Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “social evolution”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources
PubMed1981

[Institutional care of severely handicapped - how does it happen? - or: can the patient's career be influenced?].

The project "Analysis of the placement of handicapped in institutions from a social point of view (example: multiple sclerosis); has the objectives to improve knowledge about the situation of institutionalized MS-patients and to analyse the patient's way towards institutionalization. As far as this way is concerned, numerous examples show that the evolution of social factors in a wider sense is at least as important as the evolution of the medical factors. With regard to these social factors, the problem solving processes both of the patients and of their aides, professionals or not, are of primary importance together with the problem of being in control of the situation. Repression of the illness and uncertainty about the future are both barriers towards the search for new aims of life. Often, help is asked for in a moment when a great number of possible solutions for the problem are not anymore feasible. Furthermore, the "unique" patient is confronted with the well-tested problem solving process of the aide and thus, his own initiative is reduced and his dependency increased. These mechanisms do also exist within an institution where they have a major impact upon quality of life and influence it much more than the visible structure of the institution, e.g. buildings and equipments.

Community Health Services↗
PubMed2003

The co-evolution of individual behaviors and social institutions.

We present agent-based simulations of a model of a deme-structured population in which group differences in social institutions are culturally transmitted and individual behaviors are genetically transmitted. We use a standard extended fitness accounting framework to identify the parameter space for which this co-evolutionary process generates high levels of group-beneficial behaviors. We show that intergroup conflicts may explain the evolutionary success of both: (a) altruistic forms of human sociality towards unrelated members of one's group; and (b) group-level institutional structures such as food sharing which have emerged and diffused repeatedly in a wide variety of ecologies during the course of human history. Group-beneficial behaviors may evolve if (a) they inflict sufficient fitness costs on outgroup individuals and (b) group-level institutions limit the individual fitness costs of these behaviors and thereby attenuate within-group selection against these behaviors. Thus, the evolutionary success of individually costly but group-beneficial behaviors in the relevant environments during the first 90,000 years of anatomically modern human existence may have been a consequence of distinctive human capacities in social institution building.

Altruism↗
PubMed2004

The phylogeny of the social wasp subfamily Polistinae: evidence from microsatellite flanking sequences, mitochondrial COI sequence, and morphological characters.

BACKGROUND: Social wasps in the subfamily Polistinae (Hymenoptera: Vespidae) have been important in studies of the evolution of sociality, kin selection, and within colony conflicts of interest. These studies have generally been conducted within species, because a resolved phylogeny among species is lacking. We used nuclear DNA microsatellite flanking sequences, mitochondrial COI sequence, and morphological characters to generate a phylogeny for the Polistinae (Hymenoptera) using 69 species. RESULTS: Our phylogeny is largely concordant with previous phylogenies at higher levels, and is more resolved at the species level. Our results support the monophyly of the New World subgenera of Polistini, while the Old World subgenera are a paraphyletic group. All genera for which we had more than one exemplar were supported as monophyletic except Polybia which is not resolved, and may be paraphyletic. CONCLUSION: The combination of DNA sequences from flanks of microsatellite repeats with mtCOI sequences and morphological characters proved to be useful characters establishing relationships among the different subgenera and species of the Polistini. This is the first detailed hypothesis for the species of this important group.

Animals↗
PubMed2005

Sociality and the rate of molecular evolution.

The molecular clock does not tick at a uniform rate in all taxa but may be influenced by species characteristics. Eusocial species (those with reproductive division of labor) have been predicted to have faster rates of molecular evolution than their nonsocial relatives because of greatly reduced effective population size; if most individuals in a population are nonreproductive and only one or few queens produce all the offspring, then eusocial animals could have much lower effective population sizes than their solitary relatives, which should increase the rate of substitution of "nearly neutral" mutations. An earlier study reported faster rates in eusocial honeybees and vespid wasps but failed to correct for phylogenetic nonindependence or to distinguish between potential causes of rate variation. Because sociality has evolved independently in many different lineages, it is possible to conduct a more wide-ranging study to test the generality of the relationship. We have conducted a comparative analysis of 25 phylogenetically independent pairs of social lineages and their nonsocial relatives, including bees, wasps, ants, termites, shrimps, and mole rats, using a range of available DNA sequences (mitochondrial and nuclear DNA coding for proteins and RNAs, and nontranslated sequences). By including a wide range of social taxa, we were able to test whether there is a general influence of sociality on rates of molecular evolution and to test specific predictions of the hypothesis: (1) that social species have faster rates because they have reduced effective population sizes; (2) that mitochondrial genes would show a greater effect of sociality than nuclear genes; and (3) that rates of molecular evolution should be correlated with the degree of sociality. We find no consistent pattern in rates of molecular evolution between social and nonsocial lineages and no evidence that mitochondrial genes show faster rates in social taxa. However, we show that the most highly eusocial Hymenoptera do have faster rates than their nonsocial relatives. We also find that social parasites (that utilize the workers from related species to produce their own offspring) have faster rates than their social relatives, which is consistent with an effect of lower effective population size on rate of molecular evolution. Our results illustrate the importance of allowing for phylogenetic nonindependence when conducting investigations of determinants of variation in rate of molecular evolution.

Animals↗
PubMed2000

Sexual size dimorphism in shorebirds, gulls, and alcids: the influence of sexual and natural selection.

Charadrii (shorebirds, gulls, and alcids) have an unusual diversity in their sexual size dimorphism, ranging from monomorphism to either male-biased or female-biased dimorphism. We use comparative analyses to investigate whether this variation relates to sexual selection through competition for mates or natural selection through different use of resources by males and females. As predicted by sexual selection theory, we found that in taxa with socially polygynous mating systems, males were relatively larger than females compared with less polygynous species. Furthermore, evolution toward socially polyandrous mating systems was correlated with decreases in relative male size. These patterns depend on the kinds of courtship displays performed by males. In taxa with acrobatic flight displays, males are relatively smaller than in taxa in which courtship involves simple flights or displays from the ground. This result remains significant when the relationship with mating system is controlled statistically, thereby explaining the enigma of why males are often smaller than females in socially monogamous species. We did not find evidence that evolutionary changes in sexual dimorphism relate to niche division on the breeding grounds. In particular, biparental species did not have greater dimorphism in bill lengths than uniparental species, contrary to the hypothesis that selection for ecological divergence on the breeding grounds has been important as a general explanation for patterns of bill dimorphism. Taken together, these results strongly suggest that sexual selection has had a major influence on sexual size dimorphism in Charadrii, whereas divergence in the use of feeding resources while breeding was not supported by our analyses.

Animals↗
PubMed1994

The etiology of social phobia.

Human beings are by nature social animals, but for some, social scrutiny is a source of extreme anguish. Those with social phobia, for example, suffer excessive and often disabling concern about potential and real social-evaluative threat. As new and effective therapies for this condition are pursued, there is a simultaneous movement to extend the understanding of this disorder's etiology. In psychiatry, as in the rest of medicine, this development of new treatments often occurs in parallel with increasing sophistication about causes of illness. Advances in one area typically inform and predictably lead to advances in the other. Social phobia is recognized as a relatively common and significantly impairing anxiety disorder. As with other psychiatric disorders, emerging models of the etiology of social phobia are derived from converging evidence of interacting biological and environmental contributions. Current theories regarding the evolution of social phobia will be addressed, including biological preparedness to fear scrutiny by others, genetically transmitted predisposition to fear acquisition, nongenetic familial and environmental factors, as well as other possible causes and antecedents. Additionally, we describe recent work on behavioral inhibition in infancy as an identifiable early marker of proneness to the development of anxiety disorders, including social phobia.

Adolescent↗
PubMed1993

Social Security and older workers.

Many observers have noted that the long-term decline in labor-force participation by older Americans may reflect the evolution of social institutions that effectively discourage work. Often cited factors include employer discrimination against older workers, private pension plans that penalize continued employment, and the Social Security system. Various policies, such as eliminating Social Security's retirement test, have been proposed with a view to eliminating or lessening employment barriers. This article summarizes the economic evidence that addresses the role played by the Old-Age and Survivors Insurance (OASI) programs in retirement decisions. OASI is shown to have statistically significant effects on both the timing of retirement and the amount of postretirement work; however, the influence is not large relative to the many other factors that determine the labor-supply decisions of older workers. Consequently, changes in Social Security policy of the type and magnitude that are politically feasible are unlikely to result in large changes in retirement behavior.

Age Distribution↗
PubMed1976

[Various aspects of current evolution of zoonoses].

The author analyzes current pecularities attending the clinico-epidemiological characteristics of a number of zoonozes as a mainifestation of the process of their socially conditioned evolution. Possible sequelae of the anthropogenic transformation of the surrounding environment for the dynamics of the nozoareals of the zoonosis infections are considered.

Animals↗
PubMed2006

A mixed strategy model for the emergence and intensification of social learning in a periodically changing natural environment.

Based on a population genetic model of mixed strategies determined by alleles of small effect, we derive conditions for the evolution of social learning in an infinite-state environment that changes periodically over time. Each mixed strategy is defined by the probabilities that an organism will commit itself to individual learning, social learning, or innate behavior. We identify the convergent stable strategies (CSS) by a numerical adaptive dynamics method and then check the evolutionary stability (ESS) of these strategies. A strategy that is simultaneously a CSS and an ESS is called an attractive ESS (AESS). For certain parameter sets, a bifurcation diagram shows that the pure individual learning strategy is the unique AESS for short periods of environmental change, a mixed learning strategy is the unique AESS for intermediate periods, and a mixed learning strategy (with a relatively large social learning component) and the pure innate strategy are both AESS's for long periods. This result entails that, once social learning emerges during a transient era of intermediate environmental periodicity, a subsequent elongation of the period may result in the intensification of social learning, rather than a return to innate behavior.

Genotype↗
PubMed1985

[Submitting to disease, controlling disease, industrialization and medical technology: the case of tuberculosis].

This article presents an overview of the research work undertaken in France and Algeria on tuberculosis and the application of tuberculosis treatments. Tuberculosis is one of the best medical pointers to social inequality. The disease is seen here as typical of the links between industrialization and health, with regard to the evolution of the epidemiological model and the influence of innovational+ treatments, based on chemotherapy, on the organization of care for tubercular patients, together with the socio-economic and cultural changes that have affected both French and Algerian society during the twentieth century. The first part of the article shows how the epidemiology of tuberculosis tends to vary in accordance with the dynamic evolution of social relationships as industrialization occurs in each country, and how world-wide epidemiological trends are one of the best medical pointers to the North-South divide. The second part of the article is given over to a study of the way in which the application of tuberculosis treatments in both France and Algeria is a function of the organization of the health system in each country, of the status and power of the medical profession within society, and of the impact of technical innovations on the changing forms of care for tubercular patients in both countries. In France, it can be seen that the structure of the system set up to combat tuberculosis in the inter-war years has tended to remain unchanged, despite the opportunities for re-organization of tuberculosis treatment and for making therapy less onerous which have arisen as the incidence of the disease has dropped and antibiotics have been introduced. This resistance to change seems due primarily to the difficulty of achieving redeployment of medical staff, and the inertia caused by the rigid structure of tuberculosis care within the French socio-medical system.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2025

Chromosome-level genome assembly of the large carpenter bee Xylocopa dejeanii Lepeletier, 1841 (Hymenoptera: Apidae).

Xylocopinae, a diverse bee subfamily comprising over 1,000 bee species, and also a major model system for studying the pollination and evolution of sociality. The lack of chromosome-level genome assembly resources for the Xylocopinae limits our research of their biology and evolution. Here, we provided the first pseudo-chromosomes genome assembly of the Xylocopa dejeanii combined PacBio CLR long reads, Illumina sequences, and Hi-C data. The final genome is 194.44 Mb located in 16 chromosomes. Our assembly includes 141 scaffolds, with a scaffold N50 length of 13.15 Mb. BUSCO analysis revealed 99.00% completeness. Genome annotation identified 28.27 Mb of repetitive elements, 10,970 protein-coding genes, and 432 ncRNAs. This high-quality X. dejeanii assembly advances our understanding of Xylocopinae genomics and provides new insights into bee evolution.

Animals↗
PubMed2004

Evolution of coordinated alternating reciprocity in repeated dyadic games.

A genetic algorithm incorporating mutation and crossing-over was used to investigate the evolution of social behaviour in repeated Prisoner's Dilemma, Chicken (Hawk-Dove), Battle of the Sexes, and Leader games. The results show that the strategic structure of an interaction has a crucial determining effect on the type of social behaviour that evolves. In particular, simulations using repeated Prisoner's Dilemma and Chicken (Hawk-Dove) games lead to the emergence of genes coding for symmetric reciprocity and the evolution of mutual cooperation, whereas simulations using repeated Battle of the Sexes and Leader games lead to near-fixation of genes coding for asymmetric strategic choices and the evolution of coordinated alternating reciprocity. A mechanism is suggested whereby, in games with asymmetric equilibrium points, coordinated alternating reciprocity might evolve without insight or communication between players.

Algorithms↗
PubMed2002

Sexual segregation in ungulates: a comparative test of three hypotheses.

In most social ungulate species, males are larger than females and the sexes live in separate groups outside the breeding season. It is important for our understanding of the evolution of sociality to find out why sexual segregation is so widespread not only in ungulates but also in other mammals. Sexual body size dimorphism was proposed as a central factor in the evolution of sexual segregation in ungulates. We tested three hypotheses put forward to explain sexual segregation: the predation-risk, the forage-selection, and the activity budget hypothesis. We included in our analyses ungulate species ranging from non-dimorphic to extremely dimorphic in body size. We observed oryx, zebra, bighorn sheep and ibex in the field and relied on literature data for 31 additional species. The predation-risk hypothesis predicts that females will use relatively predator-safe habitats, while males are predicted to use habitats with higher predation risk but better food quality. Out of 24 studies on different species of ungulates, females and their offspring chose poorer quality but safer habitat in only eight cases. The forage-selection hypothesis predicts that females would select habitat based on food quality, while males should prefer high forage biomass. In fact, females selected higher quality food in only six out of 18 studies where males and females segregated, in eight studies there was no difference in forage quality and in four studies males were in better quality habitat. The activity budget hypothesis predicts that with increasing dimorphism in body size males and females will increasingly differ in the time spent in different activities. Differences in activity budgets would make it difficult for males and females to stay in mixed-sex groups due to increased costs of synchrony to maintain group cohesion. The predictions of the activity budget hypothesis were confirmed in most cases (22 out of 23 studies). The heavier males were compared to females, the more time females spent foraging compared to males. The bigger the dimorphism in body mass, the more males spent time walking compared to females. Lactating females spent more time foraging than did non-lactating females or males. Whether species were mainly bulk or intermediate feeders did not affect sexual differences in time spent foraging. We conclude that sexual differences in activity budgets are most likely driving sexual segregation and that sexual differences in predation risk or forage selection are additive factors.

Animals↗
PubMed2000

Trends in social class inequalities in health status, health-related behaviors, and health services utilization in a Southern European urban area (1983-1994).

BACKGROUND: The objective of this study was to describe the evolution of social class inequalities in Barcelona (Spain) residents in perceived health status, health-related behaviors, and utilization of health services between 1983 and 1994. METHODS: The information was obtained from the Health Interview Surveys conducted in 1983, 1986, 1992, and 1994 in Barcelona. In this study we included noninstitutionalized people ages >14 years. Social class was obtained from the Spanish adaptation of the British Registrar General classification. We studied health status, health-related behaviors, and health services utilization variables. Age-adjusted percentages and the relative index of inequality were obtained. RESULTS: Of the health status variables, having been confined to bed and acute restriction of activity in the 2 weeks prior to the interview showed an increase in inequalities by social class in 1994. The pattern of chronic conditions by social class in men did not change between 1983 and 1994. Women had a higher prevalence of chronic conditions and the inequalities among social classes had increased. In men there were no social class inequalities in smoking in 1983. In 1992 and 1994 smoking was more prevalent in men of social classes IV and V. In women, smoking was more prevalent in social classes I and II in 1983 than in social classes IV and V, something that had changed by 1994. Lack of usual physical activity in men was always more prevalent in social classes I and II, and this difference increased since more people of advantaged classes moved into inactivity. Health services utilization showed no inequalities in the years studied. CONCLUSION: The changing pattern according to social class of smoking and physical activity practice needs to be taken into account by policy-makers and public health workers.

Adolescent↗
PubMed1990

Role blurring and the hospital social worker's search for a clear domain.

Hospital social workers strive to define their professional domain to avoid blurring their roles with those of other health care professionals. Hospital social workers are concerned with gaining and retaining recognition by patients, families, and colleagues of their distinct professional contribution. This article reviews the evolution of social workers' roles and functions in hospitals and reflects on the frequently noted discrepancy between self-ascribed roles and those conceded to social workers by other health care professionals. Issues of collaboration in the context of interdisciplinary activity are considered, and the impact of overlapping roles on social work practice is assessed. The value and drawbacks of role ambiguity are discussed, and strategies for role clarification and development of a better-defined domain for social workers in hospitals are recommended.

Hospital Departments↗
PubMed1992

Developments and trends in Social Security, 1990-1992: overview of principal trends.

The article that follows is a reprint of Part I of a report presented by Dalmer D. Hoskins, Secretary General of the International Social Security Association (ISSA), to the organization's XXIVth General Assembly (November 1992, Acapulco). It identifies and interprets the major trends currently influencing the evolution of social security programs around the world, and analyzes these developments against the backdrop of the current economic, demographic, and social environment in which these programs operate. (Part II of the report analyzes the changes according to each major branch of social security; an annex to the report provides more detailed information and source citations in reference to these changes.) The ISSA is a nongovernmental international organization headquartered in Geneva, Switzerland. It is made up of 321 social security-related institutions, including the U.S. Social Security Administration, in 122 countries. The Association's aim is to protect, promote, and develop social security worldwide.

International Agencies↗
PubMed2001

Genetic consequences of polygyny and social structure in an Indian fruit bat, Cynopterus sphinx. I. Inbreeding, outbreeding, and population subdivision.

Population subdivision into behaviorally cohesive kin groups influences rates of inbreeding and genetic drift and has important implications for the evolution of social behavior. Here we report the results of a study designed to test the hypothesis that harem social structure promotes inbreeding and genetic subdivision in a population with overlapping generations. Genetic consequences of harem social structure were investigated in a natural population of a highly polygynous fruit bat, Cynopterus sphinx (Chiroptera: Pteropodidae), in western India. The partitioning of genetic variance within and among breeding groups was assessed using 10-locus microsatellite genotypes for 431 individually marked bats. Genetic analysis of the C. sphinx study population was integrated with field data on demography and social structure to determine the specific ways in which mating, dispersal, and new social group formation influenced population genetic structure. Microsatellite data revealed striking contrasts in genetic structure between consecutive offspring cohorts and between generations. Relative to the 1998 (dry-season) offspring cohort, the 1997 (wet-season) cohort was characterized by a more extensive degree of within-group heterozygote excess (F(IS) = -0.164 vs. -0.050), a greater degree of among-group subdivision (F(ST) = 0.123 vs. 0.008), and higher average within-group relatedness (r = 0.251 vs. 0.017). Differences in genetic structure between the two offspring cohorts were attributable to seasonal differences in the number and proportional representation of male parents. Relative to adult age-classes, offspring cohorts were characterized by more extensive departures from allelic and genotypic equilibria and a greater degree of genetic subdivision. Generational differences in F-statistics indicated that genetic structuring of offspring cohorts was randomized by natal dispersal prior to recruitment into the breeding population. Low relatedness among harem females (r = 0.002-0.005) was primarily attributable to high rates of natal dispersal and low rates of juvenile survivorship. Kin selection is therefore an unlikely explanation for the formation and maintenance of behaviorally cohesive breeding groups in this highly social mammal.

Animals↗