The Evolution of Social Dominance II: Multi-Player Models

Behaviour ◽  
2003 ◽  
Vol 140 (10) ◽  
pp. 1333-1358 ◽  
Author(s):  
G. Sander Van Doorn ◽  
Franz Weissing ◽  
Geerten Hengeveld
Keyword(s):  
Extreme Case ◽  
Evolutionarily Stable Strategies ◽  
Social Hierarchies ◽  
Natural Systems ◽  
Fighting Ability ◽  
Winner And Loser Effects ◽  
History Of ◽  
Linear Hierarchies ◽  
High Degree ◽  
Evolutionarily Stable

AbstractThe social hierarchies observed in natural systems often show a high degree of transitivity. Transitive hierarchies do not only require rank differentiation within pairs of individuals but also a higher level ordering of relations within the group. Several authors have suggested that the formation of linear hierarchies at the group level is an emergent property of individual behavioural rules, referred to as winner and loser effects. Winner and loser effects occur if winners of previous conflicts are more likely to escalate the current conflict, whereas the losers of previous conflicts are less likely to do so. According to this idea, an individual's position in a hierarchy may not necessarily reflect its fighting ability, but may rather result from arbitrary historical asymmetries, in particular the history of victories and defeats. However, if this is the case, it is difficult to explain from an evolutionary perspective why a low ranking individual should accept its subordinate status. Here we present a game theoretical model to investigate whether winner and loser effects giving rise to transitive hierarchies can evolve and under which conditions they are evolutionarily stable. The main version of the model focuses on an extreme case in which there are no intrinsic differences in fighting ability between individuals. The only asymmetries that may arise between individuals are generated by the outcome of previous conflicts. We show that, at evolutionary equilibrium, these asymmetries can be utilized for conventional conflict resolution. Several evolutionarily stable strategies are based on winner and loser effects and these strategies give rise to transitive hierarchies.

The Evolution of Social Dominance I: Two-player Models

Behaviour ◽  
2003 ◽  
Vol 140 (10) ◽  
pp. 1305-1332 ◽  
Author(s):  
Geerten Hengeveld ◽  
G. Sander Van Doorn ◽  
Franz Weissing
Keyword(s):  
Dominance Rank ◽  
Extreme Case ◽  
Point Of View ◽  
Resource Holding Potential ◽  
Evolutionarily Stable Strategies ◽  
Fighting Ability ◽  
Dominance Relations ◽  
Winner And Loser Effects ◽  
Evolutionarily Stable ◽  
Do So

AbstractA difference in dominance rank is an often-used cue to resolve conflicts between two animals without escalated fights. At the group level, adherence to a dominance convention efficiently reduces the costs associated with conflicts, but from an individual's point of view, it is difficult to explain why a low ranking individual should accept its subordinate status. This is especially true if, as suggested by several authors, dominance not necessarily reflects differences in fighting ability but rather results from arbitrary historical asymmetries. According to this idea, rank differentiation emerges from behavioural strategies, referred to as winner and loser effects, in which winners of previous conflicts are more likely to win the current conflict, whereas the losers of previous conflicts are less likely to do so. In order to investigate whether dominance, based on such winner and loser effects, can be evolutionarily stable, we analyse a game theoretical model. The model focuses on an extreme case in which there are no differences in fighting ability between individuals at all. The only asymmetries that may arise between individuals are generated by the outcome of previous conflicts. By means of numerical analysis, we find alternative evolutionarily stable strategies, which all utilize these asymmetries for conventional conflict resolution. One class of these strategies is based on winner and loser effects, thus generating evolutionarily stable dominance relations even in the absence of differences in resource holding potential.

The study of evolutionary parasitology

2021 ◽  
pp. 9-18
Author(s):  
Paul Schmid-Hempel
Keyword(s):  
Life History ◽  
Comparative Studies ◽  
Life History Theory ◽  
Evolutionary Process ◽  
Evolutionarily Stable Strategies ◽  
Basic Scheme ◽  
Biological Phenomena ◽  
History Of ◽  
Evolutionarily Stable

An overview of the evolutionary process and the four basic questions that can be asked for biological phenomena. Furthermore, what biological units evolve, and the particular role of genes, is explained. Life history is introduced as a basic scheme that applies to individuals as well as to infections within a host. In particular, life history theory highlights the relevance of transmission as an equivalent to reproduction in the life history of individuals. The last section mentions several major methods for studying evolutionary parasitology; in particular, optimality approaches, the study of evolutionarily stable strategies, and comparative studies. Introducing the disease space as an illustrative tool for major topics in the book chapters.

THE R.J. CHAMBERS COLLECTION: AN “ARCHIVIST'S” REVELATIONS OF 20th CENTURY ACCOUNTING THOUGHT AND PRACTICE

2006 ◽  
Vol 33 (1) ◽  
pp. 145-166 ◽  
Author(s):  
Graeme W. Dean ◽  
Peter W. Wolnizer ◽  
Frank L. Clarke
Keyword(s):  
Prima Facie ◽  
Accounting Education ◽  
Hard Copy ◽  
Accounting History ◽  
Research Areas ◽  
Archival Source ◽  
Inflation Accounting ◽  
History Of ◽  
High Degree ◽  
Accounting Standard Setting

A major, unique accounting archival source, the R.J. Chambers Collection comprises both hard copy and, utilizing cutting-edge search technology, internet accessible materials. From his academic beginnings, Chambers was an orderly person, an archivist of the extensive and varied evidence that underpinned his proposals for accounting reform. Opening research areas for accounting biography, the development of accounting thought, the history of accounting institutions, prosopography, public sector accounting history, and comparative international accounting history are foremost amongst the myriad justifications for seeking to unravel the accounting history “lodes” in archives such as the Goldberg, Chambers, and Briloff Collections [Potter, 2003]. The archiving of the meticulously kept Chambers papers from 1947–1999 provides an opportunity for unfolding the background to events previously withheld from accounting history scholars. Professional episodes in relation to inflation accounting, standard setting, proposals to reform accounting education, and the like that appeared prima facie to be worth investigating are now open to scrutiny from a different angle, with a different type of evidence available in this Collection. This Collection provides a high degree of archival provenance. In particular, it represents an orderly retention of past documentation of what Chambers wrote, and perhaps uniquely for accounting historians, received; thus, providing an extensive window from which to examine the disorderly present environment of acounting.

scholarly journals Euglycemic Diabetic Ketoacidosis after a Single Dose of Empagliflozin in a Patient with Pancreatitis

2021 ◽  
Vol 11 (2) ◽  
pp. 216-218
Author(s):  
Marta Brandão Calçada ◽  
Luís Fernandes ◽  
Rita Soares Costa ◽  
Sara Montezinho ◽  
Filipa Martins Duarte ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Diabetic Ketoacidosis ◽  
Drug Class ◽  
Clinical Suspicion ◽  
Laboratory Findings ◽  
Sodium Glucose Cotransporter ◽  
History Of ◽  
High Degree ◽  
Euglycemic Diabetic Ketoacidosis

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are the most recently approved drug class for the treatment of type 2 diabetes mellitus (T2D). Although they are largely well-tolerated, their intake has been associated with euglycemic diabetic ketoacidosis (DKA) in some rare cases. We report the case of a 70-year-old male with type 2 diabetes and no history of DKA, who started therapy with empagliflozin one day before presenting with acute pancreatitis and laboratory findings consistent with euglycemic DKA. SGLT2i can induce euglycemic DKA from the first dose. Given the atypical presentation, a high degree of clinical suspicion is required to recognize this complication.

929 Not Another Abscess - A Case of Streptococcal Myositis Misdiagnosed as a Right Axillary Abscess

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
O Oyende ◽  
J Jackman
Keyword(s):  
White Cell Count ◽  
General Surgeon ◽  
High Dose ◽  
General Anaesthetic ◽  
Microbiological Analysis ◽  
Reactive Protein ◽  
Affected Tissue ◽  
Life Threatening ◽  
History Of ◽  
High Degree

Abstract Introduction Streptococcal myositis is a rare form of infectious myositis caused by Lansfield A beta-haemolytic streptococci. It is characterised by rapidly spreading inflammation that can result in severe systemic toxicity and necrosis of the affected tissue if not diagnosed and aggressively treated. Presentation We report a case of a 42-year-old male who presented with a one-week history of worsening right axillary swelling that progressed to painful swelling of his arm. Inflammatory markers were significantly elevated with a white cell count of 17 ×109/L and C-reactive protein of 212 mg/L. On examination, a fluctuant axillary swelling was appreciated, and a decision was made for incision and drainage under general anaesthetic. Intraoperative aspiration of his arm revealed copious purulent fluid prompting intraoperative orthopaedic consult and exploration of the anterior compartment in which there was extensive involvement of the biceps muscle. The microbiological analysis revealed gram-positive cocci in chains, and microbiology advice sought for tailoring of antibiotic regimen. He has recovered well. Discussion Though uncommon, the emergency general surgeon should have a high degree of suspicion when evaluating soft tissue infections to avert potentially disastrous outcomes. Conclusion Early diagnosis, aggressive management with high-dose intravenous antibiotics, and surgical debridement are principles to treat this rare, life-threatening infection.

scholarly journals The Return of National Self-Sufficiency? Excavating Autarkic Thought in a De-Globalizing Era

2021 ◽  
Author(s):  
Eric Helleiner
Keyword(s):  
Intellectual History ◽  
International Political Economy ◽  
Economic Thought ◽  
John Maynard Keynes ◽  
New Politics ◽  
Self Sufficiency ◽  
National Economic ◽  
History Of ◽  
High Degree ◽  
Rich History

Abstract As the global crisis triggered by the COVID-19 virus unfolded, The Economist magazine published a cover in May 2020 titled “Goodbye globalization: the dangerous lure of self-sufficiency.” The title summed up well the new political interest in the ideology of national economic self-sufficiency in the pandemic context. Unfortunately, contemporary textbooks in the field of international political economy (IPE) say little about this kind of “autarkic” thought. No survey of the history of autarkic thought exists even within specialist IPE literature or in the fields of intellectual history and the history of economic thought. Filling this gap in existing scholarship, this article highlights a rich history of autarkic thought that includes the ideas of famous thinkers such as Jean-Jacques Rousseau, Johann Fichte, Mohandas Gandhi, and John Maynard Keynes. Three core rationales for a high degree of national self-sufficiency have been advanced in the past: (1) insulation from foreign economic influence, (2) insulation from foreign political and/or cultural influence, and (3) the promotion of international peace. At the same time, considerable disagreements have existed among autarkists about some of these rationales and their relative importance, as well as about the precise meaning of national self-sufficiency. These disagreements stemmed not just from differences in their specific goals but also from the different conditions across time and space in which autarkic thought was developed. In addition to improving understanding of the autarkic ideological tradition, this article contributes to emerging scholarship attempting to overcome Western-centrism in IPE scholarship as well as literature exploring the new politics of de-globalization in the current era.

scholarly journals Multi-Locus Selection and the Structure of Variation at the white Gene of Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 635-645 ◽  
Author(s):  
David A Kirby ◽  
Wolfgang Stephan
Keyword(s):  
Drosophila Melanogaster ◽  
White Gene ◽  
Transcriptional Unit ◽  
North American Population ◽  
Evolutionary Mechanisms ◽  
Locus Selection ◽  
Neutral Equilibrium ◽  
History Of ◽  
High Degree ◽  
Very High

Abstract We surveyed sequence variation and divergence for the entire 5972-bp transcriptional unit of the white gene in 15 lines of Drosophila melanogaster and one line of D. simulans. We found a very high degree of haplotypic structuring for the polymorphisms in the 3′ half of the gene, as opposed to the polymorphisms in the 5′ half. To determine the evolutionary mechanisms responsible for this pattern, we sequenced a 1612-bp segment of the white gene from an additional 33 lines of D. melanogaster from a European and a North American population. This 1612-bp segment encompasses an 834bp region of the white gene in which the polymorphisms form high frequency haplotypes that cannot be explained by a neutral equilibrium model of molecular evolution. The small number of recombinants in the 834bp region suggests epistatic selection as the cause of the haplotypic structuring, while an investigation of nucleotide diversity supports a directional selection hypothesis. A multi-locus selection model that combines features from both-hypotheses and takes the recent history of D. melanogaster into account may be the best explanation for these data.

scholarly journals Evolutionary Stability for Interactions among Kin under Quantitative Inheritance.

Genetics ◽  
1989 ◽  
Vol 121 (4) ◽  
pp. 877-889
Author(s):  
A B Harper
Keyword(s):  
Inclusive Fitness ◽  
Fitness Function ◽  
Quantitative Inheritance ◽  
Evolutionarily Stable Strategies ◽  
Environmental Variance ◽  
Pairwise Interactions ◽  
Simplifying Assumptions ◽  
Multilocus Model ◽  
Evolutionarily Stable

Abstract The theory of evolutionarily stable strategies (ESS) predicts the long-term evolutionary outcome of frequency-dependent selection by making a number of simplifying assumptions about the genetic basis of inheritance. I use a symmetrized multilocus model of quantitative inheritance without mutation to analyze the results of interactions between pairs of related individuals and compare the equilibria to those found by ESS analysis. It is assumed that the fitness changes due to interactions can be approximated by the exponential of a quadratic surface. The major results are the following. (1) The evolutionarily stable phenotypes found by ESS analysis are always equilibria of the model studied here. (2) When relatives interact, one of the two conditions for stability of equilibria differs between the two models; this can be accounted for by positing that the inclusive fitness function for quantitative characters is slightly different from the inclusive fitness function for characters determined by a single locus. (3) The inclusion of environmental variance will in general change the equilibrium phenotype, but the equilibria of ESS analysis are changed to the same extent by environmental variance. (4) A class of genetically polymorphic equilibria occur, which in the present model are always unstable. These results expand the range of conditions under which one can validly predict the evolution of pairwise interactions using ESS analysis.

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