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 577 records · Page 32Linked to original sources
PubMed2003

Prisoners' dilemma in real-world acquaintance networks: spikes and quasiequilibria induced by the interplay between structure and dynamics.

We study Nowak and May's spatial prisoners' dilemma game driven by mutations (random choices of suboptimal strategies) on empirical social networks. The time evolution of the cooperation level is highly complex containing spikes and steps between quasistable levels. A statistical characterization of the quasistable states and a study of the mechanisms behind the steps are given. We argue that the crucial structural ingredients causing the observed behavior is an inhomogeneous degree distribution and that the connections within vertices of highest degree are rather sparse. Based on these observations we construct model networks with a similar complex time evolution of the cooperation level.

Journal Article↗
PubMed2005

Canalizing Kauffman networks: nonergodicity and its effect on their critical behavior.

Boolean networks have been used to study numerous phenomena, including gene regulation, neural networks, social interactions, and biological evolution. Here, we propose a general method for determining the critical behavior of Boolean systems built from arbitrary ensembles of Boolean functions. In particular, we solve the critical condition for systems of units operating according to canalizing functions and present strong numerical evidence that our approach correctly predicts the phase transition from order to chaos in such systems.

Biophysics↗
PubMed2003

Parasite remains in archaeological sites.

Organic remains can be found in many different environments. They are the most significant source for paleoparasitological studies as well as for other paleoecological reconstruction. Preserved paleoparasitological remains are found from the driest to the moistest conditions. They help us to understand past and present diseases and therefore contribute to understanding the evolution of present human sociality, biology, and behavior. In this paper, the scope of the surviving evidence will be briefy surveyed, and the great variety of ways it has been preserved in different environments will be discussed. This is done to develop to the most appropriated techniques to recover remaining parasites. Different techniques applied to the study of paleoparasitological remains, preserved in different environments, are presented. The most common materials used to analyze prehistoric human groups are reviewed, and their potential for reconstructing ancient environment and disease are emphasized. This paper also urges increased cooperation among archaeologists, paleontologists, and paleoparasitologists.

Animals↗
PubMed1997

The prevalence of hypertension in seven populations of west African origin.

OBJECTIVES: This study was undertaken to describe the distribution of blood pressures, hypertension prevalence, and associated risk factors among seven populations of West African origin. METHODS: The rates of hypertension in West Africa (Nigeria and Cameroon), the Caribbean (Jamaica, St. Lucia, Barbados), and the United States (metropolitan Chicago, Illinois) were compared on the basis of a highly standardized collaborative protocol. After researchers were given central training in survey methods, population-based samples of 800 to 2500 adults over the age of 25 were examined in seven sites, yielding a total sample of 10014. RESULTS: A consistent gradient of hypertension prevalence was observed, rising from 16% in West Africa to 26% in the Caribbean and 33% in the United States. Mean blood pressures were similar among persons aged 25 to 34, while the increase in hypertension prevalence with age was twice as steep in the United States as in Africa. Environmental factors, most notably obesity and the intake of sodium and potassium, varied consistently with disease prevalence across regions. CONCLUSION: The findings demonstrate the determining role of social conditions in the evolution of hypertension risk in these populations.

Adult↗
PubMed2003

[Gerocomia, a stage in the history of geriatrics].

It is studied the evolution of medical and social attention to aged persons in the historical period, and this task is known under the name of Gerocomia. They are analyzed the historical reasons that make it understandable and the ones which, in the last part of the 19th century, impose its superseding due to the clinical differentiation of the process of aged persons getting ill; in this way, a new chapter is added to the pathology which will be called Geriatrics.

Geriatrics↗
PubMed1992

[Gene pool and gene geography of the USSR population].

Gene pool and gene geography are discussed from the point of view of their conceptual history beginning from the original concept of A.S. Serebrovskiĭ (1928). Difference between the present-day gene geography and gene geography of gene pool is accentuated: the former only represents a portion of the latter. Historical and territorial integrity of the USSR population gene pool, in conjunction with its huge diversity, is the main problem being analysed by various means of computerized genetic cartography. Coupled with the gene frequency mapping, following methods were also used: mapping of average heterozygosity, of interpopulation differentiation, of principal component scores and mapping of geographical trend for each mapped genetic parameter. The work is based on 100 allelic genes and haplotypes from 30 independent loci studied on the average in 225 local populations. Statistical analysis of gene geographical maps is based on 3975 nodes of regular cartographic net for the USSR territory. The wind rose of systematic changes in the USSR gene pool has three main geographic orientations: W-E, SW-NE and S-N. At the same time, there are only two main systematic forces of gene pool evolution: the force of social history with predominant W-E orientation and the force of natural history with predominant S-N orientation of their actions. The heterozygosity level of gene pool declines strictly in accordance with the resultant in the SW-NE direction.

Alleles↗
PubMed1989

Occupational medicine and worker's compensation in Oklahoma.

The worker's compensation system in Oklahoma is the product of a long history of evolution involving influences from social, legal, political, cultural, and economic realms. This process of adaptation continues today. Most recently the system was amended effective November 1986. The basic principles of a worker's compensation program are important, as well as the new changes resulting from recent reforms.

Accidents, Occupational↗
PubMedDate not supplied

[Refractory depression: therapeutic alternatives].

A group of 89 patients admitted to the Psychiatric Unit of a General Hospital, with diagnosis of depression according to ICD-9 criteria and randomly chosen were studied. 26 of them (29.2%) were resistant depressions and 63 (7.82%) responded to treatment. Both groups were composed retrospectively in order to analyse resistance or lack of response to a first treatment with tricyclic or tetracyclic antidepressants in effective dosages. We considered: the personality type; the associated somatic pathology; prolonged social stress; period of evolution of the disorder; previous treatments; type of disorder uni or bipolar; familial morbidity; diagnosis reconsideration; analysis of therapeutic compliance; side effects and intolerance. We observed a statistically significant difference with regard to prophylactic treatment (38.4% resistant versus 98.3% non-resistant, p less than 0.0001); a greater suspicion of psycho-organicity in the resistant group (p less than 0.05); a longer interval of time for the resistant group between the beginning of the disorder and the beginning of treatment in our service (F: 1.45, t: 2.58, p less than 0.01). The alternatives used with our patients are analysed and we propose schedules for tackling this kind of problem.

Antidepressive Agents↗
PubMed1998

Evolutionary psychopathology: why isn't the mind designed better than it is?

This paper outlines some of the basic issues in evolutionary thinking when applied to psychopathology. It aims to give some background and context to the papers that follow. Particular attention is given to the way evolution is constrained by previous design features, the importance of trade offs between advantages and disadvantages of different traits, the way social dilemmas and conflicts have shaped the evolution of human motivational systems, and the psychology that supports them. The paper concludes with a plea to avoid thinking of evolutionary approaches as a reductionist science, when the focus needs to be on the way evolution theory informs the study of the social-biological interface.

Biological Evolution↗
PubMed1987

Chaos and transformation: implications of nonequilibrium theory for social science and society.

This article deals with all levels of both living (biological, psychological, sociological, and cultural) and nonliving (physical, chemical, and mathematical) systems. The idea of applying the natural scientific self-organizing, evolutionary, and non-equilibrium or "chaos" theory associated with the names of Prigogine and others to world problems of impending social, political, economic, and ecological "chaos" is gaining ground. The leap from natural science to social action, however, is impossible without considerable attention to the main intervening step: the development of "chaos"-equivalent, evolution-, systems-, and action-oriented social theory. Construction of such theory requires understanding by social scientists of natural scientific "chaos" theory as well as their own "chaos" theoretical heritage, of natural scientists of the now seemingly far distant social problem-solving potential of their nonequilibrium and self-organizing theories, and of both natural and social scientists of how advancement at both levels could help gain a peaceful as well as humanistic "order out of chaos" in this troubled world of ours. This paper surveys relevant concepts, problems, theorists, research, and works in progress within a perspective of the challenge of survival at a critical juncture in the evolution of our species.

Biological Evolution↗
PubMed2005

Evolution of cooperation: does selfishness restraint lie within?

Traditional models of how cooperative strategies succeed in evolution have largely focused on social interactions among individuals and selection acting at kin and group levels. A recent study at the genetic level suggests that cooperation may also be promoted by the evolution of gene-trait relationships that limit the range of possible cheating mechanisms that can evolve.

Animals↗
PubMed2000

Sociality, mating system and reproductive skew in marmots: evidence and hypotheses.

Marmot species exhibit a great diversity of social structure, mating systems and reproductive skew. In particular, among the social species (i.e. all except Marmota monax), the yellow-bellied marmot appears quite different from the others. The yellow-bellied marmot is primarily polygynous with an intermediate level of sociality and low reproductive skew among females. In contrast, all other social marmot species are mainly monogamous, highly social and with marked reproductive skew among females. To understand the evolution of this difference in reproductive skew, I examined four possible explanations identified from reproductive skew theory. From the literature, I then reviewed evidence to investigate if marmot species differ in: (1) the ability of dominants to control the reproduction of subordinates; (2) the degree of relatedness between group members; (3) the benefit for subordinates of remaining in the social group; and (4) the benefit for dominants of retaining subordinates. I found that the optimal skew hypothesis may apply for both sets of species. I suggest that yellow-bellied marmot females may benefit from retaining subordinate females and in return have to concede them reproduction. On the contrary, monogamous marmot species may gain by suppressing the reproduction of subordinate females to maximise the efficiency of social thermoregulation, even at the risk of departure of subordinate females from the family group. Finally, I discuss scenarios for the simultaneous evolution of sociality, monogamy and reproductive skew in marmots.

Journal Article↗
PubMed1989

Poverty, disease, responsibility: Arthur Newsholme and the public health dilemmas of British liberalism.

As the understanding of poverty changed in the first part of the twentieth century, British government officials were forced to reexamine assumptions about the relation between poverty and disease. In contrast to the predominant Victorian view that disease caused poverty, Arthur Newsholme argued that poverty and disease were interrelated. Yet, analysis of the social components of disease was complex and often self-contradictory: Were individuals responsible for behavior that placed them at risk, or were they massive victims of social circumstances? For Newsholme the ethical evolution of society and the moral reform of individuals were not substitutes for social reform; rather, they were essential components of it.

Attitude to Health↗