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Data from: Individual niche trajectories drive fitness variation
1. Variation in fitness across individuals is central to population growth, species coexistence, and evolution by natural selection. Fitness variation associated with resource use is hugely consequential, but how this variation is generated and maintained within natural populations remains unclear. In particular, individual fitness may depend on many cumulative foraging decisions over time, but this hypothesis remains untested. 2. We used multi-tissue stable isotope analysis to determine isotopic niche trajectories within species, populations and sexes of thin-toed frogs, and explored how this temporal dimension of diet affects individual reproductive investment, body condition, and parasite load. 3. We found that individual frogs shifted their diets less than expected under a null model, likely due to functional tradeoffs that limit the incorporation of new prey types over time. However, within the observed range of diet shifts, individuals that modified their diet to a greater degree exhibited higher fitness, although this effect was sex-dependent. 4. We suggest that these different relationships between isotopic niche trajectory length and fitness within thin-toed frogs are driven by variability in the resource environment, negative density-dependence and allometric constraints. These strong fitness effects suggest that the temporal dimension of diet change is a potential target of natural selection and, therefore, could drive correlated evolution in phenotypic traits underlying diet flexibility. Our findings add a new level of complexity to the understanding of ecological and evolutionary consequences of niche variation by demonstrating that temporal variation in foraging consistency within populations leads to different fitness payoffs.
Data from: Associations between habitat quality, body size, and reproductive fitness in the alpine endemic spider Vesubia jugorum
Aim. In theory, the highest-quality habitat across a species' range should support individuals with the highest fitness, making it possible to evaluate the outputs of species distribution models (SDM) by exploring the relation between habitat quality and functional traits related to species' fitness. However, this relation has been tested almost exclusively in plants. We investigated the degree to which morphological and reproductive traits of an alpine spider varied along a gradient of habitat quality projected via species distribution models. Location. Southwestern Alps (France and Italy) Time period. 2007–2018 Major taxa studied. Vesubia jugorum (Arachnida: Araneae: Lycosidae) Methods. We used climatic, topographical and geomorphological variables at a resolution of 250 m to model habitat quality for V. jugorum, with multiple algorithms (generalized additive models, boosted regression trees, and maximum entropy models). We collected spiders in the field and measured their body size and egg-case size (a functional trait related to reproductive success). We tested the relation between functional traits and habitat quality with linear mixed models. Results. All SDM algorithms we tested fit the data well, with similar explanatory ability. Models revealed a positive relation between the probability of presence and cumulative precipitation and percentage of rock. An additional important variable in the SDMs was duration of snow coverage, with optimal projected habitat quality between 40 and 100 days/year with snow. Modeled habitat quality was positively associated with maximum body and egg-case size. Main conclusions. Our work provides evidence of a positive association between projected habitat quality and traits of a terrestrial invertebrate. A model that fits the data well potentially can be used to predict variations in species' traits, thus offering an experimental test of SDM projections with field-collected data. We encourage SDM users to incorporate data on functional traits into their modeling fitting exercises.
Dysbiosis individualizes fitness effect of antibiotic resistance in the mammalian gut
<p>The fitness cost of antibiotic resistance in the absence of antibiotics is crucial to the success of suspending antibiotics as a strategy to lower resistance. Here we show that after antibiotic treatment the cost of resistance within the complex ecosystem of the mammalian gut is personalized. Using mice as an <i>in vivo</i> model, we find that the fitness effect of the same resistant mutation can be deleterious in a host, but neutral or even beneficial in other hosts. Such antagonistic pleiotropy is shaped by the microbiota, as in germ-free mice resistance is consistently costly across all hosts and in hosts with similar microbiotas the host specific effect of resistance is reduced. An eco-evolutionary model of competition for resources identifies a general mechanism underlying between host variation and predicts that the dynamics of compensatory evolution of resistant bacteria should be host specific, a prediction that was supported by experimental evolution<i> in vivo</i>. The microbiome of each human is close to unique and our results suggest that the short-term costs of resistance and its long-term within-host evolution will also be highly personalized, a finding that may contribute to the observed variable outcome of withdrawing antibiotics to reduce resistance levels.</p>
Data from: Measuring the effect of environmental stress on inbreeding depression alone obscures the relative importance of inbreeding-stress interactions on overall fitness in Callosobruchus maculatus
<p>Environmental stress can have a profound effect on inbreeding depression. Quantifying this effect is of particular importance in threatened populations, which are often simultaneously subject to both inbreeding and environmental stress. But while the prevalence of inbreeding-stress interactions is well known, the importance and broader applicability of such interactions in conservation are not clearly understood. We used seed beetles, Callosobruchus maculatus, as a model system to quantify how environmental stressors (here host quality and temperature stress) interact with inbreeding as measured by changes in the magnitude of8inbreeding depression, δ, as well as the relative importance of inbreeding-stress interactions to overall fitness. We found that while both environmental stressors caused substantial inbreeding-stress interactions as measured by change in δ, the relative importance of these interactions to overall survival was modest. This suggests that assessing inbreeding-stress interactions within the framework of δ alone may give an inaccurate representation of the relevance of interactions to population persistence. Furthermore, we found that the effect of environmental stress on fitness, but not inbreeding depression, varied strongly among populations. These results suggest that the outcomes of inbreeding-stress interactions are not easily generalized, an important consideration in conservation settings.</p>
Habitat features and colony characteristics influencing ant personality and its fitness consequences
<p>Several factors can influence individual and group behavioral variation that can have important fitness consequences. In this study, we tested how two habitat types (semi-natural meadows and meadows invaded by <i>Solidago</i> plants) and factors like colony and worker size and nest density influence behavioral (activity, meanderness, exploration, aggression, nest displacement) variation on different levels of the social organization of <i>Myrmica rubra </i>ants and how these might affect the colony productivity. We assumed that the factors within the two habitat types exert different selective pressure on individual and colony behavioral variation that affects colony productivity. Our results showed individual-/colony-specific expression of both mean and residual behavioral variation of the studied behavioral traits. Although habitat type did not have any direct effect, habitat-dependent factors, like colony size and nest density influenced the individual mean and residual variation of several traits. We also found personality at the individual level and at the colony level. Exploration positively influenced the total- and worker production in both habitats. Worker aggression influenced all the productivity parameters in semi-natural meadows, whereas activity had a positive effect on the worker and total production in invaded meadows. Our results suggest that habitat type, through its environmental characteristics, can affect different behavioral traits both at the individual and colony level and those with a high influence on colony productivity will form the personality of individuals. Our results highlight the need for complex studies on the behavioral variation of social insects to fully understand the effects shaping their behavior and productivity parameters.</p>
Data from Koch et al. 2020 Evolution: Genetic variance in fitness and its cross-sex covariance predict adaptation during experimental evolution.
<p><strong>Abstract</strong></p> <p>In presence of rapid environmental changes, it is of particular importance to assess the adaptive potential of populations, which is mostly determined by the additive genetic variation (V<sub>A</sub>) in fitness. In this study we used <em>Tribolium castaneum </em>(red flour beetles) to investigate its adaptive potential in three new environmental conditions (Dry, Hot, Hot-Dry). We tested for potential constraints that might limit adaptation, including negative genetic covariance between female and male fitness. Based on V<sub>A</sub> estimates for fitness, we expected the highest relative fitness increase in the most stressful condition Hot-Dry and similar increases in single stress conditions Dry and Hot. High adaptive potential in females in Hot was reduced by a negative covariance with male fitness. We tested adaptation to the three conditions after 20 generations of experimental evolution and found that observed adaptation mainly matched our predictions. Given that body size is commonly used as a proxy for fitness, we also tested how this trait and its genetic variance (including non-additive genetic variance) were impacted by environmental stress. In both traits, variances were sex and condition dependent, but they differed in their variance composition, cross-sex and cross-environment genetic covariances, as well as in the environmental impact on V<sub>A</sub>.</p> <p> </p> <p><strong>Method</strong></p> <p><em>Strain and environmental conditions</em></p> <p>We used the <em>Tribolium castaneum</em> Cro1 strain collected from a wild population in 2010 and adapted to lab standard conditions (33°C, 70% relative humidity) for more than 20 generations. Beetles were kept in 24h darkness on organic wheat flour mixed with 10% organic baker's yeast. We sterilized flour and yeast by heating them for 12h at 80°C before use. To test for adaptation to new environmental conditions we used replicate lines and exposed them to three treatments and Control conditions. The conditions in the treatments were: Dry: 33°C and 30% relative humidity; Hot: 37°C and 70% r. h.; Hot-Dry: 37°C and 30% r. h.</p> <p> </p> <p><em>Crossing, fitness assay and measurement of body size</em></p> <p>In order to be able to estimate genetic variances, we applied a split-brood paternal half-sib breeding design. We produced 147 half-sib families by mating virgin males to three virgin females. Half- as well as full-sib families were split across all conditions. Male and female offspring (four females and two males per full-sib family and condition) were separated at the pupal stage and transferred to 10 mL tubes with 1 g of medium and remained there until they were used for the fitness assay eight weeks later.</p> <p>To estimate fitness, we mated each virgin male with two unrelated virgin females from the same condition in 15mL tube with 1g medium. The male was removed after 24h and females transferred into two separate tubes. Females were removed from the tubes after one week of egg laying, and 9g medium was added to provide food for the developing offspring. After five weeks the number of adult offspring was counted. While we conducted the matings for the fitness assay, we followed a specific crossing design and always crossed two pairs of full-sib families. Individuals resulting from these crosses (the F2 genaration) were double first cousins.</p> <p>Body size was measured in the F2, i.e. in the offspring of beetles that were used for the fitness assay. To estimate body size, we used the centroid size of the abdominal segment IV as proxy for total size since it can be measured more accurately than dry weight in very small insects and shows a high correlation with body mass.</p> <p> </p> <p><em>Experimental evolution</em></p> <p>We used ten replicate lines per condition originating from the same ancestral population (Cro1) and let them adapt for 20 generations. Each new generation was set up by randomly selecting 120 pupae and placing them into a new vial with 70g medium. One selection line in Dry became extinct. Adult beetles of generation 20 from all selection lines were transferred to control conditions, in which they stayed for one week to mate and lay eggs. After removal of the adults, we waited until their offspring had reached the pupal stage and separated males and females. These individuals (generation 21) developed completely in control conditions. When they had reached the adult stage, each virgin male was mated with a virgin female of the same selection line and their offspring was transferred to all four conditions in the egg stage, resulting in full-sib families split across all conditions . As soon as these offspring (generation 22) had reached the pupal stage, males and females were separated. To compare fitness of different selection lines and test for adaptation, a virgin male and a virgin female of the same selection line in the same condition, but from different families were mated and the number of adult offspring produced within four days of mating and egg laying was used as a fitness estimate.</p> <p> </p> <p> </p> <p><strong>Files</strong></p> <p>This data publication contains the following files:</p> <p>Fitness_data.txt: Fitness data (offspring number) of the first generation in new environmental conditions.</p> <p>ANIMAL: ID of female individuals; male: ID of mating partner, father of the offspring; fitness: number of adult offspring per female produced within one week of egg laying; condition: condition under which the individuals grew up, mated, reproduced (CTL: control, D: dry, H: hot, HD: hot-dry, see Methods for details); MOTHER: mother of the female; Batch: samples where fitness assay was started on the same day</p> <p> </p> <p>Size_data.txt: Centroid size of abdominal segment IV.</p> <p>ANIMAL: ID of measured individuals; condition: condition under which the individuals grew up (CT: control, D: dry, H: hot, HD: hot-dry, see Methods for details); sex: sex of individuals (f: female, m: male); AS: centroid size [Pixel] of abdominal segment IV; Mother: ID of their mother; batch: Batches represent individuals that grew up at the same time, and thus accounts for variations in the medium or lab temperature</p> <p> </p> <p>Pedigree.txt: Pedigree of measured individuals.</p> <p>ANIMAL: individual ID ; MOTHER: mother ID; FATHER: father ID</p> <p> </p> <p>Transplant_data.txt: Offspring number of different selection lines under different conditions after 20 generations of experimental evolution.</p> <p>Line: Selection-line ID; Selection: condition, in which the selection-line spent 20 generations (CT: Control; D: Dry; Hot; HD: Hot-Dry); Fam: each selection line consisted of several families; Treatment: condition, in which offspring number was measured; offspring: number of adult offspring that a female produced within four days of egg-laying</p>
Data from: Individual asymmetry as a predictor of fitness in the bat Carollia perspicillata
The measurement of fitness in wild populations is a challenging task, and a number of proxies have been proposed with different degrees of success. Developmental instability/stability (DI) is an organismal property associated with variance in bilateral asymmetry (fluctuating asymmetry – FA), and a correlated effect on fitness. This study provides evidence to corroborate the hypothesis that asymmetry partly reflects DI and is correlated with a reduction in fitness measured by survival and reproduction in bats. We studied two Colonies of the bat Carollia perspicillata in Southeastern Brazil over five years, marking and recapturing individuals. Gaussian mixture models for signed forearm asymmetry distribution indicated that ~20% of asymmetry variation was due to DI heterogeneity among individuals. Forearm Asymmetry (ForA), Body Condition (Scaled Mass Index – SMI) and Forearm Length (ForL) were used as predictors of survival probability in Cormack-Jolly-Seber models. Asymmetry was negatively associated with survival, whereas SMI and ForL were positively associated. The male C. perspicillata defend sites within the roost that are favoured by female harems, but there are mating opportunities for bachelor males, leading to both territorial disputes and sperm competition. As predicted by sexual selection, ForA was negatively associated with relative Testicle Length, a measure of reproductive potential. In females, ForA was negatively associated with the probability of two pregnancies (as opposed to one) in a given breeding season. The effect magnitudes and directions of associations suggest that asymmetry, even though not perfectly reflecting DI variation, is a useful predictor for fitness components in C. perspicillata.
Pollen transfer networks reveal alien species as main heterospecific pollen donors with fitness consequences for natives
<ol> <li>The ecological dynamics of co-flowering communities are largely mediated by pollinators. However, current understanding of pollinator-mediated interactions primarily relies on how co-flowering plants influence attraction of shared pollinators, and much less is known about plan-plant interactions that occur via heterospecific pollen (HP) transfer. Invaded communities in particular can be highly affected by the transfer of alien pollen, but the strength, drivers, and fitness consequences of these interactions at a community scale are not well understood.</li> <li>Here we analyze HP transfer networks in nine coastal communities in the Yucatan Mexico that vary in the relative abundance of invasive flowers to evaluate how HP donation and receipt varies between native and alien plants. We further evaluate whether HP donation and receipt are mediated by floral traits (e.g. display, flower size) or pollinator visitation rate. Finally, we evaluated whether post-pollination success (proportion of pollen tubes produced) was affected by alien HP receipt and whether the effect varied between native and alien recipients.</li> <li>HP transfer networks exhibit relatively high connectance (<i>ca</i>. 15%), suggesting high HP transfer within the studied communities. Significant network nestedness further suggests the existence of species that predominantly act as HP donors or recipients in the community. Species-level analyses showed that natives receive 80% more HP compared to alien species, and that alien plants donate 40% more HP than natives. HP receipt and donation were mediated by different floral traits and such effects were independent of plant origin (native or alien). The proportion of alien HP received significantly affected conspecific pollen tube success in natives, but not that of alien species.</li> <li> <i>Synthesis</i>. Our results suggest that HP transfer in invaded communities is widespread, and that native and alien species play different roles within HP transfer networks, which are mediated by a different suite of floral traits. Alien species, in particular, play a central role as HP donors and are more tolerant to HP receipt than natives—a finding that points to two overlooked mechanisms facilitating alien plant invasion and success within native co-flowering communities.</li> </ol>
No evidence for early fitness penalty in glyphosate-resistant biotypes of Conyza canadensis: common garden experiments in the absence of glyphosate
<p>Strong selection from herbicides has led to the rapid evolution of herbicide-resistant weeds, greatly complicating weed management efforts worldwide. In particular, overreliance on glyphosate, the active ingredient in RoundUp®, has spurred the evolution of resistance to this herbicide in ≥40 species. Previously, we reported that <i>Conyza canadensis</i> (horseweed) has evolved extreme resistance to glyphosate, surviving at 40x the original 1x effective dosage. Here, we tested for underlying fitness effects of glyphosate resistance to better understand whether resistance could persist indefinitely in this self-pollinating, annual weed. We sampled seeds from a single maternal plant ("biotype") at each of 26 horseweed populations in Iowa, representing 9 susceptible biotypes (S), 8 with low-level resistance (LR), and 9 with extreme resistance (ER). In 2016 and 2017, we compared early growth rates and bolting dates of these biotypes in common garden experiments at two sites near Ames, Iowa. Nested ANOVAs showed that, as a group, ER biotypes attained similar or larger rosette size after 6 weeks compared to S or LR biotypes, which were similar to each other in size. Also, ER biotypes bolted 1-2 weeks earlier than S or LR biotypes. These fitness-related traits also varied among biotypes within the same resistance category, and time to bolting was inversely correlated with rosette size across all biotypes. Disease symptoms affected 40% of all plants in 2016 and 78% in 2017, so we did not attempt to measure lifetime fecundity. In both years, the frequency of disease symptoms was greatest in S biotypes and similar in LR vs. ER biotypes. Overall, our findings indicate there is no early growth penalty and possibly no lifetime fitness penalty associated with glyphosate resistance, including extremely strong resistance. We conclude that glyphosate resistance is likely to persist in horseweed populations, with or without continued selection pressure from exposure to glyphosate.</p>
Fitness effects for Ace insecticide resistance mutations are determined by ambient temperature
Background <p>Insect pest control programs often use periods of insecticide treatment with intermittent breaks, to prevent fixing of mutations conferring insecticide resistance. Such mutations are typically costly in an insecticide free environment, and their frequency is determined by the balance between insecticide treatment and cost of resistance. Ace, a key gene in neuronal signaling, is a prominent target of many insecticides and across several species three amino acid replacements (I161V, G265A and F330Y) provide resistance against several insecticides. Because temperature disturbs neuronal signaling homeostasis, we reasoned that the cost of insecticide resistance could be modulated by ambient temperature.</p> Results <p>Experimental evolution of a natural Drosophila simulans population at hot and cold temperature regimes uncovered a surprisingly strong effect of ambient temperature. In the cold temperature regime, the resistance mutations were strongly counter selected (s= -0.055), but in a hot environment the fitness costs of resistance mutations were reduced by almost 50% (s=-0.031). We attribute this unexpected observation to the advantage of the reduced enzymatic activity of resistance mutations in hot environments.</p> Conclusion <p>We show that fitness costs of insecticide resistance genes are temperature-dependent, and suggest that duration of insecticide-free periods need to be adjusted for different climatic regions to reflect these costs. We suggest that such environment-dependent fitness effects may be more common than previously assumed and pose a major challenge for modeling climate change.</p>
Raw fitness data (offspring number and weight), main dataset for manuscript: Female-specific resource limitation does not make the opportunity for selection more female biased
<p>The present dataset contains the entirety of the raw empirical data used in the manuscript entitled: "Female-specific resource limitation does not make the opportunity for selection more female biased". This data is composed of offspring count and weight, which represent proxys of fitness. Fitness was assessed for males and females independently, and across three different experimental treatments. These fitness measures are used to calculate the opportunity for selection, as the variance in realtive fitness. Detailed methods regarding data collection can be found in the main manuscript.</p>
Context-dependent variability in the population prevalence and individual fitness effects of plant-fungal symbiosis
<p>1. Heritable symbionts, found within a diverse array of flora and fauna, are often observed at intermediate prevalence within host populations, despite expectations that positive fitness feedbacks should drive beneficial symbionts to fixation. Intermediate prevalence may reflect neutral dynamics of symbionts with weak fitness effects, transient dynamics of symbionts trending toward fixation (or elimination), or a stable intermediate outcome determined by the balance of fitness effects and failed symbiont transmission. Theory suggests these outcomes should depend on symbiont-conferred effects and vertical transmission efficiency, which may both depend on environmental context.</p> <p>2. We tested these alternatives by tracking temporal change in population-level symbiont prevalence in a three-year field experiment with grasses and vertically transmitted fungal endophytes under the context of manipulated precipitation. Precipitation can mediate endophyte effects on host grasses, and is a relevant context, as global climate models predict changes in precipitation amount and seasonal distribution.</p> <p>3. We found evidence for each of the three proposed mechanisms for intermediate symbiont prevalence, but the outcome differed qualitatively across years and precipitation treatments. Specifically, within the first study year, all populations under ambient precipitation trended toward symbiont fixation, whereas elevated precipitation literally neutralized the interaction resulting in no long-run equilibrium. The second study year yielded a different result with long-run equilibria at an intermediate prevalence for both ambient and elevated precipitation treatments. We linked these population-level outcomes with individual-level symbiont effects on grasses and showed that the benefits of symbiosis were concentrated at the seedling stage, especially under drought stress during the time period coinciding with recruitment. The drought stress evident during the first year of the study was not present in the second year due to greater ambient precipitation during this time period. Together, these findings provide the first experimental evidence that population-level outcomes of host-symbiont interactions, which arise from the composite outcome of demographic vital rates and transmission, can be dynamically stable and can fluctuate in response to shifts in spatio-temporal context.</p> <p>4. Synthesis: Overall, these results indicate that intermediate prevalence of heritable microbial symbionts likely reflects a combination of neutral, transient, and stable mechanisms, and context-dependent fluctuations among them.</p>
Fitness implications of nonlethal injuries in scorpions: females, but not males pay reproductive costs
<p>The ability to detach a body part in response to a predation attempt is known as autotomy, and it is perhaps the most intensively studied form of nonlethal injury in animals. Although autotomy enhances survival, it may impose reproductive costs to both males and females. We experimentally investigated how autotomy affects the reproductive success of males and females of a scorpion species. Individuals of Ananteris balzani autotomize the last abdominal segments ("tail"), losing the anus and leading to lifelong constipation since regeneration does not occur. Although male "tail" is used during courtship and sperm transfer, autotomy had no effect on male mating success. The combined effect of increased mortality and reduced fecundity resulted in autotomized females producing nearly 35% less offspring than intact females. In conclusion, the negative effects of "tail" autotomy are clearly sex-dependent, probably because the factors that influence reproductive success in males and females are markedly different.</p>
Data from: When does growth rate influence fitness in a colonial marine invertebrate?
<p>Growth rate affects body size, and larger body sizes are often associated with the capacity to produce more surviving offspring. However, the assumption that growth rate should positively relate to fitness is rarely tested, especially in colonial marine invertebrates where size and age can be decoupled. We measured growth, survival, and reproduction through repeated census of 97 colonies from two populations of a marine bryozoan in the field from settlement to the end of their reproductive season in the northern Gulf of Mexico. Despite large population differences in fitness when grown in a common garden setting, selection within populations on variation in relative growth rate prior to reproduction was similar. In both populations, colonies that grew faster early after settlement, hence were larger, did not consistently have higher fitness than colonies that grew slower after settlement. Instead, early juvenile growth was uncorrelated to later juvenile growth, and colonies that grew faster just prior to the onset of reproduction had higher fitness than colonies that grew slower during this time. Growth rates then declined with the onset of reproduction. Our results show that, rather than being a simple consequence of selection on body size, growth rate can directly affect variation in fitness in ways that are not directly attributable to juvenile size. Colony size and growth rate in modular animals are not always reliable surrogates for direct estimates of survival and reproduction, without identifying when and how growth affects fitness.</p>
Ecological fitting is a sufficient driver of tight interactions between sunbirds and ornithophilous plants
<p>1. Plant-bird pollination interactions evolved independently on different continents. Specific adaptations can lead to their restriction when potential partners from distant evolutionary trajectories come into contact. Alternatively, these interactions can be enabled by convergent evolution and subsequent ecological fitting.<br> 2. We studied the interactions between New World plants from the genus Heliconia, Asian plants of genus Etlingera and African sunbirds on a local farm in Cameroon. Heliconia evolved together with hummingbirds and Etlingera spp. with spiderhunters - an oriental subgroup of the sunbird family. <br> 3. Sunbirds fed on all studied plants and individual plant species were visited by a different sunbird spectrum. We experimentally documented a higher number of germinated pollen grains in sunbird visited flowers of Etlingera spp. For Heliconia spp. this experiment was not successful and pollen tubes were rarely observed, even in hand pollinated flowers, where enough pollen was deposited. The analyses of contacts with plant reproductive organs nevertheless confirmed that sunbirds are good pollen vectors for both Heliconia and Etlingera species.<br> 4. Our study demonstrated a high ecological fit between actors of distinct evolutionary history and the general validity of bird-pollination syndrome. We moreover show that trait matching and niche differentiation are important ecological processes also in semi-artificial plant-pollinator systems.</p>
Net benefits of a mutualism: influence of the quality of extrafloral nectar on the colony fitness of a mutualistic ant
<p><span><span><span><span><span><span><span><span><span><span><span><strong>Aim</strong>: Extrafloral nectar, a carbohydrate-rich liquid, is the main plant-based resource offered in exchange for ant protection. The positive results of this protection provided by ants are widely studied and supported; however, studies showing the benefits that ants and their colonies have from the resources offered by plants such as extrafloral nectar are scarce. Here, we evaluated how extrafloral nectar and artificial food resources with different nutrient concentration benefit short- and long-term <i>Camponotus crassus</i> colony fitness (number and weight of individuals) and survival. </span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span><strong>Methods</strong>: We conducted two sets of experiments: (1) in the field we attached artificial ant nests to plants with clogged and unclogged extrafloral nectaries; and (2) in the laboratory we offered artificial food resources with different carbohydrate-protein ratios to ant colonies. With these experiments we evaluated the number and weight of queens, adult workers, pupae, larvae, and eggs, as well as the survival probability of the colonies.</span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span><strong>Results</strong>: In the first experiment, the short-term provision of extrafloral nectar resulted in a larger number and weight of individuals with access to this resource. In the second experiment, regardless of time, the supply of more concentrated carbohydrate and nitrogen food increased ant colony fitness and survival. Conclusion: We provided new evidence that extrafloral nectar significantly benefits ant colonies. Our results corroborate the assertion that these relationships are reciprocally beneficial. </span></span></span></span></span></span></span></span></span></span></span></p>
Fitness consequences of seasonally different life histories? A match-mismatch experiment
To survive and reproduce successfully, animals have to find the optimal time of breeding. Species living in non-tropical environments often adjust their reproduction plastically according to seasonal changes of the environment. Information about the prevailing season can be transmitted in utero, leading to adaptation of the offspring to the prevailing season. After birth, animals acquire additional personal information about the environment which allows them to adjust their reproductive investment. Here, we tested in a full-factorial match-mismatch experiment the influence of reproductive adjustments according to maternal and personal information. We bred wild cavies (Cavia aperea), a precocial rodent, either into increasing (spring) or decreasing (autumn) photoperiod and subsequently, after weaning, transferred female offspring to the matching or mismatching season. We measured growth, specific metabolic rate (sRMR) and reproductive events across six months. Although sRMR was elevated for females primed for good (spring) conditions when transferred to the mismatching autumn condition, we found no maternal effects on reproduction. Females adjusted their reproductive decisions according to the season they personally experienced, thereby implying a potentially high level of plasticity. Females reproducing in spring started reproduction earlier with a lower reproductive effort than females reproducing in autumn but ultimately, the two groups did not differ in survival, growth or reproduction. These data suggest important developmental plasticity, highlight the use of personal information acquired after weaning over early information provided until weaning and point out the potential value of multiple cues such as food abundance and quality and temperature besides photoperiod.
Data from: Fitness benefits to bacteria of carrying prophages and prophage-encoded antibiotic-resistance genes peak in different environments
<p>Understanding the role of horizontal gene transfer (HGT) in adaptation is a key challenge in evolutionary biology. In microbes, an important mechanism of HGT is prophage acquisition (phage genomes integrated into bacterial chromosomes). Prophages can influence bacterial fitness via transfer of beneficial genes (including antibiotic-resistance genes, ARGs), protection from superinfecting phages, or switching to a lytic lifecycle which releases free phages infectious to competitors. We expect these effects to depend on environmental conditions because of, for example, environment-dependent induction of the lytic lifecycle. However, it remains unclear how costs/benefits of prophages vary across environments. Here, studying prophages with/without ARGs in <i>Escherichia coli</i>, we disentangled effects of prophages alone and adaptive genes they carry. In competition with prophage-free strains, benefits from prophages and ARGs peaked in different environments. Prophages were most beneficial when induction of the lytic lifecycle was common, whereas ARGs were more beneficial upon antibiotic exposure and with reduced prophage induction. Acquisition of prophage-encoded ARGs by competing strains was most common when prophage induction, and therefore free phages, were common. Thus, selection on prophages and adaptive genes they carry varies independently across environments, which is important for predicting the spread of mobile/integrating genetic elements and their role in evolution</p>
Data from: Identifying 'useful' fitness models: balancing the benefits of added complexity with realistic data requirements in models of individual plant fitness
<p>Direct species interactions are commonly included in individual fitness models used for coexistence and local-diversity modeling. Though widely considered important for such models, direct interactions alone are often insufficient for accurately predicting fitness, coexistence or diversity outcomes. Incorporating higher-order interactions (HOIs) can lead to more accurate individual fitness models, but also adds many model terms, which can quickly result in model over-fitting. We explore approaches for balancing the trade-off between tractability and model accuracy that occurs when HOIs are added to individual fitness models. To do this, we compare models parameterized with data from annual plant communities in Australia and Spain, varying in the extent of information included about the focal and neighbor species. The best performing models for both datasets were those that grouped neighbors based on origin status and life form, a grouping approach that reduced the number of model parameters substantially while retaining important ecological information about direct interactions and HOIs. Results suggest that specific focal- or neighbor-species identity is not necessary for building well-performing fitness models that include HOIs. In fact, grouping neighbors by even basic functional information seems sufficient to maximize model accuracy, an important outcome for the practical use of HOI-inclusive fitness models.</p>
Data from: Compensatory growth in C. elegans is regulated by a thermosensitive TRP channel and increases reproductive fitness
<p>Animals are often not growing at the maximum rate, but can compensate for a bad start of life by further increasing growth rate. While this compensatory growth is widespread, its direct fitness consequences are seldom investigated and its genetic basis is unknown. We investigated the genetic regulation, as well as fitness and lifespan consequences of compensatory growth in response to temperature, using <i>C. elegans</i> knockout of the thermo-sensitive TRP ion channel TRPA-1, involved in temperature recognition. We exposed juvenile worms to cold, normal or warm temperatures in order to delay or speed up development. After returning to normal temperature, we found that wild-type worms where early development was delayed, expressed compensatory growth and catched up in size, while juvenile exposure to warm temperatures expressed slowed-down growth and small size. Compensatory growth also altered the reproductive schedule towards early reproduction, so that rate-sensitive individual fitness increased even though total reproduction was unaffected. Surprisingly, no lifespan cost of compensatory growth was found. In contrast, juvenile temperature did not induce compensatory or slowed-down growth in the <i>trpa-1</i> knockout mutants, and consequently did not affect fitness. We show that temperature-induced compensatory growth in <i>C. elegans</i> is regulated by the <i>trpa-1</i> and can increase fitness.</p>
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Understand access before you commit
These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.