scholarly journals Environmental quality mediates the ecological dominance of cooperatively breeding birds

Author(s):  
Sheng-Feng Shen ◽  
Yu-Heng Lin ◽  
Ying-Yu Chen ◽  
Dustin Rubenstein ◽  
Mark Liu

Abstract Species as diverse as humans and ants are among the most abundant organisms on Earth, partly because of their ability to form cooperative societies1-3. Yet, animals form groups for many reasons4,5, and how these differences affect their ‘social conquests’2 remains unknown. Here we use a theoretical model to demonstrate that the different fitness benefits that animals receive by forming groups4,6 depend on the quality of their environment, which in turn impacts their ecological dominance and resilience to global change. Our model predicts species that group because of environmental hardships will have wider ecological niches, larger geographic ranges, and higher abundances than non-social species, whereas those that group because of intraspecific resource competition will not. As predicted, an analysis of >1500 avian species finds that cooperative breeders occurring in harsh and fluctuating environments have larger ranges and higher abundances than non-cooperative breeders, whereas cooperative breeders occurring in benign and stable environments do not. These results are consistent with our model predictions showing that species cooperating in harsh or fluctuating environments will be less vulnerable to climate change than non-social species and those cooperating against intra-specific competitors in benign or stable environments. Ultimately, by combining macroecological and sociobiological perspectives, our study helps understand and predict the past, present, and future state of social species, including our own.

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Erica Ponzi ◽  
Magne Thoresen ◽  
Therese Haugdahl Nøst ◽  
Kajsa Møllersen

Abstract Background Cancer genomic studies often include data collected from several omics platforms. Each omics data source contributes to the understanding of the underlying biological process via source specific (“individual”) patterns of variability. At the same time, statistical associations and potential interactions among the different data sources can reveal signals from common biological processes that might not be identified by single source analyses. These common patterns of variability are referred to as “shared” or “joint”. In this work, we show how the use of joint and individual components can lead to better predictive models, and to a deeper understanding of the biological process at hand. We identify joint and individual contributions of DNA methylation, miRNA and mRNA expression collected from blood samples in a lung cancer case–control study nested within the Norwegian Women and Cancer (NOWAC) cohort study, and we use such components to build prediction models for case–control and metastatic status. To assess the quality of predictions, we compare models based on simultaneous, integrative analysis of multi-source omics data to a standard non-integrative analysis of each single omics dataset, and to penalized regression models. Additionally, we apply the proposed approach to a breast cancer dataset from The Cancer Genome Atlas. Results Our results show how an integrative analysis that preserves both components of variation is more appropriate than standard multi-omics analyses that are not based on such a distinction. Both joint and individual components are shown to contribute to a better quality of model predictions, and facilitate the interpretation of the underlying biological processes in lung cancer development. Conclusions In the presence of multiple omics data sources, we recommend the use of data integration techniques that preserve the joint and individual components across the omics sources. We show how the inclusion of such components increases the quality of model predictions of clinical outcomes.


Author(s):  
Stefan Hahn ◽  
Jessica Meyer ◽  
Michael Roitzsch ◽  
Christiaan Delmaar ◽  
Wolfgang Koch ◽  
...  

Spray applications enable a uniform distribution of substances on surfaces in a highly efficient manner, and thus can be found at workplaces as well as in consumer environments. A systematic literature review on modelling exposure by spraying activities has been conducted and status and further needs have been discussed with experts at a symposium. This review summarizes the current knowledge about models and their level of conservatism and accuracy. We found that extraction of relevant information on model performance for spraying from published studies and interpretation of model accuracy proved to be challenging, as the studies often accounted for only a small part of potential spray applications. To achieve a better quality of exposure estimates in the future, more systematic evaluation of models is beneficial, taking into account a representative variety of spray equipment and application patterns. Model predictions could be improved by more accurate consideration of variation in spray equipment. Inter-model harmonization with regard to spray input parameters and appropriate grouping of spray exposure situations is recommended. From a user perspective, a platform or database with information on different spraying equipment and techniques and agreed standard parameters for specific spraying scenarios from different regulations may be useful.


2019 ◽  
Vol 374 (1780) ◽  
pp. 20180067 ◽  
Author(s):  
Emily C. Lynch ◽  
Virpi Lummaa ◽  
Win Htut ◽  
Mirkka Lahdenperä

Preferential treatment of kin is widespread across social species and is considered a central prerequisite to the evolution of cooperation through kin selection. Though it is well known that, among most social mammals, females will remain within their natal group and often bias social behaviour towards female maternal kin, less is known about the fitness consequences of these relationships. We test the fitness benefits of living with maternal sisters, measured by age-specific female reproduction, using an unusually large database of a semi-captive Asian elephant ( Elephas maximus ) population. This study system is particularly valuable to an exploration of reproductive trends in a long-lived mammal, because it includes life-history data that span multiple generations, enabling a study of the effects of kinship across a female's lifespan. We find that living near a sister significantly increased the likelihood of annual reproduction among young female elephants, and this effect was strongest when living near a sister 0–5 years younger. Our results show that fitness benefits gained from relationships with kin are age-specific, establish the basis necessary for the formation and maintenance of close social relationships with female kin, and highlight the adaptive importance of matriliny in a long-lived mammal. This article is part of the theme issue ‘The evolution of female-biased kinship in humans and other mammals'.


2019 ◽  
Vol 374 (1770) ◽  
pp. 20180114 ◽  
Author(s):  
Emma I. K. Vitikainen ◽  
Faye J. Thompson ◽  
Harry H. Marshall ◽  
Michael A. Cant

Kin selection theory defines the conditions for which altruism or ‘helping’ can be favoured by natural selection. Tests of this theory in cooperatively breeding animals have focused on the short-term benefits to the recipients of help, such as improved growth or survival to adulthood. However, research on early-life effects suggests that there may be more durable, lifelong fitness impacts to the recipients of help, which in theory should strengthen selection for helping. Here, we show in cooperatively breeding banded mongooses ( Mungos mungo ) that care received in the first 3 months of life has lifelong fitness benefits for both male and female recipients. In this species, adult helpers called ‘escorts’ form exclusive one-to-one caring relationships with specific pups (not their own offspring), allowing us to isolate the effects of being escorted on later reproduction and survival. Pups that were more closely escorted were heavier at sexual maturity, which was associated with higher lifetime reproductive success for both sexes. Moreover, for female offspring, lifetime reproductive success increased with the level of escorting received per se , over and above any effect on body mass. Our results suggest that early-life social care has durable benefits to offspring of both sexes in this species. Given the well-established developmental effects of early-life care in laboratory animals and humans, we suggest that similar effects are likely to be widespread in social animals more generally. We discuss some of the implications of durable fitness benefits for the evolution of intergenerational helping in cooperative animal societies, including humans. This article is part of the theme issue ‘Developing differences: early-life effects and evolutionary medicine’.


2020 ◽  
Vol 117 (47) ◽  
pp. 29759-29766 ◽  
Author(s):  
Rufus A. Johnstone ◽  
Michael A. Cant ◽  
Dominic Cram ◽  
Faye J. Thompson

Collective conflicts among humans are widespread, although often highly destructive. A classic explanation for the prevalence of such warfare in some human societies is leadership by self-serving individuals that reap the benefits of conflict while other members of society pay the costs. Here, we show that leadership of this kind can also explain the evolution of collective violence in certain animal societies. We first extend the classic hawk−dove model of the evolution of animal aggression to consider cases in which a subset of individuals within each group may initiate fights in which all group members become involved. We show that leadership of this kind, when combined with inequalities in the payoffs of fighting, can lead to the evolution of severe intergroup aggression, with negative consequences for population mean fitness. We test our model using long-term data from wild banded mongooses, a species characterized by frequent intergroup conflicts that have very different fitness consequences for male and female group members. The data show that aggressive encounters between groups are initiated by females, who gain fitness benefits from mating with extragroup males in the midst of battle, whereas the costs of fighting are borne chiefly by males. In line with the model predictions, the result is unusually severe levels of intergroup violence. Our findings suggest that the decoupling of leaders from the costs that they incite amplifies the destructive nature of intergroup conflict.


Author(s):  
Timothy S. Weeks ◽  
J. David McColskey ◽  
Mark D. Richards ◽  
Yong-Yi Wang ◽  
Marie Quintana

Curved-wide plate (CWP) tests are frequently used for assessing the quality of pipeline girth welds. Despite a large number of CWP tests having been conducted at great expense over many decades, an industry consensus standard remains unavailable. Considerable effort at several research institutions is focused on the standardization of test protocols. It is widely recognized that comparing results from CWP tests from different institutions is difficult without accounting for all the possible parametric differences. This paper presents the procedural details recently used in testing X100 girth welds. The protocols cover (1) specimen design and dimensions, (2) instrumentation plan and data acquisition, (3) specimen fabrication and preparation, (4) preparing and executing the tests, (5) processing of raw test data and (6) post-test metallurgical examination. The evaluation of specimen deformation, flaw growth, and comparison of test data with model predictions will be presented in a future paper. Selected CWP test data from this program were evaluated and compared to tensile strain models of the girth welded pipe in a recent paper [1].


2021 ◽  
Vol 83 (5) ◽  
pp. 331-336
Author(s):  
Sofia S. Oliveira ◽  
Joana Pereira ◽  
Paulo Santos ◽  
Ruth Pereira

Soil provides innumerable valuable ecosystem services, such as the production of food and the direct support of wildlife, by ensuring the availability of adequate habitat. However, unsustainable human activities are resulting in degradation of soils worldwide. Hence, it is of utmost importance to raise awareness about this often-overlooked environmental issue. This article presents an inquiry-based activity that challenges students to assess the ecological quality of soil in the surroundings of their classroom. Plus, students and teachers are invited to become citizen scientists by sharing their data with researchers, thus contributing to a future endeavor to map soil quality through broad geographic ranges.


2020 ◽  
Vol 117 (7) ◽  
pp. 3663-3669 ◽  
Author(s):  
Jörn Pagel ◽  
Martina Treurnicht ◽  
William J. Bond ◽  
Tineke Kraaij ◽  
Henning Nottebrock ◽  
...  

The ecological niche of a species describes the variation in population growth rates along environmental gradients that drives geographic range dynamics. Niches are thus central for understanding and forecasting species’ geographic distributions. However, theory predicts that migration limitation, source–sink dynamics, and time-lagged local extinction can cause mismatches between niches and geographic distributions. It is still unclear how relevant these niche–distribution mismatches are for biodiversity dynamics and how they depend on species life-history traits. This is mainly due to a lack of the comprehensive, range-wide demographic data needed to directly infer ecological niches for multiple species. Here we quantify niches from extensive demographic measurements along environmental gradients across the geographic ranges of 26 plant species (Proteaceae; South Africa). We then test whether life history explains variation in species’ niches and niche–distribution mismatches. Niches are generally wider for species with high seed dispersal or persistence abilities. Life-history traits also explain the considerable interspecific variation in niche–distribution mismatches: poorer dispersers are absent from larger parts of their potential geographic ranges, whereas species with higher persistence ability more frequently occupy environments outside their ecological niche. Our study thus identifies major demographic and functional determinants of species’ niches and geographic distributions. It highlights that the inference of ecological niches from geographical distributions is most problematic for poorly dispersed and highly persistent species. We conclude that the direct quantification of ecological niches from demographic responses to environmental variation is a crucial step toward a better predictive understanding of biodiversity dynamics under environmental change.


Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 184
Author(s):  
Mateusz Szumilas ◽  
Krzysztof Lewenstein ◽  
Elżbieta Ślubowska ◽  
Stanisław Szlufik ◽  
Dariusz Koziorowski

Parkinson’s disease results in motor impairment that deteriorates patients’ quality of life. One of the symptoms negatively interfering with daily activities is kinetic tremor which should be measured to monitor the outcome of therapy. A new instrumented method of quantification of the kinetic tremor is proposed, based on the analysis of circles drawn on a digitizing tablet by a patient. The aim of this approach is to obtain a tremor scoring equivalent to that performed by trained clinicians. Models are trained with the least absolute shrinkage and selection operator (LASSO) method to predict the tremor scores on the basis of the parameters computed from the patients’ drawings. Signal parametrization is derived from both expert knowledge and the response of an artificial neural network to the raw data, thus the approach was named multimodal. The fitted models are eventually combined into model ensembles that provide aggregated scores of the kinetic tremor captured in the drawings. The method was verified with a set of clinical data acquired from 64 Parkinson’s disease patients. Automated and objective quantification of the kinetic tremor with the presented approach yielded promising results, as the Pearson’s correlations between the visual ratings of tremor and the model predictions ranged from 0.839 to 0.890 in the best-performing models.


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