scholarly journals Intriguing effects of selection intensity on the evolution of prosocial behaviors

2021 ◽  
Vol 17 (11) ◽  
pp. e1009611
Author(s):  
Alex McAvoy ◽  
Andrew Rao ◽  
Christoph Hauert
Keyword(s):  
Evolutionary Dynamics ◽  
Prosocial Behaviors ◽  
Global Competition ◽  
Evolutionary Models ◽  
Selection Intensity ◽  
Sweet Spot ◽  
Biologically Relevant ◽  
Long Run ◽  
Selection Intensities

In many models of evolving populations, genetic drift has an outsized role relative to natural selection, or vice versa. While there are many scenarios in which one of these two assumptions is reasonable, intermediate balances between these forces are also biologically relevant. In this study, we consider some natural axioms for modeling intermediate selection intensities, and we explore how to quantify the long-term evolutionary dynamics of such a process. To illustrate the sensitivity of evolutionary dynamics to drift and selection, we show that there can be a “sweet spot” for the balance of these two forces, with sufficient noise for rare mutants to become established and sufficient selection to spread. This balance allows prosocial traits to evolve in evolutionary models that were previously thought to be unconducive to the emergence and spread of altruistic behaviors. Furthermore, the effects of selection intensity on long-run evolutionary outcomes in these settings, such as when there is global competition for reproduction, can be highly non-monotonic. Although intermediate selection intensities (neither weak nor strong) are notoriously difficult to study analytically, they are often biologically relevant; and the results we report suggest that they can elicit novel and rich dynamics in the evolution of prosocial behaviors.

scholarly journals Intriguing effects of selection intensity on the evolution of prosocial behaviors

2021 ◽  
Author(s):  
Alex McAvoy ◽  
Andrew Rao ◽  
Christoph Hauert
Keyword(s):  
Evolutionary Dynamics ◽  
Prosocial Behaviors ◽  
Global Competition ◽  
Evolutionary Models ◽  
Selection Intensity ◽  
Sweet Spot ◽  
Biologically Relevant ◽  
Long Run ◽  
Selection Intensities

AbstractIn many models of evolving populations, genetic drift has an outsized role relative to natural selection, or vice versa. While there are many scenarios in which one of these two assumptions is reasonable, intermediate balances between these forces are also biologically relevant. In this study, we consider some natural axioms for modeling intermediate selection intensities, and we explore how to quantify the long-term evolutionary dynamics of such a process. To illustrate the sensitivity of evolutionary dynamics to drift and selection, we show that there can be a “sweet spot” for the balance of these two forces, with sufficient noise for rare mutants to become established and sufficient selection to subsequently spread. In particular, this balance allows prosocial traits to evolve in evolutionary models that were previously thought to be unconducive to the emergence and spread of altruistic behaviors. Furthermore, the effects of selection intensity on long-run evolutionary outcomes in these settings, such as when there is global competition for reproduction, can be highly non-monotonic. Although intermediate selection intensities (neither weak nor strong) are notoriously difficult to study analytically, they are often biologically relevant; and the results we report here suggest that they can elicit novel and rich dynamics in the evolution of prosocial behaviors.

scholarly journals Optimum selection intensities in artificial selection programmes: an experimental evaluation

1977 ◽  
Vol 30 (2) ◽  
pp. 115-119 ◽  
Author(s):  
R. Frankham
Keyword(s):  
Experimental Evaluation ◽  
Selection Intensity ◽  
Effective Population ◽  
Term Selection ◽  
Optimum Selection ◽  
Selection For ◽  
Selection Intensities ◽  
Selection Of ◽  
Better Than

SUMMARYAn experimental evaluation of Robertson's (1970) theory concerning optimum intensities of selection for selection of varying durations has been carried out using published results from a long term selection study in Drosophila. Agreement of predicted rankings of treatments with expectations was excellent for low values of t/T (generations/total number scored) but poor for larger values of t/T. This was due to the 20% selection intensity treatments responding worse than expected and the 40% treatments relatively better than expected. Several possible reasons for the discrepancies exist but the most likely explanation is considered to be the greater reduction in effective population size due to selection in treatments with more intense selection.

Infrastructure mortgage in Russia: Opportunities and prospects

2019 ◽  
pp. 114-133
Author(s):  
G. I. Idrisov ◽  
Y. Yu. Ponomarev
Keyword(s):  
Federal Government ◽  
Public Debt ◽  
Budget Deficit ◽  
Expert Assessment ◽  
Inflation Expectations ◽  
Direct Impact ◽  
Long Run ◽  
Gdp Growth Rate ◽  
Negative Effect

The article shows that depending on the goals pursued by the federal government and the available interbudgetary tools a different design of infrastructure mortgage is preferable. Three variants of such mortgage in Russia are proposed, each of which is better suited for certain types of projects and uses different forms of subsidies. According to our expert assessment the active use of infrastructure mortgage in Russia can increase the average annual GDP growth rate by 0.5 p. p. on the horizon of 5—7 years. In the long run the growth of infrastructure financing through the use of infrastructure mortgage could increase long-term economic growth by 0.9 p. p., which in 20—30 years can add 20—30% of GDP to the economy. However, the change in the structure of budget expenditures in the absence of an increase in the budget deficit and public debt will cause no direct impact on monetary policy. The increase in the deficit and the build-up of public debt will have a negative effect on inflation expectations, which will require monetary tightening for a longer time to stabilize them.

The Evolutionary Dynamics of Decision Rule Selection

2017 ◽  
Author(s):  
Michael Laver ◽  
Ernest Sergenti
Keyword(s):  
Decision Rule ◽  
Positive Feedback ◽  
Party System ◽  
Evolutionary Dynamics ◽  
Decision Rules ◽  
Past Performance ◽  
Party Leaders ◽  
Track Record ◽  
Long Run ◽  
Survival Of The Fittest

This chapter extends the survival-of-the-fittest evolutionary environment to consider the possibility that new political parties, when they first come into existence, do not pick decision rules at random but instead choose rules that have a track record of past success. This is done by adding replicator-mutator dynamics to the model, according to which the probability that each rule is selected by a new party is an evolving but noisy function of that rule's past performance. Estimating characteristic outputs when this type of positive feedback enters the dynamic model creates new methodological challenges. The simulation results show that it is very rare for one decision rule to drive out all others over the long run. While the diversity of decision rules used by party leaders is drastically reduced with such positive feedback in the party system, and while some particular decision rule is typically prominent over a certain period of time, party systems in which party leaders use different decision rules are sustained over substantial periods.

PENGARUH INFRASTRUKTUR SECARA SPASIAL TERHADAP KONVERGENSI PERTUMBUHAN EKONOMI DI INDONESIA

INFO ARTHA ◽  
2017 ◽  
Vol 1 ◽  
pp. 17-28
Author(s):  
Anisa Fahmi
Keyword(s):  
Economic Growth ◽  
Regional Economics ◽  
Developed Countries ◽  
Road Infrastructure ◽  
Long Run ◽  
Catch Up ◽  
The Developed Countries ◽  
Positive Effect ◽  
Neoclassical Growth Theory

Motivated by inter-regional disparities condition that occurs persistently, this study examines the Indonesian economy in the long run in order to know whether it tends to converge or diverge. This convergence is based on the Solow Neoclassical growth theory assuming the existence of diminishing returns to capital so that when the developed countries reach steady state conditions, developing countries will continuously grow up to 'catch-up' with developed countries. Based on regional economics perspective, each region can not be treated as a stand-alone unit,therefore, this study also focuses on the influence of spatial dependency and infrastructure. Economical and political situations of a region will influence policy in that region which will also have an impact to the neighboring regions. The estimation results of spatial cross-regressive model using fixed effect method consistently confirmed that the Indonesian economy in the long term will likely converge with a speed of 8.08 percent per year. Other findings are road infrastructure has a positive effect on economic growth and investment and road infrastructure are spatially showed a positive effect on economic growth. In other words, the investment and infrastructure of a region does not only affect the economic growth of that region but also to the economy of the contiguous regions. 

From Help Giving to Helping Relations

2018 ◽  
pp. 464-488
Author(s):  
Arie Nadler
Keyword(s):  
Well Being ◽  
Psychological Research ◽  
Psychological Needs ◽  
Social Psychological ◽  
Significant Relationships ◽  
Long Run ◽  
Help Giving ◽  
Social Psychological Research ◽  
Practical Implications

This chapter reviews social psychological research on help giving and helping relations from the 1950s until today. The first section considers the conditions under which people are likely to help others, personality dispositions that characterize helpful individuals, and motivational and attributional antecedents of helpfulness. The second section looks at long-term consequences of help and examines help in the context of enduring and emotionally significant relationships. Research has shown that in the long run help can increase psychological and physical well-being for helpers but discourage self-reliance for recipients. The third section analyzes helping from intra- and intergroup perspectives, considering how its provision can contribute to helpers’ reputations within a group or promote the positive social identity of in-groups relative to out-groups. Help is thus conceptualized as a negotiation between the fundamental psychological needs for belongingness and independence. Theoretical and practical implications are discussed.

scholarly journals Long-Term Cocirculation of Two Strains of Pepino Mosaic Virus in Tomato Crops and Its Effect on Population Genetic Variability

2020 ◽  
Vol 110 (1) ◽  
pp. 49-57 ◽  
Author(s):  
C. Alcaide ◽  
M. P. Rabadán ◽  
M. Juárez ◽  
P. Gómez
Keyword(s):  
Genetic Variability ◽  
Mosaic Virus ◽  
Evolutionary Dynamics ◽  
Geographical Area ◽  
Viral Fitness ◽  
Mixed Infections ◽  
Supporting Evidence ◽  
Pepino Mosaic Virus ◽  
Nucleotide Variability

Mixed viral infections are common in plants, and the evolutionary dynamics of viral populations may differ depending on whether the infection is caused by single or multiple viral strains. However, comparative studies of single and mixed infections using viral populations in comparable agricultural and geographical locations are lacking. Here, we monitored the occurrence of pepino mosaic virus (PepMV) in tomato crops in two major tomato-producing areas in Murcia (southeastern Spain), supporting evidence showing that PepMV disease-affected plants had single infections of the Chilean 2 (CH2) strain in one area and the other area exhibited long-term (13 years) coexistence of the CH2 and European (EU) strains. We hypothesized that circulating strains of PepMV might be modulating the differentiation between them and shaping the evolutionary dynamics of PepMV populations. Our phylogenetic analysis of 106 CH2 isolates randomly selected from both areas showed a remarkable divergence between the CH2 isolates, with increased nucleotide variability in the geographical area where both strains cocirculate. Furthermore, the potential virus–virus interaction was studied further by constructing six full-length infectious CH2 clones from both areas, and assessing their viral fitness in the presence and absence of an EU-type isolate. All CH2 clones showed decreased fitness in mixed infections and although complete genome sequencing indicated a nucleotide divergence of those CH2 clones by area, the magnitude of the fitness response was irrespective of the CH2 origin. Overall, these results suggest that although agroecological cropping practices may be particularly important for explaining the evolutionary dynamics of PepMV in tomato crops, the cocirculation of both strains may have implications on the genetic variability of PepMV populations.

scholarly journals Shades between Black and Green Investment: Balance or Imbalance?

2021 ◽  
Vol 13 (9) ◽  
pp. 5024
Author(s):  
 Vítor Manuel de Sousa Gabriel ◽  
María Mar Miralles-Quirós ◽  
José Luis Miralles-Quirós
Keyword(s):  
Risk Factor ◽  
Oil Prices ◽  
Oil Price ◽  
Short Term ◽  
Environmental Indices ◽  
Long Run ◽  
Green Investment ◽  
Bounds Test

This paper analyses the links established between environmental indices and the oil price adopting a double perspective, long-term and short-term relationships. For that purpose, we employ the Bounds Test and bivariate conditional heteroscedasticity models. In the long run, the pattern of behaviour of environmental indices clearly differed from that of the oil prices, and it was not possible to identify cointegrating vectors. In the short-term, it was possible to conclude that, in contemporaneous terms, the variables studied tended to follow similar paths. When the lag of the oil price variable was considered, the impacts produced on the stock market sectors were partially of a negative nature, which allows us to suppose that this variable plays the role of a risk factor for environmental investment.

scholarly journals Sector Volatility Spillover and Economic Policy Uncertainty: Evidence from China’s Stock Market

Mathematics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1411
Author(s):  
Xiaqing Su ◽  
Zhe Liu
Keyword(s):  
Economic Policy ◽  
Stock Market ◽  
Asset Allocation ◽  
Policy Uncertainty ◽  
Volatility Spillover ◽  
Economic Policy Uncertainty ◽  
Long Run ◽  
Transmission Structure ◽  
Long Term Impact

Following generalized variance decomposition, we identify the transmission structure of financial shock among ten sectors in China. Then, we examine whether economic policy uncertainty (EPU) affects it through GARCH-MIDAS regression. We find that consumer discretionary, industrials, and materials sectors are systemically important industries during the sample period. Further research of dynamic analysis shows that each sector acts in a time-varying role in this structure. The results of the GARCH-MIDAS regression indicate that none of the selected EPU indexes has a significant long-term impact on the total volatility spillover of the inter-sector stock market in China. However, the EPUs do affect some sectors’ spillover indexes in the long run, and they are significantly heterogeneous. This paper can provide regulatory suggestions for policymakers and reasonable asset allocation and risk avoidance methods for investors.

scholarly journals EFFECTS OF POPULATION SIZE AND SELECTION INTENSITY ON SHORT-TERM RESPONSE TO SELECTION FOR POSTWEANING GAIN IN MICE

Genetics ◽  
1973 ◽  
Vol 73 (3) ◽  
pp. 513-530
Author(s):  
J P Hanrahan ◽  
E J Eisen ◽  
J E Legates
Keyword(s):  
Population Size ◽  
Selection Response ◽  
Selection Intensity ◽  
Realized Heritability ◽  
Family Selection ◽  
Effective Population ◽  
Population Sizes ◽  
Selection For ◽  
Selection Intensities ◽  
Term Response

ABSTRACT The effects of population size and selection intensity on the mean response was examined after 14 generations of within full-sib family selection for postweaning gain in mice. Population sizes of 1, 2, 4, 8 and 16 pair matings were each evaluated at selection intensities of 100% (control), 50% and 25% in a replicated experiment. Selection response per generation increased as selection intensity increased. Selection response and realized heritability tended to increase with increasing population size. Replicate variability in realized heritability was large at population sizes of 1, 2 and 4 pairs. Genetic drift was implicated as the primary factor causing the reduced response and lowered repeatability at the smaller population sizes. Lines with intended effective population sizes of 62 yielded larger selection responses per unit selection differential than lines with effective population sizes of 30 or less.

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