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Selection against mismatched traits in hybrids is the phenotypic analogue of intrinsic hybrid incompatibilities. Mismatch occurs when hybrids resemble one parent population for some phenotypic traits and the other parent population for other traits, and is caused by dominance in opposing directions or from segregation of alleles in recombinant hybrids. In this study, we used threespine stickleback fish (Gasterosteus aculeatus L.) to test the theoretical prediction that trait mismatch in hybrids should increase with the magnitude of phenotypic divergence between parent populations. We measured morphological traits in parents and hybrids in crosses between a marine population representing the ancestral form and twelve freshwater populations that have diverged from this ancestral state to varying degrees according to their environments. We found that trait mismatch was greater in more divergent crosses for both F1 and F2 hybrids. In the F1, the divergence–mismatch relationship was caused by traits having dominance in different directions, whereas it was caused by increasing segregating phenotypic variation in the F2. Our results imply that extrinsic hybrid incompatibilities accumulate as phenotypic divergence proceeds.

Hybridization and resulting introgression can play both a destructive and a creative role in the evolution of diversity. Thus, characterizing when and where introgression is most likely to occur can help us understand the causes of diversification dynamics. Here, we examine the prevalence of and variation in introgression using phylogenomic data from a large (1300+ species), geographically widespread avian group, the suboscine birds. We first examine patterns of gene tree discordance across the geographic distribution of the entire clade. We then evaluate the signal of introgression in a subset of 206 species triads using Patterson's D-statistic and test for associations between introgression signal and evolutionary, geographic, and environmental variables. We find that gene tree discordance varies across lineages and geographic regions. The signal of introgression is highest in cases where species occur in close geographic proximity and in regions with more dynamic climates since the Pleistocene. Our results highlight the potential of phylogenomic datasets for examining broad patterns of hybridization and suggest that the degree of introgression between diverging lineages might be predictable based on the setting in which they occur.

Life-history theory posits that investment into reproduction might occur at the expense of investment into somatic maintenance, including immune function. If so, reduced or curtailed reproductive effort might be expected to increase immunity. In support of this notion, work in Caenorhabditis elegans has shown that worms lacking a germline exhibit improved immunity, but whether the antagonistic relation between germline proliferation and immunity also holds for other organisms is less well understood. Here, we report that transgenic ablation of germ cells in late development or early adulthood in Drosophila melanogaster causes elevated baseline expression and increased induction of Toll and Imd immune genes upon bacterial infection, as compared to fertile flies with an intact germline. We also identify immune genes whose expression after infection differs between fertile and germline-less flies in a manner that is conditional on their mating status. We conclude that germline activity strongly impedes the expression and inducibility of immune genes and that this physiological trade-off might be evolutionarily conserved.

After initial reports of anaphylaxis to the messenger RNA (mRNA) COVID-19 vaccines, the Centers for Disease Control and Prevention (CDC) put forth guidance stating that patients with a history of anaphylaxis to vaccine components like polyethylene glycol (PEG) should not receive the mRNA COVID-19 vaccines.1 To address this clinical challenge and decrease vaccine hesitancy, we published an approach to guide COVID-19 vaccination in high-risk allergy individuals.2-4 While the etiology of anaphylaxis to mRNA COVID-19 vaccines remains unclear, PEG continues to be an important focus.5,6 Paclitaxel contains polyoxyl-35 castor oil --a PEG derivative and structurally similar to the excipient in Pfizer-BioNTech and Moderna COVID-19 vaccines-- and docetaxel contains polysorbate 80 --the excipient in Janssen COVID-19 vaccine. Given this, we sought to assess the utility of pre-vaccine excipient skin testing (ST), risk stratification and COVID-19 vaccine tolerability in oncology patients with a history of paclitaxel or docetaxel hypersensitivity reaction (HSR).

The description of spatial patterns in species distributions is central to research throughout ecology. In this manuscript, we demonstrate that five of the most widely used species‐level spatial patterns are not only related, but can in fact be quantitatively derived from each other under minimal assumptions: the occupancy area curve, Taylor's Law, the neighborhood density function, a two‐plot variant of Taylor's Law and two‐plot single‐species turnover. We present an overarching mathematical framework and derivations for several theoretical example cases, along with a simulation study and empirical analysis that applies the framework to data from the Barro Colorado Island tropical forest plot. We discuss how knowledge of this mathematical relationship can support the testing of ecological theory, suggest efficient field sampling schemes, highlight the relative importance of plot area and abundance in driving turnover patterns and lay the groundwork for future unified theories of community‐level spatial metrics and multi‐patch spatial patterns., We show that several widely used single species spatial metrics (the occupancy area curve, Taylor's Law, the neighborhood density function and plot‐based turnover) are all derivable from each other under minimal assumptions. We provide example equations showing this relationship and demonstrate its application to simulated and empirical data.

Hamilton's local mate competition theory provided an explanation for extraordinary female-biased sex ratios in a range of organisms. When mating takes place locally, in structured populations, a female-biased sex ratio is favored to reduce competition between related males, and to provide more mates for males. However, there are a number of wasp species in which the sex ratios appear to more female biased than predicted by Hamilton's theory. It has been hypothesized that the additional female bias in these wasp species results from cooperative interactions between females. We investigated theoretically the extent to which cooperation between related females can interact with local mate competition to favor even more female-biased sex ratios. We found that (i) cooperation between females can lead to sex ratios that are more female biased than predicted by local competition theory alone, and (ii) sex ratios can be more female biased when the cooperation occurs from offspring to mothers before dispersal, rather than cooperation between siblings after dispersal. Our models formally confirm the verbal predictions made in previous experimental studies, which could be applied to a range of organisms. Specifically, cooperation can help explain sex ratio biases in Sclerodermus and Melittobia wasps, although quantitative comparisons between predictions and data suggest that some additional factors may be operating.

Despite the far-reaching evolutionary implications of sexual conflict, the effects of metapopulation structure, when populations are subdivided into several demes connected to some degree by migration, on sexual conflict dynamics are unknown. Here, we used experimental evolution in an insect model system, the seed beetle Callosobruchus maculatus, to assess the independent and interacting effects of selection histories associated with mating system (monogamy vs. polygamy) and population subdivision on sexual conflict evolution. We confirm traditional predictions from sexual conflict theory by revealing increased resistance to male harm in females from populations with a history of intense sexual selection (polygamous populations) compared to females from populations with a history of relaxed sexual selection (monogamous populations). However, selection arising from metapopulation structure reversed the classic pattern of sexually antagonistic coevolution and led to reduced resistance in females from polygamous populations. These results underscore that population spatial structure moderates sexual selection and sexual conflict, and more broadly, that the evolution of sexual conflict is contingent on ecological context. The findings also have implications for population dynamics, conservation biology, and biological control., This research was supported by the Spanish Ministry of Economy and the Spanish Ministry of Science, Innovation and Universities (grants CGL2012-34685, CGL2016-76173-P, and PID2019-105547GB-I00, cofunded by the European Regional Development Fund, to F.G.G.), and by the Spanish Research Council (grant 201730I034 to F.G.G.). E.R.E. was supported by a contract (BES-2013-065192) from the Spanish Ministry of Economy.

Identifying environmental predictors of phenotype is fundamentally important to many ecological questions, from revealing broadscale ecological processes to predicting extinction risk. However, establishing robust environment—phenotype relationships is challenging, as powerful case studies require diverse clades which repeatedly undergo environmental transitions at multiple taxonomic scales. Actinopterygian fishes, with 32,000+ species, fulfil these criteria for the fundamental habitat divisions in water. With four datasets of body size (ranging 10,905–27,226 species), I reveal highly consistent size‐by‐habitat‐use patterns across nine scales of observation. Taxa in marine, marine‐brackish, euryhaline and freshwater‐brackish habitats possess larger mean sizes than freshwater relatives, and the largest mean sizes consistently emerge within marine‐brackish and euryhaline taxa. These findings align with the predictions of seven mechanisms thought to drive larger size by promoting additional trophic levels. However, mismatches between size and trophic‐level patterns highlight a role for additional mechanisms, and support for viable candidates is examined in 3439 comparisons., Establishing environmental predictors of body size is of fundamental importance to ecology. With data from over 27,000 species of fishes, I establish general size rules between the major aquatic habitat types, revealing that various marine‐influenced environments contain larger taxa than those in freshwaters. The findings align with the predictions of seven mechanisms thought to drive larger size by promoting additional trophic levels, yet I demonstrate a need for additional mechanisms, and support for viable candidates is examined in 3439 comparisons.

Actinopterygians (ray‐finned fishes) are the most diversified group of vertebrates and are characterized by a variety of protective structures covering their integument, the evolution of which has intrigued biologists for decades. Paleontological records showed that the first mineralized vertebrate skeleton was composed of dermal bony plates covering the body, including odontogenic and skeletogenic components. Later in evolution, the exoskeleton of actinopterygian's trunk was composed of scale structures. Although scales are nowadays a widespread integument cover, some contemporary lineages do not have scales but bony plates covering their trunk, whereas other lineages are devoid of any such structures. To understand the evolution of the integument coverage and particularly the transition between different structures, we investigated the pattern of scale loss events along with actinopterygian evolution and addressed the functional relationship between the scaleless phenotype and the ecology of fishes. Furthermore, we examined whether the emergence of trunk bony plates was dependent over the presence or absence of scales. To this aim, we used two recently published actinopterygian phylogenies, one including >11,600 species, and by using stochastic mapping and Bayesian methods, we inferred scale loss events and trunk bony plate acquisitions. Our results reveal that a scaled integument is the most frequent state in actinopterygians, but multiple independent scale loss events occurred along their phylogeny with essentially no scale re‐acquisition. Based on linear mixed models, we found evidence supporting that after a scale loss event, fishes tend to change their ecology and adopt a benthic lifestyle. Furthermore, we show that trunk bony plates appeared independently multiple times along the phylogeny. By using fitted likelihood models for character evolution, we show that trunk bony plate acquisitions were dependent on a previous scale loss event. Overall, our findings support the hypothesis that integument cover is a key evolutionary trait underlying actinopterygian radiation.

Comparative genomics has contributed to the growing evidence that sexual selection is an important component of evolutionary divergence and speciation. Divergence by sexual selection is implicated in faster rates of divergence of the X chromosome and of genes thought to underlie sexually selected traits, including genes that are sex-biased in expression. However, accurately inferring the relative importance of complex and interacting forms of natural selection, demography and neutral processes which occurred in the evolutionary past is challenging. Experimental evolution provides an opportunity to apply controlled treatments for multiple generations and examine the consequent genomic divergence. Here we altered sexual selection intensity, elevating sexual selection in polyandrous lines and eliminating it in monogamous lines, and examined patterns of divergence in the genome ofDrosophila pseudoobscuraafter more than 160 generations of experimental evolution. Divergence is not uniform across the genome but concentrated in “islands”, many of which contain candidate genes implicated in mating behaviours and other sexually selected phenotypes. These are more often seen on the X chromosome, which shows divergence greater than neutral expectations. There are characteristic signatures of selection seen in these regions, with lower diversity and greaterFSTon the X chromosome than the autosomes, and differences in diversity on the autosomes between selection regimes. Reduced Tajima’s D implies that selective sweeps have occurred within some of the divergent regions, despite considerable recombination. These changes are associated with both differential gene expression between the lines and sex-biased gene expression within the lines. Our results are very similar to those thought to implicate sexual selection in divergence in natural populations, and hence provide experimental support for the likely role of sexual selection in driving such types of genetic divergence, but also illustrate how variable outcomes can be for different genomic regions.Impact SummaryHow does sexual selection contribute to the divergence of genomes? It is often thought that sexual selection is a potent force in evolutionary divergence, but finding ‘signatures’ of sexual selection in the genome is not straight-forward, and has been quite controversial recently. Here we used experimental evolution to allow replicate populations of fruit fly to evolve under relaxed or strengthened sexual selection for over 160 generations, then sequenced their genomes to see how they had diverged. The features we find are very similar to those reported in populations of natural species thought to be under strong sexual selection. We found that genomic divergence was concentrated in small patches of the genome rather than widespread. These are more often seen on the X chromosome, which overall shows especially elevated divergence. There are also characteristic signatures of selection seen in these regions, with lower genetic diversity suggesting that selection was strong in these regions. The changes are associated with both differential gene expression between the lines and sex-biased gene expression within the lines. Many of the patches of divergence also contain candidate genes implicated in mating behaviours and other sexually selected phenotypes. Our results provide experimental support for the likely role of sexual selection in driving such types of genetic divergence.

Processes driving the divergence of floral traits may be integral to the extraordinary richness of flowering plants and the assembly of diverse plant communities. Several models of pollinator-mediated floral evolution have been proposed; floral divergence may (i) be directly involved in driving speciation or may occur after speciation driven by (ii) drift or local adaptation in allopatry or (iii) negative interactions between species in sympatry. Here, we generate predictions for patterns of trait divergence and community assembly expected under these three models, and test these predictions in Hakea (Proteaceae), a diverse genus in the Southwest Australian biodiversity hotspot. We quantified functional richness for two key floral traits (pistil length and flower color), as well as phylogenetic distances between species, across ecological communities, and compared these to patterns generated from null models of community assembly. We also estimated the statistical relationship between rates of trait evolution and lineage diversification across the phylogeny. Patterns of community assembly suggest that flower color, but not floral phenology or morphology, or phylogenetic relatedness, is more divergent in communities than expected. Rates of lineage diversification and flower color evolution were negatively correlated across the phylogeny and rates of flower colour evolution were positively related to branching times. These results support a role for diversity-dependent species interactions driving floral divergence during the Hakea radiation, contributing to the development of the extraordinary species richness of southwest Australia., Evolution Letters, 5 (3)

The maternal inheritance of mitochondrial genomes entails a sex-specific selective sieve, whereby mutations in mitochondrial DNA can only respond to selection acting on females. In theory, this enables male-harming mutations to accumulate in mitochondrial genomes as long as they are neutral, beneficial, or only slightly deleterious to females. Ultimately, this bias could drive the evolution of male-specific mitochondrial mutation loads, an idea known as mother's curse. Earlier work on this hypothesis has mainly used small Drosophila panels, in which naturally sourced mitochondrial genomes were coupled to an isogenic nuclear background. The lack of nuclear genetic variation in these designs has precluded robust generalization. Here, we test the predictions of mother's curse using a large Drosophila mitonuclear genetic panel, comprising nine isogenic nuclear genomes coupled to nine mitochondrial haplotypes, giving a total of 81 different mitonuclear genotypes. Following a predictive framework, we tested the mother's curse hypothesis by screening our panel for wing size. This trait is tightly correlated with overall body size and is sexually dimorphic in Drosophila. Moreover, growth is heavily reliant on metabolism and mitochondrial function, making wing size an ideal trait for the study of the impact of mitochondrial variation. We detect high levels of mitonuclear epistasis, and more importantly, we report that mitochondrial genetic variance is larger in male than female Drosophila for eight out of the nine nuclear genetic backgrounds used. These results demonstrate that the maternal inheritance of mitochondrial DNA does indeed modulate male life history traits in a more generalisable way than previously demonstrated.

With globalisation facilitating the movement of plants and seeds beyond the native range, preventing potentially harmful introductions requires knowledge of what drives the successful establishment and spread of alien plants. Here, we examined global‐scale relationships between naturalisation success (incidence and extent) and invasiveness, soil seed bank properties (type and densities) and key species traits (seed mass, seed dormancy and life form) for 2350 species of angiosperms. Naturalisation and invasiveness were strongly associated with the ability to form persistent (vs. transient) seed banks but relatively weakly with seed bank densities and other traits. Our findings suggest that seed bank persistence is a trait that better captures the ability to become naturalised and invasive compared to seed traits more widely available in trait databases. Knowledge of seed persistence can contribute to our ability to predict global naturalisation and invasiveness and to identify potentially invasive flowering plants before they are introduced., We examine global‐scale relationships between naturalization success and invasiveness, soil seed bank properties (type and density), and key species traits (seed mass, seed dormancy, and life form) for 2350 angiosperm taxa. We found that the ability to form persistent reserves of viable seeds in the soil is a consistent indicator of the incidence and extent of naturalization and of the likelihood of them becoming invasive. We also showed that seed bank persistence is a trait that better captures the ability of angiosperms to become naturalized and invasive compared to seed traits more widely available in trait databases. ​

Climate change is increasing drought intensity, threatening biodiversity. Rapid evolution of drought adaptations might be required for population persistence, particularly in rear-edge populations that may already be closer to physiological limits. Resurrection studies are a useful tool to assess adaptation to climate change, yet these studies rarely encompass the geographic range of a species. Here, we sampled 11 populations of scarlet monkeyflower (Mimulus cardinalis), collecting seeds across the plants’ northern, central, and southern range to track trait evolution from the lowest to the greatest moisture anomaly over a 7-year period. We grew families generated from these populations across well-watered and terminal drought treatments in a greenhouse and quantified five traits associated with dehydration escape and avoidance. When considering pre-drought to peak-drought phenotypes, we find that later date of flowering evolved across the range of M. cardinalis, suggesting a shift away from dehydration escape. Instead, traits consistent with dehydration avoidance evolved, with smaller and/or thicker leaves evolving in central and southern regions. The southern region also saw a loss of plasticity in these leaf traits by the peak of the drought, whereas flowering time remained plastic across all regions. This observed shift in traits from escape to avoidance occurred only in certain regions, revealing the importance of geographic context when examining adaptations to climate change.

ObjectiveTakotsubo stress cardiomyopathy is characterized by dysfunction of the left ventricle of the heart including apical ballooning and focal wall‐motion abnormalities. Although reported in association with seizures and intracerebral hemorrhage, there are no studies reporting its occurrence in patients having stereoelectroencephalography (sEEG).MethodsA 38‐year‐old lady with no prior history of cardiac disease experienced sudden onset chest pain and acute left ventricular failure 4 hours following explantation of stereoelectroencephalogram electrodes.ResultsA small parenchymal hematoma related to the right posterior temporal electrode had been noted postelectrode insertion but was asymptomatic. Focal‐onset seizures from nondominant mesial temporal structures were recorded during sEEG. Following the presentation with LVF, new‐onset anterolateral T‐wave inversion with reciprocal changes in leads II, III, and aVF was noted on electrocardiogram (ECG) and the chest X‐ray findings were consistent with pulmonary edema. Echocardiography demonstrated hypokinesis of the cardiac apex and septum consistent with Takotsubo stress cardiomyopathy.SignificanceAwareness of the possible complication of Takotsubo stress cardiomyopathy is required in an epilepsy surgery program.

This paper examines the impact of daily activities on the performance of a body‐mounted radio frequency identification (RFID) tag inkjet printed onto tattoo transfer paper. This paper aims to assess how robust RFID tags of this nature are when mounted on the skin while the user undergoes various daily activities. The factors considered for these robustness tests are the effect of sweat and wear and tear on these tags during everyday use and also how it stands up to being exposed to water and soap during showering. Performance assessment was carried out using parameters such as point‐to‐point surface DC resistance as well as read range. Results show marginal effects on the tag performance and the tag continued to function during a normal day's activities, which lasted for 8 h, and rigorous activities like exercising but stopped functioning when there was severe damage to tag.

The desire of many engineers is to see their work end up as a final product offering a real benefit to society—for a lecturer/professor at a university, this is a dream often out of reach of the majority. However, the university academic is a changed species from the early days of the binary line between Universities and Polytechnics and when a lecturer meant just that—teaching to future engineers. This article describes the process and experience gained by a university engineer to spin out their research from the university sector and achieve the goal of a product reaching a global audience.

Human-driven habitat fragmentation and loss have led to a proliferation of small and isolated plant and animal populations with high risk of extinction. One of the main threats to extinction in these populations is inbreeding depression, which is primarily caused by recessive deleterious mutations becoming homozygous due to inbreeding. The typical approach for managing these populations is to maintain high genetic diversity, increasingly by translocating individuals from large populations to initiate a “genetic rescue.” However, the limitations of this approach have recently been highlighted by the demise of the gray wolf population on Isle Royale, which declined to the brink of extinction soon after the arrival of a migrant from the large mainland wolf population. Here, we use a novel population genetic simulation framework to investigate the role of genetic diversity, deleterious variation, and demographic history in mediating extinction risk due to inbreeding depression in small populations. We show that, under realistic models of dominance, large populations harbor high levels of recessive strongly deleterious variation due to these mutations being hidden from selection in the heterozygous state. As a result, when large populations contract, they experience a substantially elevated risk of extinction after these strongly deleterious mutations are exposed by inbreeding. Moreover, we demonstrate that, although genetic rescue is broadly effective as a means to reduce extinction risk, its effectiveness can be greatly increased by drawing migrants from small or moderate-sized source populations rather than large source populations due to smaller populations harboring lower levels of recessive strongly deleterious variation. Our findings challenge the traditional conservation paradigm that focuses on maximizing genetic diversity in small populations in favor of a view that emphasizes minimizing strongly deleterious variation. These insights have important implications for managing small and isolated populations in the increasingly fragmented landscape of the Anthropocene.

Disturbance is a key factor shaping ecological communities, but little is understood about how the effects of disturbance processes accumulate over time. When disturbance regimes change, historical processes may influence future community structure, for example, by altering invasibility compared to communities with stable regimes. Here, we use an annual plant model to investigate how the history of disturbance alters invasion success. In particular, we show how two communities can have different outcomes from species introduction, solely due to past differences in disturbance regimes that generated different biotic legacies. We demonstrate that historical differences can enhance or suppress the persistence of introduced species, and that biotic legacies generated by stable disturbance history decay over time, though legacies can persist for unexpectedly long durations. This establishes a formal theoretical foundation for disturbance legacies having profound effects on communities, and highlights the value of further research on the biotic legacies of disturbance., Disturbance has many effects on communities, and much is still not known about how these effects accumulate over time. We use an annual plant model to demonstrate how legacies of disturbance can affect future community composition, long after disturbance regimes have changed. In particular, we show that differences in disturbance history can alter invasion success even when present disturbance regimes are identical.

Models of “plasticity-first” evolution are attractive because they explain the rapid evolution of new complex adaptations. Nevertheless, it is unclear whether plasticity can facilitate rapid microevolutionary change between diverging populations. Here, we show how plasticity may have generated adaptive differences in fecundity between neighboring wild populations of burying beetles Nicrophorus vespilloides. These populations occupy distinct Cambridgeshire woodlands that are just 2.5 km apart and that probably originated from a common ancestral population about 1000-4000 years ago. We find that populations are divergently adapted to breed on differently sized carrion. Adaptive differences in clutch size and egg size are associated with divergence at loci connected with oogenesis. The populations differ specifically in the elevation of the reaction norm linking clutch size to carrion size (i.e., genetic accommodation), and in the likelihood that surplus offspring will be lost after hatching. We suggest that these two processes may have facilitated rapid local adaptation on a fine-grained spatial scale.

Reciprocal adaptation is the hallmark of arms race coevolution. Local coadaptation between natural enemies should generate a geographic mosaic pattern where both species have roughly matched abilities across their shared range. However, mosaic variation in ecologically relevant traits can also arise from processes unrelated to reciprocal selection, such as population structure or local environmental conditions. We tested whether these alternative processes can account for trait variation in the geographic mosaic of arms race coevolution between resistant garter snakes (Thamnophis sirtalis) and toxic newts (Taricha granulosa). We found that predator resistance and prey toxin levels are functionally matched in co-occurring populations, suggesting that mosaic variation in the armaments of both species results from the local pressures of reciprocal selection. By the same token, phenotypic and genetic variation in snake resistance deviates from neutral expectations of population genetic differentiation, showing a clear signature of adaptation to local toxin levels in newts. Contrastingly, newt toxin levels are best predicted by genetic differentiation among newt populations, and to a lesser extent, by the local environment and snake resistance. Exaggerated armaments suggest that coevolution occurs in certain hotspots, but prey population structure seems to be of particular influence on local phenotypic variation in both species throughout the geographic mosaic. Our results imply that processes other than reciprocal selection, like historical biogeography and environmental pressures, represent an important source of variation in the geographic mosaic of coevolution. Such a pattern supports the role of “trait remixing” in the geographic mosaic theory, the process by which non-adaptive forces dictate spatial variation in the interactions among species.

SARS-CoV-2 infection can cause severe pneumonia (COVID-19). There is evidence that patients with comorbidities are at higher risk of a severe disease course. The role of immunosuppression in the disease course is not clear. In the present report, we first describe two cases of persisting SARS-CoV-2 viraemia with fatal outcome in patients after rituximab therapy.

Domesticated animals display suites of altered morphological, behavioral, and physiological traits compared to their wild ancestors, a phenomenon known as the domestication syndrome (DS). Because these alterations are observed to co-occur across a wide range of present day domesticates, the traits within the DS are assumed to covary within species and a single developmental mechanism has been hypothesized to cause the observed co-occurrence. However, due to the lack of formal testing it is currently not well-resolved if the traits within DS actually covary. Here, we test the hypothesis that the presence of the classic morphological domestication traits white pigmentation, floppy ears, and curly tails predict the strength of behavioral correlations in support of the DS in 78 dog breeds. Contrary to the expectations of covariation among DS traits, we found that morphological traits did not covary among themselves, nor did they predict the strength of behavioral correlations among dog breeds. Further, the number of morphological traits in a breed did not predict the strength of behavioral correlations. Our results thus contrast with the hypothesis that the DS arises due to a shared underlying mechanism, but more importantly, questions if the morphological traits embedded in the DS are actual domestication traits or postdomestication improvement traits. For dogs, it seems highly likely that strong selection for breed specific morphological traits only happened recently and in relation to breed formation. Present day dogs therefore have limited bearing of the initial selection pressures applied during domestication and we should reevaluate our expectations of the DS accordingly.

Cities are emerging as models for addressing the fundamental question of whether populations evolve in parallel to similar environments. Here, we examine the environmental factors that drive parallel evolutionary urban-rural clines in a Mendelian trait — the cyanogenic antiherbivore defense of white clover (Trifolium repens). We sampled over 700 urban and rural clover populations across 16 cities along a latitudinal transect in eastern North America. In each population, we quantified the frequency of genotypes that produce hydrogen cyanide (HCN), and in a subset of the cities we estimated the frequency of the alleles at the two genes (CYP79D15 and Li) that epistatically interact to produce HCN. We then tested the hypothesis that winter environmental conditions cause the evolution of clines in HCN by comparing the strength of clines among cities located along a gradient of winter temperatures and frost exposure. Overall, half of the cities exhibited urban-rural clines in the frequency of HCN, whereby urban populations evolved lower HCN frequencies. The weakest clines in HCN occurred in cities with the lowest temperatures but greatest snowfall, supporting the hypothesis that snow buffers plants against winter frost and constrains the formation of clines. By contrast, the strongest clines occurred in the warmest cities where snow and frost are rare, suggesting that alternative selective agents are maintaining clines in warmer cities. Additionally, some clines were driven by evolution at only CYP79D15, consistent with stronger and more consistent selection on this locus than on Li. Together, our results demonstrate that both the agents and targets of selection vary across cities and highlight urban environments as large-scale models for disentangling the causes of parallel evolution in nature.Impact SummaryUnderstanding whether independent populations evolve in the same way (i.e., in parallel) when subject to similar environments remains an important problem in evolutionary biology. Urban environments are a model for addressing the extent of parallel evolution in nature due to their convergent environments (e.g. heat islands, pollution, fragmentation), such that two distant cities are often more similar to one another than either is to nearby nonurban habitats. In this paper, we used white clover (Trifolium repens) as a model to study the drivers of parallel evolution in response to urbanization. We collected >11,000 plants from urban and rural habitats across 16 cities in eastern North America to examine how cities influence the evolution of a Mendelian polymorphism for an antiherbivore defense trait – hydrogen cyanide (HCN). This trait had previously been shown to exhibit adaptive evolution to winter temperature gradients at continental scales. Here we tested the hypothesis that winter environmental conditions cause changes in the frequency of HCN between urban and rural habitats. We found that half of all cities had lower frequency of HCN producing genotypes relative to rural habitats, demonstrating that cities drive parallel losses of HCN in eastern North America. We then used environmental data to understand why cities vary in the extent to which they drive reduction in HCN frequencies. The warmest cities showed the greatest reductions in HCN frequencies in urban habitats, while colder, snowier cities showed little change in HCN between urban and rural habitats. This suggests that snow weakens the strength of natural selection against HCN in cities. However, it additionally suggests alternative ecological or evolutionary mechanisms drive the strong differences in HCN between urban and rural habitats in the warmest cities. Overall, our work highlights urban environments as powerful, large-scale models for disentangling the causes of parallel and non-parallel evolution in nature.

Authors thank NERC, BBSRC, AXA research fund, Royal Society (AB & AG) and ERC 370 (AG) for funding. Heterogeneity in resources is a ubiquitous feature of natural landscapes affecting many aspects of biology. However, the effect of environmental heterogeneity on the evolution of cooperation has been less well studied. Here, using a mixture of theory and experiments measuring siderophore production by the bacterium Pseudomonas aeruginosa as a model for public goods based cooperation, we explore the effect of heterogeneity in resource availability. We show that cooperation in metapopulations that were spatially heterogeneous in terms of resources can be maintained at a higher level than in homogeneous metapopulations of the same average resource value. The results can be explained by a positive covariance between fitness of cooperators, population size, and local resource availability, which allowed cooperators to have a disproportionate advantage within the heterogeneous metapopulations. These results suggest that natural environmental variation may help to maintain cooperation. Publisher PDF

The efficiency of carbon sequestration by the biological pump could decline in the coming decades because respiration tends to increase more with temperature than photosynthesis. Despite these differences in the short‐term temperature sensitivities of photosynthesis and respiration, it remains unknown whether the long‐term impacts of global warming on metabolic rates of phytoplankton can be modulated by evolutionary adaptation. We found that respiration was consistently more temperature dependent than photosynthesis across 18 diverse marine phytoplankton, resulting in universal declines in the rate of carbon fixation with short‐term increases in temperature. Long‐term experimental evolution under high temperature reversed the short‐term stimulation of metabolic rates, resulting in increased rates of carbon fixation. Our findings suggest that thermal adaptation may therefore have an ameliorating impact on the efficiency of phytoplankton as primary mediators of the biological carbon pump., The primary production of marine phytoplankton could decline with warming if rates of respiration increase more with rising temperature than photosynthesis. We found that respiration was consistently more temperature dependent than photosynthesis across 18 diverse marine phytoplankton taxa, resulting in universal declines in the rate of carbon fixation with short‐term increases in temperature. Whereas, by contrast, long‐term experimental evolution under high temperature acted to reverse the short‐term stimulation of metabolic rates, resulting in increased rates of carbon fixation.

Many theoretical models predict when genetic evolution and phenotypic plasticity allow adaptation to changing environmental conditions. These models generally assume stabilizing selection around some optimal phenotype. We however often ignore how optimal phenotypes change with the environment, which limit our understanding of the adaptive value of phenotypic plasticity. Here, we propose an approach based on our knowledge of the causal relationships between climate, adaptive traits, and fitness to further these questions. This approach relies on a sensitivity analysis of the process-based model Phenofit, which mathematically formalizes these causal relationships, to predict fitness landscapes and optimal budburst dates along elevation gradients in three major European tree species. Variation in the overall shape of the fitness landscape and resulting directional selection gradients were found to be mainly driven by temperature variation. The optimal budburst date was delayed with elevation, while the range of dates allowing high fitness narrowed and the maximal fitness at the optimum decreased. We also found that the plasticity of the budburst date should allow tracking the spatial variation in the optimal date, but with variable mismatch depending on the species, ranging from negligible mismatch in fir, moderate in beech, to large in oak. Phenotypic plasticity would therefore be more adaptive in fir and beech than in oak. In all species, we predicted stronger directional selection for earlier budburst date at higher elevation. The weak selection on budburst date in fir should result in the evolution of negligible genetic divergence, while beech and oak would evolve counter-gradient variation, where genetic and environmental effects are in opposite directions. Our study suggests that theoretical models should consider how whole fitness landscapes change with the environment. The approach introduced here has the potential to be developed for other traits and species to explore how populations will adapt to climate change.

Autosomal recessive cerebellar ataxias (ARCAs) comprisecomplex genetic ataxia disorders with variable central andperipheral nervous system involvement and systemic changes.They can overlap with other conditions such as hereditary spas-tic paraplegia, inborn errors of metabolism, and genetic enceph-alopathies.1While usually starting in childhood or youngadulthood, late adult-onset may occur. The advanced applica-tion of next-generation sequencing has allowed the moleculardefinition of many previously undetermined ARCAs in the lastdecade, including many new ARCA genes.

The origin of eusociality in the Hymenoptera is a question of major interest. Theory has tended to focus on genetic relatedness, but ecology can be just as important a determinant of whether eusociality evolves. Using the model of Fu et al. (2015), we show how ecological assumptions critically affect the conclusions drawn. Fu et al. inferred that eusociality rarely evolves because it faces a fundamental ‘risk‐return tradeoff’. The intuitive logic was that worker production represents an opportunity cost because it delays realising a reproductive payoff. However, making empirically justified assumptions that (1) workers take over egg‐laying following queen death and (2) productivity increases gradually with each additional worker, we find that the risk‐return tradeoff disappears. We then survey Hymenoptera with more specialised morphological castes, and show how the interaction between two common features of eusociality – saturating birth rates and group size‐dependent helping decisions – can determine whether eusociality outperforms other strategies., Theories concerning the origin of eusociality in Hymenoptera have tended to focus on genetic relatedness, but ecology can be just as important. With realistic ecological assumptions, we show that eusociality does not face a previously postulated ‘risk‐return tradeoff’. We find that the interaction between two common features of eusociality – birth rates that saturate at large group sizes, and group‐size dependent helping decisions – can instead determine whether eusociality outperforms other strategies.

Maximising survival requires animals to balance the competing demands of maintaining energy balance and avoiding predation. Here, quantitative modelling shows that optimising the daily timing of activity and rest based on the encountered environmental conditions enables small mammals to maximise survival. Our model shows that nocturnality is typically beneficial when predation risk is higher during the day than during the night, but this is reversed by the energetic benefit of diurnality when food becomes scarce. Empirical testing under semi‐natural conditions revealed that the daily timing of activity and rest in mice exposed to manipulations in energy availability and perceived predation risk is in line with the model’s predictions. Low food availability and decreased perceived daytime predation risk promote diurnal activity patterns. Overall, our results identify temporal niche switching in small mammals as a strategy to maximise survival in response to environmental changes in food availability and perceived predation risk.

Explaining how cooperation can persist in the presence of cheaters, exploiting the cooperative acts, is a challenge for evolutionary biology. Microbial systems have proved extremely useful to test evolutionary theory and identify mechanisms maintaining cooperation. One of the most widely studied system is the secretion and sharing of iron‐scavenging siderophores by Pseudomonas bacteria, with many insights gained from this system now being considered as hallmarks of bacterial cooperation. Here, we introduce siderophore secretion by the bacterium Burkholderia cenocepacia H111 as a novel parallel study system, and show that this system behaves differently. For ornibactin, the main siderophore of this species, we discovered a novel mechanism of how cheating can be prevented. Particularly, we found that secreted ornibactin cannot be exploited by ornibactin‐defective mutants because ornibactin receptor and synthesis genes are co‐expressed from the same operon, such that disruptive mutations in synthesis genes compromise receptor availability required for siderophore uptake and cheating. For pyochelin, the secondary siderophore of this species, we found that cheating was possible, but the relative success of cheaters was positive frequency dependent, thus diametrically opposite to the Pseudomonas and other microbial systems. Altogether, our results highlight that expanding our repertoire of microbial study systems leads to new discoveries and suggest that there is an enormous diversity of social interactions out there in nature, and we might have only looked at the tip of the iceberg so far.

Inversions often underlie complex adaptive traits, but the genic targets inside them are largely unknown. Gene expression profiling provides a powerful way to link inversions with their phenotypic consequences. We examined the effects of the Cf-Inv(1) inversion in the seaweed fly Coelopa frigida on gene expression variation across sexes and life stages. Our analyses revealed that Cf-Inv(1) shapes global expression patterns but the extent of this effect is variable with much stronger effects in adults than larvae. Furthermore, within adults, both common as well as sex specific patterns were found. The vast majority of these differentially expressed genes mapped to Cf-Inv(1). However, genes that were differentially expressed in a single context (i.e. in males, females or larvae) were more likely to be located outside of Cf-Inv(1). By combining our findings with genomic scans for environmentally associated SNPs, we were able to pinpoint candidate variants in the inversion that may underlie mechanistic pathways that determine phenotypes. Together the results in this study, combined with previous findings, support the notion that the polymorphic Cf-Inv(1) inversion in this species is a major factor shaping both coding and regulatory variation resulting in highly complex adaptive effects.

There is still a lack of consensus on the efficacy of convalescent plasma (CP) treatment in COVID-19 patients. We performed a systematic review and meta-analysis to investigate the efficacy of CP vs standard treatment/non-CP on clinical outcomes in COVID-19 patients.Cochrane Library, PubMed, EMBASE and ClinicalTrials.gov were searched from December 2019 to 16 July 2021, for data from clinical trials and observational studies. The primary outcome was all-cause mortality. Risk estimates were pooled using a random-effect model. Risk of bias was assessed by Cochrane Risk of Bias tool for clinical trials and Newcastle-Ottawa Scale for observational studies.In total, 18 peer-reviewed clinical trials, 3 preprints and 26 observational studies met the inclusion criteria. In the meta-analysis of 18 peer-reviewed trials, CP use had a 31% reduced risk of all-cause mortality compared with standard treatment use (pooled risk ratio [RR] = 0.69, 95% confidence interval [CI]: 0.56-0.86, P = .001, IConvalescent plasma use was associated with reduced risk of all-cause mortality in severe or critical COVID-19 patients. However, the findings were limited with a moderate degree of heterogeneity. Further studies with well-designed and larger sample size are needed.