Conflict over non-partitioned resources may explain between-species differences in declines: the anthropogenic competition hypothesis

This is the final version of the article. Available from Springer Verlag via the DOI in this record.Human alterations of habitats are causing declines in many species worldwide. The extent of declines varies greatly among closely related species, for often unknown reasons that must be understood in order to maintain biodiversity. An overlooked factor is that seasonally breeding species compete for nest sites, which are increasingly limited in many anthropogenically degraded environments. I used evolutionary game theory to predict the outcome of competition between individuals that differ in their competitive ability and timing of nesting. A range of species following evolutionarily stable strategies can co-exist when there are sufficient nest sites, but my model predicts that a reduction in nest site availability has greater impacts on late-nesting species, especially the stronger competitors, whereas early-nesting, stronger species decline only slightly. These predictions are supported by data on 221 bird and 43 bumblebee species worldwide. Restoration and provision of nest sites should be an urgent priority in conservation efforts. More broadly, these results indicate a new ecological principle of potentially widespread importance: rapid reductions in the abundance of resources for which species’ preferences have not diversified will result in unprecedented conflicts that reduce the potential for species co-existence.This work was supported by the European Research Council (Advanced Grant 250209 to Alasdair Houston), a residential fellowship at the Wissenschaftskolleg zu Berlin and a NERC Independent Research Fellowship (NE/L011921/1)

Comment on 'Are physicists afraid of mathematics?'

This is the final version of the article. Available from the publisher via the DOI in this record.In 2012, we showed that the citation count for articles in ecology and evolutionary biology declines with increasing density of equations. Kollmeret al (2015 New J. Phys. 17 013036) claim this effect is an artefact of the manner in which we plotted the data. They also present citation data from Physical Review Letters and argue, based on graphs, that citation counts are unrelated to equation density. Here we show that both claims are misguided. We identified the effects in biology not by visual means, but using the most appropriate statistical analysis. Since Kollmeret al did not carry out any statistical analysis, they cannot draw reliable inferences about the citation patterns in physics. We show that when statistically analysed their data actually do provide evidence that in physics, as in biology, citation counts are lower for articles with a high density of equations. This indicates that a negative relationship between equation density and citations may extend across the breadth of the sciences, even those in which researchers are well accustomed to mathematical descriptions of natural phenomena. We restate our assessment that this is a genuine problem and discuss what we think should be done about it.This work was supported by a European Research Council Advanced Grant (250209) awarded to Alasdair Houston and NERC Independent Research Fellowship (NE/L011921/1) awarded to ADH. We are indebted to the American Physical Society and Physical Review Letters for granting access to their article data and Jonathan Kollmer, Thorsten Pöschel and Jason Gallas for supplying it

An adaptive response to uncertainty can lead to weight gain during dieting attempts

This is the final version of the article. Available from the publisher via the DOI in this record.Background and objectives: Peoples’ attempts to lose weight by low calorie diets often result in weight gain because of over-compensatory overeating during lapses. Animals usually respond to a change in food availability by adjusting their foraging effort and altering how much energy reserves they store. But in many situations the long-term availability of food is uncertain, so animals may attempt to estimate it to decide the appropriate level of fat storage. Methodology: We report the results of a conceptual model of feeding in which the animal knows whether food is currently abundant or limited, but does not know the proportion of time, there will be an abundance in the long-term and has to learn it. Results: If the food supply is limited much of the time, such as during cycles of dieting attempts, the optimal response is to gain a lot of weight when food is abundant. Conclusions and implications: This implies that recurring attempts to diet, by signalling to the body that the food supply is often insufficient, will lead to a greater fat storage than if food was always abundant. Our results shed light on the widespread phenomenon of weight gain during weight cycling and indicate possible interventions that may reduce the incidence of obesityThis work was supported by the European Research Council (Advanced Grant 250209 to Alasdair Houston) and a Natural Environmental Research Council Independent Research Fellowship (NE/L011921/1) awarded to A.D.

Current Incentives for Scientists Lead to Underpowered Studies with Erroneous Conclusions

This is the final version of the article. Available from Public Library of Science via the DOI in this record.We can regard the wider incentive structures that operate across science, such as the priority given to novel findings, as an ecosystem within which scientists strive to maximise their fitness (i.e., publication record and career success). Here, we develop an optimality model that predicts the most rational research strategy, in terms of the proportion of research effort spent on seeking novel results rather than on confirmatory studies, and the amount of research effort per exploratory study. We show that, for parameter values derived from the scientific literature, researchers acting to maximise their fitness should spend most of their effort seeking novel results and conduct small studies that have only 10%-40% statistical power. As a result, half of the studies they publish will report erroneous conclusions. Current incentive structures are in conflict with maximising the scientific value of research; we suggest ways that the scientific ecosystem could be improved.Funding: Medical Research Council and the University of Bristol (grant number MC_UU_12013/6).Received by MRM. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Natural Environment Research Council (grant number NE/L011921/1).Received by ADH. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. MRM is a member of the UK Centre for Tobacco and Alcohol Studies, a UKCRC Public Health Research: Centre of Excellence. Funding from British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, and the National Institute for Health Research, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledge

Towards a behavioural ecology of obesity

This is the author accepted manuscript. The final version is available from Cambridge University Press via the DOI in this record.Addressing the obesity epidemic depends on a holistic understanding of the reasons that people become and maintain excessive fat. Theories about the causes of obesity usually focus proximately or evoke evolutionary mismatches, with minimal clinical value. There is potential for substantial progress by adapting strategic bodymass regulation models from evolutionary ecology to human obesity by assessing the role of information

Adaptive Use of Information during Growth Can Explain Long-Term Effects of Early Life Experiences.

Development is a continuous process during which individuals gain information about their environment and adjust their phenotype accordingly. In many natural systems, individuals are particularly sensitive to early life experiences, even in the absence of later constraints on plasticity. Recent models have highlighted how the adaptive use of information can explain age-dependent plasticity. These models assume that information gain and phenotypic adjustments either cannot occur simultaneously or are completely independent. This assumption is not valid in the context of growth, where finding food results both in a size increase and learning about food availability. Here, we describe a simple model of growth to provide proof of principle that long-term effects of early life experiences can arise through the coupled dynamics of information acquisition and phenotypic change in the absence of direct constraints on plasticity. The increase in reproductive value from gaining information and sensitivity of behavior to experiences declines across development. Early life experiences have long-term impacts on age of maturity, yet-due to compensatory changes in behavior-our model predicts no substantial effects on reproductive success. We discuss how the evolution of sensitive windows can be explained by experiences having short-term effects on informational and phenotypic states, which generate long-term effects on life-history decisions.This research was funded by the European Union’s Seventh Framework Programme (FP7/2007-2011) under grant 259679 (IDEAL) awarded to T.U. T.W.F., A.D.H., and P.C.T. were supported by the European Research Council (ERC Advanced Grant 250209 Evomech to A. Houston). T.U. was supported by the Royal Society of London and the Knut and Alice Wallenberg Foundation. A.D.H. was supported by fellowships from the Wissenschaftskolleg zu Berlin and the Natural Environment Research Council (grant NE/L011921/1)

The locus of sexual selection: moving sexual selection studies into the post-genomics era

Sexual selection drives fundamental evolutionary processes such as trait elaboration and speciation. Despite this importance, there are surprisingly few examples of genes unequivocally responsible for variation in sexually selected phenotypes. This lack of information inhibits our ability to predict phenotypic change due to universal behaviors, such as fighting over mates and mate choice. Here, we discuss reasons for this apparent gap and provide recommendations for how it can be overcome by adopting contemporary genomic methods, exploiting underutilized taxa that may be ideal for detecting the effects of sexual selection, and adopting appropriate experimental paradigms. Identifying genes that determine variation in sexually selected traits has the potential to improve theoretical models and reveal whether the genetic changes underlying phenotypic novelty utilize common or unique molecular mechanisms. Such a genomic approach to sexual selection will help answer questions in the evolution of sexually selected phenotypes that were first asked by Darwin and can furthermore serve as a model for the application of genomics in all areas of evolutionary biology. This article is protected by copyright. All rights reserved

Code Status Discussions Between Attending Hospitalist Physicians and Medical Patients at Hospital Admission

BackgroundBioethicists and professional associations give specific recommendations for discussing cardiopulmonary resuscitation (CPR).ObjectiveTo determine whether attending hospitalist physicians' discussions meet these recommendations.DesignCross-sectional observational study on the medical services at two hospitals within a university system between August 2008 and March 2009.ParticipantsAttending hospitalist physicians and patients who were able to communicate verbally about their medical care.Main measuresWe identified code status discussions in audio-recorded admission encounters via physician survey and review of encounter transcripts. A quantitative content analysis was performed to determine whether discussions included elements recommended by bioethicists and professional associations. Two coders independently coded all discussions; Cohen's kappa was 0.64-1 for all reported elements.Key resultsAudio-recordings of 80 patients' admission encounters with 27 physicians were obtained. Eleven physicians discussed code status in 19 encounters. Discussions were more frequent in seriously ill patients (OR 4, 95% CI 1.2-14.6), yet 66% of seriously ill patients had no discussion. The median length of the code status discussions was 1 min (range 0.2-8.2). Prognosis was discussed with code status in only one of the encounters. Discussions of patients' preferences focused on the use of life-sustaining interventions as opposed to larger life goals. Descriptions of CPR as an intervention used medical jargon, and the indication for CPR was framed in general, as opposed to patient-specific scenarios. No physician quantitatively estimated the outcome of or provided a recommendation about the use of CPR.ConclusionsCode status was not discussed with many seriously ill patients. Discussions were brief, and did not include elements that bioethicists and professional associations recommend to promote patient autonomy. Local and national guidelines, research, and clinical practice changes are needed to clarify and systematize with whom and how CPR is discussed at hospital admission

Suffering in long-term cancer survivors: An evaluation of the PRISM-R2 in a population-based cohort

The Pictorial Representation of Illness and Self Measure-Revised 2 (PRISM-R2) has been developed as generic measure to assess suffering. The aim of this study was to evaluate the ability of this instrument to identify long-term cancer survivors with high levels of suffering who may need additional support. 1299 cancer survivors completed the PRISM-R2, the Short Form Health Survey (SF-36), and the Quality of Life-Cancer Survivors questionnaire (QoL-CS). The PRISM-R2 distinguishes between the Self-Illness Separation (SIS) and Illness Perception Measure (IPM), both measuring aspects of suffering. 112 (9%) cancer survivors reported high suffering according to IPM. This group had a higher cancer stage at diagnosis, more cancer recurrences, more comorbidities, and were lower educated compared to people reporting less suffering. The PRISM-R2 could explain substantial amounts of variance (10-14%) in the psychological aspects of the SF-36 and QoL-CS. The IPM also discriminated statistically and clinically significant between high- and low-health status. The PRISM-R2 proved to be able to discriminate between individuals with good and deteriorated levels of QoL. Further evaluation of its validity and screening potential is recommended

Spider Movement, UV Reflectance and Size, but Not Spider Crypsis, Affect the Response of Honeybees to Australian Crab Spiders

According to the crypsis hypothesis, the ability of female crab spiders to change body colour and match the colour of flowers has been selected because flower visitors are less likely to detect spiders that match the colour of the flowers used as hunting platform. However, recent findings suggest that spider crypsis plays a minor role in predator detection and some studies even showed that pollinators can become attracted to flowers harbouring Australian crab spider when the UV contrast between spider and flower increases. Here we studied the response of Apis mellifera honeybees to the presence of white or yellow Thomisus spectabilis Australian crab spiders sitting on Bidens alba inflorescences and also the response of honeybees to crab spiders that we made easily detectable painting blue their forelimbs or abdomen. To account for the visual systems of crab spider's prey, we measured the reflectance properties of the spiders and inflorescences used for the experiments. We found that honeybees did not respond to the degree of matching between spiders and inflorescences (either chromatic or achromatic contrast): they responded similarly to white and yellow spiders, to control and painted spiders. However spider UV reflection, spider size and spider movement determined honeybee behaviour: the probability that honeybees landed on spider-harbouring inflorescences was greatest when the spiders were large and had high UV reflectance or when spiders were small and reflected little UV, and honeybees were more likely to reject inflorescences if spiders moved as the bee approached the inflorescence. Our study suggests that only the large, but not the small Australian crab spiders deceive their preys by reflecting UV light, and highlights the importance of other cues that elicited an anti-predator response in honeybees