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The extended phenotype of helical burrowing behavior in animals has evolved independently many times since the Cambrian explosion (~540 million years ago [MYA]). A number of hypotheses have been proposed to explain the evolution of helical burrowing in certain taxa, but no study has searched for a general explanation encompassing all taxa. We reviewed helical burrowing in both extant and extinct animals and from the trace fossil record and compiled 10 hypotheses for why animals construct helical burrows, including our own ideas. Of these, six are post-construction hypotheses-benefits to the creator or offspring, realized after burrow construction-and four are construction hypotheses reflecting direct benefits to the creator during construction. We examine the fit of these hypotheses to a total of 21 extant taxa and ichnotaxa representing 59-184 possible species. Only two hypotheses, antipredator and biomechanical advantage, cannot be rejected for any species (possible in 100% of taxa), but six of the hypotheses cannot be rejected for most species (possible in 86%-100% of taxa): microclimate buffer, reduced falling sediment (soil), anticrowding, and vertical patch. Four of these six are construction hypotheses, raising the possibility that helical burrowing may have evolved without providing post-construction benefits. Our analysis shows that increased drainage, deposit feeding, microbial farming, and offspring escape cannot explain helical burrowing behavior in the majority of taxa (5%-48%). Overall, the evidence does not support a general explanation for the evolution of helical burrowing in animals. The function and evolution of the helix as an extended phenotype seems to provide different advantages for different taxa in different environments under different physicochemical controls (some traces/tracemakers are discussed in more detail due to their association with body fossils and well-constrained physicochemical parameters). Although direct tests of many of the hypotheses would be difficult, we nevertheless offer ways to test some of the hypotheses for selected taxa., (© 2024 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

AbstractWhere dramatic sexual displays are involved in attracting a mate, individuals can enhance their performances by manipulating their physical environment. Typically, individuals alter their environment either in preparation for a performance by creating a "stage" or during the display itself by using discrete objects as "props." We examined an unusual case of performative manipulation of an entire stage by male Albert's lyrebirds ( Menura alberti ) during their complex song and dance displays. We found that males from throughout the species' range shake the entangled forest vegetation of their display platforms, creating a highly conspicuous and stereotypical movement external to their bodies. This "stage shaking" is performed in two different rhythms, with the second rhythm an isochronous beat that matches the beat of the coinciding vocalizations. Our results provide evidence that stage shaking is an integral, and thus likely functional, component of male Albert's lyrebird sexual displays and so highlight an intriguing but poorly understood facet of complex communication.

To complete its parasitic lifecycle, Salmacisia buchloëana, a biotrophic fungus, manipulates reproductive organ development, meristem determinacy, and resource allocation in its dioecious plant host, buffalograss (Bouteloua dactyloides; Poaceae). To gain insight into S. buchloëana's ability to manipulate its host, we sequenced and assembled the 20.1 Mb genome of S. buchloëana into 22 chromosome-level pseudomolecules. Phylogenetic analysis suggests that S. buchloëana is nested within the genus Tilletia and diverged from Tilletia caries and Tilletia walkeri ∼40 MYA. We find that S. buchloëana contains a novel chromosome arm with no syntenic relationship to other publicly available Tilletia genomes, and that genes on the novel arm are upregulated upon infection, suggesting that this unique chromosomal segment may have played a critical role in S. buchloëana's evolution and host specificity. Salmacisia buchloëana has one of the largest fractions of serine peptidases (1.53% of the proteome) and one of the highest GC contents (62.3%) in all classified fungi. Analysis of codon base composition indicated that GC content is controlled more by selective constraints than directional mutation, and that S. buchloëana has a unique bias for the serine codon UCG. Finally, we identify 3 inteins within the S. buchloëana genome, 2 of which are located in a gene often used in fungal taxonomy. The genomic and transcriptomic resources generated here will aid plant pathologists and breeders by providing insight into the extracellular components contributing to sex determination in dioecious grasses., Competing Interests: Conflicts of interest The authors declare no conflict of interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of The Genetics Society of America.)

To complete their life cycle, a wide range of parasites must manipulate the behavior of their hosts. 1 This manipulation is a well-known example of the "extended phenotype, 2 " where genes in one organism have phenotypic effects on another organism. Recent studies have explored the parasite genes responsible for such manipulation of host behavior, including the potential molecular mechanisms. 3 , In a fascinating example of the extended phenotype, nematomorph parasites have evolved the ability to induce their terrestrial insect hosts to enter bodies of water, where the parasite then reproduces. Here, we comprehensively analyzed nematomorphs and their mantid hosts, focusing on the transcriptomic changes associated with host manipulations and sequence similarity between host and parasite genes to test molecular mimicry. The nematomorph's transcriptome changed during host manipulation, whereas no distinct changes were found in mantids. We then discovered numerous possible host-derived genes in nematomorphs, and these genes were frequently up-regulated during host manipulation. Our findings suggest a possible general role of horizontal gene transfer (HGT) in the molecular mechanisms of host manipulation, as well as in the genome evolution of manipulative parasites. The evidence of HGT between multicellular eukaryotes remains scarce but is increasing and, therefore, elucidating its mechanisms will advance our understanding of the enduring influence of HGT on the evolution of the web of life.4 However, little is known about how parasites have acquired the genes involved in manipulating phylogenetically distinct hosts. 4 In a fascinating example of the extended phenotype, nematomorph parasites have evolved the ability to induce their terrestrial insect hosts to enter bodies of water, where the parasite then reproduces. Here, we comprehensively analyzed nematomorphs and their mantid hosts, focusing on the transcriptomic changes associated with host manipulations and sequence similarity between host and parasite genes to test molecular mimicry. The nematomorph's transcriptome changed during host manipulation, whereas no distinct changes were found in mantids. We then discovered numerous possible host-derived genes in nematomorphs, and these genes were frequently up-regulated during host manipulation. Our findings suggest a possible general role of horizontal gene transfer (HGT) in the molecular mechanisms of host manipulation, as well as in the genome evolution of manipulative parasites. The evidence of HGT between multicellular eukaryotes remains scarce but is increasing and, therefore, elucidating its mechanisms will advance our understanding of the enduring influence of HGT on the evolution of the web of life., Competing Interests: Declaration of interests There are no competing interests in this manuscript., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Since the early twentieth century, the outer layer (mantle) of honeybees ( Apis mellifera ) in the winter cluster has been said to insulate the cluster core. This has encouraged enforced clustering, by the beekeepers' dominant use of inadequately insulated hives and, in North America, refrigeration. This is often seen as a benign or even a necessary process, with beekeeping and academic research considering these conditions of extreme heat loss, compared with the honeybee's natural habitat, as natural and normal. By using porous material correlations, analysis of previous findings and a model of a cluster within a hive in a landscape that implements convection, conduction and radiation, we show that a honeybee colony increases in thermal conductivity, on transition from pre-cluster to dense mantle, by a factor of approximately 2, and insulation R -value can decrease by more than 11. These results show that the mantle does not act like insulation and that clustering is not benign, but instead is an evolutionary behavioural reaction to an existential threat that results in increased cold and exertion stress. Thus the attitude to forced clustering, i.e. deliberately provoking a stressful survival behaviour, needs revision as avoidable forced stress upon animals may be regarded as cruel.

Many animals use self-built structures (extended phenotypes) to enhance body functions, such as thermoregulation, prey capture or defence. Yet, it is unclear whether the evolution of animal constructions supplements or substitutes body functions-with disparate feedbacks on trait evolution. Here, using brown spiders (Araneae: marronoid clade), we explored if the evolutionary loss and gain of silken webs as extended prey capture devices correlates with alterations in traits known to play an important role in predatory strikes-locomotor performance (sprint speed) and leg spination (expression of capture spines on front legs). We found that in this group high locomotor performance, with running speeds of over 100 body lengths per second, evolved repeatedly-both in web-building and cursorial spiders. There was no correlation with running speed, and leg spination only poorly correlated, relative to the use of extended phenotypes, indicating that web use does not reduce selective pressures on body functions involved in prey capture and defence per se . Consequently, extended prey capture devices serve as supplements rather than substitutions to body traits and may only be beneficial in conjunction with certain life-history traits, possibly explaining the rare evolution and repeated loss of trapping strategies in predatory animals.

The effect of parasites on host behaviour is generally considered an example of the extended phenotype, implying that parasite genes alter host behaviour to benefit the parasite. While the extended phenotype is a valid perspective supported by empirical examples, this approach was proposed from an evolutionary perspective and it does not fully explain all processes that occur at ecological time scales. For instance, the roles of the ontogenetic environment, memory and learning in forming the host phenotype are not explicitly mentioned. Furthermore, the cumulative effect of diverse populations or communities of parasites on host phenotype cannot be attributed to a particular genotype, much less to a particular gene. Building on the idea that the behaviour of a host is the result of a complex process, which certainly goes beyond a specific parasite gene, we use Niche Construction Theory to describe certain systems that are not generally the main focus in the extended phenotype model. We introduce three niche construction models with corresponding empirical examples that capture the diversity and complexity of host-parasite interactions, providing predictions that simpler models cannot generate. We hope that this novel perspective will inspire further research on the topic, given the impact of ecological factors on both short-, and long-term effects of parasitism., Competing Interests: Declaration of Competing Interest The authors have no conflicts to declare., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Form follows function throughout the development of an organism. This principle should apply beyond the organism to the nests they build, but empirical studies are lacking. Honeybees provide a uniquely suited system to study nest form and function throughout development because we can image the three-dimensional structure repeatedly and non-destructively. Here, we tracked nest-wide comb growth in six colonies over 45 days (control colonies) and found that colonies have a stereotypical process of development that maintains a spheroid nest shape. To experimentally test if nest structure is important for colony function, we shuffled the nests of an additional six colonies, weekly rearranging the comb positions and orientations (shuffled colonies). Surprisingly, we found no differences between control and shuffled colonies in multiple colony performance metrics-worker population, comb area, hive weight and nest temperature. However, using predictive modelling to examine how workers allocate comb to expand their nests, we show that shuffled colonies compensate for these disruptions by accounting for the three-dimensional structure to reconnect their nest. This suggests that nest architecture is more flexible than previously thought, and that superorganisms have mechanisms to compensate for drastic architectural perturbations and maintain colony function.

Background: The state of Uttarakhand, bordering countries such as Tibet and Nepal, is a multi-ethnic region. Further, erythrocyte alloimmunization may arise from the incompatibility of major and/or minor blood groups between ethnically diverse donors and recipients. We aimed to screen Uttarakhand blood donors (UBDs) for extended phenotyping of their erythrocytes serologically., Methods: This prospective cross-sectional analysis involved all UBD samples collected at the blood centre of our tertiary-care hospital. Samples were obtained over 9 months (Mar'22 to Nov'22). Donors who were O-typed, DAT-negative and non-reactive for TTI markers were processed further for serological testing using the column agglutination technique utilizing 21 different monoclonal antisera (Ortho diagnostics Pvt ltd, Mumbai India). The research was financially aided by UCOST, Uttarakhand, Government of India., Results: Of the 5,407 blood samples collected, the total number of O-typed samples collected was 1622. Of these 1622, 329 (20.2 %) O-typed samples were selected based on our inclusion criteria and hence further phenotyped. Amongst these 329 UBDs, the average age was 32.7 ± 9.32 (18-52) years and the male-to-female ratio was (M: F = 12:1). The prevalence of high- and low-frequency blood antigens in our study was Rh (D 96.6 %, C 84.8 %, c 63.5 %, E 27.9 % and e 92 %), Lewis (Le a 6.3 %, Le b 31.9 %), Kidd (Jk a 87.8 %, Jk b 63.2 %), Kell (K 1.8 %, k 96.3 %) and Duffy (Fy a 63.5 %, Fy b 10.6 %). And in the MNS system we received 21.2 % as M, 10.9 % N, 37 % S and 51.3 % as s respectively. We also identified some very rare minor antigens such as Di a 1.8 %, In a 1.8 %, C w 0.6 % and, 1.2 % Mur positive donors, which are not common in our population, as per the published literature. Moreover, we also identified one Bombay blood phenotype (O h ) in one of our UBD recruits., Conclusion: To sum up, practically with the outcome of this research, we were also able to identify rare phenotypes among the local people and a rare blood donor registry was created. This repository shall also come in use for our multi-transfused patients having different oncological and haematological ailments., (Copyright © 2023 Société française de transfusion sanguine (SFTS). Published by Elsevier Masson SAS. All rights reserved.)

Background and Aim: Despite knowing benefits of extended phenotyping, a vast majority feel that phenotype matched units add to the cost of blood banking. The purpose of this study was to discuss advantages and disadvantages of performing Rh Kell phenotyping in Indian scenario., Materials and Methods: This was a prospective, observational study conducted at a tertiary healthcare center between July 2014 and February 2020. All consecutive whole blood donors and all consecutive patients whose samples were sent for Rh-Kell phenotyping were included for calculating antigen, phenotype and gene frequencies. For rate of alloimmunization in patients transfused with phenotype matched units, all patients who were given Rh-Kell phenotype matched transfusions were included in the prophylactic antigen matched (PAM) category and those who were given random units were included in the non-PAM category., Results: A total of 37,588 donors and 258 patients were included in the study for calculation of antigen, phenotype and gene frequencies. Percentage similarity of phenotypes between patient and donor populations was 33.8%. For rate of alloimmunization, results of a total of 31,991 patient samples revealed 0.94% prevalence of unexpected antibodies; highest against the Rh system. Three patients in the non-PAM category and one in the PAM category were alloimmunized during follow-up. Significant clinical and laboratory impact of phenotyping was observed in terms of reduced turnaround time and consumption of resources., Conclusion: Rh-Kell phenotyping of donors can prevent alloimmunization, reduce cost burden on the patient and the laboratory and help the laboratory personnel in smooth routine testing., (Copyright © 2023 Société française de transfusion sanguine (SFTS). Published by Elsevier Masson SAS. All rights reserved.)

Animals use inter-specific cues as a source of information in decisions-making, but the full costs and benefits of inter-specific information use are unknown. We tested whether pied flycatchers use the body size and clutch size of great tits as cues in their reproductive decisions and what are the possible fitness consequences as a function of great tit size. The size of great tit females associated positively with flycatcher's probability to settle near a tit nest over a territory further away. Flycatcher egg mass was positively correlated with great tit female size regardless of flycatcher territory choice. However, in flycatchers that had chosen to nest near great tits, the size of nestlings decreased in relation to increasing great tit female size. Our results demonstrate the use of size of inter-specifics as a cue in reproductive decisions and the trade-off between the value of information and costs of competition information users face when using inter-specific information in decision-making., (© The Author(s) 2022. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology.)

Understanding community-level selection using Lewontin's criteria requires both community-level inheritance and community-level heritability, and in the discipline of community and ecosystem genetics, these are often conflated. While there are existing studies that show the possibility of both, these studies impose community-level inheritance as a product of the experimental design. For this reason, these experiments provide only weak support for the existence of community-level selection in nature. By contrast, treating communities as interactors (in line with Hull's replicator-interactor framework or Dawkins's idea of the "extended phenotype") provides a more plausible and empirically supportable model for the role of ecological communities in the evolutionary process.

Background: Changes in host phenotype following parasite infection are often considered as host manipulation when they seem advantageous for the parasite. However, putative cases of host manipulation by parasites are rarely tested in field-realistic conditions. Infection-induced phenotypic change cannot be conclusively considered as host manipulation if no evidence shows that this trait is adaptive for the parasite in the wild. Plasmodium sp., the parasites causing malaria in vertebrates, are hypothesized to "manipulate" their host by making their odour more attractive to mosquitoes, their vector and final host. While this is fairly well supported by studies on mice and humans, studies focusing on avian malaria give contradictory results., Methods: In the present study, genotyped birds at different stages (uninfected, acute and chronic) of Plasmodium relictum infection were exposed, in a large outdoor aviary, to their natural vector, the mosquito Culex pipiens., Results: After genotyping the blood meals of more than 650 mosquitoes, we found that mosquitoes did not bite infected birds more than they bit them before infection, nor more than they bit uninfected hosts., Conclusions: Our study highlights the importance of testing ecological behaviours under natural conditions and suggests that different processes might be at play in mammals and birds regarding potential manipulation of attractiveness by malaria parasites., (© 2022. The Author(s).)

Every organism on Earth depends on interactions with other organisms to survive. In each of these interactions, an organism must utilize the limited toolbox of genes and proteins it possesses to successfully manipulate or cooperate with another species, but it can also co-opt the genome machinery of its partner to expand its available tools. Insect-induced plant galls are an extreme example of this, wherein an insect hijacks the plant's genome to direct the initiation and development of galls consisting of plant tissue. However, previous transcriptomic studies have not evaluated individual tissues within a gall to determine the full extent to which a galling insect manipulates its host plant. Here we demonstrate that the cynipid wasp Dryocosmus quercuspalustris creates a complex parasite-specific organ from red oak tissue via massive changes in host gene expression. Our results show that the gall wasp is not merely modifying oak leaf tissue but creating extensive changes in gene expression between galled and ungalled tissue (differential expression in 28% of genes) and distinct gall tissue types (20% of genes). The outer gall tissue shows increases in various plant defence systems, which is consistent with its predicted functional role of protecting the wasp larva. The inner larval capsule shows suppression of large parts of the plant innate immune system and evidence for the wasp utilizing the plant's RNA interference mechanisms, which may be a potential mechanism for the wasp's control on gall growth., (© 2021 John Wiley & Sons Ltd.)

The postulates of developmental instability-sexual selection hypothesis is intensely debated among evolutionary biologists, wherein despite a large amount of empirical data, evidence for or against it has been largely inconclusive. A key assumption of this hypothesis is that animals assess symmetry in potential mates as an indicator of genetic quality (developmental stability), and consequently use this information to discriminate against those with higher asymmetries while choosing mates. However, the perceptional basis that must underlie such discriminatory behavior (is symmetry a signal or is symmetry signaled) is not clearly defined. It is also argued that since asymmetry levels in natural populations are very low, the low signal-to-noise ratio would make accurate assessment of symmetry both difficult and costly. Rather than attempting to validate this hypothesis or even as to whether animals assess mate symmetry, this review simply aims to examine the plausibility that animals perceive symmetry (directly or indirectly) and consequently discriminate against asymmetric mates in response to perceived irregularities during courtship. For this, we review mate choice and courtship literature to identify potential sensory cues that might advertise asymmetry or lead to discrimination of asymmetric individuals. Although signaling associated with mate choice is commonly multimodal, previous studies on asymmetry have mainly focused on visual perception. In the light of a recent study (Vijendravarma et al., 2022, Proceedings of the National Academy of Sciences of the United States of America , 119, e2116136119), this review attempts to balance this bias by emphasizing on non-visual perception of asymmetry. In conclusion, we discuss the methodological challenges associated with testing the role of multimodal cues in detecting mate asymmetry, and highlight the importance of considering ecological, behavioral, and evolutionary aspects of animals while interpreting empirical data that test such hypothesis., Competing Interests: Both RKV and PL declare that they have no conflict of interest., (© 2022 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

Galling insects gain food and shelter by inducing specialized anatomical structures in their plant hosts. Such galls often accumulate plant defensive metabolites protecting the inhabiting insects from predation. We previously found that, despite a marked natural chemopolymorphism in natural populations of Pistacia palaestina, the monoterpene content in Baizongia pistaciae-induced galls is substantially higher than in leaves of their hosts. Here we show a general up-regulation of key structural genes in both the plastidial and cytosolic terpene biosynthetic pathways in galls as compared with non-colonized leaves. Novel prenyltransferases and terpene synthases were functionally expressed in Escherichia coli to reveal their biochemical function. Individual Pistacia trees exhibiting chemopolymorphism in terpene compositions displayed differential up-regulation of selected terpene synthase genes, and the metabolites generated by their gene products in vitro corresponded to the monoterpenes accumulated by each tree. Our results delineate molecular mechanisms responsible for the formation of enhanced monoterpene in galls and the observed intraspecific monoterpene chemodiversity displayed in P. palaestina. We demonstrate that gall-inhabiting aphids transcriptionally reprogram their host terpene pathways by up-regulating tree-specific genes, boosting the accumulation of plant defensive compounds for the protection of colonizing insects., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The conspicuous warning signal of aposematic animals is learned by their predators, and the resulting avoidance benefits both parties. 1-4 Given evidence that birds can distinguish the profitability of prey from the environmental context in which they appear, 5 aposematic insects' host plants might also provide an important cue to foraging predators. 6 The aposematic cinnabar moth (Tyria jacobaeae) larva is a specialist on its ragwort (Senecio spp.) host plant, 7 presenting a consistent environment with which it could be reliably associated. Additionally, ragwort's defensive toxins prevent non-specialist, profitable insects from feeding on it. 8 Thus, avian predators may recognize cues from ragwort, most likely its conspicuous yellow flowers, 9 and use this information to avoid cinnabars. To test this hypothesis, we exposed artificial cinnabar and non-signaling "caterpillar" targets to wild avian predation by presenting them on ragwort and non-toxic host plants. We also manipulated the presence or absence of ragwort flowers on hosts. In doing so, we show that both targets are better protected on the cinnabar's natural ragwort host and that birds use ragwort's distinctive yellow flowers as the cue to avoidance. Additionally, we found that naive predators do not make prey host foraging distinctions, indicating that this avoidance behavior is learned through experience. Our findings are among the first to suggest that a host plant's features act as an extended phenotype that signals the toxicity of the prey that live on it. This prey-host relationship may facilitate the initial evolution of toxicity in non-signaling prey, but also inhibit the evolution of aposematic signals themselves. VIDEO ABSTRACT., 10 and use this information to avoid cinnabars. To test this hypothesis, we exposed artificial cinnabar and non-signaling "caterpillar" targets to wild avian predation by presenting them on ragwort and non-toxic host plants. We also manipulated the presence or absence of ragwort flowers on hosts. In doing so, we show that both targets are better protected on the cinnabar's natural ragwort host and that birds use ragwort's distinctive yellow flowers as the cue to avoidance. Additionally, we found that naive predators do not make prey host foraging distinctions, indicating that this avoidance behavior is learned through experience. Our findings are among the first to suggest that a host plant's features act as an extended phenotype that signals the toxicity of the prey that live on it. This prey-host relationship may facilitate the initial evolution of toxicity in non-signaling prey, but also inhibit the evolution of aposematic signals themselves. VIDEO ABSTRACT., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Parental care can be partitioned into traits that involve direct engagement with offspring and traits that are expressed as an extended phenotype and influence the developmental environment, such as constructing a nursery. Here, we use experimental evolution to test whether parents can evolve modifications in nursery construction when they are experimentally prevented from supplying care directly to offspring. We exposed replicate experimental populations of burying beetles ( Nicrophorus vespilloides ) to different regimes of posthatching care by allowing larvae to develop in the presence (Full Care) or absence of parents (No Care). After only 13 generations of experimental evolution, we found an adaptive evolutionary increase in the pace at which parents in the No Care populations converted a dead body into a carrion nest for larvae. Cross-fostering experiments further revealed that No Care larvae performed better on a carrion nest prepared by No Care parents than did Full Care larvae. We conclude that parents construct the nursery environment in relation to their effectiveness at supplying care directly, after offspring are born. When direct care is prevented entirely, they evolve to make compensatory adjustments to the nursery in which their young will develop. The rapid evolutionary change observed in our experiments suggests there is considerable standing genetic variation for parental care traits in natural burying beetle populations-for reasons that remain unclear., Competing Interests: The authors declare no competing interest., (Copyright © 2021 the Author(s). Published by PNAS.)

Sphagnum peat mosses have an extraordinary impact on the global carbon cycle as they control long-term carbon sequestration in boreal peatland ecosystems. Sphagnum species engineer peatlands, which harbour roughly a quarter of all terrestrial carbon, through peat accumulation by constructing their own niche that allows them to outcompete other plants. Interspecific variation in peat production, largely resulting from differences in tissue decomposability, is hypothesized to drive niche differentiation along microhabitat gradients thereby alleviating competitive pressure. However, little empirical evidence exists for the role of selection in the creation and maintenance of such gradients. In order to document how niche construction and differentiation evolved in Sphagnum , we quantified decomposability for 54 species under natural conditions and used phylogenetic comparative methods to model the evolution of this carbon cycling trait. We show that decomposability tracks the phylogenetic diversification of peat mosses, that natural selection favours different levels of decomposability corresponding to optimum niche and that divergence in this trait occurred early in the evolution of the genus prior to the divergence of most extant species. Our results demonstrate the evolution of ecosystem engineering via natural selection on an extended phenotype, of a fundamental ecosystem process, and one of the Earth's largest soil carbon pools.

Do animals set the course for the evolution of their lineage when manipulating their environment? This heavily disputed question is empirically unexplored but critical to interpret phenotypic diversity. Here, we tested whether the macroevolutionary rates of body morphology correlate with the use of built artifacts in a megadiverse clade comprising builders and nonbuilders-spiders. By separating the inferred building-dependent rates from background effects, we found that variation in the evolution of morphology is poorly explained by artifact use. Thus natural selection acting directly on body morphology rather than indirectly via construction behavior is the dominant driver of phenotypic diversity., Competing Interests: The authors declare no competing interest., (Copyright © 2021 the Author(s). Published by PNAS.)

Host organisms show altered phenotypic reactions when parasitised, some of which result from adaptive host manipulation, a phenomenon that has long been debated. Here, we provide an overview and discuss the rationale in distinguishing adaptive versus nonadaptive host behavioural manipulation. We discuss Poulin's criteria of adaptive host behavioural manipulation within the context of Tinbergen's four questions of ethology, while highlighting the importance of both the proximate and evolutionary explanations of such traits. We also provide guidelines for future studies exploring the adaptiveness of host behavioural manipulation. Through this article, we seek to encourage researchers to consider both the proximate and ultimate causes of host behavioural manipulation to infer on the adaptiveness of such traits., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

A wide range of animal species accumulate objects in, on, and/or around structures they build. Sometimes, these accumulations serve specific functions (e.g. structural or isolating features) or are purely incidental, while in other cases the materials are deliberately displayed to serve signalling purposes (extended phenotype signals). In this pilot study, we employed systematic in situ observations and camera trapping to describe for the first time that both partners of a territorial shorebird, the black-faced sheathbill (Chionis minor ssp minor) collect, carry, and arrange colourful marine shells and dry twigs within and around their nest cavity. Our observations expand the taxonomic breadth of avian extended phenotype signals, by showing that at least one species within a largely understudied group i.e., Charadriiformes, exhibits nest-decoration behaviour. Multiple manipulative experiments are needed to explore further the signalling function of these decorations, which opens new exciting avenues for animal communication and cognition research., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The architectural design of animal structures forms part of an individual's extended phenotype that can be subjected to strong selection pressures. We examined cocoon architectural dimorphism in robin moths (Hyalophora cecropia), which construct multilayered silk-woven cocoons that possess either a 'baggy' or 'compact' morphology. These dimorphic cocoons reflect extended phenotypes that can enable survival during a critical developmental period (pupal stage to adult emergence), with cocoons occurring either sympatrically or as monomorphic groups across different climatic regions in North America. We hypothesized that cocoon dimorphism is related to the cocoon's role as a mediating barrier for moisture. We predicted that the macro- and micro-architectural differences between the cocoon morphs would be consistent with this function. We compared the cocoon morphs in terms of their orientation when spun under natural field conditions, examined how these orientations affected cocoon water absorption under simulated rain trials, and performed material surface tests to compare the hydrophobicity of cocoons. We found that compact cocoons had traits that increased water resistance, as they had significantly greater hydrophobicity than baggy cocoons, because they absorbed less water and released water vapor faster. In contrast, the increased water absorptiveness of baggy cocoons can allow for greater moisture retention, a function related to the prevention of desiccation. Our study suggests that cocoon dimorphism in robin moths reflects distinct architectural syndromes, in which cocoons are spun to optimize either water resistance or retention. These different functions are consistent with strategies that act to respond to uncertain external environmental conditions that an individual might encounter during development., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)

Most species are either parasites or exploited by parasites, making parasite-host interactions a driver of evolution. Parasites with complex life cycles often evolve strategies to facilitate transmission to the definitive host by manipulating their intermediate host. Such manipulations could explain phenotypic changes in the ant Temnothorax nylanderi , the intermediate host of the cestode Anomotaenia brevis . In addition to behavioral and morphological alterations, infected workers exhibit prolonged lifespans, comparable to that of queens, which live up to two decades. We used transcriptomic data from cestodes and ants of different castes and infection status to investigate the molecular underpinnings of phenotypic alterations in infected workers and explored whether the extended lifespan of queens and infected workers has a common molecular basis. Infected workers and queens commonly upregulated only six genes, one of them with a known anti-aging function. Both groups overexpressed immune genes, although not the same ones. Our findings suggest that the lifespan extension of infected workers is not achieved via the expression of queen-specific genes. The analysis of the cestodes' transcriptome revealed dominant expression of genes of the mitochondrial respiratory transport chain, which indicates an active metabolism and shedding light on the physiology of the parasite in its cysticercoid stage.

Gravity is very important for many organisms, including web-building spiders. Probably the best approach to study the relevance of gravity on organisms is to bring them to the International Space Station. Here, we describe the results of such an experiment where two juvenile Trichonephila clavipes (L.) (Araneae, Nephilidae) spiders were observed over a 2-month period in zero gravity and two control spiders under otherwise identical conditions on Earth. During that time, the spiders and their webs were photographed every 5 min. Under natural conditions, Trichonephila spiders build asymmetric webs with the hub near the upper edge of the web, and they always orient themselves downwards when sitting on the hub whilst waiting for prey. As these asymmetries are considered to be linked to gravity, we expected the spiders experiencing no gravity to build symmetric webs and to show a random orientation when sitting on the hub. We found that most, but not all, webs built in zero gravity were indeed quite symmetric. Closer analysis revealed that webs built when the lights were on were more asymmetric (with the hub near the lights) than webs built when the lights were off. In addition, spiders showed a random orientation when the lights were off but faced away from the lights when they were on. We conclude that in the absence of gravity, the direction of light can serve as an orientation guide for spiders during web building and when waiting for prey on the hub.

Ecosystem engineers that modify landforms can be valuable tools for restoring habitat, but their use has frequently resulted in unanticipated outcomes. Departures from expectations might arise because applications discount the possibility that geomorphic processes are influenced by heritable phenotypic variation. We conducted a field-scale common garden experiment to assess whether shoreline erosion reflects intraspecific variation in the landform engineer Spartina alterniflora . Replicated plots on a shoreline denuded by the Deepwater Horizon oil spill were revegetated using plants from four genetically distinct sources: the local population, a nonlocal population, and two nursery stocks. We assessed variation in biomass, tissue nutrients, and functional traits alongside soil shear strength, surface elevation, and shoreline erosion rates over 2 years. We found that productivity, traits, nutrient content, and erosion rates varied according to plant provenance. Erosion reflected traits like root architecture more so than coarser metrics of growth. Erosion was significantly higher in plots with nonlocal plants that exhibited lower productivity, likely due to nitrogen limitation. Our results indicate that restoration practices should account for intraspecific variation in landform engineers and that in situ trials should be performed at sites slated for restoration to evaluate donor source suitability, particularly if introductions might modify local populations., Competing Interests: None declared., (© 2020 The Authors. Evolutionary Applications published by John Wiley & Sons Ltd.)

Birds, among various other taxa, construct nests. Nests form an extended phenotype of the individual building it. Nests are used to extend control over the conditions in which offspring develop, and are therefore commonly considered to be shaped by selection. Nevertheless, scarcely any scientific evidence exist that nest composition is under selection. Here, we demonstrate with data from over 400 blue tit ( Cyanistes caeruleus ) nests collected over 8 years that a higher proportion of feathers in the nest lining is positively associated with the probability of offspring to recruit as a breeding adult later in life. Strikingly, the extended phenotype (nest) was associated stronger with recruitment probability than phenotypic traits that have typically been considered important in selection (laying date, and female size and condition). Our findings suggest that the choice of nest material could be a maternal behavior with potential lifelong effects on her offspring., Competing Interests: The authors declare they have no conflict of interest., (© 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

Complex life cycle parasites can manipulate the behavior of intermediate hosts in order to reduce their fitness and increase the chance of completing life cycle. In order to understand the effects of the trematode parasites of the genus Clinostomum on host fish Loricariichthys platymetopon, a filmed experiment was carried out to quantify the foraging activity of hosts with different intensities of infection. The results suggest that hosts with higher parasite intensities reduced foraging activity early in the morning when compared to hosts with low intensities. This period may be critical for hosts since birds, the target hosts of such trematodes, forage intensively at dawn., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Soil is used for the construction of structures by many animals, at times admixed with endogenous secretions. These additives, along with soil components, are suggested to have a role in biocementation. However, the relative contribution of endogenous and exogenous materials to soil strength has not been adequately established. Termite mounds are earthen structures with exceptional strength and durability including weathering resistance to wind and rain. With in situ and laboratory-based experiments, we demonstrate that the fungus-farming termite Odontotermes obesus which builds soil nest mounds, when given a choice, prefers soil close to its liquid limit for construction. At this moisture content, the soil-water mixture alone even in the absence of termite handling undergoes self-weight consolidation and upon drying attains a monolithic, densely packed structure with compressive strength comparable to the in situ strength of the mound soil; however, the soil-water mixture alone has lower resistance to water erosion than the in situ mound samples, suggesting that termite secretions impart weathering resistance and thereby long-term stability to the mound. Therefore, weathering resistance and compressive strength are conferred by different aspects of termite soil manipulation. Our work provides novel insights into termite mound construction and strength correlates for earthen structures built by animals., Competing Interests: We declare we have no competing interests., (© 2020 The Authors.)

A diverse set of pathogens have evolved extended phenotypes that manipulate the moribund behavior of their various insect hosts. By elevating host positioning at death, a phenomenon called "summit disease", these pathogens have been shown to have higher fitness. Though a few summit disease systems have been intensively characterized, in particular the Ophiocordyceps-ant system, summit diseases lack an overarching theory for the underlying mechanisms of this complex behavioral manipulation. In this article, we combine the gamut of summiting systems into a cohesive framework: we propose two types of summit disease (juvenile and adult), which both exploit natural insect behaviors during periods of quiescence. We place this framework in the context of available literature and propose investigations that follow from this comprehensive understanding of summit disease in insects., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Parasitism can result in dramatic changes in host phenotype, which are themselves underpinned by genes and their expression. Understanding how hosts respond at the molecular level to parasites can therefore reveal the molecular architecture of an altered host phenotype. The entomoparasitic nematode Sphaerularia bombi is a parasite of bumblebee (Bombus) hosts where it induces complex behavioural changes and host castration. To examine this interaction at the molecular level, we performed genome-wide transcriptional profiling using RNA-Sequencing (RNA-Seq) of S. bombi-infected Bombus terrestris queens at two critical time-points: during and just after overwintering diapause. We found that infection by S. bombi affects the transcription of genes underlying host biological processes associated with energy usage, translation, and circadian rhythm. We also found that the parasite affects the expression of immune genes, including members of the Toll signalling pathway providing evidence for a novel interaction between the parasite and the host immune response. Taken together, our results identify host biological processes and genes affected by an entomoparasitic nematode providing the first steps towards a molecular understanding of this ecologically important host-parasite interaction., (© 2019 The Royal Entomological Society.)

Phenotypic features extending beyond the body, or EPs, may vary plastically across environments. EP constructs, such as spider webs, vary in property across environments as a result of changes to the physiology of the animal or interactions between the environment and the integrity of the material from which the EP is manufactured. Due to the complexity of the interactions between EP constructs and the environment, the impact of climate change on EP functional integrity is poorly understood. Here we used a dynamic model to assess how temperature and humidity influence spider web major ampullate (MA) silk properties. MA silk is the silk that absorbs the impact of prey striking the web, hence our model provides a useful interpretation of web performance over the temperature (i.e. 20-55°C) and humidity (i.e. 15-100%) ranges assessed. Our results showed that extremely high or low humidity had direct negative effects on web capture performance, with changes in temperature likely having indirect effects. Undeniably, the effect of temperature on web architecture and its interactive effect with humidity on web tension and capture thread stickiness need to be factored into any further predictions of plausible climate change impacts. Since our study is the first to model plasticity in an EP construct's functionality and to extrapolate the results to predict climate change impacts, it stands as a template for future studies that endeavour to make predictions about the influence of climate change on animal EPs., (© The Author(s) 2019. Published by Oxford University Press and the Society for Experimental Biology.)

Physical structures built by animals challenge our understanding of biological processes and inspire the development of smart materials and green architecture. It is thus indispensable to understand the drivers, constraints, and dynamics that lead to the emergence and modification of building behavior. Here, we demonstrate that spider web diversification repeatedly followed strikingly similar evolutionary trajectories, guided by physical constraints. We found that the evolution of suspended webs that intercept flying prey coincided with small changes in silk anchoring behavior with considerable effects on the robustness of web attachment. The use of nanofiber based capture threads (cribellate silk) conflicts with the behavioral enhancement of web attachment, and the repeated loss of this trait was frequently followed by physical improvements of web anchor structure. These findings suggest that the evolution of building behavior may be constrained by major physical traits limiting its role in rapid adaptation to a changing environment., (© 2019 The Author(s). Evolution © 2019 The Society for the Study of Evolution.)

Parasites of animals and plants can encounter trade-offs between their specificity to any single host and their fitness on alternative hosts. For parasites that manipulate their host's behaviour, the added complexity of that manipulation may further limit the parasite's host range. However, this is rarely tested. The recently described crypt-keeper wasp, Euderus set , changes the behaviour of the gall wasp Bassettia pallida such that B. pallida chews a significantly smaller exit hole in the side of its larval chamber and 'plugs' that hole with its head before dying. Euderus set benefits from this head plug, as it facilitates the escape of the parasitoid from the crypt after it completes development. Here, we find direct and indirect evidence that E. set attacks and manipulates the behaviour of at least six additional gall wasp species, and that these hosts are taxonomically diverse. Interestingly, each of E. set 's hosts has converged upon similarities in their extended phenotypes: the galls they induce on oaks share characters that may make them vulnerable to attack by E. set . The specialization required to behaviourally manipulate hosts may be less important in determining the range of hosts in this parasitoid system than other dimensions of the host-parasitoid interaction, like the host's physical defences.

Sexual dimorphism is widespread, but we have a limited understanding of its significance for communities and ecosystems. Several new experiments demonstrate that sexual dimorphism can have far-reaching ecological effects. These results suggest that sexual dimorphism and sexual selection are potent, but largely overlooked components of eco-evolutionary dynamics., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Nests play a critical role for offspring development across the animal kingdom. Nest quality may contribute to the builder's extended phenotype and serve as an ornament during mate choice. We examined male and female nest choice in the common goby ( Pomatoschistus microps ), a benthic fish with male-only parental care where females deposit eggs in male-built nests. Using prebuilt nest models, we independently manipulated two candidate nest quality traits: (a) nest entrance width with a role in oxygen ventilation, and (b) extent of sand cover with a role in camouflage. In simultaneous choice trials, male gobies exhibited no preference for any nest model type. This suggests that initial characteristics of a nesting substrate have minor importance for males, which usually remodel the nest. Females were given a choice between two males occupying either entrance- or cover-manipulated nests. The same pair of males was then exposed to a second female but now with alternated nest types assigned. Most females were consistent in choosing the same, typically the heavier male of the two regardless of nest properties. However, the females that chose the same nest regardless of the male preferred low over high sand coverage and narrow over wide nest entrance. Our results indicate that females base their mating decision on a combination of male phenotype and nest traits. While we found no indication that females are attracted to highly decorated nests, our study is the first in fishes to disentangle a preference for narrow (and thus more protective) nest entrances independent of nest coverage., Competing Interests: The authors declare that they have no competing interests.

The behavioral phenotype of an organism results from selective processes acting on variation in behavioral traits during ontogeny (during life span) and phylogeny (across generations). Different adaptive processes can be categorized as environment-phenotype feedback loops. In this cross-disciplinary approach, we discuss the interaction of ontogenetic selective processes, traditionally studied by behavior analysts, and phylogenetic selection processes, traditionally studied by biologists. We elaborate upon the Extended Evolutionary Synthesis by addressing the connection between selection as a domain-general process and phenomena such as classical and operant conditioning, imprinting, adjunctive behavior, and gene-culture coevolution. Selection is in this context understood as a dynamic iterative feedback loop producing a phenotype beyond the strict morphotype. The extended phenotype is related to the concept of niche construction in which the behavior of organisms shapes their environment, which again selects the behavior of the organisms in an iterative process. A discussion of interacting environmental factors selecting human food choice both during phylogeny and ontogeny exemplifies the generality of selection processes acting on behavior., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Most animal traps are constructed from self-secreted silk, so antlions are rare among trap builders because they use only materials found in the environment. We show how antlions exploit the properties of the substrate to produce very effective structures in the minimum amount of time. Our modelling demonstrates how antlions: (i) exploit self-stratification in granular media differentially to expose deleterious large grains at the bottom of the construction trench where they can be ejected preferentially, and (ii) minimize completion time by spiral rather than central digging. Both phenomena are confirmed by our experiments. Spiral digging saves time because it enables the antlion to eject material initially from the periphery of the pit where it is less likely to topple back into the centre. As a result, antlions can produce their pits-lined almost exclusively with small slippery grains to maximize powerful avalanches and hence prey capture-much more quickly than if they simply dig at the pit's centre. Our demonstration, for the first time to our knowledge, of an animal using self-stratification in granular media exemplifies the sophistication of extended phenotypes even if they are only formed from material found in the animal's environment.

The thermal limit of ectotherms provides an estimate of vulnerability to climate change. It differs between contrasting microhabitats, consistent with thermal ecology predictions that a species' temperature sensitivity matches the microclimate it experiences. However, observed thermal limits may differ between ectotherms from the same environment, challenging this theory. We resolved this apparent paradox by showing that ectotherm activity generates microclimatic deviations large enough to account for differences in thermal limits between species from the same microhabitat. We studied upper lethal temperature, effect of feeding mode on plant gas exchange, and temperature of attacked leaves in a community of six arthropod species feeding on apple leaves. Thermal limits differed by up to 8 °C among the species. Species that caused an increase in leaf transpiration (+182%), thus cooling the leaf, had a lower thermal limit than those that decreased leaf transpiration (-75%), causing the leaf to warm up. Therefore, cryptic microclimatic variations at the scale of a single leaf determine the thermal limit in this community of herbivores. We investigated the consequences of these changes in plant transpiration induced by plant-insect feedbacks for species vulnerability to thermal extremes. Warming tolerance was similar between species, at ±2 °C, providing little margin for resisting increasingly frequent and intense heat waves. The thermal safety margin (the difference between thermal limit and temperature) was greatly overestimated when air temperature or intact leaf temperature was erroneously used. We conclude that feedback processes define the vulnerability of species in the phyllosphere, and beyond, to thermal extremes., Competing Interests: The authors declare no conflict of interest., (Copyright © 2019 the Author(s). Published by PNAS.)

Host manipulation is a parasite-induced alteration of a host's phenotype that increases parasite fitness. However, if genetically encoded in the parasite, it should be under selection in the parasite. Such host manipulation has often been assumed to be energetically costly, which should restrict its evolution. Evidence of such costs, however, remains elusive. The trophically transmitted cestode Schistocephalus solidus manipulates the activity of its first intermediate copepod host to reduce its predation susceptibility before the parasite is ready for transmission. Thereafter, S. solidus increases host activity to facilitate transmission to its subsequent fish host. I selected S. solidus for or against host manipulation over three generations to investigate the evolvability of manipulation and identify potential trade-offs. Host manipulation responded to selection, confirming that this trait is heritable in the parasite and hence can present an extended phenotype. Changes in host manipulation were not restrained by any obvious costs.

Very few primate species give birth to litters and build nests in which to care for them. Those that do are small-bodied, nocturnal, and solitary. Variegated lemurs are exceptional in that they bear litters in arboreal nests, yet are relatively large-bodied, day-active, and gregarious. Furthermore, they raise their young cooperatively and practice absentee parenting; non-clinging young are transported orally and periodically stashed in arboreal spots that are supportive, sheltered, and usually concealed. Following birth, infant nest and stash trees were mapped, measured, and taxonomically identified in a population of red variegated lemurs in Masoala National Park. About 40 trees were used per litter for nesting and stashing young in adjacent, non-overlapping core areas within the community. These were the largest trees in the forest, even larger than those used for feeding. Furthermore, most occur in valleys and are laced with lianas, creating sites that buffer young from predation, accidental falls, and to some degree, thermal stress. In combination, the number of nest and stash trees used per litter, their characteristics, and their geo-spatial arrangement indicate that such sites are both select and limited in the landscape, exposing the dependence of red variegated lemurs on intact forest canopies for raising non-clinging young within the context of an absentee parenting system. Nest and stash sites are in effect Varecia's extended phenotype. Logging of large trees in Madagascar's eastern rain forests is considered a major factor resulting in local extinctions of variegated lemurs because they rely heavily upon large, mature trees for fruit. However, this study suggests that removal of large trees may more directly precipitate local extinctions by impeding their ability to reproduce. Long-term survival of red variegated lemurs will depend upon efforts to end harmful timber extraction in its remaining stronghold, the Masoala Peninsula., (© 2018 Wiley Periodicals, Inc.)

Structures such as nests and burrows are an essential component of many organisms' life-cycle and require a complex sequence of behaviours. Because behaviours can vary consistently among individuals and be correlated with one another, we hypothesized that these structures would (1) show evidence of among-individual variation, (2) be organized into distinct functional modules and (3) show evidence of trade-offs among functional modules due to limits on energy budgets. We tested these hypotheses using the alfalfa leafcutting bee, Megachile rotundata, a solitary bee and important crop pollinator. Megachile rotundata constructs complex nests by gathering leaf materials to form a linear series of cells in pre-existing cavities. In this study, we examined variation in the following nest construction traits: reproduction (number of cells per nest and nest length), nest protection (cap length and number of leaves per cap), cell construction (cell size and number of leaves per cell) and cell provisioning (cell mass) from 60 nests. We found a general decline in investment in cell construction and provisioning with each new cell built. In addition, we found evidence for both repeatability and plasticity in cell provisioning with little evidence for trade-offs among traits. Instead, most traits were positively, albeit weakly, correlated (r ~ 0.15), and traits were loosely organized into covarying modules. Our results show that individual differences in nest construction are detectable at a level similar to that of other behavioural traits and that these traits are only weakly integrated. This suggests that nest components are capable of independent evolutionary trajectories., (© 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.)

Parasites can enhance their fitness by modifying the behavior of their hosts in ways that increase rates of production and transmission of parasite larvae. We used an antihelminthic drug to experimentally alter infections of lungworms ( Rhabdias pseudosphaerocephala ) in cane toads ( Rhinella marina ). We then compared subsequent behaviors of dewormed toads versus toads that retained infections. Both in the laboratory and in the field, the presence of parasites induced hosts to select higher body temperatures (thereby increasing rates of lungworm egg production), to defecate in moister sites, and to produce feces with higher moisture content (thereby enhancing survival of larvae shed in feces). Because those behavioral modifications enhance rather than decrease parasite fitness, they are likely to have arisen as adaptive manipulations of host behavior rather than as host adaptations to combat infection or as nonadaptive consequences of infection on host physiology. However, the mechanisms by which lungworms alter cane toad thermal preference and defecation are not known. Although many examples of host manipulation by parasites involve intermediate hosts facilitating their own demise, our findings indicate that manipulation of definitive hosts can be as subtle as when and where to defecate.

Many animals actively defend their offspring using a range of behaviours from calling and mobbing in birds, to physical grappling in crustaceans, and the expression of these behaviours positively scale with offspring value. While this role of behaviour in defence is well studied, very little is known about how other traits, specifically the structure of architectural constructions such as webs and nests, contribute to offspring defence. Additionally, although some tax a show consistent individual differences in offspring defence behaviour, it is completely unknown whether individuals also differ in defensive structures. We addressed these questions in the redback spider, Latrodectus hasselti , by measuring how a female laying an eggcase influences female behaviour and web structure, and whether those traits scale with relative reproductive investment. Our results show that females modified web structure in response to an eggcase, but only the protective elements of web structure positively scaled with the relative value of that eggcase. Finally, despite the significant correlations, fixed effects (e.g. eggcase possession/value) in the models explained only 5-23% of the variation in behaviour and web structure, while the random effect of individual identity explained 46-65% of the variation. This variation drove moderate to high repeatability estimates across all traits, suggesting that some individuals consistently invest relatively more in defence, while some invest less. These results highlight that extended phenotypic traits may be a critical component of offspring defence in some taxa. Furthermore, individual variation in these traits suggest that different reproductive strategies may exist, whereby some individuals invest more in reproduction at a cost to safety/foraging and vice versa.

We expand the Kosaki overgrowth syndrome (KOGS) phenotype by over 70% to include 24 unreported KOGS symptoms, in a first male patient, the third overall associated with the PDGFRB c.1751C>G p.(Pro584Arg) mutation. Eighteen of these symptoms are unique to our patient, the remaining six are shared with other patients. Of the 24 unreported features overall, 6 show marked phenotype evolution and varying time of onset. The triangular face detected at 14 months and long palpebral fissures with lateral ectropion at 4 years are present in other members of the cohort. The remaining 4 are unique to Patient 5: pronounced macrocephaly from birth, increasingly triangular anterior skull from 14 months, camptodactyly, emerging at 4 years and worsening joint contractures from 6 years. Compilation of all new symptoms reported here with published clinical data further identifies at least 18 clinical parameters common to all cases to date, encompassing both known KOGS-associated PDGFRB mutations. We therefore propose a set of 18 core KOGS symptoms, with 16 present in early childhood. These results should also impact diagnostic/prognostic scope, intervention and outcome potential for KOGS patients, particularly for developmentally progressive conditions such as scoliosis and myofibroma., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Parasite-mediated competition can shape community structure and host distribution. If two species compete for resources, parasites may indirectly change the outcome of competition. We tested the role of a trematode parasite in mediating microhabitat use by congeneric isopods Austridotea annectens and Austridotea lacustris Although both isopods share resources, they rarely co-occur in the same discrete microhabitats. We set up mesocosms with and without competition and/or parasites to examine the role of parasites in host distribution and habitat segregation. Austridotea annectens showed a clear preference for one microhabitat type regardless of competition or parasitic infection. By contrast, A. lacustris showed little habitat selection in the absence of competition, but favoured sandy habitats in the presence of uninfected A. annectens and rocky habitats when competing with infected A. annectens Our results suggest that parasites in one species affect the distribution of another species, and mediate competition between these species. We demonstrated the impacts of a parasite on the microhabitat use of its host's competitor. This also represents an example of a super-extended phenotype, where a parasite affects the phenotype of a non-host., (© 2018 The Author(s).)

Insect behavior can be manipulated by parasites, and in many cases, such manipulation involves the central and peripheral nervous system. Neuroparasitology is an emerging branch of biology that deals with parasites that can control the nervous system of their host. The diversity of parasites that can manipulate insect behavior ranges from viruses to macroscopic worms and also includes other insects that have evolved to become parasites (notably, parasitic wasps). It is remarkable that the precise manipulation observed does not require direct entry into the insect brain and can even occur when the parasite is outside the body. We suggest that a spatial view of manipulation provides a holistic approach to examining such interactions. Integration across approaches from natural history to advanced imaging techniques, omics, and experiments will provide new vistas in neuroparasitology. We also suggest that for researchers interested in the proximate mechanisms of insect behaviors, studies of parasites that have evolved to control such behavior is of significant value.

A central challenge in biology is to understand how innate behaviors evolve between closely related species. One way to elucidate how differences arise is to compare the development of behavior in species with distinct adult traits [1]. Here, we report that Peromyscus polionotus is strikingly precocious with regard to burrowing behavior, but not other behaviors, compared to its sister species P. maniculatus. In P. polionotus, burrows were excavated as early as 17 days of age, whereas P. maniculatus did not build burrows until 10 days later. Moreover, the well-known differences in burrow architecture between adults of these species-P. polionotus adults excavate long burrows with an escape tunnel, whereas P. maniculatus dig short, single-tunnel burrows [2-4]-were intact in juvenile burrowers. To test whether this juvenile behavior is influenced by early-life environment, we reciprocally cross-fostered pups of both species. Fostering did not alter the characteristic burrowing behavior of either species, suggesting that these differences are genetic. In backcross hybrids, we show that precocious burrowing and adult tunnel length are genetically correlated and that a P. polionotus allele linked to tunnel length variation in adults is also associated with precocious onset of burrowing in juveniles, suggesting that the same genetic region-either a single gene with pleiotropic effects or linked genes-influences distinct aspects of the same behavior at these two life stages. These results raise the possibility that genetic variants affect behavioral drive (i.e., motivation) to burrow and thereby affect both the developmental timing and adult expression of burrowing behavior., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Some microbes possess the ability to adaptively manipulate host behavior. To better understand how such microbial parasites control animal behavior, we examine the cell-level interactions between the species-specific fungal parasite Ophiocordyceps unilateralis sensu lato and its carpenter ant host ( Camponotus castaneus ) at a crucial moment in the parasite's lifecycle: when the manipulated host fixes itself permanently to a substrate by its mandibles. The fungus is known to secrete tissue-specific metabolites and cause changes in host gene expression as well as atrophy in the mandible muscles of its ant host, but it is unknown how the fungus coordinates these effects to manipulate its host's behavior. In this study, we combine techniques in serial block-face scanning-electron microscopy and deep-learning-based image segmentation algorithms to visualize the distribution, abundance, and interactions of this fungus inside the body of its manipulated host. Fungal cells were found throughout the host body but not in the brain, implying that behavioral control of the animal body by this microbe occurs peripherally. Additionally, fungal cells invaded host muscle fibers and joined together to form networks that encircled the muscles. These networks may represent a collective foraging behavior of this parasite, which may in turn facilitate host manipulation., Competing Interests: The authors declare no conflict of interest., (Copyright © 2017 the Author(s). Published by PNAS.)