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Religion, a shared social system that connects people with a supernatural power, exists in human populations worldwide. Scientists have long debated whether religion is a cultural or evolutionary phenomenon; that is, whether religion is a learned set of values, beliefs, and behaviors, or instead the result of gene variants that have increased in frequency over time. In this paper, I argue that natural selection, the process by which the frequency of certain genes increases over generations due to their reproductive benefit, has played a role in the persistence of religion. I begin by providing background on the definitions of religion, biological evolution, and adaptation, which are necessary to clarify before analyzing the role of biological evolution and adaptivity in religion. I then explain and provide evidence for how religion meets the three conditions of natural selection. Finally, I present multiple adaptive hypotheses to explain how religion might increase fitness. This work clarifies scientific understanding of how natural selection impacts religion and expands on existing adaptive hypotheses that explain how religion might increase biological fitness.

Bacterial plasmids and other extrachromosomal DNA elements frequently carry genes with important fitness effects for their hosts. Multicopy plasmids can additionally carry distinct alleles of host-fitness-relevant genes on different plasmid copies, allowing for heterozygosity not possible for loci on haploid chromosomes. Plasmid-mediated heterozygosity may increase the fitness of bacterial cells in circumstances where there is an advantage to having multiple distinct alleles (heterozyogote advantage); however, plasmid-mediated heterozygosity is also subject to constant loss due to random segregation of plasmid copies on cell division. We analyze a multitype branching process model to study the evolution and maintenance of plasmid-mediated heterozygosity under a heterozygote advantage. We focus on an evolutionary rescue scenario in which a novel mutant allele on a plasmid must be maintained together with the wild-type allele to allow population persistance (although our results apply more generally to the maintenance of heterozygosity due to heterozygote advantage). We determine the probability of rescue and derive an analytical expression for the threshold on the fitness of heterozygotes required to overcome segregation and make rescue possible; this threshold decreases with increasing plasmids copy number. We further show that the formation of cointegrates from the fusion of plasmid copies increases the probability of rescue. Overall, our results provide a rigorous quantitative assessment of the conditions under which bacterial populations can adapt to multiple stressors through plasmid-mediated heterozygosity. Many of the results are furthermore applicable to the related problem of the maintenance of incompatible plasmids in the same cell under selection for both. [ABSTRACT FROM AUTHOR]

The common earwig Doru luteipes (Dermaptera: Forficulidae) is a generalist/omnivorous predator which is easily reared and is commonly found in many agricultural crops. The attendance of males during rearing may represent a hindrance, affecting longevity, food consumption, and use of other rearing-related resources. During dermapteran mating, a ritual between males and females is common; however, this has not been reported for D. luteipes. We observed D. luteipes mating and evaluated the role that male attendance plays in the reproductive success of D. luteipes females and progeny generation. We used three treatments: i) one male × a newly emerged female for 24 h after mating, ii) three males × the newly emerged female from mating up until the first egg laying, and iii) three males × a female from mating until death. Subsequently, only a female or female + male were held in plastic containers with an artificial diet and shelter for oviposition. There were differences among the treatments in the pre-oviposition period, percentage of nymph hatching, percentage of fertilized eggs, and duration of maternal care for inviable eggs. Female longevity was higher in the treatments that had a lower nymph hatching rate. This can be attributed to the fact that the females spent less energy caring for newly hatched nymphs or egg cannibalism. Our results indicate that for females to lay fertile eggs, factors such as mate acceptance, male competition, or a higher quantity of sperm in the spermatheca that can influence the percentage of nymph hatching and offspring generation. [ABSTRACT FROM AUTHOR]

The ecological success of ants hinges on their ability to adjust foraging strategies. Foragers are crucial for securing food resources and display heterogeneities in exploring their foraging area, learning new environmental cues to successfully return to their nests. Despite reports that old workers typically handle foraging and abiotic factors that impact foraging of ants, the specifics of the foraging behavior of Ectatomma vizottoi — such as time dedicated to food search, trajectory, and area — remain unknown. Therefore, this study aimed to assess the foraging behavior of this species. We observed foragers from 12 colonies during 126 field trips, recording behaviors, forager displacements, and estimating prey size. Foragers of this species devoted most of their time searching for food, adopting a sit-and-wait behavior in most foraging trips until concluding the search; encounters with conspecifics from different colonies resulted in aggression. A positive correlation was found between time spent outside the nest and total forager trajectory. While no preferential directions were observed, foraging areas did not overlap with foraging areas of neighboring nests. Therefore, this species is territorial, and its foraging appears to be influenced by various factors, including prey availability and size, and competition. [ABSTRACT FROM AUTHOR]

Premise of research. The functional significance of sterile flowers represents an interesting topic in floral biology and evolution. Sterile flowers have been hypothesized to attract pollinators, increasing plant fitness. Additionally, there may be postpollination effects through resource allocation from sterile to fertile flowers, also aiding in reproduction. I tested these two hypotheses in the grape hyacinth Muscari armeniacum , in which sterile flowers are inconspicuous, few, and small, located at the apex of a racemose inflorescence. Methodology. I carried out field experiments in which sterile flowers were left intact or removed early (beginning of flowering) or late (end of flowering) and recorded insect visitation and fruit and seed production. Pivotal results. The presence of sterile flowers did not increase insect attraction or the number of visited flowers. Flower position within inflorescences showed a significant association with fruiting not related to the presence or closeness to sterile flowers. Reproductive success was considerably low and not affected by early or late removal of sterile flowers, and seed output was not influenced by flower position. There was a significant negative effect of the number of flowers per inflorescence on fruit set. Conclusions. No evidence was found for either Darwin's hypothesis that sterile flowers promote attraction or the hypothesis that there are postpollination effects through resource allocation from sterile to fertile flowers for reproduction. The findings suggest that top sterile flowers could be vestigial features. [ABSTRACT FROM AUTHOR]

Crop production must cope with the increasing challenges of feeding 9.8 billion people by 2050. This challenge is further compounded by many abiotic stressors such as drought stress, high temperatures or low nutrient efficiency in crop production systems imposing a foremost restrain to global food security. Extreme and instantaneous variations in global climatic conditions have caused a surge in new weed flora with widened weed shifts. Weed species such as Echinochola crus-galli, Amaranthus spp., Xanthium strumarium , Sorghum halepense, to name few, survive and disperse under severe environmental conditions. Weeds have evoked physiological adaptation mechanisms with higher phytoelicitor activity that contribute their resistance to wider environments. They possess many unique ecophysiological traits with considerably high concentration of bioactive compounds such as trisaccharide, glycol alkaloids, chaconine, solanine and their hydrolysed metabolites that enable them to adapt and enhance their survival and invasive capabilities. Weed based bioactive compounds gain momentum in crop production systems owing to their unique phytostimulatory properties and effects linked to upregulation of defense related pathways in plant system. For example, weed biostimulants are reported to increase yield by 18 % in cereals, legumes, fruits and vegetables under drought stress. The projected increase of these substances globally is expected to increase by US$3.4 Bn in 2023 to US$ 9.6 Bn in 2033. This work focuses on the analysis of these compounds produced by individual weed species, which could hold an essential role in plant-environment interactions potentially improving metabolomics and evolutionary fitness of the crops towards abiotic stress. [ABSTRACT FROM AUTHOR]

SUMMARY: Reproductive behaviour plays a crucial role in goose production. To date, in most production systems, natural mating is favoured, which has a large impact on successful fertilisation. Two-thirds of the courtships and copulations occurred before noon in Zatorska and Grimaud geese. Depending on the breed, mating activity showed a seasonal pattern (peaking around January–February in Zatorska geese), ranged between 0.5 and 8.5 mating/day, was twice as common in the morning, varied with age and correlated with fertility. To accommodate a less stressful environment for laying and to protect the eggs, individual nest boxes (0.5 × 0.5 × 0.5 m, made of wood, bedded with straw) should be provided along the walls of the shed. Depending on the breed, oviposition interval may vary greatly (between 29 and 60 h), and egg laying may occur in specific times of the day or throughout the day. Broodiness in intensive production systems, due to artificial incubation, is an unwanted behaviour. Despite persistent selection, the occurrence of broodiness is almost 100% in some goose breeds (e.g. Magang or Zhedong geese), while in others, it is less than 5% (Rhine or Huozan geese). Parental care is not relevant in intensive production systems; however, occasionally, goslings are naturally hatched, and the observation of parental behaviours may give insight into the needs of the goslings. Proper environmental conditions and husbandry practices that mimic natural settings can enhance reproductive success, increase gosling survival rates and maintain a healthy social structure within the flock. By recognising and integrating goose reproductive behaviours into management practices, farm managers can optimise production, improve breeding outcomes and ensure the welfare of the animals. This approach leads to healthier flocks, better reproductive performance and, ultimately, more sustainable and humane goose farming operations. [ABSTRACT FROM AUTHOR]

The Antarctic midge, Belgica antarctica, is a unique insect endemic to Antarctica. It has a 2-year life cycle, with larvae overwintering in two different instars and adults emerging the following summer. This seasonality is crucial for adaptation to Antarctica's harsh climates and ephemeral growing seasons; however, the underlying mechanisms remain unclear. We found that, under summer-like conditions, larvae could develop from egg to the fourth-instar larval stage without interruption, but they never pupated. Spontaneous developmental arrest at this stage suggests that they overwinter in obligate diapause, a genetically determined period of dormancy. The winter cold can terminate this diapause, and long-term cold exposure is more effective. Although this species can utilise two alternative cold tolerance strategies with diapause for overwintering, freezing was more successful than cryoprotective dehydration in allowing survival and developmental resumption in our experimental conditions. In contrast, the first three larval instars continued their development under the same conditions as the fourth-instar larvae. Although we do not exclude the possibility of facultative diapause, they likely overwinter in a quiescent state, an immediate developmental arrest in response to adversity, to maximise exploitation of the short Antarctic summer. Diapause and quiescence ensure developmental and reproductive success in this extremophile insect. [ABSTRACT FROM AUTHOR]

Light functions as the universal language in the deep sea (>200 m). Both bioluminescent emissions and downwelling light sources dimly illuminate the water column and can drive sensory system evolution. In pelagic environments, vertically migrating animals can experience drastic changes to their lighting environment across depth, subjecting them to unique selective pressures, possibly to distinguish between changes in ambient light and bioluminescent sources. Here we show that visual opsin diversity across a group of variable vertical migrators -bioluminescent deep-sea shrimp belonging to the Superfamily Oplophoroidea- is higher among species who migrate to shallower waters with more variable light conditions. Further, we provide evidence for adaptive visual evolution among species who have evolved an additional mode of bioluminescence (photophores), including positive selection for a putative mid-wavelength sensitive opsin that may facilitate light source discrimination. Diversification of this opsin appears to play an important role in the visual ecologies of photophore-bearing shrimp with its diversification in Oplophoroidea likely playing a critical role in the fitness and evolutionary success of this group. Diversification of a mid-wavelength opsin appears to play an important role in the visual ecologies of bioluminescent shrimps with a higher diversity of opsins in taxa that migrate to shallower waters with more variable light conditions. [ABSTRACT FROM AUTHOR]

Breeding success and survival in colonial seabirds are influenced by nest location, physical surroundings, and external disturbances. Nest location may also directly or indirectly affect individual foraging behavior and physiological conditions, shaping reproductive success and survival. Despite these influences, few studies have integrated the analysis of nest location, behavior, and physiological status. In this study, we analyzed 20 black-tailed gulls (Larus crassirostris) nesting in the center of a colony within a protected area (Central Group, CG) and five gulls on the periphery outside the protected area, where human disturbance is frequent (Peripheral Group, PG). Using GPS movement trajectories and physiological indicators, we found that although clutch sizes were similar between the CG and PG, the PG exhibited shorter foraging trip durations, maximum distances from the nest, and a lower daily frequency of foraging trips. Antioxidant capacity did not differ between the groups; however, oxidation levels were lower in the PG. These behavioral and physiological differences associated with nest location may partly result from the incubation period influenced by human activity. The PG individuals remained in the peripheral group for at least 2 years (some for over 15 years), with all reproductive attempts failing, suggesting consistently low reproductive success. However, reduced foraging activity and lower oxidative stress levels reflect an energy-saving strategy that may mitigate the costs of repeated breeding failures. These findings suggest a potential life-history trade-off, in which individuals prioritize survival over reproductive success. This highlights how external disturbances and nest location can shape energy allocation strategies within a colony's peripheral-central distribution. [ABSTRACT FROM AUTHOR]

Photoperiodic responses shape plant fitness to the changing environment and are important regulators of growth, development, and productivity. Photoperiod sensing is one of the most important cues to track seasonal variations. It is also a major cue for reproductive success. The photoperiodic information conveyed through the combined action of photoreceptors and the circadian clock orchestrates an output response in plants. Multiple responses such as hypocotyl elongation, induction of dormancy, and flowering are photoperiodically regulated in seed plants (eg. angiosperms). Flowering plants such as Arabidopsis or rice have served as important model systems to understand the molecular players involved in photoperiodic signalling. However, photoperiodic responses in non-angiosperm plants have not been investigated and documented in detail. Genomic and transcriptomic studies have provided evidence on the conserved and distinct molecular mechanisms across the plant kingdom. In this review, we have attempted to compile and compare photoperiodic responses in the plant kingdom with a special focus on non-angiosperms. [ABSTRACT FROM AUTHOR]

Cryptic genetic variation is increasingly being identified in numerous coral species, with prior research indicating that different cryptic genetic lineages can exhibit varied responses to environmental changes. This suggests a potential link between cryptic coral lineages and local environmental conditions. In this study, we investigate how communities of cryptic coral lineages vary along environmental gradients. We began by identifying cryptic genetic lineages within six coral species sampled around St. Croix, USVI based on 2b-RAD sequencing data. We then analyzed associations between the distributions of cryptic lineages across the six coral species (i.e., "cryptic coral community composition") and ecoregions, or geographically distinct environmental conditions. Our findings show that depth is a more significant predictor of community composition than ecoregions and is the most influential factor among the 40 abiotic variables that characterize ecoregions. These results imply that cryptic coral communities are influenced by both depth and local environmental conditions, although the exact environmental factors driving these patterns remain unknown. Understanding community turnover across a seascape is important to consider when outplanting corals to restore a reef, as locally-adapted lineages may have differential fitness in different environmental conditions. [ABSTRACT FROM AUTHOR]

Beetles that feed on the nutritionally depauperate and recalcitrant tissues provided by the leaves, stems, and roots of living plants comprise one-quarter of herbivorous insect species. Among the key adaptations for herbivory are plant cell wall-degrading enzymes (PCWDEs) that break down the fastidious polymers in the cell wall and grant access to the nutritious cell content. While largely absent from the non-herbivorous ancestors of beetles, such PCWDEs were occasionally acquired via horizontal gene transfer (HGT) or by the uptake of digestive symbionts. However, the macroevolutionary dynamics of PCWDEs and their impact on evolutionary transitions in herbivorous insects remained poorly understood. Through genomic and transcriptomic analyses of 74 leaf beetle species and 50 symbionts, we show that multiple independent events of microbe-to-beetle HGT and specialized symbioses drove convergent evolutionary innovations in approximately 21,000 and 13,500 leaf beetle species, respectively. Enzymatic assays indicate that these events significantly expanded the beetles' digestive repertoires and thereby contributed to their adaptation and diversification. Our results exemplify how recurring HGT and symbiont acquisition catalyzed digestive and nutritional adaptations to herbivory and thereby contributed to the evolutionary success of a megadiverse insect taxon. [Display omitted] • Genomics and transcriptomics resolve the phylogeny of leaf beetle subfamilies • Plant cell wall-degrading enzymes (PCWDEs) show a dynamic evolutionary history • Multiple symbiont acquisitions and horizontal gene transfers contributed new PCWDEs • Symbiosis and HGT expanded beetles' digestive repertoires, fueling their success Leaf beetles are among the most speciose herbivores on earth. Kirsch et al. show that multiple independent symbiont acquisitions and microbe-to-host horizontal gene transfers shaped the beetles' repertoire of plant cell wall-degrading enzymes, catalyzing digestive adaptations and contributing to the evolutionary success of this megadiverse taxon. [ABSTRACT FROM AUTHOR]

Background: The oceanic microbiome is dominated by members of the SAR11 clade. Despite their abundance, challenges in recovering the full genetic diversity of natural populations have hindered our understanding of the eco-evolutionary mechanisms driving intra-species variation. In this study, we employed a combination of single-amplified genomes and long-read metagenomics to recover the genomic diversity of natural populations within the SAR11 genomospecies Ia.3/VII, the dominant group in the Mediterranean Sea. Results: The reconstruction of the first complete genome within this genomospecies revealed that the core genome represents a significant proportion of the genome (~ 81%), with highly divergent areas that allow for greater strain-dependent metabolic flexibility. The flexible genome was concentrated in small regions, typically containing a single gene, and was located in equivalent regions within the genomospecies. Each variable region was associated with a specific set of genes that, despite exhibiting some divergence, maintained equivalent biological functionality within the population. The environmental pangenome is large and enriched in genes involved in nutrient transport, as well as cell wall synthesis and modification, showing an extremely high degree of functional redundancy in the flexible genome (i.e. paralogisms). Conclusions: This genomic architecture promotes polyclonality, preserving genetic variation within the population. This, in turn, mitigates intraspecific competition and enables the population to thrive under variable environmental conditions and selective pressures. Furthermore, this study demonstrates the power of long-read metagenomics in capturing the full genetic diversity of environmental SAR11 populations, overcoming the limitations of second-generation sequencing technologies in genome assembly. 26-nWf5Sa4kxKi3nEWFJBw Video Abstract [ABSTRACT FROM AUTHOR]

Mytella strigata, a potentially invasive species native to South America, is rapidly spreading across various aquatic ecosystems around the globe, posing a threat to native mussels. This study presents the first comprehensive de novo transcriptome assembly of M. strigata. We generated 254 million reads, which were processed and assembled using the Trinity assembler, resulting in 60362 transcripts with an N50 of 1,578 bp and over 93–98% completeness, as confirmed by BUSCO analysis with multiple ortho-datasets. A number of databases were used for functional annotation, including UniProt, KEGG, Reactome, InterPro, and eggNOG. Gene Ontology and pathway analyses identified transcripts associated with key biological processes, including those associated with cell signalling, metabolism, stress responses, cancer pathways, and immune regulation. This dataset enriches the bivalve database by advancing the understanding of the adaptive success and evolutionary resilience of this invasive species. The present study provides a fundamental framework for future research on the ecological and evolutionary impacts of this invasive species. [ABSTRACT FROM AUTHOR]

Reports of primate violence frequently note wounds to the genital region, raising the possibility that attackers target genitals to eliminate the reproductive capacity of rivals. Alternatively, in chimpanzees (Pan troglodytes) and other species with prominent genitals, injuries may occur simply because large size makes genitals easy targets. To test these hypotheses, we compiled records of wounds suffered by chimpanzees in four communities at three long-term study sites (Gombe, Tanzania; Kibale, Uganda; Fongoli, Senegal), including both nonlethal (N = 1,268 wounds; N = 891 male wounds; N = 377 female wounds) and lethal attacks (N = 258 wounds), to determine whether genital wounding occurred more frequently than expected by chance. In nonfatal cases, wounds occurred in the genital region more often than expected for females (Kasekela: N = 9/80 wounds, Mitumba: N = 8/61 wounds, Fongoli: N = 11/84 wounds, Kanyawara: N = 31/152 wounds), but only in Kasekela did males suffer genital wounds more often than expected by chance (Kasekela: N = 3/80 wounds, Mitumba: N = 2/48 wounds, Fongoli: N = 6/413 wounds, Kanyawara: N = 4/350 wounds). In contrast, killings of males involved genital wounds more often than expected (N = 12/258 wounds). Increased genital wounding may occur when genitals are more accessible, such as when females flee from male aggression, exposing their hindquarters, or when victims are immobilized during fatal attacks. [ABSTRACT FROM AUTHOR]

Despite the advantages of lasting pair bonds and the prevalence of monogamy, at least in avian species, some individuals switch mates (divorce). Divorce is generally considered to be adaptive (i.e., conferring net fitness benefits), although its causes and consequences often remain unclear, most notably regarding the genetic basis of this behavior. Using more than 30 years of data in a long-lived bird with obligate biparental care, the Alpine swift, we first described the overall patterns of mate and nest site fidelity and investigated the predictors of between-year divorce. We show that 16.6% of pairings ended in divorce, with low reproductive success and young age as predictors of divorce, and that males retained the nest site more often than females. By then studying individual repeatability and heritability of divorce, we show moderate repeatability in females and low repeatability in males and little additive genetic variance in either sex. Finally, we assessed the fitness consequences of divorce and report that an active decision to modify the pair bond (divorce) may be more beneficial than reactionary re-pairing following a partner's death. Overall, divorce may provide some reproductive benefits for Alpine swifts, but no microevolutionary potential of this behavior is evident in this population. [ABSTRACT FROM AUTHOR]

Evolutionary theorists have emphasized for over half a century that population sampling must be conducted at the intergenerational boundary if the distinct effects of selection and inheritance are to be reliably quantified, with individuals recognized at the point of conception and lifetime reproductive success (LRS) defined as the total number of zygotic offspring produced per zygote. However, in those species whose ecology is otherwise well-suited to individual-level population studies, the prenatal part of an individual's life is often difficult to observe. While uncertainty has long surrounded the fertilization status of unhatched bird eggs—hatching failure can arise through fertilization failure or prenatal mortality—2 recent studies show fertilization failure to be extremely rare within 2 of the most popular avian study species. As such, unhatched eggs are highly reliable indicators of prenatal mortality. Although the generality of these results remains unclear, they demonstrate that prenatality can be incorporated into the observable lifespan of free-living animals. This allows zygotic LRS to be retrospectively quantified using historical nest observations and facilitates a more complete characterization of the evolutionary dynamics of wild populations. [ABSTRACT FROM AUTHOR]

Bacteria in the genus Vibrio, including at least 152 species, thrive in marine and estuarine environments and are frequently detected in aquatic products worldwide. Of these, 12 species have been implicated in human infectious diseases, such as the life-threatening pandemic cholera, acute gastroenteritis, and severe sepsis. Nevertheless, molecular mechanisms of their pathogenesis are not fully uncovered yet. Prophages are found prevalent in Vibrio spp. genomes, carrying a number of genes with various functions. In this review, we deciphered the evolutionary relationship between prophages and Vibrio species and highlighted the impact of prophages on the bacterial pathogenicity, environmental fitness, and genome evolution, based on 149 newly discovered intact prophages located in the genomes of 82 Vibrio spp., which we searched and collected from Web of Science Core Collection in the most recent 5 years. The effects of prophages on resistance to superinfection, strain competition, and their regulation were also discussed. This review underscored crucial roles of prophages in shaping Vibrio spp. genomes and their implications for food safety and public health. [ABSTRACT FROM AUTHOR]

Background: Urbanization is rapidly altering our ecosystem. While most wild species refrain from entering urban habitats, some flourish in cities and adapt to the new opportunities these offer. Urban individuals of various species have been shown to differ in physiology, morphology, and behavior compared to their rural counterparts. While several studies have suggested that urban dwelling alters the reproductive cycle in birds, such evidence currently has not been shown for mammals. Egyptian fruit bats are highly flexible mammals that roost and forage in both urban and rural habitats. Urban-dwelling fruit bats encounter higher average temperatures and a richer supply of food (mainly fruit) during winter. Results: Here, we set out to determine whether urban-dwelling fruit bats take advantage of urbanization and reproduce earlier in the annual cycle than rural fruit bats. We sampled ten fruit bat colonies located in different urbanization levels, over 3 years. We monitored the bats' reproductive state and the size of the pups following parturition. Indeed, we found that urban fruit bats gave birth ~ 2.5 weeks earlier in spring than rural fruit bats. We also found that roosting in urban colonies did not decrease the bats' reproductive success, in contrast to what has been suggested for some urban birds. Conclusions: Our study provides new insights into the adaptation to urban living and its exploitation by one of the most common mammalian groups found in cities worldwide—bats. [ABSTRACT FROM AUTHOR]

We know more about the costs of chronic stress than the benefits of the acute stress response--an adaptive response that buffers organisms from life-threatening challenges. As yet, no primate study has empirically identified how the stress response adaptively affects evolutionary fitness. Here, we take advantage of a natural experiment--an El Niño drought--that produced unprecedented mortality for wild white-faced capuchins. Using a reaction norm approach, we provide evidence from primates that a more robust stress response to a challenge, measured using fecal glucocorticoids, predicts a greater likelihood of survival. We show that individuals with greater stress responsiveness to previous droughts later had higher survival across a severe El Niño drought. Evolutionary models need empirical data on how stress responsivity varies in adaptive ways. While we cannot buffer subjects from catastrophic events, we can use them to understand which aspects of the stress response help animals to "weather the storm.". [ABSTRACT FROM AUTHOR]

The intensity and direction of sexual selection are intricately linked to the social and ecological context. Both operational sex ratios (OSRs) and population densities can affect the ability of males to monopolize resources and mates, and thus the form and intensity of sexual selection on them. Here, we studied how the mating system of the promiscuous and strongly sexually dimorphic fruit fly Drosophila prolongata responds to changes in the OSR and population density. We recorded groups of flies over five days and quantified territory occupancy, mating success (MS) and competitive fertilization success. Although sexual selection was stronger under male-biased than even OSRs but unrelated to density, realized selection on morphological traits was higher under even OSRs and increased with density. Larger and more territorial males achieved both higher MS and competitive fertilization success, but only under even OSRs. Our combined results also support a shift in the mating system from territorial contest competition to scramble competition under male-biased OSRs and potentially at low density, where there was no clear contribution of the measured traits to reproductive success. Our study emphasizes the limitations of traditional selection metrics and the role of the socio-ecological context in predicting adaptation to a changing environment. [ABSTRACT FROM AUTHOR]

Background: Hybridization between evolutionary lineages has profound impacts on the fitness and ecology of hybrid progeny. In extreme cases, the effects of hybridization can transcend ecological timescales by introducing trait novelty upon which evolution can act. Indeed, hybridization can even have macroevolutionary consequences, for example, as a driver of adaptive radiations and evolutionary innovations. Accordingly, hybridization is now recognized as a motor for macrobial evolution. By contrast, there has been substantially less progress made towards understanding the positive eco-evolutionary consequences of hybridization on holobionts. Rather, the emerging paradigm in holobiont literature is that hybridization disrupts symbiosis between a host lineage and its microbiome, leaving hybrids at a fitness deficit. These conclusions, however, have been drawn based on results from predominantly low-fitness hybrid organisms. Studying "dead-end" hybrids all but guarantees finding that hybridization is detrimental. This is the pitfall that Dobzhansky fell into over 80 years ago when he used hybrid sterility and inviability to conclude that hybridization hinders evolution. Goldschmidt, however, argued that rare saltational successes—so-called hopeful monsters—disproportionately drive positive evolutionary outcomes. Goldschmidt's view is now becoming a widely accepted explanation for the prevalence of historical hybridization in extant macrobial lineages. Aligning holobiont research with this broader evolutionary perspective requires recognizing the importance of similar patterns in host–microbiome systems. That is, rare and successful "hopeful holobionts" (i.e., hopeful monsters at the holobiont scale) might be disproportionately responsible for holobiont evolution. If true, then it is these successful systems that we should be studying to assess impacts of hybridization on the macroevolutionary trajectories of host–microbiome symbioses. Results: In this paper, we explore the effects of hybridization on the gut (cloacal) and skin microbiota in an ecologically successful hybrid lizard, Aspidoscelis neomexicanus. Specifically, we test the hypothesis that hybrid lizards have host-associated (HA) microbiota traits strongly differentiated from their progenitor species. Across numerous hybrid microbiota phenotypes, we find widespread evidence of transgressive segregation. Further, microbiota restructuring broadly correlates with niche restructuring during hybridization. This suggests a relationship between HA microbiota traits and ecological success. Conclusion: Transgressive segregation of HA microbiota traits is not only limited to hybrids at a fitness deficit but also occurs in ecologically successful hybrids. This suggests that hybridization may be a mechanism for generating novel and potentially beneficial holobiont phenotypes. Supporting such a conclusion, the correlations that we find between hybrid microbiota and the hybrid niche indicate that hybridization might change host microbiota in ways that promote a shift or an expansion in host niche space. If true, hybrid microbiota restructuring may underly ecological release from progenitors. This, in turn, could drive evolutionary diversification. Using our system as an example, we elaborate on the evolutionary implications of host hybridization within the context of holobiont theory and then outline the next steps for understanding the role of hybridization in holobiont research. 4jG8sjCYdGxE5fGZBJG38v Video Abstract [ABSTRACT FROM AUTHOR]

Conspicuous sexual signals come with costs and benefits. Such signals increase reproductive success but may also reduce survival or viability. It has recently been suggested that non-signal traits may alleviate some of those costs (termed "compensatory traits"). In this perspective piece, we argue that biological rhythms should be considered in the milieu of compensatory traits, as they can reduce the natural selection burden of signaling. This may be particularly true for the many sexual signals that are ephemeral (i.e., only periodically present like a courtship dance). Biological rhythms (e.g., circadian and circannual rhythms) are ubiquitous in nature and help organisms perform the right activity at the right time—this includes the timing of many sexual signals and reproductive traits. Timing itself may, in fact, reduce the costs of such sexual signals. Here, we review sexual signals that are governed by biological rhythms and discuss how signal modality and type (ornament, weapon, dominance trait) account for differences in how chronobiology may act as a compensatory trait. We then consider how biologists might examine the untested role of chronobiology as a compensatory trait and set forth compelling questions for future work. [ABSTRACT FROM AUTHOR]

Compared with green plants, brown algae are characterized by their ability to accumulate iodine, contributing to their ecological adaptability in high-iodide coastal environments. Vanadium-dependent haloperoxidase (V-HPO) is the key enzyme for iodine synthesis. Despite its significance, the evolutionary origin of V-HPO genes remains underexplored. This study investigates the genomic and evolutionary dynamics of V-HPOs in brown algae, focusing on Laminariales species, particularly Saccharina japonica. Genomic analyses revealed the extensive expansion of the V-HPO gene family in brown algae, with 88 V-HPOs identified in S. japonica, surpassing the number in red algae. Phylogenetic analysis demonstrated distinct evolutionary divergence between brown and red algal V-HPOs, with the brown algal clade closely related to bacterial V-HPOs. These findings suggest horizontal gene transfer (HGT) played a key role in acquiring V-HPO genes, particularly from Acidobacteriota, a bacterial phylum known for genomic plasticity. Additionally, enriched active transposable elements were identified around V-HPO genomic clusters, highlighting their role in tandem gene duplications and rapid HGT processes. Expression profiling further revealed dynamic regulation of V-HPOs in response to environmental conditions. This study provides new insights into how HGT has driven kelp genomic adaptations and enhances understanding of marine ecological success and evolutionary processes. [ABSTRACT FROM AUTHOR]

Multi-modal multi-objective optimization problems (MMOPs) are challenging due to multiple solutions sharing similar objective values. Existing algorithms for solving MMOPs typically evaluate the crowding in the decision space and objective space independently, leading to an imbalance in diversity between the two spaces. We introduce a mechanism that balances diversity in both the decision and objective spaces, aiming to enhance diversity while maintaining convergence in both spaces. We propose a multi-modal multi-objective evolutionary algorithm (MMEA) that selects qualified solutions based on Gaussian similarity. Gaussian similarity assesses the closeness of solution pairs and serves as the diversity fitness criterion for the algorithm. We conducted experiments on 28 benchmark problems and compared MMEA-GS with five state-of-the-art approaches. The results demonstrate that MMEA-GS effectively addresses most MMOPs, achieving higher diversity and convergence. [ABSTRACT FROM AUTHOR]

Background: Stress responses are key the survival of parasites and, consequently, also the evolutionary success of these organisms. Despite this importance, our understanding of the evolution of molecular pathways dealing with environmental stressors in parasitic animals remains limited. Here, we tested the link between adaptive evolution of parasite stress response genes and their ecological diversity and species richness. We comparatively investigated antioxidant, heat shock, osmoregulatory, and behaviour-related genes (foraging) in two model parasitic flatworm lineages with contrasting ecological diversity, Cichlidogyrus and Kapentagyrus (Platyhelminthes: Monopisthocotyla), through whole-genome sequencing of 11 species followed by in silico exon bait capture as well as phylogenetic and codon analyses. Results: We assembled the sequences of 48 stress-related genes and report the first foraging (For) gene orthologs in flatworms. We found duplications of heat shock (Hsp) and oxidative stress genes in Cichlidogyrus compared to Kapentagyrus. We also observed positive selection patterns in genes related to mitochondrial protein import (Hsp) and behaviour (For) in species of Cichlidogyrus infecting East African cichlids—a host lineage under adaptive radiation. These patterns are consistent with a potential adaptation linked to a co-radiation of these parasites and their hosts. Additionally, the absence of cytochrome P450 and kappa and sigma-class glutathione S-transferases in monogenean flatworms is reported, genes considered essential for metazoan life. Conclusions: This study potentially identifies the first molecular function linked to a flatworm radiation. Furthermore, the observed gene duplications and positive selection indicate the potentially important role of stress responses for the ecological adaptation of parasite species. [ABSTRACT FROM AUTHOR]

Species are disappearing worldwide, and changes in climate and land use are commonly assumed to be the most important causes. Organisms are counteracting the negative effects of environmental factors on their survival by evolving various defence strategies, which positively affect their fitness. Here, the question addressed is: can evolution shape these defence strategies so that they positively affect the fitness of an organism? This question is complex and depends on the taxa and environmental factors. Therefore, here, only a special case of this question is studied in deceptive species of orchids: reproductive success (RS, ratio of the number of fruits to the number of flowers produced by a plant during the whole season), a commonly used measure of fitness is used to develop a model describing how RS affects the number of flowers, n, of a plant. This model predicts that: (i) the resulting relationship between RS and n is a positively skewed parabola, (ii) the distribution of the numbers of individuals with a specific number (n) of flowers, NI(n), also resembles a parabola and is also positively skewed, and that (iii) the peak of the distribution of NI is to the left of the peak of RS. A large set of data is presented that supports these predictions. If the data set is small, the concave positively skewed parabolic RS–n dependence is obscured by other factors. [ABSTRACT FROM AUTHOR]

A key issue in predicting how ecosystems will respond to environmental change is understanding why populations and communities are able to live and reproduce in some parts of ecological and geographical space, but not in others. The limits to adaptation that cause ecological niches to vary in position and width across taxa and environmental contexts determine how communities and ecosystems emerge from selection on phenotypes and genomes. Ecological trade-offs mean that phenotypes can only be optimal in some environments unless these trade-offs can be reshaped through evolution. However, the amount and rate of evolution are limited by genetic architectures, developmental systems (including phenotypic plasticity) and the legacies of recent evolutionary history. Here, we summarize adaptive limits and their ecological consequences in time (evolutionary rescue) and space (species' range limits), relating theoretical predictions to empirical tests. We then highlight key avenues for future research in this area, from better connections between evolution and demography to analysing the genomic architecture of adaptation, the dynamics of plasticity and interactions between the biotic and abiotic environment. Progress on these questions will help us understand when and where evolution and phenotypic plasticity will allow species and communities to persist in the face of rapid environmental change. This article is part of the discussion meeting issue 'Bending the curve towards nature recovery: building on Georgina Mace's legacy for a biodiverse future'. [ABSTRACT FROM AUTHOR]

The article discusses the pivotal role of stomatal regulation in plant responses to environmental stresses, focusing on the uptake of volatile danger signals and the subsequent defense priming. Stomata, microscopic pores in plant leaves, play a crucial role in regulating gas exchange, leaf temperature, and water potential in response to various stimuli. The study highlights how stomatal conductance affects the plant's ability to optimize resource management and coordinate responses to biotic and abiotic stresses, emphasizing the importance of understanding the integration of different environmental signals through stomata for multi-stress tolerance. [Extracted from the article]

Summary Grasses are exceptionally productive, yet their hydraulic adaptation is paradoxical. Among C3 grasses, a high photosynthetic rate (Aarea) may depend on higher vein density (Dv) and hydraulic conductance (Kleaf). However, the higher Dv of C4 grasses suggests a hydraulic surplus, given their reduced need for high Kleaf resulting from lower stomatal conductance (gs). Combining hydraulic and photosynthetic physiological data for diverse common garden C3 and C4 species with data for 332 species from the published literature, and mechanistic modeling, we validated a framework for linkages of photosynthesis with hydraulic transport, anatomy, and adaptation to aridity. C3 and C4 grasses had similar Kleaf in our common garden, but C4 grasses had higher Kleaf than C3 species in our meta‐analysis. Variation in Kleaf depended on outside‐xylem pathways. C4 grasses have high Kleaf : gs, which modeling shows is essential to achieve their photosynthetic advantage. Across C3 grasses, higher Aarea was associated with higher Kleaf, and adaptation to aridity, whereas for C4 species, adaptation to aridity was associated with higher Kleaf : gs. These associations are consistent with adaptation for stress avoidance. Hydraulic traits are a critical element of evolutionary and ecological success in C3 and C4 grasses and are crucial avenues for crop design and ecological forecasting. [ABSTRACT FROM AUTHOR]

Background: Increased backfat thickness of sows in early gestation is negative to reproductive performance. Endometrial receptivity is an important determinant of reproductive success, but it is unclear whether the effect of sow backfat thickness on litter size is associated with endometrial receptivity and whether melatonin treatment may have benefits. The present study seeks to answer these questions through in vitro and in vivo investigations. Results: Excessive lipid deposition and lower melatonin levels in the uterus are detrimental to endometrial receptivity and embryo implantation in high backfat thickness sows. In cells treated with melatonin, the MT2/PI3K/LIF axis played a role in reducing lipid accumulation in porcine endometrial epithelium cells and improved endometrial receptivity. Furthermore, we found a reduction of lipids in the uterus after eight weeks of intraperitoneal administration of melatonin to HFD mice. Notably, melatonin treatment caused a significant reduction in the deposition of endometrial collagen, an increase in the number of glands, and repair of the pinopode structure, ultimately improving endometrial receptivity, promoting embryo implantation, and increasing the number of litter size of mice. Conclusions: Collectively, the finding reveals the harmful effects of high backfat thickness sows on embryo implantation and highlight the role of melatonin and the MT2/PI3K/LIF axis in improving endometrial receptivity by enhancing metabolism and reducing the levels of uterine lipids in obese animals. [ABSTRACT FROM AUTHOR]

Many plants have precise pollen placement strategies, ensuring that large amounts of pollen are deposited on small and discrete areas of pollinators' bodies. This may lead to male–male competition if pre‐existing pollen (1) is smothered or displaced by pollen from subsequent male flowers or (2) prevents subsequent pollen from attaching to pollinators. We investigated these alternative hypotheses using caged sunbirds (Cinnyris chalybeus) and sunbird‐pollinated flowers (Tritoniopsis antholyza). We labelled pollen from two different male‐phase flowers with quantum dots, enabling us to distinguish their pollen grains. We offered these two male‐phase flowers in succession to sunbirds before they were allowed to visit a female‐phase flower. In a separate trial, we offered sunbirds a quantum‐dot‐labelled male‐phase flower followed by a flower without reproductive structures. The last trial established whether pollen loss over time (time effect) influenced our results, such as pollen falling off or being groomed from the pollinator. We found that pollen from the second male‐phase flower was better represented on the stigmas of the subsequently visited female‐phase flowers. This advantage was not attributable to a time effect (i.e. less time for the last male's pollen to fall off the pollinator). Instead, our results suggest that pollen from earlier‐visited flowers is smothered or displaced by subsequently visited flowers. Because the last‐male visited may have a reproductive advantage (similar to last‐male sperm precedence in animals), plants are likely to evolve strategies to exploit or mitigate this effect. Synthesis: Our study demonstrates that pollen grains compete for space on pollinators' bodies. By uncovering how interference competition affects male reproductive success, our findings underscore the importance of pollen‐related traits in sexual selection and open new avenues for investigating floral evolution. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Wild animals typically organize activity around a 24-h day and daily timing across the year is optimized for both survival and reproductive success. Among-individual variation in chronotype, where individuals differ in when they begin or end their active day relative to a cue such as photoperiod, often exists within a population. Both intrinsic and extrinsic factors contribute to this variation and activity patterns may change across and within different life-history stages as energetic investment changes. Here we describe population level changes in free-living female great tit (Parus major) activity patterns of onset and offset of activity as well as assess variation and repeatability in daily activity both within- and across-breeding stages. We fitted individual females with accelerometers to track activity prior to nest building through chick rearing. Prior to clutch initiation females began their active day before sunrise, however, in the days prior to laying their first egg, activity was delayed until after sunrise. Females ended activity prior to sunset across the monitoring period and earliest during egg laying and incubation. In addition, females exhibited greater among- and within-individual variance in activity during parental care. Female daily activity was moderately repeatable within breeding stages and strongly covaried across several breeding stages. These findings expand our understanding of individual variation in activity patterns during reproduction and the potential fitness implications of chronotype in wild animals. [ABSTRACT FROM AUTHOR]

Prolonged reproductive interactions can lead to social plasticity and fitness differences for a focal individual in response to their partner's characteristics. Age can provide a way to manipulate the influence of a social partner due to its predictable consequences for mate quality and reproductive effort. Here, we use a full factorial design to examine the interactions between male and female age on behavior and reproductive performance in the obligately caring, frequently biparental burying beetle Nicrophorus orbicollis. We found that both males and females increased their reproductive effort with age. However, this response was weaker than that of a related, more uniparental species that provides facultative care, indicating that details of age-related behavior are predictable based on species differences. We also found that male and female behavior depended on both their own and their partner's age, as well as their partner's behavior. Lastly, we found that mismatched age pairs had the highest levels of reproductive success. These results indicate that reproductive senescence does occur but that it can be mitigated by having a young social partner. This also suggests a rarely found pattern wherein age-mismatching may have beneficial consequences for both parental and offspring fitness. [ABSTRACT FROM AUTHOR]

The physiological costs of inbreeding in wild animals are well-documented, but the potential cognitive costs of inbreeding have received far less attention. A growing body of evidence indicates that inbreeding is associated with impaired learning ability and aberrant innate behaviors in model systems, as well as intellectual disability and lower general intelligence in humans. As highlighted in this review, however, far less is known about inbreeding-linked cognitive impairments for wild populations and the potential behavioral and fitness implications of these impairments. Here, we review evidence indicating that, through its negative effects on song and other courtship behaviors, as well as its association with deficits in mating behavior and parental care, inbreeding is likely to have negative consequences for reproductive success in wild animals. The impairment of specific cognitive abilities, such as learning, innovation, and decision-making, may be particularly detrimental for inbred animals in changing environments, where individuals must adjust their behavior appropriately to deal with novel threats and resources. [ABSTRACT FROM AUTHOR]

The evolution of mating systems reflects a balance of the often-conflicting interests of males and females. Polygyny, a mating system in which males have multiple mates, presents a fitness benefit to males, but the consequences for females are less clear. Females with polygynous social mates may suffer reduced fitness, especially secondary females who typically receive less male support. We used 32 yr of detailed reproductive data on a population of Savannah sparrows (Passerculus sandwichensis) breeding on Kent Island, NB, Canada, to investigate the effects of females' social mating status on 6 indices of female fitness: survival, clutch size, fledging success, number of fledglings produced per nest and annually, and recruitment of offspring. Secondary females produced fewer fledglings per nest and annually than did monogamous or primary females, and their young were less likely to recruit into the breeding population. Yearling secondary females also had lower survival rates than older secondary females. Combined with higher rates of partial brood loss among secondary females, our results suggest that secondary females are unable to provide enough care to consistently fledge all nestlings in their broods, likely due to reduced male provisioning. Given that the sex ratio of breeders in the population is female-biased, we suggest that polygyny persists despite its fitness costs because some females must mate polygynously to "make the best of a bad situation." Our study demonstrates the value of detailed, long-term population monitoring data for understanding mating systems and using multiple indices of fitness to analyze the costs of polygyny. [ABSTRACT FROM AUTHOR]

Nest defence is one component of parental investment by which individuals can increase the survival of their offspring. Aggressive behaviours and the time spent protecting nests are determining factors in the reproductive success of cichlid species. The Mexican mojarra is the only cichlid native to the Balsas River Basin in Mexico. At least four invasive cichlids have been introduced, including the convict cichlid and the spotcheek cichlid. These three species establish their nests in the River and defend them aggressively. We quantified the number of nests, aggressive behaviours and time spent in the nest by parents of the native species and these two invasive species. We expected that the invasive parents would be more aggressive during defence, spent more time protecting the eggs, and would have a higher density of nests. We also explored differences in nest defence between the sexes within each species. We found that invasive cichlids had a greater number of nests than the Mexican mojarra. In the two invasive species, there was no difference between males and females in the time spent in the nest or the number of aggressive behaviours. In contrast, male Mexican mojarras spent less time in the nest and performed fewer aggressive behaviours than their mates. The smaller number of nests and nest defence behaviour of this native species could compromise its reproductive success and population size. This differential nest defence between the Mexican mojarra and the invasive cichlids could have negative implications for the physiology, reproduction, and health of this native cichlid. [ABSTRACT FROM AUTHOR]

Senescence is ubiquitous yet highly variable among species, populations, and individuals, for reasons that are poorly understood. It is not clear how environmental conditions affect senescence, especially in the wild. We explored the influence of environment on the degree of laying date age-specific variation and reproductive success senescence in wild blue tits. We disentangled the effects of age from those of previously encountered environmental conditions by introducing two complementary estimates of "relative environmental age." These estimates quantify the cumulative past environment experienced by an individual through two population-level metrics: average breeding failure and adult mortality. Results confirmed that laying date first advanced and annual reproductive success first increased with age up until about 3 years old, when these trends were reversed, consistent with a senescent decline. Both proxies for environmental conditions influenced laying date age-specific rates, such that females experiencing a more favorable environment had faster phenological decline. Conversely, environmental age did not affect reproductive success and its senescence. This study demonstrates that past environment can shape phenological age-specific change beyond the effects of chronological age and suggests that senescence will be best understood by investigating the deterioration of performances with accumulating exposure to detrimental conditions across a variety of traits. [ABSTRACT FROM AUTHOR]

One of the conservation measures of the globally near-threatened cinereous vulture is restoring populations via translocations, with some vultures originating from breeding centers. These centers need to have reproductive success, and securing good welfare levels should be a priority due to the negative implications a compromised welfare has on reproduction. Thus, assessing welfare in breeding centers is essential. Remote methods should be preferred, such as behavior analysis and use of space using camera systems. The study's first objective was to develop an activity budget that could be used as a baseline for detecting behavior irregularities. The second was to determine if behavior analysis and use of space could detect potential welfare issues in a breeding center. The study developed an activity budget that could be used as a standard for behavior analysis for the captive population. Behavior irregularities were detected, and the potential need to improve the enclosure and its surroundings were noticed. Altogether, the proposed methodology and results will contribute to the detection of possible welfare issues in breeding centers and, consequently, improve reproductive success and species' conservation. [ABSTRACT FROM AUTHOR]

This paper constructs a multi-imp act path model of personality traits on fitness behavior, based on theories of personality psychology and normative ethics, empirically tests the relationships between constructs in the model, and reveals the influence mechanisms of economic value orientation and machiavellian personality traits on fitness behavior. A total of 278 fitness enthusiasts from 26 provinces in China, each with at least one year of fitness experience, were selected as research subjects using convenience and snowball sampling methods. A questionnaire survey was conducted to examine the relationships among their personality traits, moral orientation, and fitness behavior. Descriptive and visual analysis was performed using SPSS 25.0 and R 4.2.2, and the structural equation model of the multi-impact path model on fitness behavior was tested using AMOS 20.0. (1) Economic value orientation personality traits significantly positively influence normative fitness behavior; (2) Machiavellian personality traits significantly positively influence anomie fitness behavior; (3) Teleological ethics partial mediating role between economic value orientation personality traits and normative fitness behavior; (4) Deontological ethics partial mediating role between machiavellian personality traits and anomie fitness behavior, itness enthusiasts with economic value orientation personality traits who adhere to fitness pragmatism are more likely to exhibit a sense of social responsibility, pay more attention to pursuing moral purposes, focus on social fairness and justice, and the results and impacts of fitness behavior, thereby leading to more normative fitness behavior. Conversely, those with machiavellian personality traits who adhere to utilitarianism often face dilemmas where their moral beliefs conflict with practical benefits and disadvantages. They are more likely to violate moral standards and social order, resulting in unethical anomie fitness behavior. [ABSTRACT FROM AUTHOR]

Sleep is a universally conserved behavior whose origin and evolutionary purpose are uncertain. Using phylogenomics, this article investigates the evolutionary foundations of sleep from a never before used perspective. More specifically, it identifies orthologs of human sleep-related genes in the Lokiarchaeota of the Asgard superphylum and examines their functional role. Our findings indicate that a conserved suite of genes associated with energy metabolism and cellular repair is involved, thus suggesting that sleep plays a primordial role in cellular maintenance. The data cited lend credence to the idea that sleep improves organismal fitness across evolutionary time by acting as a restorative process. Notably, our approach demonstrates that phylogenomics is more useful than standard phylogenetics for clarifying common evolutionary traits. By offering insight into the evolutionary history of sleep and putting forth a novel model framework for sleep research across taxa, these findings contribute to our growing understanding of the molecular foundation of sleep. This study lays the groundwork for further investigations into the importance of sleep in various organisms. Such investigations could have consequences for improving human health and more generally could provide a deeper comprehension of the fundamental processes of life. [ABSTRACT FROM AUTHOR]

Temperature is a critical environmental factor influencing insect development, physiology, and distribution. Global warming is predicted to increase the frequency and severity of extreme heat events, influencing insects differently across life stages. This study investigates the effects of short- and long-term thermal stress on the tobacco cutworm, Spodoptera litura , a polyphagous pest damaging over 389 plant species. We exposed eggs, larvae, pupae, and adults to elevated temperatures of 42°C and 46°C for four hours and one hour, respectively, in single and repeated occasions for two, four, two and two days for egg, larva, pupa and adults, respectively. Our results demonstrate significant variation in biological and reproductive fitness parameters across treatments. Notably, thermal stress skewed the sex ratio towards females. We also observed impacts on offspring survival and potential negative carry-over effects. Overall, the effects of heat stress were dependent on temperature, exposure duration, and life stage, with adults exhibiting the highest tolerance. These findings suggest that S. litura possesses a degree of heat tolerance that may enable it to survive summer heat waves, but its offspring and other life stages could be more vulnerable under future climate scenarios. [ABSTRACT FROM AUTHOR]

Appraising sexual asymmetry during maximum gonad investment (MGI) offers a sharp tool to evaluate the reproductive response of species to climate by coupling extrinsic and intrinsic factors. We comparatively analyze how the mass and physiological male and female gonad investments of the broadcast-spawning intertidal Chiton articulatus in two populations from the Mexican Tropical Pacific respond to the thermal phases of cold "La Niña" and warm "El Niño." We found that local rather than regional temperature modulates MGI intensity and breadth in this species, evidencing higher MGI levels in the southern tropical zone (Oaxaca). Male gonad investment was higher than that of females during neutral and cold phases compared to warm thermal phases. Physiological gonad investment during MGI suggests that males spawn before females, and the adult sex ratio of each population was close to unity. Our results suggest reproductive success regulation through sexual asymmetry in both mass and physiological gonad investment, modulated by temperature changes due to thermal phases. The male bias in gonad investment found under neutral to cold temperatures suggests physiological resilience in this species, especially considering its habitat and the impact of climate change· The MGI value is a phenotypic trait that varies as a function of temperature. [ABSTRACT FROM AUTHOR]

[Display omitted] • Alanine was a key biomarker of BPH adaptation to resistant rice variety IR36. • ALT-mediated alanine transfer to pyruvate was necessary and sufficient for the adaptation. • The high level of ALT activity rendered more energy reserves in the adapted BPH population. • Higher energy reserves improved detoxification and ecological fitness recovery in BPH consuming IR36-resistant rice. During the adaptation to host plant resistance, herbivorous insects faced the challenge of overcoming plant defenses while ensuring their own development and reproductive success. To achieve this, a strategic allocation of energy resources for detoxification and ecological fitness maintenance became essential. This study aimed to elucidate the intricate energy allocation mechanisms involved in herbivore adaptation that are currently poorly understood. The rice Oryza sativa and its monophagous pest, the brown planthopper (BPH), Nilaparvata lugens were used as a model system. An integrated analysis of metabolomes and transcriptomes from different BPH populations were conducted to identify the biomarkers. RNA interference of key genes and exogenous injection of key metabolites were performed to validate the function of biomarkers. We found that alanine was one of the key biomarkers of BPH adaptation to resistant rice variety IR36. We also found that alanine flow determined the adaptation of BPH to IR36 rice. The alanine aminotransferase (ALT)-mediated alanine transfer to pyruvate was necessary and sufficient for the adaptation. This pathway may be conserved, at least to some extent, in BPH adaptation to multiple rice cultivars with different resistance genes. More importantly, ALT-mediated alanine metabolism is the foundation of downstream energy resource allocation for the adaptation. The adapted BPH population exhibited a significantly higher level of energy reserves in the fat body and ovary when fed with IR36 rice, compared to the unadapted population. This rendered the elevated detoxification in the adapted BPH and their ecological fitness recovery. Overall, our findings demonstrated the crucial role of ALT-mediated alanine metabolism in energy allocation during the adaptation to resistant rice in BPH. This will provide novel knowledge regarding the co-evolutionary mechanisms between herbivores and their host plants. [ABSTRACT FROM AUTHOR]

Insect herbivory has attracted enormous attention from researchers due to its effects on plant fitness. However, there remain questions such as what are the most important leaf traits that determine consumption levels, whether there are latitudinal gradients in herbivore pressure, or whether there are differences in susceptibility between hybrids and their parental species. In this work, we address all these issues in two species of Mediterranean Quercus (Quercus faginea subsp. faginea Lam. and Quercus pyrenaica Wild.) and their hybrids. Over 2 years, we analyzed leaf emergence and 11 leaf traits (biomechanical, chemical and morphological), as well as the levels of herbivory by insects in leaves of the three genetic groups in different locations distributed along a climatic gradient. The hybrids showed intermediate values between both species in leaf emergence, chemical traits and structural reinforcement. By contrast, they were more similar to Q. faginea in leaf size and shape. Despite their intermediate leaf traits, hybrids always showed lower losses by consumption than both parental species, which suggests that they possess inherent higher resistance to herbivores, which cannot be explained by their dissimilarities in leaf traits. Within each genetic group, differences in leaf size were the most important determinant of differences in herbivory losses, which increased with leaf size. In turn, leaf size increased significantly with the increase in mean annual temperatures across the climatic gradient, in parallel with herbivory losses. In conclusion, contrary to our expectations, hybrids maintained lower levels of herbivory than their parent species. Given the potential negative effect of leaf herbivory on carbon fixation, this advantage of the hybrids would imply a threat to the persistence of both pure species. More research is needed to elucidate possible alternative mechanisms that allow for maintaining species integrity in the absence of reproductive barriers. [ABSTRACT FROM AUTHOR]

Background and Aims The majority of the Earth's land area is currently occupied by humans. Measuring how terrestrial plants reproduce in these pervasive environments is essential for understanding their long-term viability and their ability to adapt to changing environments. Methods We conducted hierarchical and phylogenetically independent meta-analyses to assess the overall effects of anthropogenic land-use changes on pollination, and male and female fitness in terrestrial plants. Key Results We found negative global effects of land-use change (i.e. mainly habitat loss and fragmentation) on pollination and on female and male fitness of terrestrial flowering plants. Negative effects were stronger in plants with self-incompatibility systems and in plants pollinated by invertebrates, regardless of life form and sexual expression. Pollination and female fitness of pollination-generalist and pollination-specialist plants were similarly negatively affected by land-use change, whereas male fitness of specialist plants showed no effects. Conclusions Our findings indicate that angiosperm populations remaining in fragmented habitats negatively affect pollination, and female and male fitness, which will probably decrease the recruitment, survival and long-term viability of plant populations remaining in fragmented landscapes. We underline the main current gaps of knowledge for future research agendas and call not only for a decrease in the current rates of land-use changes across the world but also to embark on active restoration efforts to increase the area and connectivity of remaining natural habitats. [ABSTRACT FROM AUTHOR]

Background and Aims The Arctic is warming at an alarming rate, leading to earlier spring conditions and plant phenology. It is often unclear to what degree changes in reproductive fitness (flower, fruit and seed production) are a direct response to warming versus an indirect response through shifting phenology. The aim of this study was to quantify the relative importance of these direct and indirect pathways and project the net effects of warming on plant phenology and reproductive fitness under current and future climate scenarios. Methods We used two long-term datasets on 12 tundra species in the Canadian Arctic as part of the International Tundra Experiment (ITEX). Phenology and reproductive fitness were recorded annually on tagged individual plants at both Daring Lake, Northwest Territories (64° 52' N, - 111° 35' W) and Alexandra Fiord, Nunavut (78° 49' N, - 75° 48' W). The plant species encompassed a wide taxonomic diversity across a range of plant functional types with circumpolar/boreal distributions. We used hierarchical Bayesian structural equation models to compare the direct and indirect effects of climate warming on phenology and reproductive fitness across species, sites and years. Key Results We found that warming, both experimental and ambient, drove earlier flowering across species, which led to higher numbers of flowers and fruits produced, reflecting directional phenotypic selection for earlier flowering phenology. Furthermore, this indirect effect of climate warming mediated through phenology was generally about two to three times stronger than the direct effect of climate on reproductive fitness. Under future climate predictions, individual plants showed a ~2- to 4.5-fold increase in their reproductive fitness (flower counts) with advanced flowering phenology. Conclusions Our results suggest that, on average, the benefits of early flowering, such as increased development time and subsequent enhanced reproductive fitness, might outweigh its risks. Overall, this work provides important insights into population-level consequences of phenological shifts in a warming Arctic over multi-decadal time scales. [ABSTRACT FROM AUTHOR]

Fishes of the genus Rhinogobius (Gobiidae) display paternal care of their nests, constructed beneath stones. Rhinogobius flumineus often coexist with larger Rhinogobius congeners (hence, stronger competitors for the nest site). To understand how R. flumineus reproduce successfully with the presence of a potential nest site competitor, nest-use characteristics of R. flumineus and Rhinogobius nagoyae were investigated in two rivers in southern central Honshu, Japan: one site with both species in sympatry and the other site with R. flumineus in allopatry. Analyses of nest stone, egg clutch, and male body sizes demonstrated that reproductive success, namely the number of eggs deposited, increased with male body size in both species and was positively correlated with nest stone size only in R. nagoyae. The pattern that R. flumineus males are less insistent on using large stones for nesting may partly explain the coexistence mechanism of the two species. [ABSTRACT FROM AUTHOR]

Simple Summary: Urban beekeeping is growing in popularity, but it raises questions about the quality and safety of bee products and the health of bee colonies in city environments. While the safety of honey and other products has been well-studied, bees' health has received less attention. How does city life impact bees and their colonies? This study analyzed the strength of honeybee colonies and levels of vitellogenin, a protein vital for bee health and longevity, in worker bees from an urban apiary from May to August. Results were compared to those of a rural (agricultural) apiary. We found that urban bee colonies were more populous than rural areas. In addition, insects in urban colonies showed a unique mechanism: During periods of bee shortage in the colonies, the level of vitellogenins—proteins responsible for extending the bees' life—increased in the tissues of workers. This compensation mechanism may help explain the evolutionary success of social insects like honeybees in diverse environments. The study aimed to verify whether urban beekeeping affects the strength of the honeybee (Apis mellifera) colonies from urban apiaries and the variability of the crucial for their health and long-life protein—vitellogenins. For this purpose, honeybees were kept in two locations—in a city apiary on a roof in the city center and in agricultural areas. Each of the apiaries consisted of six colonies, with the sister queens artificially inseminated with semen from the same pool of drones. The bee colony strength and the variability of the vitellogenins in various tissues in foragers from both apiaries were analyzed from May to August. Here, we revealed that colonies from the urban apiary were more abundant than those from the rural apiary. We observed the compensation mechanism during periods of worker deficiency in the bee colony, which was expressed as a change in the Vgs level in the forager tissues. Using the vitellogenin level as a biomarker of the honeybee colony strength can predict the fate of colonies, especially those with low numbers. The high level of Vgs can be a candidate for bee colony depopulation biomarker. [ABSTRACT FROM AUTHOR]