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 55 records · Page 3Linked to original sources
PubMed2005

[Group intervention with children with problematic behavior: behavioral, affective and social evolution].

The purpose of this research is to examine the evolution of children with problematic sexual behaviour following their participation in a group treatment program. The sample was made up of 43 children (33 boys and 10 girls) with an average age of 9 years, 7 months (SD = 1.85) The evolution of the children is measured administering behavioural rating instruments, both before and after the treatment program, on multiple dimensions of problematic sexual behaviour, externalizing and internalizing problems and social skills. The actual level of the children's participation is documented. The results indicate improvement for a significant portion of the children treated, particularly for those with problematic sexual behaviour, internalizing problems and social skills. This study highlights that treatment group might be a relevant choice of treatment modality.

Child↗
PubMed2006

Inbreeding ancestors: the role of sibmating in the social evolution of gall thrips.

We used microsatellite data to estimate levels of inbreeding in four species of solitary gall thrips that are in the same clade as the six species with soldier castes. Three of the four species were highly inbred (Fis 0.54-0.68), and the other apparently mated randomly (Fis near zero). These estimates, combined with previous data from species with soldiers, suggest that inbreeding is a pervasive life-history feature of the gall-inducing thrips on Australian Acacia. Mapping of inbreeding estimates onto the phylogeny of the gall inducers showed that the ancestral lineage that gave rise to soldiers was apparently highly inbred, and therefore, inbreeding could have played a role in the origin of sociality within this group. Moreover, there was a trend from high levels of inbreeding at the origin of soldiers to low levels in the most derived species with soldiers, which exhibits the highest levels of reproductive division of labor and soldier altruism. These patterns are consistent with considerations from population genetics, which show that the likelihood of the origin of soldier altruism is higher in inbreeding populations but that, once soldiers have evolved, a reduction in inbreeding levels may facilitate the evolution of enhanced division of labor and reproductive skew.

Acacia↗
PubMed1991

"Runaway" social evolution: reinforcing selection for inbreeding and altruism.

Kin selection theory predicts that altruistic behaviors, those that decrease the fitness of the individual performing the behavior but increase the fitness of the recipient, can increase in frequency if the individuals interacting are closely related. Several studies have shown that inbreeding therefore generally increases the effectiveness of kin selection when fitnesses are linear, additive functions of the number of altruists in the family, although with extreme forms of altruism, inbreeding can actually retard the evolution of altruism. These models assume that a constant proportion of the population mates at random and a constant proportion practices some form of inbreeding. In order to investigate the effect of inbreeding on the evolution of altruistic behavior when the mating structure is allowed to evolve, we examined a two-locus model by computer simulation of a diploid case and illustrated the important qualitative features by mathematical analysis of a haploid case. One locus determines an individual's propensity to perform altruistic social behavior and the second locus determines the probability that an individual will mate within its sibship. We assumed positive selection for altruism and no direct selection at the inbreeding locus. We observed that the altruistic allele and the inbreeding allele become positively associated, even when the initial conditions of the model assume independence between these loci. This linkage disequilibrium becomes established, because the altruistic allele increases more rapidly in the inbreeding segment of the population. This association subsequently results in indirect selection on the inbreeding locus. However, the dynamics of this model go beyond a simple "hitch-hiking" effect, because high levels of altruism lead to increased inbreeding, and high degrees of inbreeding accelerate the rate of change of the altruistic allele in the entire population. Thus, the dynamics of this model are similar to those of "runaway" sexual selection, with gene frequency change at the two loci interactively causing rapid evolutionary change.

Alleles↗
PubMed2006

Social evolution: cooperation by conflict.

A recent study suggests that aggression between wasps depends upon the costs and benefits of fighting, as determined by the position of individuals in a dominance hierarchy.

Aggression↗
PubMed2001

The social evolution of bacterial pathogenesis.

Many of the genes responsible for the virulence of bacterial pathogens are carried by mobile genetic elements that can be transferred horizontally between different bacterial lineages. Horizontal transfer of virulence-factor genes has played a profound role in the evolution of bacterial pathogens, but it is poorly understood why these genes are so often mobile. Here, I present a hypothetical selective mechanism maintaining virulence-factor genes on horizontally transmissible genetic elements. For virulence factors that are secreted extracellularly, selection within hosts may favour mutant 'cheater' strains of the pathogen that do not produce the virulence factor themselves but still benefit from factors produced by other members of the pathogen population within a host. Using simple mathematical models, I show that if this occurs then selection for infectious transmission between hosts favours pathogen strains that can reintroduce functional copies of virulence-factor genes into cheaters via horizontal transfer, forcing them to produce the virulence factor. Horizontal gene transfer is thus a novel mechanism for the evolution of cooperation. I discuss predictions of this hypothesis that can be tested empirically and its implications for the evolution of pathogen virulence.

Bacteria↗
PubMed2005

BrainMap: the social evolution of a human brain mapping database.

Human brain mapping is an experimental discipline that establishes structure-function correspondences in the brain through the combined application of experimental psychology, human neuroscience, and noninvasive neuroimaging. A deep and diverse literature on the functional organization of the human brain is emerging, which has pushed neuroimaging squarely into the scientific mainstream. Because of this rapid growth, there is a great need to effectively collect and synthesize the body of literature in this field. The BrainMap database was created in response to this need as an electronic environment for modeling the human brain through quantitative meta-analysis of the brain mapping literature. BrainMap was originally conceived in 1987 and has received continuous funding from 1988 to 2004. During this time, BrainMap has consistently evolved to meet the challenges of an ever-changing field and continues to strive toward higher levels of applicability. In this article, we discuss BrainMap's structure and utility, and relate its progress and development as a neuroinformatics tool.

Brain Mapping↗