[The evolution of social balneology in France since the 1st International Congress of 1947].
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Balneology↗
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Results for “social evolution”
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A stochastic model for evolution of sociality in insects.
We study population biology of eusocial insects such as Ropalidia marginata through a stochastic model based on random (matrix) difference equations. This facilitates a study of dynamics of such populations when the survival and other rates vary randomly over time. The worker-brood relatedness, which is a function of the underlying population structure, can be used to explain theories on the evolution of altruism. The effect of demographic parameters and the queen takeover probabilities on the worker-brood relatedness has been studied. Based on the proposed model, we simulate insect colonies where queens are replaced. Simulation results help us to study the effect of various factors on the worker-brood relatedness. Further, we study two estimators of the worker-brood relatedness and suggest procedures for estimating their standard errors. Approximate confidence intervals for the same can be constructed with the help of these results.
Animals↗
Does genetic diversity hinder parasite evolution in social insect colonies?
Polyandry is often difficult to explain because benefits of the behaviour have proved elusive. In social insects, polyandry increases the genetic diversity of workers within a colony and this has been suggested to improve the resistance of the colony to disease. Here we examine the possible impact of host genetic diversity on parasite evolution by carrying out serial passages of a virulent fungal pathogen through leaf-cutting ant workers of known genotypes. Parasite virulence increased over the nine-generation span of the experiment while spore production decreased. The effect of host relatedness upon virulence appeared limited. However, parasites cycled through more genetically diverse hosts were more likely to go extinct during the experiment and parasites cycled through more genetically similar hosts had greater spore production. These results indicate that host genetic diversity may indeed hinder the ability of parasites to adapt while cycling within social insect colonies.
Animals↗
Adaptive evolution of social traits: origin, trajectories, and correlations of altruism and mobility.
Social behavior involves "staying and helping," two individual attributes that vary considerably among organisms. Investigating the ultimate causes of such variation, this study integrates previously separate lines of research by analyzing the joint evolution of altruism and mobility. We unfold the network of selective pressures and derive how these depend on physiological costs, eco-evolutionary feedbacks, and a complex interaction between the evolving traits. Our analysis highlights habitat saturation, both around individuals (local aggregation) and around unoccupied space (local contention), as the key mediator of altruism and mobility evolution. Once altruism and mobility are allowed to evolve jointly, three general insights emerge. First, the cost of mobility affects the origin of altruism, determining whether and how quickly selfishness is overcome. Second, the cost of altruism determines which of two qualitatively different routes to sociality are taken: an evolutionary reduction of mobility, resulting in higher habitat saturation, is either preceded or followed by the adaptive rise of altruism. Third, contrary to conventional expectations, a positive correlation between evolutionarily stable levels of altruism and mobility can arise; this is expected when comparing populations that evolved under different constraints on mobility or that differ in other life-history traits.
Adaptation, Physiological↗
The evolution of social behavior in the prehistoric American southwest.
Long House Valley, located in the Black Mesa area of northeastern Arizona (USA), was inhabited by the Kayenta Anasazi from circa 1800 B.C. to circa A.D. 1300. These people were prehistoric precursors of the modern Pueblo cultures of the Colorado Plateau. A rich paleoenvironmental record, based on alluvial geomorphology, palynology, and dendroclimatology, permits the accurate quantitative reconstruction of annual fluctuations in potential agricultural production (kg maize/hectare). The archaeological record of Anasazi farming groups from A.D. 200 to 1300 provides information on a millennium of sociocultural stasis, variability, change, and adaptation. We report on a multi-agent computational model of this society that closely reproduces the main features of its actual history, including population ebb and flow, changing spatial settlement patterns, and eventual rapid decline. The agents in the model are monoagriculturalists, who decide both where to situate their fields and where to locate their settlements.
Cultural Evolution↗
[Molecular biology concerning to the honeybee sociality: how can we approach the evolution of insect sociality?].
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Animals↗
Are reproductive skew models evolutionarily stable?
Reproductive skew theory has become a popular way to phrase problems and test hypotheses of social evolution. The diversity of reproductive skew models probably stems from the ease of generating new variations. However, I show that the logical basis of skew models, that is, the way in which group formation is modelled, makes use of hidden assumptions that may be problematical as they are unlikely to be fulfilled in all social systems. I illustrate these problems by re-analysing the basic concessive skew model with staying incentives. First, the model assumes that dispersal is an all-or-nothing response: all subordinates disperse as soon as concessions drop below a certain value. This leads to a discontinuous 'cliff-edge' shape of dominant fitness, and it is not clear that selection will balance a population at such an edge. Second, it is assumed that subordinates have perfect knowledge of their benefits if they stay in the group. I examine the effects of relaxing these two assumptions. Relaxing the first one strengthens reproductive skew theory, but relaxing the latter makes evolutionary stability disappear. In cases where subordinates cannot accurately measure benefits provided by the individual dominant with which they live, so that their behaviour instead evolves as a response to population-wide average benefits, the logic of reproductive skew models does not apply. This warns against too indiscriminate an application of reproductive skew theory to problems in social evolution: for example, transactional models of extra-pair paternity assume perfect knowledge of paternity, which is unlikely to hold true in nature. It is recommended that models specify the mechanisms by which individuals can adjust their behaviour to that of others, and pay attention to changes that occur in evolutionary versus behavioural time.
Animals↗
Antenatal care and maternal demographic and social characteristics. Evolution in France between 1972 and 1976.
A study was carried out on representative samples of 11 254 births in France in 1972 and 4685 births in 1976. Women were interviewed after delivery to obtain information about the medical care they had received during pregnancy. Inadequate antenatal care was defined as: first antenatal visit after the first trimester of pregnancy, or total number of visits fewer than the required minimum, or no visit to an obstetrician or the hospital maternity team. In 1972, the problem of inadequate care occurred mainly in very young women, or in those of high parity or with short birth intervals when the father's social class had been taken into account. Social status was also an important factor independently of a woman's demographic characteristics. These inequalities persisted in 1976 despite the policy adopted in 1972 to improve antenatal care for high-risk women.
Adult↗
[Social health evolution in Vall d'Uixó. Application of multivariate analysis as a new health status indicator method].
OBJECTIVES: This study evaluated the relative position of Vall d'Uixó within the province of Castellón, the Valencian Community and Spain. DESIGN: The study covers the period from 1981 to 1993. A multivariate analysis of the main components was performed. This compared the interrelationship of these indicators in the different zones analysed. PATIENTS AND OTHER PARTICIPANTS: Our study focused on an area of 27,387 population, geographically within the province of Castellón in the south-west of La Plana county. RESULTS: The analysis showed that Vall d'Uixó had a low level of development and little economic activity. It had a relatively young population. CONCLUSIONS: The health problems were linked to the social and economic situation. Apart from the re-creation of industrial jobs, it would be desirable to improve programmes to monitor TB and cardiovascular diseases.
Cause of Death↗
Phylogeny of Lasius ants based on mitochondrial DNA and morphology, and the evolution of social parasitism in the Lasiini (Hymenoptera: Formicidae).
Phylogeny of ants of the tribe Lasiini (Lasius, Acanthomyops, Prenolepis, Euprenolepis, Paratrechina, Pseudolasius, and Myrmecocystus) was analysed using 81 morphological, ecological, and behavioural characters (for 41 species) and mitochondrial DNA sequences (COI, COII, tRNA-Leu; for 19 species). The free-living subgenus Lasius s. str. is paraphyletic with respect to the rest of genus; the traditional "genus" Acanthomyops should be considered a part of Lasius s. lat.; free-living subgenus Cautolasius is a member of the clade of socially parasitic Lasius ants (=Chtonolasius+Acanthomyops+Austrolasius+Dendrolasius). The tree topology is congruent with two alternative scenarios of origin of the temporary social parasitism: (i) a single origin of the parasitic strategy in a derived subclade of Lasius and a secondary loss of this trait in Cautolasius, (ii) a parallel origin of the social parasitism within the clade of hypogeic Lasius ants (in Chtonolasius, and in Acanthomyops+Dendrolasius+Austrolasius). Emery's rule in the strict sense does not apply to this group because most parasites exploit any ecologically available, even phylogenetically distant host species. The parasitic strategy in Lasius could have originated from the aggressive interactions between cofounding queens during pleometric colony founding and/or from the secondary queen adoption.
Animals↗
Evolution of social concerns and environmental policies for chemical mutagens.
The founding of the Environmental Mutagen Society 20 years ago coincided with the beginning of general social concern about exposure to chemical mutagens. Initially, this concern focused on the potential of chemicals to induce heritable genetic damage in humans. Within a few years, however, mutagenicity tests came to be regarded primarily as short-term tests for carcinogenicity. Serious doubts have recently been cast upon the relationship between mutagenicity and carcinogenicity, and, as a result the real utility of mutagenicity tests is being questioned. Justification for the continued use of these tests will require 1) more detailed mechanistic knowledge concerning the role of genetic changes in the development of cancer and 2) an improved ability to relate the results of mutagenicity tests to the potential for inducing heritable genetic effects in humans.
Carcinogens, Environmental↗
The genetical evolution of social behaviour. I.
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Behavior↗
The genetical evolution of social behaviour. II.
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Behavior↗
The evolution of social work education in England: a critical review of its connections and commonalities with nurse education.
Social work education in England underwent significant change in its move to degree status in 2003. It is hoped that the result will be increased professional standing for social workers, an improvement in the current widespread problems with recruitment, and assurance that all newly qualified social workers meet the National Occupational Standards for Social Work (Available from: http://www.topssengland.net/files/cd/). This change has pre-occupied social work educators and debate within the profession has concentrated on the practicalities and expectations of reform. This paper suggests that those working in nurse education may observe a number of similarities with its own earlier reforms and with current debates on whether nursing should move to an all-graduate profession. It then highlights three aspects of the new requirements for social work training: service user involvement, the place of research-minded practice, and the primacy of practice--that may be of interest and relevance to nursing colleagues.
Credentialing↗
Evolution of social learning: a mathematical analysis.
Social learning is an important ability seen in a wide range of animals including humans. It has been argued that individual learning, social learning, and innate determination of behavior are favored by natural selection when environmental changes occur at short, intermediate, and long intervals, respectively. Only recently, however, has the hypothesis been examined by means of mathematical models. In this paper, we construct a simple model in which each organism uses one of three genetically determined strategies--it is an individual learner, a social learner or an "innate"--and the three types of organisms are in direct competition with each other. A reduced model, involving only the individual learners and innates, is effectively linear, and we show that by solving the eigenvalue problem of this reduced system we arrive at a good approximation to the global dynamics of the full model. We also study the effect of stochastic environmental changes and reversible mutations among the three strategies. Our results are consistent with the predictions of previous studies. In addition, we identify a critical level of environmental constancy below which only individual and social learners are present.
Animals↗
Evolution of social behavior through interpopulation selection.
Under certain special conditions natural selection can be effective at the level of local populations, or demes. Such interpopulation selection will favor genotypes that reduce the probability of extinction of their parent population even at the cost of a lowered inclusive fitness. Such genotypes may be characterized by altruistic traits only in a viscous population, i.e., in a population in which neighbors tend to be closely related. In a non-viscous population the interpopulation selection will instead favor spiteful traits when the populations are susceptible to extinction through the overutilization of the habitat, and cooperative traits when it is the newly established populations that are in the greatest danger of extinction.
Journal Article↗
Premature cardiovascular mortality in France: divergent evolution between social categories from 1970 to 1990.
BACKGROUND: In France, differences in cardiovascular risk factor distribution have been observed which might be responsible for some disparities in cardiovascular mortality between social categories. The goal of the study was thus to assess the differences in coronary heart disease (CHD) and cerebrovascular diseases (CVD) mortality according to social category, and to determine their trends over the last 20 years in France. METHODS: Mortality data for CHD, CVD, diseases of the circulatory system (CS) and all causes mortality (TM) were based on death certificates for 1970, 1980 and 1990, and categorized by sex, age group (35-44 and 45-54 years), region and social category. RESULTS: Among active men, from 1970 to 1990, the overall decrease observed for all causes of death was significantly slower among employees and workers for CHD, CS and TM (P < 0.001), but not for CVD. In 1990, the highest mortality rates were observed among employees and workers for CHD, CVD and CS mortality. In women, no such trend was observed for CHD, CVD or CS mortality. No statistically significant difference between social categories was observed in 1990 for CHD and CVD. In the whole active population, a negative trend for the mortality rates was observed between 1970 and 1990 whatever the cause in both sexes. The ratio between mortality rates among non-active versus active people increased during the two decades in both sexes. CONCLUSIONS: In men, the inequalities have increased over the last two decades for CHD and have not been reduced for CVD. The category of employees and workers were found to be at special risk for premature cardiovascular disease mortality. Among women, the trends were less clear, although the tendencies were the same. An increasing disparity between active and non-active people suggests that a health-related selection process towards unemployment might have contributed to the decreasing mortality rates observed among employees and workers.
Adult↗
The age and evolution of sociality in Stegodyphus spiders: a molecular phylogenetic perspective.
Social, cooperative breeding behaviour is rare in spiders and generally characterized by inbreeding, skewed sex ratios and high rates of colony turnover, processes that when combined may reduce genetic variation and lower individual fitness quickly. On these grounds, social spider species have been suggested to be unstable in evolutionary time, and hence sociality a rare phenomenon in spiders. Based on a partial molecular phylogeny of the genus Stegodyphus, we address the hypothesis that social spiders in this genus are evolutionary transient. We estimate the age of the three social species, test whether they represent an ancestral or derived state and assess diversification relative to subsocial congeners. Intraspecific sequence divergence was high in all of the social species, lending no support for the idea that they are young, transient species. The age of the social lineages, constant lineage branching and the likelihood that social species are independently derived suggest that either the social species are 'caught in sociality' or they have evolved into cryptic species.
Animals↗