scholarly journals The spontaneous emergence of conventions: An experimental study of cultural evolution

2015 ◽  
Vol 112 (7) ◽  
pp. 1989-1994 ◽  
Author(s):  
Damon Centola ◽  
Andrea Baronchelli
Keyword(s):  
Cultural Evolution ◽  
Large Scale ◽  
Social Systems ◽  
Informal Institutions ◽  
Human Populations ◽  
Collective Behaviors ◽  
Social Conventions ◽  
Evolutionary Theories ◽  
Empirical Tests ◽  
Global Agreement

How do shared conventions emerge in complex decentralized social systems? This question engages fields as diverse as linguistics, sociology, and cognitive science. Previous empirical attempts to solve this puzzle all presuppose that formal or informal institutions, such as incentives for global agreement, coordinated leadership, or aggregated information about the population, are needed to facilitate a solution. Evolutionary theories of social conventions, by contrast, hypothesize that such institutions are not necessary in order for social conventions to form. However, empirical tests of this hypothesis have been hindered by the difficulties of evaluating the real-time creation of new collective behaviors in large decentralized populations. Here, we present experimental results—replicated at several scales—that demonstrate the spontaneous creation of universally adopted social conventions and show how simple changes in a population’s network structure can direct the dynamics of norm formation, driving human populations with no ambition for large scale coordination to rapidly evolve shared social conventions.

scholarly journals Shell model description of heavy nuclei and abnormal collective motions

2018 ◽  
Vol 178 ◽  
pp. 02015
Author(s):  
Chong Qi
Keyword(s):  
Shell Model ◽  
Degrees Of Freedom ◽  
Large Scale ◽  
Model Description ◽  
Heavy Nuclei ◽  
Collective Models ◽  
Collective Behaviors ◽  
Electromagnetic Transition ◽  
Nuclear Shell ◽  
Model Approach

In this contribution I present systematic calculations on the spectroscopy and electromagnetic transition properties of intermediate-mass and heavy nuclei around 100Sn and 208Pb. We employed the large-scale configuration interaction shell model approach with realistic interactions. Those nuclei are the longest isotopic chains that can be studied by the nuclear shell model. I will show that the yrast spectra of Te isotopes show a vibrational-like equally spaced pattern but the few known E2 transitions show rotational-like behaviour. These kinds of abnormal collective behaviors cannot be reproduced by standard collective models and provide excellent background to study the competition of single-particle and various collective degrees of freedom. Moreover, the calculated B(E2) values for neutron-deficient and heavier Te isotopes show contrasting different behaviours along the yrast line, which may be related to the enhanced neutron-proton correlation when approaching N=50. The deviations between theory and experiment concerning the energies and E2 transition properties of low-lying 0+ and 2+ excited states and isomeric states in those nuclei may provide a constraint on our understanding of nuclear deformation and intruder configuration in that region.

scholarly journals Spatial confinement of active microtubule networks induces large-scale rotational cytoplasmic flow

2017 ◽  
Vol 114 (11) ◽  
pp. 2922-2927 ◽  
Author(s):  
Kazuya Suzuki ◽  
Makito Miyazaki ◽  
Jun Takagi ◽  
Takeshi Itabashi ◽  
Shin’ichi Ishiwata
Keyword(s):  
Fluid Flow ◽  
Cytoplasmic Streaming ◽  
Large Scale ◽  
Random Network ◽  
Hydrodynamic Interactions ◽  
Length Scale ◽  
Vortex Flows ◽  
Directed Flow ◽  
Collective Behaviors ◽  
In Cells

Collective behaviors of motile units through hydrodynamic interactions induce directed fluid flow on a larger length scale than individual units. In cells, active cytoskeletal systems composed of polar filaments and molecular motors drive fluid flow, a process known as cytoplasmic streaming. The motor-driven elongation of microtubule bundles generates turbulent-like flow in purified systems; however, it remains unclear whether and how microtubule bundles induce large-scale directed flow like the cytoplasmic streaming observed in cells. Here, we adopted Xenopus egg extracts as a model system of the cytoplasm and found that microtubule bundle elongation induces directed flow for which the length scale and timescale depend on the existence of geometrical constraints. At the lower activity of dynein, kinesins bundle and slide microtubules, organizing extensile microtubule bundles. In bulk extracts, the extensile bundles connected with each other and formed a random network, and vortex flows with a length scale comparable to the bundle length continually emerged and persisted for 1 min at multiple places. When the extracts were encapsulated in droplets, the extensile bundles pushed the droplet boundary. This pushing force initiated symmetry breaking of the randomly oriented bundle network, leading to bundles aligning into a rotating vortex structure. This vortex induced rotational cytoplasmic flows on the length scale and timescale that were 10- to 100-fold longer than the vortex flows emerging in bulk extracts. Our results suggest that microtubule systems use not only hydrodynamic interactions but also mechanical interactions to induce large-scale temporally stable cytoplasmic flow.

scholarly journals Ecology of the Anthropocene signals hope for consciously managing the planetary ecosystem

2021 ◽  
Vol 118 (28) ◽  
pp. e2024150118
Author(s):  
Clarence Lehman ◽  
Shelby Loberg ◽  
Michael Wilson ◽  
Eville Gorham
Keyword(s):  
Population Growth ◽  
Cultural Evolution ◽  
Human Population ◽  
Human Populations ◽  
Present Moment ◽  
Minimal Set ◽  
The Past ◽  
Food Species ◽  
Large Predators ◽  
Population Numbers

Human populations have grown to such an extent that our species has become a dominant force on the planet, prompting geologists to begin applying the term Anthropocene to recognize the present moment. Many approaches seek to explain the past and future of human population growth, in the form of narratives and models. Some of the most influential models have parameters that cannot be precisely known but are estimated by expert opinion. Here we apply a unified model of ecology to provide a macroscale summary of the net effects of many microscale processes, using a minimal set of parameters that can be known. Our models match estimates of historic and prehistoric global human population numbers and provide predictions that correspond to some of the more complicated current models. In addition to fitting the data well they reveal that, amidst enormous complexity in our human and prehuman past, three key ecological discontinuities have occurred in turn: 1) becoming dominant competitors of large predators rather than their prey, 2) becoming mutualists with food species rather than acting as predators upon them, and 3) changing from a regime of uncontrolled population growth to one of controlled fertility instead. All three processes have been interlinked with cultural evolution and all three ushered in developments of the Anthropocene. Understanding the trajectories that have delivered us to this stage can help guide prudent paths into the future.

scholarly journals Sacral rulers in pre-Christian Scandinavia: The possibilities of typological comparisons within the paradigm of cultural evolution

2016 ◽  
Vol 52 (1) ◽  
pp. 9-35
Author(s):  
Simon Nygaard
Keyword(s):  
Cultural Evolution ◽  
Main Part ◽  
Theoretical Framework ◽  
Evolutionary Theories ◽  
History Of Religions ◽  
History Of ◽  
Societal Structure ◽  
New Perspective ◽  
Cultural Evolutionary

This article offers a new perspective on the century-old discussion of sacral rulers in the history of religions generally, and pre-Christian Scandinavian religions specifically, namely the application of a cultural evolutionary theoretical framework based on the work of Robert N. Bellah. In doing this, the article opens the possibility of wider typological comparisons within this paradigm and suggests a nuancing of Bellah’s typology with the addition of the category of ‘chiefdom religion’. This is utilised in the main part of the article, which features a comparison between the figure of the sacral ruler in pre-Christian Scandinavian and pre-Christian Hawaiian religions through an analysis of: 1) the position of the ruler in society, cult, and ideology; 2) the societal structure in which these religions are found; 3) the idea of a ruler sacrifice; 4) incestuous relationships and their ideological implications; and, finally, 5) the idea of a double rulership. Following this comparison, the perspectives in and the usefulness of cultural evolutionary theories in the history of religions are briefly evaluated.

scholarly journals Pervasive cis effects of variation in copy number of large tandem repeats on local epigenetics and gene expression

2020 ◽  
Author(s):  
Paras Garg ◽  
Alejandro Martin-Trujillo ◽  
Oscar L. Rodriguez ◽  
Scott J. Gies ◽  
Bharati Jadhav ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Copy Number ◽  
Large Scale ◽  
Tandem Repeats ◽  
Local Variation ◽  
Read Depth ◽  
Variable Number ◽  
Human Populations ◽  
Functional Variation

ABSTRACTVariable Number Tandem Repeats (VNTRs) are composed of large tandemly repeated motifs, many of which are highly polymorphic in copy number. However, due to their large size and repetitive nature, they remain poorly studied. To investigate the regulatory potential of VNTRs, we used read-depth data from Illumina whole genome sequencing to perform association analysis between copy number of ~70,000 VNTRs (motif size ≥10bp) with both gene expression (404 samples in 48 tissues) and DNA methylation (235 samples in peripheral blood), identifying thousands of VNTRs that are associated with local gene expression (eVNTRs) and DNA methylation levels (mVNTRs). Using large-scale replication analysis in an independent cohort we validated 73-80% of signals observed in the two discovery cohorts, providing robust evidence to support that these represent genuine associations. Further, conditional analysis indicated that many eVNTRs and mVNTRs act as QTLs independently of other local variation. We also observed strong enrichments of eVNTRs and mVNTRs for regulatory features such as enhancers and promoters. Using the Human Genome Diversity Panel, we defined sets of VNTRs that show highly divergent copy numbers among human populations, show that these are enriched for regulatory effects on gene expression and epigenetics, and preferentially associate with genes that have been linked with human phenotypes through GWAS. Our study provides strong evidence supporting functional variation at thousands of VNTRs, and defines candidate sets of VNTRs, copy number variation of which potentially plays a role in numerous human phenotypes.

scholarly journals Health inequality as a large-scale outcome of complex social systems: Lessons for action on the sustainable development goals

2020 ◽  
Author(s):  
Anna Matheson
Keyword(s):  
Sustainable Development ◽  
Health Inequality ◽  
Large Scale ◽  
Sustainable Development Goals ◽  
Social Systems ◽  
Power Relationships ◽  
Past Century ◽  
The Sustainable Development ◽  
Development Goals ◽  
Complex Social Systems

© 2020 by the author. Licensee MDPI, Basel, Switzerland. Action on the Sustainable Development Goals (SDGs) needs to become real and impactful, taking a “whole systems” perspective on levers for systems change. This article reviews what we have learned over the past century about the large-scale outcome of health inequality, and what we know about the behaviour of complex social systems. This combined knowledge provides lessons on the nature of inequality and what effective action on our big goals, like the SDGs, might look like. It argues that economic theories and positivist social theories which have dominated the last 150 years have largely excluded the nature of human connections to each other, and the environment. This exclusion of intimacy has legitimatised arguments that only value-free economic processes matter for macro human systems, and only abstract measurement constitutes valuable social science. Theories of complex systems provide an alternative perspective. One where health inequality is viewed as emergent, and causes are systemic and compounding. Action therefore needs to be intensely local, with power relationships key to transformation. This requires conscious and difficult intervention on the intolerable accumulation of resources; improved reciprocity between social groups; and reversal of system flows, which at present ebb away from the local and those already disadvantaged.

scholarly journals Beyond Neo-liberalism: Research Policies and Society. The Case of Japan

2013 ◽  
Vol 29 (2) ◽  
pp. 58-78 ◽  
Author(s):  
Alain-Marc Rieu
Keyword(s):  
Large Scale ◽  
Social Systems ◽  
Qualitative Change ◽  
Economic Systems ◽  
Negative Effects ◽  
Science And Technology Policies ◽  
Systemic Crisis ◽  
Technology Policies ◽  
Industrial Societies

The idea of decoupling is playing a major role in various interpretations of the present systemic crisis. This crisis is understood as an effect of neo-liberal policies, which have revolutionized economic systems since the 1980s. Decoupling indicates a qualitative change in the level of autonomy of the economic sphere in industrial societies. But a new level of differentiation also generates various types of recoupling, new forms of integration, cooperation and regulation recomposing social systems at another level. The goal of this article is first to situate the idea of decoupling within its conceptual complex. Secondly, the ecological constraint is considered the source of this intense differentiation within social systems, which has intensified since the 1970s. Finally, based on the case of Japan, this paper explains why large-scale science and technology policies developed since the 1990s have to be understood as part of a recoupling process, a project to reconstruct and reach a social and economic coherence in the long term. Similar policies are now implemented by all major industrial nations. Such policies have the potential to overcome neo-liberalism's negative effects.

Heterogeneous model of schistosomiasis transmission and long-term control: the combined influence of spatial variation and age-dependent factors on optimal allocation of drug therapy

Parasitology ◽  
2004 ◽  
Vol 130 (1) ◽  
pp. 49-65 ◽  
Author(s):  
D. GURARIE ◽  
C. H. KING
Keyword(s):  
Large Scale ◽  
Optimal Allocation ◽  
Field Studies ◽  
Human Populations ◽  
Infection Prevalence ◽  
Snail Population ◽  
Extended Model ◽  
Heterogeneous Model ◽  
Age Dependent

Prior field studies and modelling analyses have individually highlighted the importance of age-specific and spatial heterogeneities on the risk for schistosomiasis in human populations. As long-term, large-scale drug treatment programs for schistosomiasis are initiated in subSaharan Africa and elsewhere, optimal strategies for timing and distribution of therapy have yet to be fully defined on the working, district-level scale, where strong heterogeneities are often observed among sublocations. Based on transmission estimates from recent field studies, we develop an extended model of heterogeneous schistosome transmission for distributed human and snail population clusters and age-dependent behaviour, based on a ‘mean worm burden+snail infection prevalence’ formulation. We analyse its equilibria and basic reproduction patterns and their dependence on the underlying transmission parameters. Our model allows the exploration of chemotherapy-based control strategies targeted at high-risk behavioural groups and localities, and the approach to an optimal design in terms of cost. Efficacy of the approach is demonstrated for a model environment having linked, but spatially-distributed, populations and transmission sites.

The Dawn of Civilization

2018 ◽  
pp. 234-263
Author(s):  
Kevin N. Laland
Keyword(s):  
Cultural Evolution ◽  
Slow Rate ◽  
Large Scale ◽  
Cultural Practices ◽  
Morphological Evolution ◽  
Biological Evolution ◽  
Genetic Evolution ◽  
The Third ◽  
The World ◽  
Adaptive Challenges

This chapter traces the evolution of human civilization from nomadic hunter-gatherer societies to the advent of agriculture and its large-scale impacts on the world. It describes this history in three ages of adaptive evolution. First, there was the age in which biological evolution dominated, in which we adapted to the circumstances of life in a manner no different from every other creature. Second came the age when gene–culture coevolution was in the ascendency. Through cultural activities, our ancestors set challenges to which they adapted biologically. In doing so, they released the brake that the relatively slow rate of independent environmental change imposes on other species. The results are higher rates of morphological evolution in humans compared to other mammals, with human genetic evolution reported as accelerating more than a hundredfold over the last 40,000 years. Now we live in the third age, where cultural evolution dominates. Cultural practices provide humanity with adaptive challenges, but these are then solved through further cultural activity, before biological evolution gets moving.

Sign in / Sign up

Export Citation Format

Share Document