios. wFem presence does not affect brood size but has a slightly negative effect on body size. Stable coexistence of wFem-positive and -negative females in the population may be explained via mate choice by males, which keeps wFem in check. Taken together, this butterfly population is an attractive model for future studies on the population dynamics of sex ratios and mating behavior.

1. IntroductionTiming of birth is a major determinant of individuals reproductive success and survival, and is driven by multiple internal and external factors. However, there is currently no quantitative assessment of the extent and support received by the drivers of the phenology of births in mammals. Due to their diverse phenology of births, large herbivores represent an ideal case study to quantify this. 2. Aimsour objective was to identify the different drivers tested for their effect on the phenology of births in large herbivores and how much empirical support they received, as well as determine thematic, taxonomic and spatial gaps in the literature. 3; MethodsWe conducted a systematic review focusing on the drivers of the phenology of births in wild large herbivores. We extracted the outcomes of 124 relevant articles and assessed the reliability of their findings using a general index based on the quality of the data and methods used. 4. Results and DiscussionAs expected, the two dominant hypotheses (seasonality and predation) received strong support regarding their effect on birth timing and synchrony, respectively. The effect of female, offspring and population characteristics remained marginally accounted for, even though there was evidence of their importance in the determination of the phenology of births. We identified a major research gap in Asian and South and Central American species. 5. ConclusionsWe encourage research in these understudied domains, as well as large scale multi-species comparative analyses to fill in the gaps and improve our understanding of reproductive phenology. Graphical abstract legend O_FIG O_LINKSMALLFIG WIDTH=113 HEIGHT=200 SRC="FIGDIR/small/694258v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@1ff01dforg.highwire.dtl.DTLVardef@d3dc99org.highwire.dtl.DTLVardef@137e41corg.highwire.dtl.DTLVardef@610382_HPS_FORMAT_FIGEXP M_FIG This systematic review confirmed the strong support received by the two dominant drivers of births phenology, the seasonality and predation hypotheses. Even though there is evidence of their importance, the effects of female, offspring and population characteristics remain marginally accounted for. Asian and South/Central American species are currently understudied. C_FIG

Substantial anthropogenic changes to the environment have motivated efforts to quantify temporal trends in population dynamics. While most ecological research has focused on the mean and variance of population density and reproduction, the frequency of these fluctuations through time may also be changing. We analyzed 1,563 datasets of population density and 1,456 datasets of plant reproduction (masting) across the globe. The average frequency of fluctuations increased by [~] 0.5 - 3% per decade within each time series, representing a moderate change (Cohens d {approx} 0.4) over a period of 60 years. We tested four hypothesized mediators of this trend: increased temperature, increased frequency of environmental forcing, increased intrinsic growth rate, and increased distance from a saddle at zero density. Although all hypotheses were rejected, changes in the frequency of environmental forcing and intrinsic growth rate exhibited positive correlations with changes in population fluctuation frequency as expected. Our results suggest that successive peaks in population and masting density fluctuations are becoming closer in time, which may reduce the effectiveness of predator satiation, resilience of food-webs, and the risk of critical transitions, such as population extinction. We suggest some alternative hypotheses for what may underlie this surprising global pattern.

O_LIThe transgenerational plasticity of maternal effects on offspring phenotypes has been well recognized, however, weather maternal effect can drive dynamic changes in population genetic structure by modifying the competitive dynamics among offspring is still unclear. C_LIO_LIAfter evaluation of the reliability of COI metabarcoding for intraspecific clone quantification using a monogonont rotifer Brachionus calyciflorus as the model animal, a high-frequency dynamic monitoring experimental system was set to measure maternal effect on temporal dynamics in gene frequencies within mixed populations containing morphologically identical clones. C_LIO_LIResults showed that maternal effects significantly enhanced the competitive fitness of the target offspring clone, leading to a rapid increase in its frequency inside the population. However, this advantage last for a few generations, and gradually diminished or even reversed as the maternal effects attenuated across generations. C_LIO_LITemperature dynamically affected the duration of maternal effect: higher temperature shortened the duration of maternal effects on population genetic dynamics, while lower temperature prolonged it. C_LIO_LIBy population dynamic monitoring, this study revealed the transient nature of maternal effect as a non-genetic buffering mechanism, providing an integrative theoretical framework for understanding the dynamic integration of short-term plasticity and long-term selection pressure in adaptive evolution of intraspecific clones. C_LI

The endemic Bornean tufted ground squirrel, Rheithrosciurus macrotis, has attracted great interest among biologists and the public recently. Nevertheless, we lack information on the most basic aspects of its biology. Here we present the first empirical data on the feeding ecology of tufted ground squirrels, and use data from 81 sympatric mammalian and avian vertebrates to place it within a broad comparative context. R. macrotis is a dedicated seed predator and shows much more extreme ecological specialization than any other vertebrate, feeding on a far smaller subset of available plant foods and demonstrating a greater reliance on a single plant species- Canarium decumanum-than any other vertebrate taxon. Our results suggest that R. macrotis plays an important, previously unknown role in the ecology of Bornean lowland forests, and highlight how much we have yet to learn about the fauna inhabiting some of the most diverse, and most severely threatened, ecosystems on the planet.

Ecological interactions can generate close associations among species, which can in turn generate a high degree of overlap in their spatial distributions. Co-occurrence is likely to be particularly intense when species exhibit obligate comigration, in which they not only overlap in spatial distributions but also travel together from patch to patch. In theory, this pattern of ecological co-occurrence should leave a distinct signature in the pattern of genetic differentiation within and among species. Perhaps the most famous mutual co-isolation partners are fig trees and their co-evolved wasp pollinators. Here, we add another tropic level to this system by examining patterns of genomic diversity in the nematode Caenorhabditis inopinata, a close relative of the C. elegans model system that thrives in figs and obligately disperses on fig wasps. We performed RADseq on individual worms isolated from the field across three Okinawan island populations. The male/female C. inopinata is about five times more diverse than the hermaphroditic C. elegans, and polymorphism is enriched on chromosome arms relative to chromosome centers. FST is low among island population pairs, and clear population structure could not be easily detected among figs, trees, and islands, suggesting frequent migration of wasps between islands. Moreover, inbreeding coefficients are elevated in C. inopinata, consistent with field observations suggesting small C. inopinata founding populations in individual figs. These genetic patterns in C. inopinata overlap with those previously reported in its specific fig wasp vector and are consistent with C. inopinata population dynamics being driven by wasp dispersal. Thus, interspecific interactions can align patterns of genetic diversity across species separated by hundreds of millions of years of evolutionary divergence. HighlightsO_LIThe fig-dwelling female/male nematode Caenorhabditis inopinata is five times more diverse than its closest relative, the self-fertilizing nematode C. elegans. C_LIO_LIC. inopinata migrates frequently among three Okinawan islands despite high levels of inbreeding within individual figs. C_LIO_LIC. inopinata has patterns of genetic diversity that mirror its fig wasp vector. C_LIO_LIEcological specialization aligns patterns of genetic differentiation in closely interacting species. C_LI