scholarly journals Coevolution of Snake Venom Toxic Activities and Diet: Evidence that Ecological Generalism Favours Toxicological Diversity

Toxins ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 711 ◽  
Author(s):  
Emma-Louise Davies ◽  
Kevin Arbuckle
Keyword(s):  
Snake Venom ◽  
Strong Support ◽  
Global Scale ◽  
Comparative Approach ◽  
General Effect ◽  
Functional Link ◽  
Selection Pressures ◽  
Functional Activities ◽  
Toxicological Effects ◽  
Toxicological Activity

Snake venom evolution is typically considered to be predominantly driven by diet-related selection pressures. Most evidence for this is based on lethality to prey and non-prey species and on the identification of prey specific toxins. Since the broad toxicological activities (e.g., neurotoxicity, coagulotoxicity, etc.) sit at the interface between molecular toxinology and lethality, these classes of activity may act as a key mediator in coevolutionary interactions between snakes and their prey. Indeed, some recent work has suggested that variation in these functional activities may be related to diet as well, but previous studies have been limited in geographic and/or taxonomic scope. In this paper, we take a phylogenetic comparative approach to investigate relationships between diet and toxicological activity classes on a global scale across caenophidian snakes, using the clinically oriented database at toxinology.com. We generally find little support for specific prey types selecting for particular toxicological effects except that reptile-feeders are more likely to be neurotoxic. We find some support for endothermic prey (with higher metabolic rates) influencing toxic activities, but differently from previous suggestions in the literature. More broadly, we find strong support for a general effect of increased diversity of prey on the diversity of toxicological effects of snake venom. Hence, we provide evidence that selection pressures on the toxicological activities of snake venom has largely been driven by prey diversity rather than specific types of prey. These results complement and extend previous work to suggest that specific matching of venom characteristics to prey may occur at the molecular level and translate into venom lethality, but the functional link between those two is not constrained to a particular toxicological route.

Performance of a points-based scoring system for assessing species limits in birds

The Auk ◽  
2021 ◽  
Author(s):  
Joseph A Tobias ◽  
Paul F Donald ◽  
Rob W Martin ◽  
Stuart H M Butchart ◽  
Nigel J Collar
Keyword(s):  
Strong Support ◽  
Molecular Data ◽  
Sympatric Species ◽  
Global Scale ◽  
Training Set ◽  
Species Limits ◽  
Phenotypic Data ◽  
Fast Tracking ◽  
Extinction Rates ◽  
Phenotypic Divergence

AbstractSpecies are fundamental to biology, conservation, and environmental legislation; yet, there is often disagreement on how and where species limits should be drawn. Even sophisticated molecular methods have limitations, particularly in the context of geographically isolated lineages or inadequate sampling of loci. With extinction rates rising, methods are needed to assess species limits rapidly but robustly. Tobias et al. devised a points-based system to compare phenotypic divergence between taxa against the level of divergence in sympatric species, establishing a threshold to guide taxonomic assessments at a global scale. The method has received a mixed reception. To evaluate its performance, we identified 397 novel taxonomic splits from 328 parent taxa made by application of the criteria (in 2014‒2016) and searched for subsequent publications investigating the same taxa with molecular and/or phenotypic data. Only 71 (18%) novel splits from 60 parent taxa have since been investigated by independent studies, suggesting that publication of splits underpinned by the criteria in 2014–2016 accelerated taxonomic decisions by at least 33 years. In the evaluated cases, independent analyses explicitly or implicitly supported species status in 62 (87.3%) of 71 splits, with the level of support increasing to 97.2% when excluding subsequent studies limited only to molecular data, and reaching 100% when the points-based criteria were applied using recommended sample sizes. Despite the fact that the training set used to calibrate the criteria was heavily weighted toward passerines, splits of passerines and non-passerines received equally strong support from independent research. We conclude that the method provides a useful tool for quantifying phenotypic divergence and fast-tracking robust taxonomic decisions at a global scale.

scholarly journals Public Financial Management, Accountability, and Citizens’ Trust

2017 ◽  
Vol 17 (3) ◽  
pp. 389-405
Author(s):  
Anto Bajo ◽  
Marko Primorac ◽  
Dario Runtić
Keyword(s):  
Financial Management ◽  
Central Government ◽  
Early Recognition ◽  
Strong Support ◽  
Global Scale ◽  
Analytical Tool ◽  
Capital Investments ◽  
The European Union ◽  
State And Local ◽  
Government Level

The main goal of the paper is to determine opportunities for the application of analytical tools to improve the management of state and local finances and increase the accountability and trust of citizens in state and local self-government units. PEFA is a useful tool for meeting such goals. PEFA is used on a global scale, primarily in countries that are beneficiaries of international aid, but also increasingly in countries that seek to increase their international credibility as well as their credibility regarding financial management in the eyes of their citizens. In the case of Croatia, PEFA was used in four cities in 2014. The implementation experience shows that PEFA allowed local government units to detect key weaknesses and technical shortcomings in their financial management, as well as to recognize the shortcomings of the provisions of certain regulations implemented at central government level. PEFA is an analytical tool that can be applied both at the national (central government) level and at the level of local self-government units. PEFA is certainly a demanding analytical tool which makes previous knowledge on financial management, budget accounting, and auditing more than desirable. For all European countries likely to join the European Union and finance part of their capital investments through EU funds, PEFA can be a very useful tool not only for the early recognition of weaknesses, but also strengths in financial management. Despite the fact that PEFA does not offer direct instructions on how to solve potential problems in financial management, the findings of the analysis with the accompanying rankings are more than sufficient to serve as recommendations for addressing weaknesses in financial management. The implementation of PEFA requires strong support of the heads of local units and the state. These are also the people expected to initiate reforms and improve financial management. As an analytical tool, PEFA can help these improvements happen much faster and more effectively.

scholarly journals Ecological correlates of crop yield growth and interannual yield variation at a global scale

Web Ecology ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 15-43
Author(s):  
Gabriela Gleiser ◽  
Nicolay Leme da Cunha ◽  
Agustín Sáez ◽  
Marcelo Adrián Aizen
Keyword(s):  
Crop Yield ◽  
Life Form ◽  
Reproductive Organs ◽  
Global Scale ◽  
Comparative Approach ◽  
Continuous Increase ◽  
Yield Variation ◽  
Ecological Correlates ◽  
Volume Production

Abstract. Artificial selection and genetic engineering plus an expanding repertoire and use of agrochemical inputs have allowed a rapid and continuous increase in crop yield (i.e., volume production per unit area) over the last century, which is needed to fulfill food demands from a growing human population. However, the first signs of yield deceleration and stagnation have already been reported for some globally important crops. Therefore, the study of the drivers of yield growth and its variation is essential for directing research and policies aiming at ensuring food security in the forthcoming years. We used data on mean and variability in annual yield growth for 107 globally important crops to assess the role of environmental (i.e., climatic region) and plant intrinsic traits (i.e., type of harvested organ, pollinator dependence, and life form) as drivers of change in yield growth and its stability. We applied a comparative approach to control for biases associated with phylogenetic non-independence among crops, an approach rarely used in agronomic studies. Average yield growth and its variation were not phylogenetically structured. Yield growth decreased with increasing pollinator dependence in tree crops but not in herbaceous and shrubby crops. Interannual yield variation tended to increase with increasing pollinator dependence, and it was higher in crops from temperate regions, in those cultivated for their reproductive organs, and in tree and shrubby crops as compared with herbaceous ones. Information on ecological correlates of crop yield growth and interannual yield variation can be used in the design of more sustainable and diversified agriculture schemes.

scholarly journals Coevolution of group-living and aposematism in caterpillars: warning colouration may facilitate the evolution from group-living to solitary habits

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lingzi Wang ◽  
Stephen J. Cornell ◽  
Michael P. Speed ◽  
Kevin Arbuckle
Keyword(s):  
Evolutionary Dynamics ◽  
Strong Support ◽  
Chemical Defence ◽  
Group Living ◽  
Warning Signal ◽  
Comparative Approach ◽  
Transition Rates ◽  
Aggregation Behaviour ◽  
Solitary Living ◽  
Antipredator Mechanisms

Abstract Background Animals use diverse antipredator mechanisms, including visual signalling of aversive chemical defence (aposematism). However, the initial evolution of aposematism poses the problem that the first aposematic individuals are conspicuous to predators who have not learned the significance of the warning colouration. In one scenario, aposematism evolves in group-living species and originally persisted due to kin selection or positive frequency-dependent selection in groups. Alternatively, group-living might evolve after aposematism because grouping can amplify the warning signal. However, our current understanding of the evolutionary dynamics of these traits is limited, leaving the relative merit of these scenarios unresolved. Results We used a phylogenetic comparative approach to estimate phenotypic evolutionary models to enable inferences regarding ancestral states and trait dynamics of grouping and aposematic colouration in a classic model system (caterpillars). We find strong support for aposematism at the root of the clade, and some (but weaker) support for ancestral solitary habits. Transition rates between aposematism and crypsis are generally higher than those between group-living and solitary-living, suggesting that colouration is more evolutionarily labile than aggregation. We also find that the transition from group-living to solitary-living states can only happen in aposematic lineage, suggesting that aposematism facilitates the evolution of solitary caterpillars, perhaps due to the additional protection offered when the benefits of grouping are lost. We also find that the high frequency of solitary, cryptic caterpillars is because this state is particularly stable, in that the transition rates moving towards this state are substantially higher than those moving away from it, favouring its accumulation in the clade over evolutionary time. Conclusions Our results provide new insights into the coevolution of colour and aggregation in caterpillars. We find support for an aposematic caterpillar at the root of this major clade, and for the signal augmentation hypothesis as an explanation of the evolution of aposematic, group-living caterpillars. We find that colouration is more labile than aggregation behaviour, but that the combination of solitary and cryptic habits is particularly stable. Finally, our results reveal that the transitions from group-living to solitary-living could be facilitated by aposematism, providing a new link between these well-studied traits.

“Lets talk about you …”

2016 ◽  
Vol 25 (5) ◽  
pp. 664-684 ◽  
Author(s):  
Terry Gibson ◽  
Ben Wisner
Keyword(s):  
Participant Observation ◽  
Academic Research ◽  
National Policy ◽  
Strong Support ◽  
Action Planning ◽  
Global Scale ◽  
Flexible Tool ◽  
Bottom Up ◽  
Content Type ◽  
Civil Society Organisations

Purpose The purpose of this paper is to report on the creation of innovative methods for engaging in conversations about everyday risk. Design/methodology/approach A range of methods from conventional survey research to open-ended, semi-structured conversations and focus groups were used in the series of studies that serve as the subject of this meta-study. The meta-study uses participant observation, key informant interviews and project reports to narrate and evaluate the evolution of Frontline as an action planning, monitoring, advocacy and research tool. Findings The Views from the Frontline (VFL) methods began as the bottom-up mirror of a top-down monitoring approach used by the United Nations (Hyogo Framework for Action Monitor). Limitations of such bottom up monitoring led to creation of guidelines for formalising local knowledge resulting from actions – Action at the Frontline (AFL) and, later, Frontline, a flexible tool for eliciting experiences of everyday risk. The earlier VFL monitoring approach had shared outsiders’ assumptions about the nature of the “problem” and limited the degree to which local residents could express their own experiences and priorities. Originality/value Extensive use of this suite of methods has shown that civil society organisations are fully capable of conducting credible research when properly supported and motivated. Use of these methods has so far provided strong support for policy advocacy at the global scale, has had moderate success in liaison with national policy makers and slow but promising results as a learning/action tool at the local scale. Frontline has as yet untapped potential as a resource for academic research.

scholarly journals Old and New Approaches to Animal Cognition: There Is Not “One Cognition”

2020 ◽  
Vol 8 (3) ◽  
pp. 28 ◽  
Author(s):  
Juliane Bräuer ◽  
Daniel Hanus ◽  
Simone Pika ◽  
Russell Gray ◽  
Natalie Uomini
Keyword(s):  
Cognitive Skills ◽  
Animal Cognition ◽  
A Priori ◽  
Human Model ◽  
Comparative Approach ◽  
Social Environments ◽  
Animal Minds ◽  
Selection Pressures ◽  
Cognitive Domains ◽  
Empirical Perspective

Using the comparative approach, researchers draw inferences about the evolution of cognition. Psychologists have postulated several hypotheses to explain why certain species are cognitively more flexible than others, and these hypotheses assume that certain cognitive skills are linked together to create a generally “smart” species. However, empirical findings suggest that several animal species are highly specialized, showing exceptional skills in single cognitive domains while performing poorly in others. Although some cognitive skills may indeed overlap, we cannot a priori assume that they do across species. We argue that the term “cognition” has often been used by applying an anthropocentric viewpoint rather than a biocentric one. As a result, researchers tend to overrate cognitive skills that are human-like and assume that certain skills cluster together in other animals as they do in our own species. In this paper, we emphasize that specific physical and social environments create selection pressures that lead to the evolution of certain cognitive adaptations. Skills such as following the pointing gesture, tool-use, perspective-taking, or the ability to cooperate evolve independently from each other as a concrete result of specific selection pressures, and thus have appeared in distantly related species. Thus, there is not “one cognition”. Our argument is founded upon traditional Darwinian thinking, which—although always at the forefront of biology—has sometimes been neglected in animal cognition research. In accordance with the biocentric approach, we advocate a broader empirical perspective as we are convinced that to better understand animal minds, comparative researchers should focus much more on questions and experiments that are ecologically valid. We should investigate nonhuman cognition for its own sake, not only in comparison to the human model.

scholarly journals Global late Quaternary megafauna extinctions linked to humans, not climate change

2014 ◽  
Vol 281 (1787) ◽  
pp. 20133254 ◽  
Author(s):  
Christopher Sandom ◽  
Søren Faurby ◽  
Brody Sandel ◽  
Jens-Christian Svenning
Keyword(s):  
Climate Change ◽  
Late Quaternary ◽  
Global Analysis ◽  
Strong Support ◽  
Global Scale ◽  
Taxonomic Resolution ◽  
Last Interglacial ◽  
Modern Humans ◽  
Mammal Species ◽  
Geographical Regions

The late Quaternary megafauna extinction was a severe global-scale event. Two factors, climate change and modern humans, have received broad support as the primary drivers, but their absolute and relative importance remains controversial. To date, focus has been on the extinction chronology of individual or small groups of species, specific geographical regions or macroscale studies at very coarse geographical and taxonomic resolution, limiting the possibility of adequately testing the proposed hypotheses. We present, to our knowledge, the first global analysis of this extinction based on comprehensive country-level data on the geographical distribution of all large mammal species (more than or equal to 10 kg) that have gone globally or continentally extinct between the beginning of the Last Interglacial at 132 000 years BP and the late Holocene 1000 years BP, testing the relative roles played by glacial–interglacial climate change and humans. We show that the severity of extinction is strongly tied to hominin palaeobiogeography, with at most a weak, Eurasia-specific link to climate change. This first species-level macroscale analysis at relatively high geographical resolution provides strong support for modern humans as the primary driver of the worldwide megafauna losses during the late Quaternary.

Digital currencies: The present and the future

2021 ◽  
Vol 27 (5) ◽  
pp. 1132-1155
Author(s):  
Husan S. UMAROV
Keyword(s):  
Large Scale ◽  
System Development ◽  
World Market ◽  
Global Scale ◽  
Comparative Approach ◽  
Global Finance ◽  
Finance Development ◽  
The World ◽  
Pros And Cons ◽  
Development Objectives

Subject. The article considers digital currencies in the context of global and national financial system development. Objectives. The purpose is to identify and justify the role of digital currencies in the global finance development and the place of modern central bank policies in the development of digital currencies, to underpin the need for changing approaches to digital currencies on the part of central banks, and to predict possible scenarios for the development of digital currencies on the global scale. Methods. The study applies methods of logical and statistical analysis, the comparative approach, and systematization. Results. The paper describes major pros and cons of digital currencies by comparing them with cryptocurrencies; identifies the beneficiaries of the introduction of digital currencies in countries with the most developed strategies for the introduction of national digital currencies. It also unveils barriers to a large-scale introduction of digital currencies to the world market, and highlights the main areas of their use. I developed three scenarios of digital currencies introduction to the world market. Conclusions. A large-scale introduction of digital currencies as a means of international settlements is not possible at the present stage, however, their use as a tool for dealing with financial crises is the most realistic scenario.

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